DNA double-strand breaks (DSBs) trigger the Ataxia telangiectasia mutated (ATM)-dependent DNA damage response (DDR), which consists of histone H2AX, MDC1, RNF168, 53BP1, PTIP, RIF1, Rev7, and Shieldin. Early stages of B and T lymphocyte development are dependent on recombination activating gene (RAG)-induced DSBs that form the basis for further V(D)J recombination. Non-homologous end joining (NHEJ) pathway factors recognize, process, and ligate DSBs. Based on numerous loss-of-function studies, DDR factors were thought to be dispensable for the V(D)J recombination. In particular, mice lacking Mediator of DNA Damage Checkpoint Protein 1(MDC1) possessed nearly wild-type levels of mature B and T lymphocytes in the spleen, thymus, and bone marrow. NHEJ factor XRCC4-like factor (XLF)/Cernunnos is functionally redundant with ATM, histone H2AX, and p53-binding protein 1 (53BP1) during the lymphocyte development in mice. Here, we genetically inactivated MDC1, XLF, or both MDC1 and XLF in murine vAbl pro-B cell lines and, using chromosomally integrated substrates, demonstrated that MDC1 stimulates the V(D)J recombination in cells lacking XLF. Moreover, combined inactivation of MDC1 and XLF in mice resulted in synthetic lethality. Together, these findings suggest that MDC1 and XLF are functionally redundant during the mouse development, in general, and the V(D)J recombination, in particular.

Background: Increased DNA damage and the propension to cancer development, depend on the modulation of the mechanisms to control and maintain genomic integrity. Poly(ADP-Ribose)Polymerase activation and automodification are early responses to genotoxic stress. Upon binding to DNA strand breaks, the enzyme, a molecular DNA nick sensor, is hyperactivated: this is the first step in a series of events leading to either DNA repair or apoptosis. Enzyme hyperactivation and automodification can be easily measured and are widely used to look at DNA damage extent in the cell. We investigated whether these two markers (increased catalytic activity and auto modification), could help to monitor DNA damage in lymphocytes of flower growers from Southern Italy, occupationally exposed to pesticides. Methods: Peripheral lymphocyte lysates were analysed for Poly(ADP-Ribose) Polymerase activity, and by SDS-PAGE and anti-Poly(ADP-Ribose)Polymerase 1-antibody to measure automodified anti-Poly(ADP-Ribose) Polymerase levels by densitometry. Results: Poly(ADP-Ribose)Polymerase activity levels were consistent with those of enzyme auto-modification. Growers daily exposed to pesticides, showed both biomarkers very high, either in the presence or in the absence of pathologies. Conclusions: PARP activity and auto-modification in peripheral blood lymphocytes are possible,non-invasive, and routinar tools to monitor the healthy conditions of floricoltorists.

Chromothripsis is a mutational mechanism leading to complex and relatively clustered chromosomal rearrangements resulting in diverse phenotypic outcomes depending on the involved genomic landscapes. It may occur both in the germ and the somatic cells resulting in congenital and developmental disorders and cancer, respectively. Asymptomatic individuals may be carriers of chromotriptic rearrangements and experience recurrent reproductive failures when two or more chromosomes are involved. Several mechanisms are postulated to underly chromothripsis. The most attractive hypothesis involves chromosome pulverization in micronuclei followed by incorrect reassembly of fragments through DNA repair to explain the clustered nature of the observed complex rearrangements. Moreover, exogenous or endogenous DNA damage induction and dicentric bridge formation may be involved. Chromosome instability is commonly observed in the cells of patients with DNA-repair disorders, such as ataxia telangiectasia, Nijmegen breakage syndrome and Bloom syndrome. In addition, germline variations of TP53 have been associated with chromothripsis in Sonic-Hedgehog medulloblastoma and acute myeloid leukemia. In the present review, we focus on the underlying mechanisms of chromothripsis and the involvement of defective DNA-repair genes resulting in chromosome instability and chromothripsis-like rearrangements.

We investigated the development of a simple and sensitive assay for the identification of minute amounts of animal and human biological material. The suggested system uses isothermal amplification of DNA in a rapid assay format, which returns the results in as little as 40 minutes from sampling. The assay used for the proof of concept employs the novel handheld SaLux19 device (Max-Planck Innovation prototype, Germany). This well-established infield detection system could also be utilized for forensic scenarios. The results presented here demonstrated that the assay is sufficiently specific and sensitive and can detect the presence of Sus scrofa nucleic acids.

Tdp1 and Tdp2 are DNA repair enzymes that repair DNA damages caused by various agents, including anticancer drugs. Thus, these enzymes resist anticancer therapy and could be the reasons of resistance to such widely used drugs as topotecan and etoposide. In the present work, we found compounds capable of inhibiting both enzymes among derivatives of (-)-usnic acid. Both (+)- and (-)-enantiomers of compounds act equally effectively against Tdp1, and only (-)-enantiomers inhibited Tdp2. Surprisingly, the compounds protect HEK293FT wild type cells from the cytotoxic effect of etoposide but potentiate it against Tdp2 knockout cells. We assume that the sensitizing effect of the compounds in the absence of Tdp2 is associated with effective inhibition of Tdp1, which could take over the functions of Tdp2.

DNA damage repair lies at the core of all cells’ survival strategy, including cancerous. Therefore, targeting such repair mechanisms forms the major goal of cancer therapeutics. The mechanism of DNA repair has been tousled with the discovery of multiple kinases. Recent studies on Tousled like Kinases have brought significant clarity on the effectors of these kinases which stands to regulate DSB repair. In addition to their well-established role in the DDR and cell cycle checkpoint mediation after DNA damage or inhibitors of replication, their suspected involvement in the actual DSB repair process has more recently been strengthened by the important finding that TLK1 phosphorylates RAD54 and regulates some of its activities and localization in the cell. Earlier findings of its regulation of RAD9 during checkpoint deactivation as well as defined steps during NHEJ ends processing were earlier hints of its important involvement broadly in DSB repair. All this has opened up new avenues to target cancer cells in combination therapy with genotoxins and TLK inhibitors.

Abstract5′,8-Cyclo-2′-deoxyadenosine (cdA), in the 5′R and 5′Sdiastereomeric forms, are typical non strand-break oxidative DNA lesions, induced by hydroxyl radicals, with emerging importance as a molecular marker. These lesions are exclusively repaired by nucleotide excision repair (NER) mechanism with a low efficiency, thus readily accumulating in the genome. Poly(ADP-ribose) polymerase1 (PARP1) acts as an early responder to DNA damage and plays a key role as a nick sensor in the maintenance of the integrity of the genome by recognizing nicked DNA. So far, it was unknown whether the diastereomeric cdA lesions could induce specific PARP1 binding. Here we provide the first evidence of PARP1 to selectively recognize the diastereomeric lesions 5′S-cdA and 5′R-cdA in vitro as compared to deoxyadenosine in model DNA substrates (23-mers) by using circular dichroism,fluorescence spectroscopy, immunoblotting analysis and gel mobility shift assay. Several features of the recognition of the damaged and undamaged oligonucleotides by PARP1were characterized. Remarkably, PARP1 efficiently binds to both cdA lesions in the double stranded (ds)-oligonucleotides. In particular, PARP1 proved to bind 5′S-cdAwith a higher affinity constant for the 5'S lesion in a model of ds DNA than 5′R-cdA, showing different recognition patterns, also compared with undamaged dA. This new finding highlights the ability of PARP1 to recognize and differentiate the distorted DNA backbone in a biomimetic system caused by different diastereomeric forms of a cdA lesion.

Abstract Background In tumors, somatic mutagenesis presumably drives DNA damage response (DDR) via altered regulatory pathways increasing genomic instability and proliferative activity. These considerations led to the standard therapeutic strategy against cancer: the disruption of mutation activated DNA repair pathways of tumors. Purpose Justifying that cancer cells are not enemies to be killed, but rather they are ill human cells having the remnants of physiologic regulatory pathways. Results 1. Genomic instability and cancer development may be originated from the flaw of estrogen signal rather than excessive estrogen signaling. 2. Healthy cells with genomic instability exhibit somatic mutations helping DNA restitution. 3. Somatic mutations in tumor cells aim the restoration of DNA damage rather than further genomic derangement. 4. In tumors, estrogen signal drives the pathways of DNA stabilization leading to apoptotic death. 5. In the peritumoral cellular infiltration, the genomic damage of tumor induces inflammatory cytokine secretion and increased estrogen synthesis. In the inflammatory cells, increased growth factor receptor (GFR) signal confers unliganded activation of estrogen receptors (ERs). 6. In tumor cells responsive to genotoxic therapy, constitutive mutations help the upregulation of estrogen signal and consequential apoptosis. In tumors non responsive to genotoxic therapy, the possibilities for ER activation via either liganded or unliganded pathway, are exhausted leading to farther genomic instability and unrestrained proliferation. Conclusion Understanding the real character and behavior of human tumors at molecular level suggests that we should learn the genome repairing methods of tumors and follow them by supportive therapy rather than provoking additional genomic damages.

DNA double-strand breakage is the most lethal damage to chromosomal DNA. It activates a series of cellular DNA damage response pathways, including DNA damage sensing, control of cell cycle arrest and apoptosis, and DNA repair. DNA damage response pathways are regulated by complex signaling machineries. Of the intracellular signaling cascades, diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to generate phosphatidic acid (PA). Because both DG and PA serve as second messengers, DGK activity induces a shift of signaling pathways from DG-mediated to PA-mediated cascades, thereby implicating DGK in the regulation of widely various functions. Reportedly, one member of the DGK family, DGKζ, is intimately involved in the regulation of stress responses through p53 and NF-κB. Stresses such as ischemia and infarction cause DGKζ downregulation. Experimental DGKζ depletion renders cells and mice vulnerable to various stressors such as chemotherapeutic agents and ionizing irradiation. Nevertheless, how DGKζ is involved in DNA repair, a critical event of DNA damage response for survival remains unknown. For this study, we examined how DGKζ depletion affects DNA repair mechanisms. We demonstrated that DGKζ depletion causes attenuation of Akt activation and DNA-PK protein expression upon DNA damage, which might engender downregulated BRCA1 protein synthesis and stability. Results suggest that DGKζ depletion attenuates BRCA1-mediated DNA repair machinery, thereby conferring vulnerability to DNA damage.

It has been more than three decades since the discovery of multifunctional factors, Non-POU Domain-Containing Octamer-Binding Protein, NonO and Splicing Factor, Proline-and Glutamine-Rich, SFPQ. Some of their functions, including their participations in transcriptional and posttranscriptional regulation as well as their contribution to paraspeckle subnuclear body organization have been well-documented. In this review, we focus on the roles of NonO and SFPQ in cell cycle with particular attention to their participation in nonhomologous end joining (NHEJ) and homologous recombination (HR) of DNA damage responses induced by irradiation. In these contexts, absence or malfunction of either or both lead to genome instability and ultimately to apoptosis, cellular senescence, and tumor development. This review also will shed light on NonO and SFPQ function in DNA/RNA/protein binding and their association with Ku heterodimer of the NHEJ pathway required for repair of DNA double-strand breaks (DSBs).

The spread of the infection caused by the new coronavirus SARS-CoV-2 (COVID-19) became pandemic on March 11, 2020. From the time of the first cases (in November 2019, Wuhan, China), to date, a large number of COVID-19 observations have been accumulated in different age groups of patients both in China and abroad. Published scientific data allows us to conclude that children suffer from COVID-19 much less often than adults and tolerate the disease in a milder form, often appear to be asymptomatic. There is currently no final answer why children are less susceptible to this virus; however, scientists are increasingly inclined to consider a complex effect of the immune response and components of the renin-angiotensin system (RAS), which according to recent studies affects not only the cardiovascular system, but is also responsible for the activation of inflammatory reactions. A hypothesis of genetic predisposition to the development of severe forms of COVID-19 has recently been made. We conducted a search for publications in the databases and showed current scientific ideas about COVID-19 pathogenesis and factors influencing the disease development in childhood. Childhood immunity may have several protective features against SARS-CoV-2: immaturity of particular elements of the innate immune response, constitutional lymphocytosis with a shift towards anti-inflammatory Th2-response, as well as "trained" immunity. The influence of renin-angiotensin system reactions in this review is shown from two perspectives: expression of ACE2 receptors and polymorphisms of certain genes of this system. It was established that ACE2 transmembrane protein is not only the entry point for the virus but also plays a regulatory role, turning the pro-inflammatory vasoconstrictor angiotensin II into anti-inflammatory angiotensin (1-7), which has vasodilating properties. Higher ACE2 content in children compared with adults helps maintain balance in the renin-angiotensin system and prevents the development of complications. It was also shown that the presence of certain genetic polymorphisms (AGTR1, AGTR2, ACE2, ACE) could determine the imbalance inside the RAS, leading to more pronounced reactions of alveolocytes, vascular endothelium and smooth muscle fibers in response to SARS-CoV-2 infection due to a shift towards vasoconstrictor, proliferative and profibrotic mechanisms.

Replication protein A (RPA) is a heterotrimeric protein complex and the main single-stranded DNA (ssDNA) binding protein in eukaryotes. RPA has key functions in most of the DNA-associated metabolic pathways and DNA damage signalling. Its high affinity for ssDNA helps to stabilise ssDNA structures and prevents the DNA sequence from nuclease attacks. RPA consists of multiple DNA-binding domains which are oligonucleotide/oligosaccharide-binding (OB)-folds, responsible for DNA binding, and interactions with proteins. These RPA-ssDNA and RPA-protein interactions are crucial for DNA replication, DNA repair, DNA damage signalling, and the conversation of the genetic information of cells. Proteins such as ATR use RPA to locate to regions of DNA damage for DNA damage signalling. Recruitment of nucleases and DNA exchange factors to sites of double strand breaks are also an important RPA function to ensure effective DNA recombination to correct these DNA lesions. Due to its high affinity to ssDNA, RPA’s removal from ssDNA is of central importance to allow these metabolic pathway to proceed and processes to exchange RPA against downstream factors are established in all eukaryotes. These facetted and multi-layered functions of RPA will be discussed in detail in the review. RPA is also a major player in a variety of human diseases, which will be discussed.

In archaea, the interaction of HerA helicase and NurA nuclease is required for 3' end resection during DNA double-stranded break repair, and its disruption results in unfaithful DNA repair. Interactions transpire by the four conserved domains, including the N-terminal HAS domain (HerA-ATP synthase), which serves as a binding site for the exonuclease NurA. As a HerA hexamer between its two subunits, the conserved C-terminal brace extension functions as an adjacent brace. DBD serves as a location for DNA binding, which causes the DNA strands to be propelled into the HerA pocket to begin unwinding. The putative pore entrance is made up of four helix coils, which provide a suitable charged surface for guiding DNA into the pore. The crystal structure of the complex HerA-NurA allows for the identification of key residues for protein-protein interaction. This allows us to predict that most archaeal HerA orthologs will be able to interact with one another. Archaeal HerA is a homo-hexameric assembly featuring a DNA-binding domain that is conserved. It also features distinctive ATP and NurA binding domains. Following the structure and sequence conservation criteria, we find one HerA ortholog in Pyrobaculum calidifontis and multiple HerA paralogs, but the role of none is established yet.Interestingly, orthologous HerA is part of an Mre11-Rad50 gene neighborhood while paralogous HerA is not, which could be misleading. As a result, it sought to describe the criteria that may be used as a possible fingerprint for identifying orthologous genes, as well as the cloning procedures and tactics that would aid in the confirmation of the HerA helicase in P. calidifontis. Their confirmation is based on PCR cloning and characterization following HerA construct creation.

DNA double-strand breaks (DSBs) are deleterious lesions that are generated in response to ionizing radiation or replication fork collapse that can lead to genomic instability and cancer. Eukaryotes have evolved two major pathways, namely homologous recombination (HR) and non-homologous end joining (NHEJ) to repair DSBs. Whereas the roles of protein-DNA interactions in HR and NHEJ have been fairly well defined, the functions of small and long non-coding RNAs and RNA-DNA hybrids in the DNA damage response is just beginning to be elucidated. This review summarizes recent discoveries on the identification of non-coding RNAs and RNA-mediated regulation of DSB repair

Base excision repair (BER) is the predominant pathway to remove most forms of hydrolytic, oxidative and alkylative DNA damage. The precise functioning of BER is achieving by the regulation of each step by regulatory/accessory proteins, with the most important of which being poly(ADP-ribose) polymerase 1 (PARP1). The PARP1 regulatory functions extend to many cellular processes including regulation of mRNA stability and decay. PARP1 can therefore affect BER both at the level of the BER proteins and at the level of their mRNAs. Systematic data on how the PARP1 content affects the activities of key BER proteins and the levels of their mRNAs in human cells are extremely limited. In this study the CRISPR/Cas9 based technique has been used to knocked out the PARP1 gene in the human HEK 293FT line. The obtained cell clones with putative PARP1 deletion were characterized by several approaches including: PCR analysis of deletions in genomic DNA, Sanger sequencing of genomic DNA, qPCR analysis of PARP1 mRNA, western-blot analysis of whole-cell-extract proteins with anti-PARP1 antibodies, and the PAR synthesis in the whole-cell-extracts. qPCR analysis of mRNAs coding the BER related proteins: PARP2, uracil DNA glycosylase 2, AP endonuclease 1, DNA polymerase β, DNA ligase III and XRCC1 did not reveal crucial influence of PARP1 knockout. The corresponding catalytic activities in the whole-cell extracts (WCEs) evaluated in parallel did not differ significantly between mutant and parental cell lines. No considerable influence of poly(ADP-ribose) synthesis on the activity of the above WCE enzymes was revealed.

This review focuses on the regulation and modulation of human DNA polymerase δ (Pol δ). The emphasis is on mechanisms that regulate the activity and properties of Pol δ in DNA repair and replication. The areas covered are the degradation of the p12 subunit of Pol δ, which converts it from a heterotetramer (Pol δ4) to a heterotrimer (Pol δ3), in response to DNA damage and also during the cell cycle. The biochemical mechanisms that lead to degradation of p12 are reviewed, as well as the properties of Pol δ4 and Pol δ3 that provide insights into their functions in DNA replication and repair. The second focus of the review involves the functions of two Pol δ binding proteins, PDIP46 and PDIP38, both of which are multi-functional proteins. PDIP46 is a novel activator of Pol δ4, and the impact of this function is discussed in relation to its potential roles in DNA replication. Several new models for the roles of Pol δ3 and Pol δ4 in leading and lagging strand DNA synthesis that integrate a role for PDIP46 are presented. PDIP38 has multiple cellular localizations including the mitochondria, the splicesosomes and the nucleus. It has been implicated in a number of cellular functions, including the regulation of specialized DNA polymerases, mitosis, the DNA damage response, Mdm2 alternative splicing and the regulation of the Nox4 NADPH oxidase.

Gastric cancer is a heterogeneous group of diseases with only a fraction of patients responds to immunotherapy. The relationships between tumor DNA damage response, the immune system and immunotherapy have recently attracted attention. Accumulating evidence indicate that DNA repair landscape is a significant factor in driving response to immune checkpoint blockade (ICB) therapy. In this study, to explore new prognostic and predictive biomarkers for gastric cancer patients who are sensitive and responsible to immunotherapy, we developed a novel 15-DNA repair gene signature (DRGS) and its related scoring system and evaluated the efficiency of DRGS in discriminating different molecular and immune characteristics and therapeutic outcomes of gastric adenocarcinoma. The results showed that DRGS high score patients showed significantly better therapeutic outcomes compared to DRGS low score patients (P < 0.001). Integrated analysis of multi-omics data demonstrated that the patients with high DRGS score were characteristic of high levels of anti-tumor lymphocytes infiltration, tumor mutation burden (TMB) and PD-L1 expression, and these patients exhibited a longer overall survival and may benefit more from ICB therapy, as compared to the low-score patients. Therefore, the DRGS and its scoring system may have implications in tailoring immunotherapy in gastric cancers.

Track-structure Monte Carlo simulations are useful tools to evaluate initial DNA damage induced by irradiation. In the previous study, we have developed a Gean4-DNA-based application to estimate the cell surviving fraction of V79 cells after irradiation, bridging the gap between the initial DNA damage and the DNA-rejoining kinetics by means of the two-lesion kinetics (TLK) model. However, since the DNA repair performance depends on cell line, the same model parameters cannot be used for the different cell lines. Thus, we extended the Geant4-DNA application with an updated TLK model for the evaluation of DNA damage repair performance in HSGc-C5 carcinoma cells which are typically used for evaluating proton/carbon radiation treatment effects. For this evaluation, we also performed experimental measurements for cell surviving fractions and DNA-rejoining kinetics of the HSGc-C5s cells. Concerning fast- and slow-DNA rejoining, the TLK model parameters were adequately optimized with the simulated initial DNA damage. Using the optimized TLK model, the Geant4-DNA simulation is now able to predict cell survival and DNA-rejoining kinetics for HSGc-C5s cells.

The DNA Damage Response (DDR) is a complex signaling network that comes into play when cells experience genotoxic stress. Upon DNA damage, cellular signaling pathways are rewired to slow down cell cycle progression and allow recovery. However, when the damage is beyond repair, cells activate complex and still not fully understood mechanisms, leading to a complete proliferative arrest or cell death. A number of conventional and novel anti-neoplastic treatments rely on causing DNA damage or on the inhibition of the DDR in cancer cells. However, the identification of molecular determinants directing cancer cells toward recovery or death upon DNA damage is still far from complete, and it is object of intense investigation. SPRY-COntaining RAN binding Proteins (Scorpins) RANBP9 and RANBP10 are evolutionarily conserved and ubiquitously expressed proteins whose biological functions are still debated. RANBP9 has been previously implicated in cell proliferation, survival, apoptosis and migration. Recent studies also showed that RANBP9 is involved in the Ataxia Telangiectasia Mutated (ATM) signaling upon DNA damage. Accordingly, cells lacking RANBP9 show increased sensitivity to genotoxic treatment. Although there is no published evidence, extensive protein similarities suggest that RANBP10 might have partially overlapping functions with RANBP9. Like RANBP9, RANBP10 bears sites putative target of PIK-kinases and high throughput studies found RANBP10 to be phosphorylated following genotoxic stress. Therefore, this second Scorpin might be another overlooked player of the DDR alone or in combination with RANBP9. This review focuses on the relatively unknown role played by RANBP9 and RANBP10 in responding to genotoxic stress.

The genetic causes of the differentiated, highly treatable and mostly non-fatal papillary thyroid cancer (PTC) are not yet fully known. The widely accepted PTC etiology blames altered sequence or/and expression level of certain biomarker genes. However, our previous studies found that the PTC biomarkers played significantly lower roles than the personalized PTC Gene Master Regulators. Our publicly accessible gene expression data from the cancer nodule and the surrounding normal tissue of surgically removed PTC tumor were re-analyzed to determine the transcriptomic effects on the genomic fabrics responsible for the DNA replication, repair and transcription. Tumor results were compared to the gene expression profiles of the papillary (BCPAP) and the anaplastic (8505C) human thyroid cancer cell lines. The analyses were carried out from the Genomic Fabric Paradigm (GFP) perspective that provides the most theoretically possible comprehensive characterization of the transcriptome and its alterations in disease. The study indicated that, in addition to regulating numerous genes, changes in the homeostatic control of transcript abundances and remodeling of the gene networks had major contributions to the PTC occurrence, resilience and proliferation. Therefore, the molecular mechanisms responsible for gene expression control and inter-coordination should also be considered when designing personalized anti-cancer gene therapies.

DNA origami has emerged in recent years as a powerful technique for designing and building 2D and 3D nanostructures. While the breadth of structures that have been produced is impressive, one of the remaining challenges, especially for DNA origami structures intended to carry out useful biomedical tasks in vivo, is to endow them with the ability to detect and respond to molecules of interest. Target molecules may be disease indicators or cell surface receptors, and the responses may include conformational changes leading to release of therapeutically relevant cargo. Nucleic acid aptamers are ideally suited to this task and are beginning to be used in DNA origami designs. In this review we consider examples of uses of DNA aptamers in DNA origami structures and summarise what is currently understood regarding aptamer-origami integration. We review three major roles for aptamers in such applications: protein immobilisation, triggering of structural transformation, and cell targeting. Finally, we consider future perspectives for DNA aptamer integration with DNA origami.

The usage of Quantum Similarity through the equation Z = {∀θ ∈ Z → ∃s ∈ S ∧ ∃t ∈ T : θ = (s, t)}, represents a way to analyze the way communication works in our DNA. Being able to create the object set reference for z being (s, t) in our DNA strands, we are able to set logical tags and representations of our DNA in a completely computational form. This will allow us to have a better understanding of the sequences that happen in our DNA. With this approach, we can also utilize mathematical formulas such as the Euler–Mascheroni constant, regression analysis, and computational proofs to answer important questions on Quantum biology, Quantum similarity, and Theoretical Physics.

Lumpy skin disease (LSD), caused by a virus within the Poxviridae family and Capripoxvirus genus, induces nodular skin lesions in cattle, spreading through direct contact and insect vectors, significantly affecting global cattle farming. Despite available vaccines, their effectiveness is limited by poor bioavailability and adverse effects. Our study aimed to identify potential inhibitors targeting LSD-associated DNA polymerase protein, selecting LSDV039 for further investigation through comprehensive analysis and computational methods. Virtual screening revealed rhein and taxifolin as potent binders among 380 phytocompounds, with respective affinities of -8.965 and -7.195 kcal/mol. Canagliflozin and tepotinib exhibited strong affinities (-9.858 and -8.856 kcal/mol) among 718 FDA-approved antiviral drugs. Molecular dynamics simulations of canagliflozin, tepotinib, rhein, and taxifolin highlighted taxifolin's superior stability and binding energy. Rhein displayed compactness in RMSD and RMSF but fluctuations in Rg and SASA, while canagliflozin demonstrated stability compared to tepotinib. The study highlights the promising potential of repurposed drugs and phytocompounds as LSD therapeutics. However, extensive validation through in-vitro, in-vivo, and clinical trials is crucial for their practical application.

This work describes practical immunization of European sea bass (Dicentrarchus labrax) juveniles against viral nervous necrosis virus (VNNV), a betanodavirus causing worldwide mortalities in many fish species. Protection was obtained with the so called spinycterin vehicles consisting in irreversibly DNA-damaged DNA-repair-less E.coli displaying at their surface a downsized antigen. In this work we, i) maximized bacterial expression levels by downsizing the C protein to a fragment (frgC91-220) containing most of its antigenicity, ii) developed an scalable autoinduction bacterial media based in soy-bean increasing membrane display and reproducibility, iii) enriched surface expression by screening different anchors from several prokaryotic origins (anchor+frgC91-220), iv) preserved frgC91-220 antigenicity by inactivating bacteria by irreversible DNA-damage by means of Ciprofloxacin, and v) increased safety using a repair-less E.coli strain as spinycterin chassis. These second generation of spinycterins protected fish against VNNV challenge with partial (Nmistic+frgC91-220) or 100 % (YBEL+frgC91-220 ) protection, in contrast to those fish immunized with frgC91-220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness, thus providing potential for small fish vaccines for sustainable aquaculture.

Base excision repair (BER) is a cellular process that removes damaged bases arising from exogenous and endogenous sources including reactive oxygen species, alkylation agents, and ionizing radiation. BER is mediated by the actions of multiple proteins that work in a highly concerted manner to resolve DNA damage efficiently to prevent toxic repair intermediates. During the initiation of BER, the damaged base is removed by one of 11 mammalian DNA glycosylases resulting in abasic sites. Many DNA glycosylases are product inhibited by binding to the abasic site more avidly than the damaged base. Traditionally apurinic/apyrimidinic endonuclease, APE1, was believed to help turnover the glycosylases to undergo multiple rounds of damaged base removal. However, in a series of papers from our laboratory we have demonstrated that UV-damaged DNA binding protein (UV-DDB) stimulates the glycosylase activities of human 8-oxoguanine glycosylase (OGG1), MUTY DNA glycosylase (MUTYH), alkyladenine glycosylase/N-methylpurine DNA glycosylase (AAG/MPG), and single-strand selective monofunctional glycosylase (SMUG1), between three-to-five-fold. Moreover, we have shown UV-DDB can assist chromatin decompaction facilitating access of OGG1 to 8-oxoguanine damage in telomeres. This review summarizes the biochemistry, single-molecule, and cell biology approaches that our group used to directly demonstrate the essential role of UV-DDB in BER.

Erlotinib inhibits epithelial growth factor receptor (EGFR) kinase activity and is used to treat non-small cell lung cancer (NSCLC). Despite its high efficacy, recurrence can occur in patients who become resistant to the drug. To address the underlying mechanism of Erlotinib resistance, we investigated additional mechanisms related to mode-of-drug-action, by multiple protein-binding interactions, besides EGFR by using drug affinity responsive target stability (DARTS) and liquid chromatography-mass spectrometry (LC-MS/MS) methods with non-labeled Erlotinib. DNA polymerase alpha subunit B (POLA2) was identified as a new Erlotinib binding protein that was validated by the DARTS platform, complemented with cellular thermal shift assays. Genetic knock-down of POLA2 promoted the anti-proliferative effect of the drug in the Erlotinib-resistant cell line H1299 with high POLA2 expression, whereas overexpression of POLA2 restored anti-proliferative effects in the Erlotinib-sensitive cell line HCC827 with low POLA2 expression. Importantly, POLA2 expression levels in four NSCLC cell lines were positively correlated with anti-proliferative Erlotinib efficacy, verified by bio-statistical analysis (Pearson correlation coefficient, R=0.9886). These results suggest that POLA2 is a novel complementary target protein of Erlotinib, and could clinically provide validity as a surrogate marker for drug resistance in patients with NSCLC.

The Ramazzottius varieornatus tardigrade is an extremotolerant terrestrial invertebrate belonging to the phylum of Tardigrada. At a length of 0.1-1.0 mm, tardigrades are small animals with an exceptional tolerance to extreme conditions such as high pressure, chemicals and irradia-tion. These properties have been attributed to the recently-discovered Dsup protein. Dsup is a nucleosome-binding protein that prevents DNA damage against X-ray and oxidative stress without impairing cell life, also in Dsup-transfected animal and plant cells. However, the precise “protective” role of this protein is still under study. We performed experiments on human cells and shows that, as compared to control cells, Dsup+ cells are more resistant to UV-C exposure and H2O2. Real-time PCR identified different expression patterns of endogenous genes involved in apoptosis, cell survival and DNA damage repair in Dsup+ cells in response to H2O2 and UV-C. While H2O2 treatment in Dsup+ cells only marginally involved the activation of pathways responsible for DNA repair reinforcing the idea of a direct protective effect of the protein on DNA, in UV-C exposed cells, Dsup efficiently upregulates DNA damage repair genes. In conclusion, our data may help to delineate the different mechanisms by which the Dsup protein operates in response to different insults.

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other divalent transition metal ions at elevated concentrations in a process to regulate the ion uptake. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86 residues. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA experimentally but Zinc plays a structural role and does not activate Fur to bind DNA.

Removal of the proliferation component of gene expression by PCNA adjustment has been addressed in numerous survival prediction studies for breast cancer and all cancers in the TCGA. These studies indicate that widespread co-regulation of proliferation upwardly biases survival prediction when gene selection is performed on a genome-wide basis. In addition, removal of the correlative effects of proliferation does not reduce the random bias associated with survival prediction using random gene selection. Since most cancers become addicted to DNA repair as a result of forced cellular replication, increased oxidation, and repair deficiencies from oncogenic loss or genetic polymorphisms, we pursued an investigation to remove the proliferation component of expression in DNA repair genes to determine survival prediction. This translational hypothesis-driven focus on DNA repair genes is directly amenable to finding new sets of DNA repair genes that could potentially be studied for inhibition therapy. Overall survival (OS) prediction was evaluated in 18 cancers by using normalized RNA-Seq data for 126 DNA repair genes with expression available in TCGA. Transformations for normality and adjustments for age at diagnosis, stage, and PCNA metagene expression were performed for all DNA repair genes. We also analyzed genomic event rates (GER) for somatic mutations, deletions, and amplification in driver genes and DNA repair genes. After performing empirical p-value testing with use of randomly selected gene sets, it was observed that OS could be predicted significantly by sets of DNA repair genes for 61% (11/18) of the cancers. Interestingly, PARP1 was not a significant predictor of survival for any of the 11 cancers. Results from cluster analysis of GERs indicates that the most opportunistic cancers for inhibition therapy may be AML, colorectal, and renal papillary, because of potentially less confounding due to lower GERs for mutations, deletions, and amplifications in DNA repair genes. However, the most opportunistic cancer for inhibition therapy is likely to be AML, since it showed the lowest GERs for mutations, deletions, and amplifications in DNA repair genes. In conclusion, our hypothesis-driven focus to target DNA repair gene expression adjusted for the PCNA metagene as a means of predicting OS in various cancers resulted in statistically significant sets of genes.

A large body of evidence indicates that environmental agents can induce alterations in DNA methylation (DNAm) profiles. Radiofrequency electromagnetic fields (RF-EMFs) are radiations emitted by everyday devices which have been classified as “possibly carcinogenic”, however their biological effects are unclear. As aberrant DNAm of genomic repetitive elements (RE) may promote genomic instability, here we sought to determine whether exposure to RF-EMFs could affect DNAm of different classes of RE, such as long interspersed nuclear element1s (LINE-1), Alu short interspersed nuclear element and ribosomal repeats. To this purpose, we analysed DNAm profiles of cervical cancer and neuroblastoma cell lines (HeLa, BE(2)C and SH-SY5Y) exposed to 900 MHz GSM-modulated RF-EMF through an Illumina-based targeted deep bisulfite sequencing approach. Our findings showed that radiofrequency exposure did not affect DNAm of Alu elements in any of the cell lines analysed. Conversely, it influenced DNAm of LINE1 and ribosomal repeats in terms of both average profiles and organization of methylated and un-methylated CpG sites, in different ways in each of the three cell lines studied.

The enterohemorrhagic Escherichia coli (EHEC) O157: H7 EspF is known to be a multifunctional effector that triggers several damage processes in the host cells. However, in the process of EHEC O157: H7 infection, the interactions between EspF, its N- or C-terminus, and host proteins are still unclear. In this work, we use co-immunoprecipitation combined with mass spectrometry (CoIP-MS) to screen the interactions between EspF/EspF-N/EspF-C terminus and host proteins. A total of 311 host proteins are analyzed. The N-terminus of EspF is found to interact with 192 proteins, whereas 205 proteins interact with the C-terminus. These proteins are mainly involved in RNA splicing, endoplasmic reticulum stress, and a variety of metabolic signaling pathways. Surprisingly, MS results reveal that EspF can also phosphorylate H2AX, suggesting that EspF may directly mediate DNA damage. Here, by western blot and immunofluorescence (IF), we verified that EspF can cause phosphorylation of H2AX and mediates cell multi-nuclearation and cell hypertrophy. Furthermore, we verify here for the first time that SMC1 interacts with EspF -C-terminus, and provide evidence that EspF increases p-SMC1 levels. p-SMC1 is known to influence S-phase cell cycle arrest and usually increases during periods of DNA damage. Our work revealed a novel interaction between EspF and the host protein SMC1 and lays a foundation for further research on EspF-mediated host DNA damage, apoptosis, and even colorectal carcinogenesis.

Proteins and DNA exhibit key physical chemical properties that make them advantageous for building nanostructures with outstanding features. Both DNA and protein nanotechnology have growth notably and proved to be fertile disciplines. The combination of both types of nanotechnologies is helpful to overcome the individual weaknesses and limitations of each one, paving the way for the continuing diversification of the structural nanotechnologies. Recent studies have implemented a synergistic combination of both biomolecules to assemble unique and sophisticate protein-DNA nanostructures. These hybrid nanostructures are highly programmable and display remarkable features that create new opportunities to build in the nanoscale. This review focuses on the strategies deployed to create hybrid protein-DNA nanostructures. Here, we will discuss strategies such as polymerization, spatial directing and organizing, coating, rigidizing or folding DNA into particular shapes or moving parts. The enrichment of structural DNA nanotechnology by incorporating protein nanotechnology has been clearly demonstrated and still shows a large potential to create useful and advanced materials with cell-like properties or dynamic systems. It can be expected that structural protein-DNA nanotechnology will open new avenues in the fabrication of nano-assemblies with unique functional applications and enrich the toolbox of bionanotechnology.

Environmental DNA (eDNA) sampling has emerged as a powerful approach for monitoring biodiversity in the context of diverse terrestrial and aquatic ecosystems, and has broad potential for both environmental surveys and species management. eDNA studies focusing on plant and animal species have capitalized on analytical methodologies developed originally for metagenomic studies of microorganisms, and on technological improvements in sample collection. However, while eDNA studies have proliferated rapidly, efforts to standardize sampling and analytical methods are still nascent. Critically, fundamental data concerning the distribution and persistence of eDNA in different ecological contexts are lacking, complicating both confidence in species detection and comparability between studies. We propose that key deficits could be addressed by using well-designed synthetic DNA standards or tracers, which are widely used in fields ranging from medical diagnostics to hydrology. In-field application of a standardized mixture of barcoded synthetic DNA fragments of varying lengths and concentrations that are recovered concommitantly with eDNA sampling should provide critical yet missing data on environmental DNA distribution and turnover, as well as an internal molecular standard to enhance both species detection and comparability between eDNA studies.

The uterine leiomyoma is the most common benign tumor in women of childbearing age. It may lead to problem of conception or complications during gestational period. The methods of treatment can be surgical (myomectomy and hysterectomy, embolization of arteries) and therapeutic treatment (Ulipristal acetate, Leuprolide acetate, Cetrorelix, Goserelin, Mifeprestone). Both approaches are efficient, but are incompatible with pregnancy planning. Therefore, there is a call for medical practice in developing therapeutical means of preventing leiomyoma onset in patients planning on pregnant. Based on the analysis of GWAS data on the search for mononucleotide polymorphisms associated with the risk of leiomyoma, meta-transcriptomic and meta-methylomic studies, target proteins have been proposed. Prospective therapeuticals of leiomyoma may be based on chemical compounds, humanized recombinant antibodies, vaccines based on markers of the uterine leiomyoma cells that are absent in the adult organism, DNA and RNA preparations. Three different nosological forms of the disease associated with driver mutations in the MED12, HMGA2 and FH genes should be considered when developing or prescribing drugs. E.g. synthetic inhibitors and vaccines based on matrix metalloproteinases MMP11 and MMP16 are expected to be effective only for the prevention of the occurrence of MED12-dependent nodules.

Zinc finger proteins (ZFP) play important roles in cellular processes. The DNA binding region of ZFP consists of 3 zinc finger DNA binding domains connected by amino acid linkers, the sequence TGQKP connects ZF1 and ZF2, and TGEKP connects ZF2 with ZF3. Linkers act to tune the zinc finger protein in the right position to bind its DNA target, the type of amino acid residues and length of linkers reflect on ZF1-ZF2-ZF3 interactions and contribute to the search and recognition process of ZF protein to its DNA target. Linker mutations and the affinity of the resulting mutants to specific and nonspecific DNA targets were studied by MD simulations and MM_GB(PB)SA. The affinity of mutants to DNA varied with type and position of amino acid residue. Mutation of K in TGQKP resulted in loss in affinity due to the loss of positive K interaction with phosphates, mutation of G showed loss in affinity to DNA, WT protein and all linker mutants showed loss in affinity to a nonspecific DNA target, this finding confirms previous reports which interpreted this loss in affinity as due to ZF1 having an anchoring role, and ZF3 playing an explorer role in the binding mechanism. The change in ZFP-DNA affinity with linker mutations is discussed in view of protein structure and role of linker residues in binding.

Structural DNA nanotechnology provides an excellent foundation for diverse nanoscale shapes that can be used in various bioapplications and materials research. From all existing DNA assembly techniques, DNA origami has proven to be the most robust one for creating custom nanoshapes. Since its invention in 2006, building from the bottom up using DNA has drastically advanced, and therefore, more and more complex DNA-based systems have become accessible. So far, vast majority of the demonstrated DNA origami frameworks are static by nature, but interestingly, there also exist dynamic DNA origami devices that are increasingly coming into view. In this review, we discuss DNA origami nanostructures that perform controlled translational or rotational movement triggered by predefined DNA strands, various molecular interactions and/or other external stimuli such as light, pH, temperature and electromagnetic fields. The rapid evolution of such dynamic DNA origami tools will undoubtedly have a significant impact on molecular scale precision measurements, targeted drug delivery and diagnostics, but they can also play a role in development of optical/plasmonic sensors, nanophotonic devices and nanorobotics for numerous different tasks.

Natural and synthetic small molecules from the NCI Developmental Therapeutics Program (DTP) were employed in molecular dynamics-based docking with DNA repair proteins whose RNA-Seq based expression was associated with overall cancer survival (OS) after adjustment for the PCNA metagene. The compounds employed were required to elicit a sensitive response (vs. resistance) in more than half of the cell lines tested for each cancer. Methodological approaches included peptide sequence alignments and homology modeling for 3D protein structure determination, ligand preparation, docking, toxicity and ADME prediction. Docking was performed for unique lists of DNA repair proteins which predict OS for AML, cancers of the breast, lung, colon, and ovaries, GBM, melanoma, and renal papillary cancer. Results indicate hundreds of drug-like and lead-like ligands with best-pose binding energies less than -6 kcal/mol. Ligand solubility for the top 20 drug-like hits approached lower bounds, while lipophilicity was acceptable. Most ligands were also blood-brain barrier permeable with high intestinal absorption rates. While the majority of ligands lacked positive prediction for Herg channel blockage and Ames carcinogenicity, there was considerable variation for predicted fathead minnow, honey bee, and Tetrahymena pyriformis toxicity. The computational results suggest the potential for new targets and mechanisms of repair inhibition and can be directly employed for in vitro and in vivo confirmatory laboratory experiments to identify new targets of therapy for cancer survival.

Several clinically useful anticancer drugs selectively kill cancer cells by inducing DNA damage; the genomic instability and DNA repair defects of cancer cells make them more vulnerable than normal cells to the cytotoxicity of DNA-damaging agents. Because epoxide-containing compounds can induce DNA damage, we have used the MTT assay to evaluate the selective cytotoxicity of three epoxyalkyl galactopyranosides against A549 lung cancer cells and MRC-5 lung normal cells. Compound (2S,3S)-2,3-Epoxydecyl 4,6-O-(S)-benzylidene-β-D-galactopyranoside (EDBGP) showed the highest selective anticancer activity and was selected for mechanistic studies. After observing that EDBGP induced cellular DNA damage (comet assay), we found that cells deficient in nucleotide excision repair were hypersensitive to the cytotoxicity of this compound; this suggests that EDBGP may induce bulky DNA adducts. EDBGP did not inhibit glycolysis (glucose consumption and lactate production). Pre-treatment of lung cancer cells with several antioxidants did not reduce the cytotoxicity of EDBGP, thereby indicating that reactive oxygen species do not participate in the anticancer activity of this compound. Finally, EDBGP was screened against a panel of cancer cells and normal cells from several tissues, including three genetically modified skin fibroblasts with increasing degree of malignancy. Our results suggest that epoxyalkyl galactopyranosides are promising lead compounds for the development of new anticancer agents.

The initiation reactions of DNA synthesis are central processes during human chromosomal DNA replication. They are separated into two main processes: the initiation events at replication origins, the start of the leading strand synthesis for each replicon, and the numerous initiation events taking place during lagging strand DNA synthesis. In addition, a third mechanism is the re-initiation of DNA synthesis after replication fork stalling, which takes place when DNA lesions hinder the progression of DNA synthesis. The initiation of leading strand synthesis at replication origin is regulated at multiple levels, from the origin recognition to the assembly and activation of replicative helicase, the Cdc45-MCM2-7-GINS (CMG) complex. In addition, the multiple interactions of the CMG complex with the eukaryotic replicative DNA polymerases such as DNA polymerase α-primase (Pol α), DNA polymerase δ and ε at replication forks play pivotal roles in the mechanism of initiation reactions including the initiation of signalling unperturbed and stalled replication forks, ‘replication stress’ events, via ATR (ATM-Rad 3-related protein kinase). All these processes are essential for the accurate transfer of the cells’ genetic information to their daughters. Failures and dysfunctions in these processes gives rise to genome instability followed by genetic diseases including cancer. Thus, in their review ‘Hallmarks of Cancer: New Dimensions‘ Hanahan and Weinberg (2022) called genome instability a fundamental function in the development process of cancer cells. In recent years, the understanding of the initiation processes and mechanisms of human DNA replication has made substantial progress at all levels which will be discussed in the review.

DNA polymerases replicate cell genomes and/or participate in the maintenance of genome integrity. DNA polymerases sharing high sequence homology with E. coli DNA polymerase I (pol I), have been grouped in Family A. Pol I participates in Okazaki fragment maturation and in bacterial genome repair. Since its discovery in 1956, pol I has been extensively studied, primarily to get deeper insights into the mechanism of DNA replication. As research on DNA polymerases advances, many novel functions of this group of polymerases are uncovered. For example, human DNA polymerase θ (a Family A DNA pol) has been shown to synthesize DNA using RNA as a template, a function typically attributed to retroviral reverse transcriptase. A heightened interest in drug discovery against pol θ has emerged due to its roles in cancer. Likewise, Pol I family enzymes also appear attractive drug-development targets against microbial infections. Development of antimalarial compounds targeting apicoplast apPOL, an ortholog of Pol I, further extends the druggability of this family of enzymes. Here, we summarize reported drug-development efforts against Family A polymerases, and future perspective regarding these enzymes as antibiotic targets. Current techniques such artificial intelligence can be used to facilitate the goal of new drugs.

Abstract: DNA fragmentation factors 40 and 45 (DFF40 and DFF45) and B-cell lymphoma 2 (Bcl-2) expression were evaluated in the normal human endometrium and myometrium. DFF40, DFF45, and Bcl-2 expression was assessed via immunohistochemistry in the proliferative, secretory, and atrophic endometrium and myometrium collected postmenopausally and premenopausally during the proliferative and secretory phases of the menstrual cycle. The endometrium showed significantly higher DFF40 and DFF45 expression than that in the uterine myometrium; compared to the stroma, endometrial glands showed the highest expression in pre- and postmenopausal specimens. Glandular expression of DFF45 was dependent on the menstrual cycle, reaching its highest level in the secretory endometrium. The glandular expression of DFF40 and DFF45 was significantly lower in postmenopausal specimens than that in premenopausal tissue. No cycle-dependent changes were reported for stromal or myometrial DFF40 or DFF45 expression. Compared to the endometrial stroma and myometrium, Bcl-2 showed the highest expression in the glandular proliferative endometrium and the lowest expression in the stromal secretory endometrium and myometrium during the secretory phase of the cycle. DFF45 and Bcl-2 showed menstrual cycle-dependent expression, which was limited to the glandular layer of the endometrium.

The approach based on molecular modeling was developed to study dNTP derivatives characterized by new polymerase-specific properties. For this purpose, the relative efficiency of PCR amplification with modified dUTPs was studied using Taq, Tth, Pfu, Vent, Deep Vent, Vent (exo-), and Deep Vent (exo-) DNA polymerases. The efficiency of PCR amplification with modified dUTPs was compared with the results of molecular modeling using the known 3D structures of KlenTaq polymerase–DNA–dNTP complexes. The dUTPs were C5-modified with bulky functional groups (the Cy5 dye analogs) or lighter aromatic groups. Comparing the experimental data and the results of molecular modeling revealed the decrease of PCR efficiency in the presence of modified dUTPs with an increase in the number of non-covalent bonds between the substituents and the DNA polymerase (about 15% decrease per one extra non-covalent bond). Generalization of the revealed patterns to all the studied polymerases of the A and B families is discussed herein. The number of non-covalent bonds between the substituents and polymerase amino acid residues is proposed to be a potentially variable parameter for regulating enzyme activity.

Covalent DNA protein crosslinks (DPCs) are common lesions that block replication. We examine here the consequence of DPCs on mutagenesis involving replicational template-switch reactions in Escherichia coli. 5-azacytidine (5azaC) is a potent mutagen for template-switching, dependent on DNA cytosine methylase (Dcm), implicating the trapped Dcm-DNA covalent complex as the initiator for mutagenesis. The leading strand of replication is more mutable than the lagging strand, explained by blocks to the replicative helicase and/or fork regression. We find that template-switch mutagenesis induced by 5-azaC does not require DSB repair via RecABCD. The ability to induce the SOS response is anti-mutagenic by an unknown mechanism. Mutants in recB, but not recA, exhibit high constitutive rates of template-switching and we suggest that RecBCD-mediated DNA degradation prevents template-switching associated with fork regression. A mutation in the DnaB fork helicase also promotes high levels of template-switching. We also find that other DPC-inducers, formaldehyde (a non-specific crosslinker) and ciprofloxacin (a topoisomerase II poison) are also strong mutagens for template-switching. Induction of mutations and genetic rearrangements that occur by template-switching may constitute a previously unrecognized component of the genotoxicity and genetic instability promoted by DPCs.

Hepatocellular carcinoma (HCC) development is associated with altered modifications in DNA methylation, changing transcriptional regulation. Emerging evidence indicates that DNA methyltransferase 1 (DNMT1) plays a key role in carcinogenesis process. This study aimed to investigate how pirfenidone (PFD) modifies this pathway and the effect generated by the association between c-Myc expression and DNMT1 activation. Rats F344 were used for HCC development using 50 mg/kg of diethylnitrosamine (DEN) and 25 mg/kg of 2-aminofluorene (2-AAF). HCC/PFD group received simultaneous doses of 300 mg/kg of PFD. All treatments lasted 12 weeks. On the other hand, HepG2 cells were used to evaluate the effects of PFD in restoring DNA methylation in the presence of the inhibitor 5-Aza. Histopathological, biochemical, immunohistochemical, and western blot analysis were carried out and our findings showed that PFD treatment reduced the amount and size of tumors along with decreased Glipican-3, β-catenin, and c-Myc expression in nuclear fractions. Also, this treatment improved lipid metabolism by modulating PPARγ and SREBP1 signaling. Interestingly, PFD augmented DNMT1 and DNMT3a protein expression, which restores global methylation, both in our in vivo and in vitro models. In conclusion, our results suggest that PFD could slow down HCC development by controlling DNA methylation.

N6-methyladenosine (M6A) modification is the most abundant internal chemical modification on RNA molecules in eukaryotes and can affect mRNA metabolism and regulate RNA transcription, nuclear export, splicing, degradation, translation, ets, and has a significant impact on various aspects of physiology or pathobiology. Radiotherapy is the most common measure of tumor treatment, variety of cellular intrinsic mechanisms affect the responses of cells to ionizing radiation (IR) and effectiveness of cancer radiotherapy. In this review, we summarize and discuss the recent advances about the roles and mechanisms of RNA M6A methylation in cellular responses to radiation-induced DNA damage response, and outcomes of cancer radiotherapy. Insights into the RNA M6A methylation in radiation biology may facilitate the improvement of therapeutic strategies for cancer radiotherapy as well as radioprotection on normal tissues.

Cholangiocarcinoma is an epithelial malignancy arising in the region between the intrahepatic bile ducts and the ampulla of Vater at the distal end of the common bile duct. The effect of current chemotherapy regimens against cholangiocarcinoma is limited, and the prognosis of patients with cholangiocarcinoma is poor. Aberrant DNA methylation and histone modification induce silencing of tumor suppressor genes and chromosomal instability during carcinogenesis. Studies have shown that the tumor suppressor genes and microRNAs (miRNAs) including MLH1, p14, p16, DAPK, miR-370 and miR-376c are frequently methylated in cholangiocarcinoma. Silencing of these tumor suppressor genes and miRNAs plays critical roles in the initiation and progression of cholangiocarcinoma. In addition, recent studies have demonstrated that DNA methylation inhibitors induce expression of endogenous retroviruses and exert the anti-tumor effect of via an anti-viral immune response. Aberrant DNA methylation of tumor suppressor genes and miRNAs could be a powerful biomarker for diagnosis and treatment of cholangiocarcinoma. Epigenetic therapy with DNA methylation inhibitors hold considerable promise for the treatment of cholangiocarcinoma through re-activation of tumor suppressor genes and miRNAs as well as induction of an anti-viral immune response.

DNA repair helps in maintaining the proper and healthy functioning for the cells in the human body. Failure in DNA repair process can lead to aberrations as well as tumorous stages. There are various types of damages that a DNA can go through, one of which is the DNA double strand breaks (DSB) that can be repaired via homologous recombination (HR). RAD51 plays a central role in HR and has been implicated as a negative/poor prognostic marker for colorectal adenocarcinoma, with high expression in colorectal cancer. Mechanistically, RAD51AP1 facilitates RAD51 during the repairing process by binding with RAD51 via two DNA binding sites, thus helping in the D-loop formation in the HR process. Often, in biology, we are faced with the problem of exploring relevant unknown biological hypotheses in the form of myriads of combination of factors that might be affecting the pathway under certain conditions. For example, RAD51AP1-XRCC2 is one such 2^nd order combination whose relation needs to be tested under the influence recently developed Porcupine-WNT inhibitor ETC-1922159. The x-ray repair cross complementing XRCC family is known to work as a mediator or stabilizer for RAD51 during the HR process. The inhibitor is known to suppress Porcupine and thus inhibit a range of oncogenes known to be directly or indirectly affected by the Wnts. In a recent unpublished work in bioRxiv, we had the opportunity to rank these unknown biological hypotheses for down regulated genes at 2^nd order level after the drug was administered. The in silico observations showed that the combination of RAD51AP1-XRCC2 was assigned a relatively lower rank, thus validating the pipeline's efficacy with the confirmed wet lab experiment that indicate that both RAD51AP1 and XRCC2 were down regulated after treatment in cancer cells. Here, we take one step further by in silico analysis of the 3^rd order combinations of RAD51-X-X & RAD51AP1-X-X (X can be known or unknown factor), from a range of 100 randomly picked down regulated genes after ETC-1922159 treatment. The pipeline uses the density based HSIC (Hibert Schmidth Information Criterion) sensitivity index with an rbf (radial basis function) kernel, which is known to be highly effective in sensitivity analysis. Various unknown/unexplored/untested RAD51/RAD51AP1 related 3^rd order biological hypotheses emerge some of which are confirmed in wet lab, while others need to be tested.

More than 50% of patients with non-small cell lung cancer (NSCLC) are treated with radiotherapy (RT) during different phases of treatment. However, radiation pneu-monitis (RP) and resistance often lead to RT failure in NSCLC patients. JWA, a tumor suppressor gene, is known to enhance DNA damage in gastric cancer cells while protect normal cells from DNA damage induced by cisplatin. Recently, we have re-ported that JWA agonist compound 4 (JAC4) effectively protects intestinal epithelium from RT triggered damage in mice. However, the potential synergistic and attenuated effects of JAC4 in chest RT of lung cancer are not been illuminated. The aim of this study was to investigate the effects of JAC4 on the radiotoxicities of both NSCLC and normal lung tissue. CCK-8 and colony formation assays showed that JAC4 played a bidirectional role in radiation-treated SPCA-1 and BEAS-2B cells. Western blotting and immunofluorescence assays showed that JAC4 in combination with RT increased DNA damage and apoptosis in SPCA-1 cells, while the opposite effect was observed in BEAS-2B cells. Mechanistically, JAC4 inhibited homologous recombination repair (HR) and non-homologous end joining (NHEJ) in SPCA-1 cells, but not in normal cells. JAC4 increased antioxidant capacity, and reduced oxidative stress and inhibited nu-clear factor Kappa-B (NF-κB, P65) translocation to the nucleus in BEAS-2B cells. Im-portantly, the bidirectional roles of JAC4 on RT were reversed by siJWA in both SPCA-1 and BEAS-2B cells. Finally, the bidirectional effects of JAC4 in combination with RT were further validated in NSCLC xenograft model mice. In conclusion, JAC4 enhanced effect of RT on tumor growth while alleviated RP and lung injury. Our re-sults may provide new strategy for optimizing RT regimen for NSCLC.

Psoralens have been used in the treatment of several skin diseases such as psoriasis and atopic eczema through PUVA (psoralen + UVA), cutaneous T-cell lymphoma through ECP (extracorporeal photochemotherapy), and recently, the treatment of solid tumors through X-PACT (x-ray psoralen activated cancer therapy). Ingesting psoralens and exposing the molecules to UVA light allows for the flat-planar psoralens to intercalate or slide in-between base pairs and then to form photo-adducts with the DNA backbone which can stop or slow DNA replication. The intrinsic ability of psoralens to bind with DNA and their therapeutic effectiveness contribute to the increased interest in the study of these molecules. Several studies measuring psoralen-DNA binding capabilities have used a variety of spectroscopic techniques and different experimental conditions. In this study, spectrofluorometry was used to measure the DNA-binding capabilities of three different psoralen derivatives (6E, AMT and 8-MOP) under identical experimental conditions. The binding constants were 0.325x106 M-1 for 8-MOP, 0.516x106 M-1 for AMT, and 7.30x106 M-1 for 6E. This direct comparison of the three different psoralens demonstrated the impact of their molecular structure on the DNA-binding capacity. 6E’s significantly greater binding constant makes it the stronger candidate for further studies looking into potential applications for cancer treatment.

Streptococcus pneumoniae is an pathogenic and opportunistic Gram-positive bacteria that is the leading cause of community acquired respiratory diseases, varying from mild- to deathly- infections. Appearance of antibiotic resistant isolates has prompted the search for novel targets. One of the most promising approaches is the structure-based knowledge of possible targets in conjunction to rational design and docking of inhibitors of the chosen targets. A useful technique to help solving protein structures is to label them with a heavy atom, like selenium, that facilitates tracing of the some of the amino acid residues. We have chosen two pneumococcal DNA-binding proteins, namely the relaxase domain of MobM protein from plasmid pMV158, and the RelB-RelE antitoxin-toxin protein complex. Through the update of a previous protocol [1] that uses seleno-L-methionine, we could achieve 100% labelling of the proteins. Furthermore, the labelled proteins retained full activity as judged from relaxation of supercoiled plasmid DNA and from gel-retardation assays.

Agaricus bisporus is belonging to family agaricaceae, which is widely acceptable and mostly cultivated among the all mushrooms. It has great nutritional values and it is rich in proteins, vitamins, carbohydrates, fibers, minerals and amino acids. It is effective in antimicrobial, anticancer, antidiabetic, antihypercholesterolemic, antihypertensive, hepatoprotective and antioxidant activities. As it is effective in anticancer property, we check the effects of chemical constituents of Agaricus Bisporus on DNA damaging protein which results its activity PARP inhibiting or vise-versa. We choose the molecular docking technique to check the effects of different chemical constituents of Agaricus Bisporus on DNA damaging protein. For that different PARP inhibitory drugs taken as the standard. We perform the molecular docking of the chemical constituents of Agaricus Bisporus, using 4UND protein with the help of PyRx software and BIOVIA Discovery studio software. Along with that PARP inhibitor drugs also run against the same protein. The results of molecular docking shows the some of the constituents of Agaricus Bisporus has better binding affinity than the standard taken PARP inhibitor drugs. The ergosterol shows the better binding affinity than the niraparib and rucaparib on the same proteins. On other hands the naringenin, quercetin, anthocyanin, folate and myricetin shows the better results than the rucaparib. That means the ergosterol shows the better results as PARP inhibitor than the niraparib and rucaparib.

Protein-DNA interactions are critical for the successful functioning of all natural systems. The key role in these interactions is played by processes of protein search for specific sites on DNA. Although it has been studied for many years, only recently microscopic aspects of these processes became more clear. In this work, we present a review on current theoretical understanding of the molecular mechanisms of the protein target search. A comprehensive discrete-state stochastic method to explain the dynamics of the protein search phenomena is introduced and explained. Our theoretical approach utilizes a first-passage analysis and it takes into account the most relevant physical-chemical processes. It is able to describe many fascinating features of the protein search, including unusually high effective association rates, high selectivity and specificity, and the robustness in the presence of crowders and sequence heterogeneity.

Bacterial resistance to antibiotics due to an increased efficiency of the efflux is a serious problem in clinics of infectious diseases. Knowledge of the factors affecting the activity of efflux pumps would help to find the solution. For this, fast and trustful methods for the efflux analysis are needed. Here we analyzed how the assay conditions affect the accumulation of efflux indicators ethidium (Et+) and tetraphenylphosphonium in Salmonella enterica ser. Typhimurium cells. An inhibitor phenyl-alanyl-arginyl-β-naphtylamide was applied to evaluate the input of RND family pumps into the total efflux. In parallel to spectrofluorimetric analysis, we used an electrochemical assessment of Et+ concentration. Results of our experiments indicated that Et+ fluorescence increases immediately after the penetration of this indicator into the cells. However, when cells bind a high amount of Et+, intensity of the fluorescence reaches the saturation level and stops reacting to the accumulated amount of this indicator. For this reason, electrochemical measurements provide more trustful information about the efficiency of efflux when cells accumulate high amounts of Et+. Measure-ments of Et+ interaction with the purified DNA demonstrated that affinity of this lipophilic cation to DNA depends on the medium composition. The capacity of DNA to bind Et+ considerably de-creases in presence of Mg2+, Polymyxin B or when DNA is incubated in high ionic strength media.

DNA damage causes the mutations that are the principal source of genetic variation. DNA damage detection and repair mechanisms therefore play a determining role in generating the genetic diversity on which natural selection acts. Speciation, it is commonly assumed, occurs at a rate set by the level of standing allelic diversity in a population. The process of speciation is driven by a combination of two evolutionary forces: genetic drift and ecological selection. Genetic drift takes place under conditions of relaxed selection, and results in a balance between rates of mutation and rates of genetic substitution. These two processes, drift and selection, are necessarily mediated by a variety of mechanisms guaranteeing genome stability in any given species. One of the outstanding questions in evolutionary biology concerns the origin of the widely varying phylogenetic distribution of biodiversity across the tree of life, and how the forces of drift and selection contribute to shaping that distribution. The following examines some of the molecular mechanisms underlying genome stability and the adaptive radiations that are associated with biodiversity and the widely varying species richness and evenness in the different eukaryotic lineages.

Radiation therapy (RT) is one of the main approaches of cancer therapy, including non-small cell lung cancer (NSCLC). Radiation-induced DNA double-stranded breaks (DSBs), single-stranded DNA breaks (SSBs) and oxidized nucleobases cause replication fork stalling, chromosomal instability or point mutagenesis and can lead to cell death. Translesion DNA synthesis (TLS) is one of the DNA damage tolerance (DDT) pathways promoting replication of damaged DNA. Here, we explored the effects of the knockout of primase-polymerase PRIMPOL (PRIMPOL −/−) and TLS polymerase POLI (POLI −/−) genes in two different monoclonal lines derived from human NSCLC A549 cells. Our study aimed to investigate the impact of their absence on the susceptibility of these cells to ionizing radiation (IR)-induced stress. Without IR, cells that do not have PRIMPOL or POLI experience a considerable rise in apoptosis by day 7 of continuous cultivation and a noteworthy decline in cell migration under spatial confinement when compared to the parental wild-type cells. Despite this, we have found that PRIMPOL −/− exhibited higher clonogenic survival compared to wild-type cell lines in response to IR stress. Both of these cell lines demonstrated remarkable resilience to radiation stress, surpassing the survival rate of the original A549 cells. POLI deficiency reduces cellular γH2AX foci accumulation, while the presence of highest number of γH2AX foci in PRIMPOL−/− cells was ATM-independent. We report for the first time that increased post-irradiation clonogenic survival of PRIMPOL −/− A549 cells might be associated with the increase of CD133+ but not CD44+ populations of cancer stem-like cells.

A hybrid material, consisting of commercially available nitrocellulose (NC) membrane non-covalently modified with amino-polyethylene glycol functionalized reduced graphene oxide (NH2-PEG-rGO) nanoparticles, was successfully synthesized for oligonucleotide extraction. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the modification of the NC membrane, revealing characteristic peaks of both compounds NC and NH2-PEG-rGO. Scanning Electron Microscopy (SEM) exhibited morphological changes in the NC/NH2-PEG-rGO hybrid membrane, marked by the introduction of NH2-PEG-rGO particles, resulting in a distinctly smothered surface compared to the porous surface of the NC control membrane. Wettability assays revealed hydrophobic behavior for the NC/NH2-PEG-rGO hybrid membrane, with a water contact angle exceeding 90°, contrasting with the hydrophilic behavior characterized by a 16.7° contact angle in the NC membrane. The performance of the NC/NH2-PEG-rGO hybrid membrane was evaluated for the extraction of ssDNA with fewer than 50 nucleotides from solutions containing various ionic species (MnCl2, MgCl2, and MnCl2/MgCl2). The NC/NH2-PEG-rGO hybrid membrane exhibited optimal performance when incubated in MgCl2, presenting the highest fluorescence emission at 525 relative fluorescence units (r.f.u.). This corresponds to the extraction of approximately 610 pg (≈13%) of the total oligo-DNA, underscoring the efficacy of the pristine material, which extracts 286 pg (≈6%) of oligo-DNA in complex solutions.

Abstract: Congenital cytomegalovirus (cCMV) infection poses significant risks to fetal development, particularly affecting the nervous system. This study reports a fetal autopsy case, examining cCMV infection and focusing on CMV DNA measurements in various fetal organs before formalin fixation, a novel approach for comprehensive CMV DNA evaluations in fetal organs affected by cCMV. A 20-week-old male fetus was diagnosed with cCMV following the detection of CMV DNA in ascites obtained via abdominocentesis in utero. After termination of pregnancy, multiple organs of the fetus, including the cerebrum, thyroid gland, heart, lungs, liver, spleen, kidneys, and adrenal glands, were extracted and examined for CMV DNA loads using real-time polymerase chain reaction. Histopathological examination involved hematoxylin-eosin and CMV-specific immunostaining. A correlation was found between CMV DNA loads and pathology, with higher CMV-infected cell numbers observed in organs positively identified with both staining methods, exhibiting CMV DNA levels of ≥1.0 × 104 copies/mL, compared to those detected solely by CMV-specific immunostaining, where CMV DNA levels ranged from 1.0 x 103 to 1.0 x 104 copies/mL. These results highlight a quantifiable relationship between organ infection extent and CMV DNA concentration, providing insights into cCMV pathogenesis and potentially informing future diagnostic and therapeutic strategies for cCMV infection.

In E. coli DNA replication forks stall on average once per cell cycle. When this occurs, replisome components disengage from the DNA, exposing an intact, or nearly intact fork. Consequently, the fork structure must be regressed away from the initial impediment so repair can occur. Regression is catalyzed by the powerful, monomeric DNA helicase, RecG. During this reaction, the enzyme couples unwinding of fork arms to rewinding of duplex DNA resulting in the formation of a Holliday junction. RecG works against large opposing forces enabling it to clear the fork of bound proteins. Following subsequent processing of the extruded junction, the PriA helicase mediates reloading of the replicative helicase DnaB leading to the resumption of DNA replication. The single-strand binding protein (SSB) plays a key role in mediating PriA and RecG functions at forks. It binds to each enzyme via linker/OB-fold interactions and controls fork loading sites in a substrate-dependent manner that involves helicase remodeling. Finally, it is displaced by RecG during fork regression. The intimate and dynamic SSB-helicase interactions play key roles in ensuring fork regression and DNA replication restart.

The study titled "Molecular Choreography of DNA: Insights and Innovations" explores the intricate dance of DNA, shedding light on its structure, function, and regulation. This comprehensive review delves into the historical significance of DNA research, from Watson and Crick's double helix discovery to recent innovations in genomics and molecular biology. The review highlights DNA's roles in replication, repair, gene regulation, and chromatin dynamics, emphasizing the precision and complexity of its molecular choreography. Innovations like CRISPR-Cas9 gene editing and advanced sequencing technologies have revolutionized our understanding of DNA, opening new avenues for scientific exploration. This study aims to provide readers with a deeper appreciation of DNA's central role in life's choreographed processes.

Radiotherapy and cisplatin-based chemotherapy belong to the main treatment modalities for head and neck squamous cell carcinoma (HNSCC), and induce cancer cell death by generating DNA damage, including the most severe double strand breaks (DSBs). Alterations in DSB response and repair genes may affect individual DNA repair capacity and treatment sensitivity, contributing to therapy resistance and poor prognosis often observed in HNSCC. In this study, we investigated the association of a panel of single nucleotide polymorphisms (SNPs) in 20 DSB signaling and repair genes with therapy results and prognosis in 505 HNSCC patients treated non-surgically with DNA damage-inducing therapies. In the multivariate analysis, there were a total of 14 variants associated with overall, locoregional recurrence-free or metastasis-free survival. Moreover, we identified 10 of these SNPs as independent predictors of therapy failure and unfavorable prognosis in the whole group or in two treatment subgroups. They were MRE11A rs2155209, XRCC5 rs828907, RAD51 rs1801321, rs12593359, LIG4 rs1805388, CHEK1 rs558351, TP53 rs1042522, ATM rs1801516, XRCC6 rs2267437 and NBS1 rs2735383. Only CHEK1 rs558351 remained statistically significant after correction for multiple testing. These results suggest that specific germline variants related to DSB response and repair may be potential genetic modifiers of therapy effects and disease progression in HNSCC treated with radiotherapy and cisplatin-based chemoradiation.

Telomeres in epithelial tumours are usually maintained by telomerase, however, in the breast cancer MDA-MB-231 cell line, polyploid cells, induced by doxorubicin (DOX) were found, after mitotic slippage, transiently shifting to recombinatory alternative telomere lengthening (ALT) in PML bodies (APBs). The involvement of the meiotic recombination proteins was evidenced here by juxta-co-localisation of SPO11, DMC1 and RAD51/γH2AX with APBs in these and melanoma SkMel28-DOX-treated cells. Using sublethal doses of DOX we also observed the formation of the PML dimeric rod tandems linking γH2AX/TRF2 foci into ribbons discontinuously inserted into lamin B1 and circumventing cell nuclei. Next, we link these PML-lamin B1 insertions and peripheral rotation of the tandemly linked telomere repeats with the mobility of the nuclear envelope limited chromatin sheets (ELCS). ELCSs comprise two layers of the criss-crossed ~30 nm granules derived from surface heterochromatin (epichromatin) which contains telomere repeats enriched in GpC, PML, and ALU. ELCS protrude, circumvent, loop, split, fuse, and rejoin polyploid cell nuclei. We propose this gear-wheel-like turnover of telomere repeats to be used for the homology search. Interstitial and end-telomere repeats flanked by fragile ALU-Z flipons become recognised by SPO11 nuclease, attract TRF2, PML, and meiotic recombinases. Subsequently, they perform ALT recombining subtelomeres and telomeres or undergo non-homologous end-joining and chromosome rearrangements with ELCS. This mechanism increases the chance of cell survival and may be involved in chromothripsis.

Cancer-associated fibroblasts (CAF) form the basis of tumor microenvironment and possess immunomodulatory functions by interacting with other cells surrounding tumor, including T lymphocytes, macrophages, dendritic cells and natural killer cells. Ionizing radiation is a broadly-used method in radiotherapy to target tumors. In mammalian cells, ionizing radiation induces various types of DNA damages and DNA damage response. Being unspecific, radiotherapy affects all the cells in tumor microenvironment, including the tumor itself, CAFs and immune cells. CAFs are extremely radio-resistant and do not initiate apoptosis even at high doses of radiation. However, following radiation, CAFs become senescent and produce a distinct combination of immunoregulatory molecules. Radiosensitivity of immune cells varies depending on the cell type due to inefficient DNA repair in, for example, monocytes and granulocytes. In this minireview, we are summarizing recent findings on the interaction between CAF, ionizing radiation and immune cells in the tumor microenvironment.

Adenoviruses (Ads) have been extensively manipulated for the development of cancer selective replication, leading to cancer cell death or oncolysis. Clinical studies using E1-modified oncolytic Ads have shown that this therapeutic platform was safe, but with limited efficacy, indicating the necessity of targeting other viral genes for manipulation. To improve the therapeutic efficacy of oncolytic Ads, we treated the entire Ad genome repeatedly with UV-light and have isolated AdUV which efficiently lyses cancer cells as reported previously [1]. In this report, we show that no mutations were observed in the early genes (E1 or E4) of AdUV while several mutations were observed within the Ad late genes which have structural or viral DNA packaging functions. This study also reported the increased release of AdUV from cancer cells. In this study, we found that AdUV inhibits tumor growth following intratumoral injection. These results indicate the potentially significant role of the viral late genes, in particular the DNA packaging genes, to enhance Ad oncolysis.

The urgent need for effective, safe and equitably accessible vaccines to tackle the ongoing spread of COVID-19 led researchers to generate vaccine candidates targeting varieties of immunogens of SARS-CoV-2. Because of its crucial role in mediating binding and entry to host cell and its proven safety profile, the subunit 1 (S1) of the spike protein represents an attractive immunogen for vaccine development. Here, we developed and assessed the immunogenicity of a DNA vaccine encoding the SARS-CoV-2 S1. Following in vitro confirmation and characterization, the humoral and cellular immune responses of our vaccine candidate (pVAX-S1) was evaluated in BALB/c mice using two different doses, 25 µg and 50 µg. Our data showed high levels of SARS-CoV-2 specific IgG and neutralizing antibodies in mice immunized with three doses of pVAX-S1. Analysis of the induced IgG subclasses showed a Th1-polarized immune response as demonstrated by the significant elevation of spike-specific IgG2a and IgG2b compared to IgG1. Furthermore, we found that immunization of mice with three doses of 50 µg of pVAX-S1 could elicit significant memory CD4+ and CD8+ T cell responses. Taken together, our data indicates that pVAX-S1 is immunogenic and safe in mice and is worthy of further preclinical and clinical evaluation.

SAMHD1 is a deoxynucleotide triphosphate (dNTP) triphosphohydrolase with important roles in the control of cell proliferation and apoptosis, either through the regulation of intracellular dNTPs levels or the modulation of the DNA damage response. However, SAMHD1 role in cancer evolution is still unknown. We performed the first in-depth study of SAMHD1 role in advanced solid tumors, by analyzing samples of 128 patients treated with chemotherapy agents based on platinum derivatives and/or antimetabolites and developing novel in vitro knock-out models to explore the mechanisms driving SAMHD1 function in cancer. Low or no expression of SAMHD1 was associated with a positive prognosis in breast, ovarian and non-small cell lung cancer (NSCLC) cancer patients. A predictive value was associated to low-SAMHD1 expression in NSCLC and ovarian patients treated with antimetabolites in combination with platinum derivatives. In vitro, SAMHD1 knock-out cells showed increased γ-H2AX and apoptosis suggesting that SAMHD1 depletion induces DNA damage leading to cell death. In vitro treatment with platinum-derived drugs significantly enhanced γ-H2AX and apoptotic markers expression in knock-out cells, indicating a synergic effect of SAMHD1 depletion and platinum-based treatment. SAMHD1 expression represents a new strong prognostic and predictive biomarker in solid tumors and thus, modulation of SAMHD1 function may constitute a promising target for the improvement of cancer therapy.

In the last two decades, plant taxonomy has bloomed, following the development of a novel technique, namely DNA Barcoding. DNA barcodes are standardized sequences, ideally unique, coding or non-coding, either from the genome of the organism or from its organelles, that are used to identify/classify an organismal group; in short the method includes amplification of the DNA barcode, sequencing and comparison with a reference database containing the relevant sequences from different species. In plants, the use a universal DNA barcode, such as COI which is used in animals, has not been achieved so far. Several DNA barcodes from single loci as well as combinations of barcodes have been successfully used in various settings; additionally, as next generation sequencing becomes affordable, very long sequences- super barcodes, such as the chloroplast genome are being used successfully especially to distinguish between close species. In this review we summarize the work done on DNA barcoding in plants and discuss different approaches used so far.

Alzheimer’s disease is associated with prion-like aggregation of the amyloid β (Aβ) peptide and the subsequent accumulation of misfolded neurotoxic aggregates in the brain. Therefore, it is critical to clearly identify the factors that trigger the cascade of Aβ misfolding and aggregation. Numerous studies have pointed out the association between microorganisms and their virulence factors and Alzheimer’s disease; however, their exact mechanisms of action remain unclear. Recently, we discovered a new pathogenic role of bacterial extracellular DNA, triggering the formation of misfolded Tau aggregates. In this study, we investigated the possible role of DNA extracted from different bacterial and eukaryotic cells in triggering Aβ aggregation in vitro. Interestingly, we found that the extracellular DNA of some, but not all, bacteria is an effective trigger of Aβ aggregation. Furthermore, the acceleration of Aβ nucleation and elongation can vary based on the concentration of the bacterial DNA and the bacterial strain from which this DNA had originated. Our findings suggest that bacterial extracellular DNA might play a previously overlooked role in the Aβ protein misfolding associated with Alzheimer’s disease pathogenesis. Moreover, it highlights a new mechanism of how distantly localized bacteria can remotely contribute to protein misfolding and diseases associated with this process. These findings might lead to the use of bacterial DNA as a novel therapeutic target for the prevention and treatment of Alzheimer’s disease.

This work demonstrates that a plasmid can function as an efficient biocatalyst in mediating the nitroaldol (Henry) reaction at high temperatures in ultrapure water. Compared with ssDNA, the plasmid displayed a remarkable catalytic efficiency (97% yield within 20 min). Aromatic aldehydes which bear strong or moderate electron-withdrawing groups reacted satisfactorily with nitromethane, which afforded the corresponding β-nitroalcohols in good yields within 2 h (up to 98%). By contrast, aliphatic and aromatic aldehydes with electron-donating groups did not react. Moreover, the yield significantly dropped when the size of the carbanion increased, and the yield was only 10% when nitropropane was used as the donor.

Theoretical and experimental approaches have been applied to study the polymer physics under-lying compaction of DNA in the bacterial nucleoid. Knowledge of the compaction mechanism is necessary to obtain a mechanistic understanding of the process of segregation of replicating chromosome arms (replichores) during the cell cycle. In the first part of this review light microscope observations are discussed that have demonstrated that the nucleoid has a lower refractive index and thus a lower density than the cytoplasm. A polymer-physical explanation for this phenomenon was given by the theory of Theo Odijk pro-posed in 1998. By assuming a phase separation between nucleoid and cytoplasm and by imposing equality of osmotic pressure and chemical potential between the two phases, a minimal energy situation is obtained in which soluble proteins are depleted from the nucleoid, thus explaining its lower density. The theory is compared with recent views for DNA compaction that are based on mere exclusion of polyribosomes from the nucleoid or on the transcriptional activity of the cell. These new views raise the question of whether they can still explain the lower refractive index or density of the nucleoid. In the second part of this review the question is discussed how DNA segregation occurs in Esche-richia coli, in the absence of the so-called active ParABS system, present in the majority of bacteria. How is entanglement prevented of nascent chromosome arms, generated at the origin in the pa-rental network of the E. coli nucleoid? The observations of the groups of Sherratt and Hansen in 2006, that the four nascent chromosome arms synthesized in the initial replication bubble, segre-gate to opposite halves of the sister nucleoids implies that extensive intermingling of daughter strands does not occur. Based on the hypothesis that leading and lagging replichores synthesized in the replication bubble, fold into micro-domains that do not intermingle, a passive "four-excluding-arms model" for segregation is proposed. This model implies that the key for seg-regation already lies in the structure of the replication bubble at the very start of DNA replication; it explains the different patterns of chromosome arms as well as the segregation distances between replicated loci as experimentally observed.

Transcription factors (TFs) and microRNAs (miRNAs) are co-actors in genome-scale decoding and regulatory networks, often targeting common genes. In this paper, we describe the algebraic geometry of both TFs and miRNAs thanks to group theory. In TFs, the generator of the group is a DNA-binding domain while, in miRNAs, the generator is the seed of the sequence. For such a generated (infinite) group $\pi$, we compute the $SL(2,\mathbb{C})$ character variety, where $SL(2,\mathbb{C})$ is simultaneously a \lq space-time' (a Lorentz group) and a \lq quantum' (a spin) group. A noteworthy result of our approach is to recognize that optimal regulation occurs when $\pi$ looks like a free group $F_r$ ($r =1$ to $3$) in the cardinality sequence of its subgroups, a result obtained in our previous papers. A non free group structure features a potential disease. A second noteworthy result is about the structure of the Groebner basis $\mathcal{G}$ of the variety. A surface with simple singularities (like the well known Cayley cubic) within $\mathcal{G}$ is a signature of a potential disease even when $G$ looks like a free group $F_r$ in its structure of subgroups. Our methods apply to groups with a generating sequence made of two to four distinct DNA/RNA bases in $\{A,T/U,G,C\}$. Several human TFs and miRNAs are investigated in detail thanks to our approach.

Drug abuse is a major issue worldwide. Methylphenidate (MPH) and alprazolam (ALZ) are commonly prescribed drugs for the treatment of ADHD and anxiety disorders, respectively. The limited studies suggest that abusers primarily use benzodiazepines to counteract adverse effects associated with methylphenidate usage. The main aim of this study was to investigate the interaction of drugs with DNA using spectroscopic methods. Female Wistar rats were administered with MPH (10, 20, 40 mg/kg) and ALZ (5, 10, 20 mg/kg) alone and in combination for a period of 28 days. The FT-IR and UV results reveal some spectral changes in a dose-dependent manner, which indicates interactions of drugs with DNA. Thus, the changes in spectral peaks provide some insight into the mechanism of the interaction of drugs with DNA.

1) Background: We tested whether AHR activation induces DNA damage, whether polymorphisms in genes related to risk of Non-Hodgkin lymphoma are associated with DNA damage, and whether the two conditions do interact with each other. 2) Methods: Our study population included 36 subjects, randomly selected among the population controls participating in a case-control study on lymphoma in Sardinia, Italy, who donated a blood sample. We investigated 47 single nucleotide polymorphisms (SNPs) previously reported to convey risk of lymphoma; the Dual-Glo® Luciferase Assay System to detect activation of the aryl hydrocarbon receptor (AhR) by the serum of study subjects; and the COMET Assay to detect DNA damage. 3) Results: Activation of the aryl hydrocarbon receptor did not increase DNA damage in our study population. On the other hand, the mutant allele (G) of rs1056932/BCL6 increased the occurrence of DNA damage (p = 0.045); such association was confirmed among AhR negative, but not AhR positive subjects. 4) Conclusions: We observed excess DNA damage associated with a gene polymorphism, namely rs1056932/ BCL6, previously reported in association with risk of lymphoma. No increase in DNA damage was associated with AhR activation per se, nor with the other gene polymorphisms we investigated.

Dried blood spot (DBS) testing on confetti is one of the most common methods used to collect and extract DNA from field samples for molecular epidemiology of malaria studies. Here, we investigated whether ethanol or other solutions used to clean scissors are a source of sample contamination. DBS were prepared from 3 drops of blood from two Plasmodium falciparum cultures spotted on confetti, and 3 solutions (water, ethanol and DNase) were used to clean scissors between spots during DNA extraction. For each cleaning solution, two blank confetti were used as negative controls. Samples were analyzed by PCR-based genotyping of merozoite surface proteins 1 & 2 (msp-1 and msp-2), and P. falciparum chloroquine resistance transporter (Pfcrt). A total of 15 samples were analyzed. Based on msp-1 and msp-2 amplification, P. falciparum was detected on blank confetti when scissors were washed with ethanol. Based on Pfcrt amplification, DNA of P. falciparum was detected on blank confetti when scissors were cleaned with ethanol or water. No P. falciparum genes were detected on blank confetti when scissors were cleaned with DNase. Scissors cleaned with DNase prevented cross-contamination between samples during processing of dried blood spots, whereas ethanol (which is commonly used) fails to avert cross-contamination.

Although the APOBEC3 family of single-stranded DNA cytosine deaminases are well-known as antiviral factors, these enzymes are rapidly gaining attention as prominent sources of mutation in cancer. APOBEC3 signature single base substitutions, C-to-T and C-to-G in TCA and TCT motifs, are evident in over 70% of human malignancies and dominate the mutational landscape of numerous individual tumors. Recent murine studies have established cause-and-effect relationships, with both human APOBEC3A and APOBEC3B proving capable of promoting tumor formation in vivo. Here, we investigate the molecular mechanism of APOBEC3A-driven tumor development using the murine Fah liver complementation and regeneration system. First, we show that APOBEC3A alone is capable of driving tumor development (without Tp53 knockdown as in prior studies). Second, we show that the catalytic glutamic acid residue of APOBEC3A (E72) is required for tumor formation. Third, we show that an APOBEC3A separation-of-function mutant with compromised DNA deamination activity and wildtype RNA editing activity is defective in promoting tumor formation. Collectively, these results indicate that APOBEC3A is a “master driver” that fuels tumor formation through a DNA deamination-dependent mechanism.

Epithelial-mesenchymal transition (EMT) networks are essential in acquiring the drug resistance and cancer malignant features in cancer stem cells (CSCs). In this regard, gene expression profiles in diffuse- and intestinal-type gastric cancer (GC) have been analyzed to reveal the network pathways in EMT and CSCs, since the diffuse-type GC has much more mesenchymal features than intestinal-type GC that has the intestinal features. The study results revealed that the activation state of several canonical pathways related to cell cycle regulation was altered. The canonical pathway on Cell cycle: G1/S checkpoint regulation was activated in diffuse-type GC, and canonical pathways on Cell cycle control of chromosomal replication and Cyclins and cell cycle regulation were activated in intestinal-type GC. Canonical pathway related to Role of BRCA1 in DNA damage response was activated in intestinal-type GC, where BRCA1, which is related to G1/S phase transition was up-regulated in intestinal-type GC. Several microRNAs (miRNAs), including mir-10, mir-17, mir-19, mir-194, mir-224, mir-25, mir-34, mir-451, and mir-605, were identified to have direct relationships of RNA-RNA interaction in Cell cycle: G1/S checkpoint regulation pathway. Additionally, cell cycle regulation may be altered in EMT conditions. The alterations in activation states of the pathways related to cell cycle regulation in diffuse- and intestinal-type GC would indicate the significance of cell cycle regulation in EMT.

Many types of banana (Musa spp.)—one of the most economically important horticultural crops—exist, and their ploidy (diploid, triploid, and tetraploid, usually) and genome types (containing A or/and B genome in most cases) differ. At present, observation and genome type detection are commonly used to identify banana germplasm resources. However, the former is tedious, while the latter cannot distinguish categories below genome types. It is therefore urgent that a simple and effective method for identifying banana germplasm resources is established. We sequenced and analyzed the ribosomal DNA internal transcribed spacer (ITS) sequences of 62 banana germplasm and found that the sequencing peaks, especially the 20 bp region near the 420 bp position (referred to as the “420 bp region”), exhibited relatively recognizable and repeatable polymorphism characteristics. Using the “420 bp region” as a marker, we were able to quickly distinguish bananas belonging to different genome type groups (comprising the AA, AB, AAA, ABB, AAB, ABBB, AAAB, and AAAA groups) or different subgroups in the same genome type group (for example, the Cavendish, Gros Michel, Red, Lakatan, and Ibota Bota subgroups in the AAA group; and the Pisang Raja, Plantain, Pome and Silk subgroups in the AAB group). Moreover, it appeared that Sanger sequencing of ITS could be used for identifying banana hybrid offspring. These results demonstrated that the banana ITS region contains rich genetic information that is useful for genotyping. In general, ITS sequencing simplifies the classification of banana germplasm resources and has potential application in several areas of Musa improvement.

Benzo[a]pyrene (B[a]P), is a family member of polycyclic aromatic hydrocarbons and a widespread environmental pollutant and neurotoxicant that contribute to the development of cancer. Microtubules are polymers of tubulin that form part of the cytoskeleton and target for anticancer drugs. Furthermore, NPY significantly increased the percentage of cells in S and G2/M phases. However, little is known about the specific role of NPY in proliferation and the underlying protective mechanism remains unclear. Hence, the aim of this work was to investigate the effect of B[a]P on SH-SY5Y neuroblastoma cells and to explore the potential mechanism for alteration of tubulin-microtubule equilibrium causing mitotic arrest and NPY expression. The present findings showed B[a]P treatment significantly increase number of SH-SY5Y cells in S and G2/M phase as compared to G1 phase and provokes cell cycle arrest that correlated with significant decrease in G0/G1 cells. Immunofluorescence study showed significantly distorted tubulin arrangement from metaphasic plate in formation of bipolar mitotic spindle apparatus. Further, higher doses of B[a]P treatment lead to chromosomal abnormalities accompanied by DNA damage due ROS causing oxidative stress showing significant decrease in tubulin protein around spindle. The results of present study demonstrated that NPY exerts a proliferative and protective effect on B[a]P-induced oxidative stress in a dose-dependent manner in vitro and importantly, these effects may be mediated via mitotic arrest and involved in spindle arrangement during cell division. Our findings addresses a novel pathological outcomes of B[a]P-induced NPY expression by oxidative stress through spindle abnormalities leading to microtubule disruption.

The sperm heads of frozen/thawed horse spermatozoa were injected into ovulated mouse oocytes where they decondensed and formed paternal pronuclei in which the DNA damage has been evaluated. The motile spermatozoa exhibit none or minor level of DNA damage and the xenogenic zygotes cleave to the two-cell embryonic stage with regular nuclei and no micronuclei (MNs). On the other hand, the immotile spermatozoa exhibit typically high levels of DNA damage and blastomeres in two-cell stage embryos contain multiple MNs. Moreover, extremely high sperm DNA damage prevents even the cleavage to the two-cell stage.Keywords: keyword 1; keyword 2; keyword 3 (List three to ten pertinent keywords specific to the article yet reasonably common within the subject discipline.)

Cellular aging has drawn the attention of researchers, scientists, and biotech businesses for the treatment of a number of medical conditions. Cellular aging is primarily defined by consistent cessation of proliferative development in response to internal and external stressors, including DNA damage, telomere shortening, mitochondrial dysfunction, and regulation of the senescence-associated secretory phenotype (SASP). Disturbances involving these factors may contribute to age-related disease development. Therefore, the current review aims to explore anti-aging factors targeting DNA damage response and SASP regulation and their detailed signaling networks. In addition, it provides an opportunity for researchers to identify not only anti-aging targets, but also anti-aging therapeutic strategies based on identified and non-identified targets.

Relative contribution of different repair pathways to the radiation-induced DNA damage responses remains a challenging issue of studying the radiation injury endpoints. Comparative manifestation of homologous recombination (HR) after application of different radiation doses greatly determines an overall effectiveness of recovery in dividing cell after irradiation, since HR is an error-free mechanism intended for repair of DNA double strand breaks (DSB) during S/G2 phases of cell cycle. In this article, we present an experimentally observed evidence of dose-dependent shift in relative contribution of HR in human fibroblasts after X-ray exposure at doses 20-1000 mGy, which is also supported by quantitative modeling of DNA DSB repair. Our findings indicate that the radiation dose increase leads to dose-dependent decrease in relative contribution of HR into the entire repair process.

Barcoding of DNA is a species identification technique that utilizes a small DNA fragment from a specific gene or genes known as "sequencing." The idea behind DNA barcoding is that a single sequence can be used to specifically identify an organism to species by comparison with a reference library of these DNA sections. Herbal adulteration can be monitored using DNA barcodes that utilize medicinal plants such as Atropa belladonna. Because it is challenging to distinguish between species solely based on morphology, other plants belonging to the same genus are replacing it in trade. Such replacement with plants not utilized for medical purposes could have negative side effects. Also, Atropa belladonna's positive effects can be completely lost. Taxonomists also have trouble distinguishing the genuine Atropa belladonna plant from cultivated items. As a result, DNA barcoding can now be used to overcome this challenge. The development of DNA barcodes may help with trade control, which protects and conserves endangered species from export outside of the country due to their economic and biological significance. In this review, we discuss the DNA barcoding of Atropa belladonna plant in the medicinal plants field.

This article provides a general overview of the bio-inspired computing method called DNA-Based Computing (DBC), including its theory and applications. The main theme of DBC is the central dogma of molecular biology (once information of DNA/RNA has got into a protein, it can’t get out again), i.e., DNA to RNA (sequences of four types of nucleotides) and DNA/RNA to protein (sequence of twenty types of amino acids) are allowed, not the reverse ones. Thus, DBC transfers few-element information (DNA/RAN-like) to many-element information (protein-like), solving a given cognitive problem. DBC can take many forms; this article elucidates two main forms, denoted as DBC-1 and DBC-2. Using arbitrary numerical examples, it is shown that DBC-1 can solve the following cognitive problems: “similarity indexing between seemingly different but inherently identical objects” and “recognizing regions of an image separated by a complex boundary.” DBC-2 can solve the following cognitive problem: “pattern recognition when the relevant information is insufficient.” Smart manufacturing-based systems (digital twins and big data analytics) must solve the abovementioned problems to make the manufacturing enablers (machine tools and monitoring systems) more self-reliant and autonomous. Consequently, DBC can improve the cognitive problem-solving ability of smart manufacturing-relevant systems and, thereby, can enhance its biologicalization.

Apurinic/apyrimidinic endonuclease 1 (APE1), also known as redox factor-1 (Ref-1), is a multifunctional protein which is widely existing in living organisms. It can specifically recognize and cleave the DNA in apurinic/apyrimidinic (AP) site in the base excision repair (BER) pathway, as well as regulate the expression of genes to activate some transcription factors. The abnormal ex-pression and disruptions in the biological functions of APE1 are linked to a number of diseases, including inflammation, immunodeficiency, and cancer. Hence, it is extremely desired to monitor the activity of APE1, acquiring a thorough understanding of the healing process of damaged DNA and making clinical diagnoses. Thanks to the advent of DNA nanotechnology, some nanodevices are used to image the activity of APE1 with great sensitivity and simplicity. In this review, we will summarize DNA nanotechnology-empowered fluorescence imaging in the past years for APE1 activity according to the types of DNA probe, which are classified into linear DNA probes, composite DNA nanomaterials and three-dimensional (3D) DNA nanostructures. We also highlight the future research directions in the field of APE1 activity imaging.

The purpose of this study is to provide an accurate formula for calculating entropy for short DNA sequences and to demonstrate how to use it to examine leukemia patient surviving. We used IDIBAPS leukemia patient’s data base with 117 anonymized records. The generalized form of the Robust Entropy Estimator (EnRE) for short DNA sequences was proposed and key EnRE futures was showed. The Survival Analysis has been done using statistical package IBM SPSS. Entropy EnRE were calculated for leukemia patients for two samples: A. 2 groups divided by median EnRE and B. 2 groups of patients were formed according to their belonging to 1st and 4th quartiles of EnRE. The result of survival analysis are statistically significant: A. p &lt; 0.05; B. p &lt; 0.005. The death hazard for a patient with EnRE below median is 1.556 times that of a patient with EnRE over median and that the death hazard for a patient of 1st quartile (lowest EnRE) is 2.143 times that of a patient of 4th quartile (highest EnRE). The transition from median to quartile patients’ groups with more EnRE differentiation confirmed the unique significance of the entropy of DNA sequences for leukemia patients surviving.

We find that the degeneracies and many peculiarities of the DNA genetic code may be described thanks to two closely related (fivefold symmetric) finite groups. The first group has signature $G=\mathbb{Z}_5 \rtimes H$ where $H=\mathbb{Z}_2 . S_4\cong 2O$ is isomorphic to the binary octahedral group $2O$ and $S_4$ is the symmetric group on four letters/bases. The second group has signature $G=\mathbb{Z}_5 \rtimes GL(2,3)$ and points out a threefold symmetry of base pairings. For those groups, the representations for the $22$ conjugacy classes of $G$ are in one-to-one correspondence with the multiplets encoding the proteinogenic amino acids. Additionally, most of the $22$ characters of $G$ attached to those representations are informationally complete. The biological meaning of these coincidences is discussed.

Advancements in DNA methods and biotechnology have enabled forensic scientists to explore the DNA evidence found as part of a criminal investigation on a much more comprehensive and predictive level. This has led to a rise in research into DNA intelligence tools such as phenotypic prediction (i.e., eye and hair colour) and inference of biogeographical ancestry. Both of which can be applied to gain further insights about a scene or sample in question. Although microorganisms have played a role in forensics for decades, investigations were focused on the pathogenicity aspect, mainly to determine the cause and time of death. Recent progress in studying the human microbiome has implicated the potential use of this data in forensics. Since each individual, place, or item has its own microbial pattern, a new suite of tools are now available to be exploited in criminal investigations. Although there is much interest and potential for these emerging metagenomic and microbial forensic tools, best practices and reference ranges need to be established before they are implemented. Here, we discuss existing DNA intelligence tools applied to forensic science, the application of microbial forensics and metagenomics along with the challenges and concerns that future developments entail.

Two novel sizable multicharged cationic complexes, of the formulae [(η6-[12]CPP)[Ru(η5-Cp)]12]Χ12 and [(η6-[11]CPP)[Ru(η5-Cp)]11]Χ11, CPP= cycloparaphenylene, Cp = cyclopentadienyl, X = [PF6]-, (1), (3) and [Cl]-, (2), (4), were synthesized and characterized using NMR techniques, high-resolution mass spectrometry, and elemental analyses. The complexes, (1) and (3) were stable in acetone and acetonitrile solutions over 48 h. In contrast, the water-soluble, (2) and (4), begins to decompose in aqueous media after 1h, due to the [Cl]- tendency for nucleophilic attack on ruthenium of the {Ru(η5-Cp)} units. Fluorescence quenching experiments conducted during the stability window of (2) with the d(5′-CGCGAATTCGCG-3′)2-EtBr adducts, revealed remarkably high values for Ksv = 1.185 × 104 ± 0.025 M-1 and Kb = 3.162 × 105 ± 0.001 M-1. Furthermore, the cytotoxic activity of (2) against A2780, A2780res, and MCF-7 cancer cell lines shows that it is highly cytotoxic with IC50 values in the range of 4.76 ± 1.85 to 16 ± 0.81 μΜ.

Previously, we reported that MTH1 inhibitors TH588 and TH1579 selectively induce oxidative damage and kill Ras expressing or transforming cancer cells, as compared to non-transforming immortalized or primary cells. While this explains the impressive anti-cancer properties of the compounds, the molecular mechanism remains elusive. Oncogenes induce replication stress, re-sulting in under replicated DNA and replication continuing into mitosis, where TH588 and TH1579 treatment cause toxicity and incorporation of oxidative damage. Hence, we hypothesized that oncogene-induced replication stress explains the cancer selectivity. To test this, we overex-pressed c-Myc in human epithelial kidney cells (HA1EB), resulting in increased proliferation, polyploidy and replication stress. TH588 and TH1579 selectively kill c-Myc overexpressing clones, enforcing the cancer cell selective killing of these compounds. Moreover, the toxicity of TH588 and TH1579 in c-Myc overexpressing cells is rescued by transcription, proteasome or CDK1 inhibitors, but interestingly not by nucleoside supplementation. This suggest that cancer selectivity is unrelated oncogene-induced replication stress. We conclude that the molecular toxi-cological mechanisms how TH588 and TH1579 kill c-Myc overexpressing cells have several com-ponents and involves MTH1-independent proteosomal degradation of c-Myc itself, c-Myc driven transcription and CDK activation, and is likely unrelated to oncogene-induced replication stress.

DNA barcoding has emerged as a powerful tool in the field of taxonomy, transforming the way we identify and classify species. This review article aims to provide an up-to-date overview of the advancements in DNA barcoding techniques, their applications, and their impact on taxonomy and biodiversity studies. We will explore the evolution of DNA barcoding, the development of standardized barcode regions, and the challenges and limitations associated with this methodology. Additionally, we will delve into the diverse range of taxonomic groups for which DNA barcoding has been applied, highlighting key case studies and their contributions to our understanding of biodiversity. Furthermore, we will discuss the integration of DNA barcoding with other molecular and bioinformatic approaches, such as metabarcoding and machine learning, to enhance species identification and biodiversity assessment. This review aims to provide a comprehensive perspective on how DNA barcoding is reshaping the field of taxonomy and its implications for conservation, ecology, and evolutionary biology.

Systematics plays the most crucial role in biodiversity conservation which is at stake due to anthropogenic activities and environmental degradations. The ever-increasing decline of classical taxonomic expertise drives the need to develop molecular marker-based tools for quick, efficient, and reliable detection of organisms, to assess their ecological impacts for deepening our understanding of systematic and evolutionary relationships between organisms which is central to biology. The pace of alpha taxonomy has quickened by its integration with an increasingly fashionable and novel concept called DNA barcoding which utilizes a short genetic marker or barcode to categorize species for enhanced biodiversity assessment. As a supplementary but not complete alternative of systematics research, DNA barcoding, however, not error-free, brings precision in identification by solving existing problems of classical taxonomy and phylogenetics, irrespective of the growth stage of organisms, particularly for known taxa rather than unknown ones. Mitochondrial gene Cytochrome C Oxidase 1 (COI) serves as a universal animal barcode but there is no such universal barcode for plants and developing a suitable one is more challenging. With the recent advancement of Next Generation Sequencing (NGS), DNA metabarcoding technology is advancing rapidly. Still, ambiguity and error prevail with the correct identification of species due to some problems. After extensive analysis of the existing DNA barcoding papers, this review discusses commonly used DNA barcodes in plants and animals, their roles, advantages, limitations to solve existing problems of conservation biology and add the author’s views and recommendations.

DNA methylation, one of the major epigenetic mechanisms, plays critical roles in regulating gene expression, genomic stability and cell lineage commitment. Establishment and maintenance of DNA methylation in mammals is achieved by two groups of DNA methyltransferases: DNMT3A and DNMT3B, which are responsible for installing DNA methylation patterns during gametogenesis and early embryogenesis, and DNMT1, which is essential for propagating DNA methylation patterns during replication. Both groups of DNMTs are multi-modular proteins, containing a large N-terminal regulatory region in addition to the C-terminal methyltransferase domain. Recent structure-function investigations of the individual domains or large fragments of DNMT1 and DNMT3A have revealed the molecular basis for their substrate recognition and specificity, intramolecular domain-domain interactions, as well as their crosstalk with other epigenetic mechanisms. These studies highlight a multifaceted regulation for both DNMT1 and DNMT3A/3B, which is essential for the precise establishment and maintenance of lineage-specific DNA methylation patterns in cells. This review summarizes current understanding of the structure and mechanism of DNMT1- and DNMT3A-mediated DNA methylation, with emphasis on the functional cooperation between the methyltransferase and regulatory domains.

Furazolidone (FZD) is a synthetic nitrofuran with the antiprotozoal and antibacterial activity. The proper mechanism of FZD induced toxicity is still unclear. This study aimed to investigate the protective effect of curcumin on FZD induced oxidative stress, DNA injury and apoptosis in human hepatocyte L02 cells. The results showed that curcumin treatment significantly ameliorated FZD induced cytotoxicity, characterized by decreasing the production of reactive oxygen species (ROS) and malondialdehyde, as well as increasing superoxide dismutase, catalase activities and glutathione contents. Moreover, curcumin pretreatment significantly inhibited FZD induced the loss of mitochondrial membrane potential, the activation caspase-9 and -3 and apoptosis. Comet assay showed that curcumin attenuated FZD induced DNA injury in a dose-dependent manner. Correspondingly, curcumin markedly reversed the up-regulation of p53, Bax, caspase-9 and -3 mRNA expressions and the down-regulation of Bcl-2 mRNA (all p<0.05 or 0.01). These results reveal that curcumin protects against FZD induced oxidative stress, DNA injury and cell apoptosis via inhibiting oxidative stress and mitochondrial pathway, which may be attributed to ROS scavenging and anti-oxidative ability of curcumin. Importantly, our study highlights that curcumin may be a potential way to prevent FZD-mediated oxidative DNA injury and apoptosis in human or animals.

The limited information available on the structure of complexes involving transcription factors and cognate DNA response elements represents a major obstacle in the quest to understand their mechanism of action at the molecular level. We implemented a concerted structural proteomics approach, which combined hydrogen-deuterium exchange (HDX), quantitative protein-protein and protein-nucleic acid cross-linking (XL), and homology analysis, to model the structure of the complex between the full-length DNA binding domain (DBD) of FOXO4 and its DNA binding element (DBE). The results confirmed that FOXO4-DBD assumes the characteristic forkhead topology shared by these types of transcription factors, but its binding mode differs significantly from those of other members of the family. The results showed that the binding interaction stabilized regions that were rather flexible and disordered in the unbound form. Surprisingly, the conformational effects were not limited only to the interface between bound components but extended also to distal regions that may be essential to recruiting additional factors to the transcription machinery. In addition to providing valuable new insights into the binding mechanism, this project provided an excellent evaluation of the merits of structural proteomics approaches in the investigation of systems that arematerial not directly amenable to traditional high-resolution techniques.

BOLD-100, a ruthenium-based complex, sodium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] (also known as IT-139, NKP1339 or KP1339), is a novel small molecule drug that demonstrated a manageable safety profile at the maximum tolerated dose and modest antitumor activity in a phase I clinical trial. BOLD-100 has been reported to inhibit the upregulation of the endoplasmic reticulum stress sensing protein GRP78. However, response to BOLD-100 varies in different cancer models and the precise mechanism of action in high-response versus low-response cancer cells remains unclear. In vitro studies have indicated that BOLD-100 induces cytostatic rather than cytotoxic effects as a monotherapy. To understand BOLD-100 mediated signaling mechanism in breast cancer cells, we used estrogen receptor positive (ER+) MCF7 breast cancer cells to obtain gene-metabolite integrated models. Particularly, BOLD-100 significantly reduced expression of genes involved in the DNA repair pathway. BOLD-100 also induced reactive oxygen species (ROS) and phosphorylation of histone H2AX, gH2AX (Ser139), suggesting disruption of proper DNA surveillance. In estrogen receptor negative (ER-) breast cancer cells, combination of BOLD-100 with a PARP inhibitor, olaparib, induced significant inhibition of cell growth and xenografts and increased gH2AX. Thus, BOLD-100 is a novel DNA repair pathway targeting agent and can be used with other chemotherapies in ER- breast cancer.

To activate gene expression, the initiation of transcription is a highly regulated process involving the interaction of proteins and DNA nucleotides at the promoter site, which consists of a small number of base pairs. As it involves interactions at the atomic scale, it is challenging to determine the mechanism of binding responsible for the great specificity between the amino acid residuals comprising the transcription binding protein and the DNA nucleotides comprising the promoter. Here, a new approach to characterize the transcription initiation process is developed and verified from analysis of comparative pharmacological efficacy data and elemental modeling. The newly developed description of a mechanism for transcription initiation involves the direct binding of small molecule ligands of approximately twenty carbon atoms, which are both structurally symmetric to DNA nucleotides, and also chemically complementary in its functional groups for interaction with the oxygen element at the carbon two position of thymine and with the phosphodiester chain. The results indicate that the activating ligands are transported to the DNA nucleotide promoter site by protein transcription factors, which serve as delivery vectors, for transfer of the ligand to the DNA nucleotide pairs. The ligands examined in this study include the steroid hormones, synthetic steroid molecules, derivatives of vitamin D, and prostaglandins, particularly PGJ2 and 15d-PGJ2. The transcription factors evaluated include glucocorticoid receptors, VDR, PPAR, and TBP. Through the developments, it is shown that because of the chemically complementary binding of the ligand to DNA nucleotide pairs, the resultant intermolecular complex produces three hydrogen bonds for the A-T and T-A configurations, which matches that of G-C and C-G. The orientation of the nucleotide base pairs is also seen to adjust as an inversion of the nominal position of the nucleobases to a dimer configuration presented via TBP transcription factor. The developments comprise a new approach to characterizing the initiation of the transcription process comprising the direct binding and interaction of ligands with DNA nucleotides as verified through comparative analysis of pharmacological activity and through perfect structural correspondence between the steroid hormone class as ligands with Watson-Crick DNA nucleotide pairings.

Recent advances in DNA sequencing technology have shown that the human milk microbiota of healthy women varies substantially. The gDNA extraction method may influence the observed variation, biasing the microbiological reconstruction after all. In this study, a genomic DNA extraction method for DNA isolation from human milk samples was standardized and compared with commercial and standard hose make methods. Spectrophotometric measurements, gel electrophoresis, and PCR amplifications were used as criteria for evaluating the quantity, quality, and functionality of the extracted DNA. Furthermore, the standardized method of extracting gDNA from human milk was evaluated for its ability to isolate functional DNA from gram-positive, and gram-negative bacteria and fungi, to improve the reconstruction of microbiological profiles. The novel DNA extraction method increased the quantity and quality of the gDNA extracted compared with commercial and standard house-make protocols. This method even allowed PCR amplification of the V3-V4 regions of the 16S ribosomal gene in all samples, and the ITS-1 region of the fungal 18S ribosomal gene in 95 % of the samples as well. It is concluded that the proposed method provides better performance for the extraction of gDNA from complex samples such as human milk.

Background: Elucidation of epigenetic mechanisms correlating with neuropathic pain in humans is crucial for the prevention and treatment of this treatment-resistant pain state. In the present study, associations between neuropathic pain characteristics and DNA methylation of the transient receptor potential ankyrin 1(TRPA1) gene were evaluated in chronic pain patients and preoperative patients. Methods: Pain and psychological states were prospectively assessed in patients who suffered chronic pain or were scheduled for thoracic surgery. Neuropathic characteristics were assessed using the Douleur Neuropathique 4 (DN4) questionnaire. DNA methylation levels of the CpG island in the TRPA1 gene were examined using whole blood. Results: Forty-eight adult patients were enrolled in this study. Increases in DNA methylation rates at CpG -51 showed positive correlations with increases in the DN4 score both in preoperative and chronic pain patients. Combined methylation rates at CpG -51 also significantly increased together with increase in DN4 scores. Conclusions: Neuropathic pain characteristics are likely associated with methylation rates at the promoter region of the TRPA1 gene in human peripheral blood.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has caused more than 600 million cases and over 6 million deaths worldwide. Vaccination has been the main strategy used to contain the spread of the virus, and to avoid hospitalizations and deaths. Currently, there are two mRNA-based and one adenovirus vectored vaccines approved and available for use in the U.S. population. The versatility, low cost and rapid-to-manufacture attributes of DNA vaccines are important advantages over other platforms. However, DNA vaccination must meet higher efficiency levels for use in humans. Importantly, in vivo DNA delivery combined with electroporation (EP) has been successfully used in the veterinary field. Here we evaluated the safety, immunogenicity and protective efficacy of a novel linear SARS-CoV-2 DNA vaccine candidate for delivered by intramuscular injection followed by electroporation (Vet-ePorator™) in ferrets. The results demonstrated that the linear SARS-CoV-2 DNA vaccine candidate did not cause unexpected side effects, and was able to elicit neutralizing antibodies and T cell responses using a low dose of the linear DNA construct in prime-boost regimen, and significantly reduced shedding of infectious SARS-CoV-2 through oral and nasal secretions in a ferret model.

The DNA Damage Response (DDR) network and the mitogen-activated protein kinase (MAPK) signaling pathway are crucial mechanisms for the survival of all living beings. An accumulating body of evidence suggests that there is a crosstalk between these two systems, thus favoring the appropriate functioning of multi-cellular organisms. On the other hand, aberrations within these mechanisms are thought to play a vital role in the onset and progression of several diseases, including cancer, as well as in the emergence of drug resistance. Here, we provide an overview of the current knowledge regarding alterations in the DDR machinery and the MAPK signaling pathway, as well as abnormalities in the DDR-MAPK functional crosstalk in multiple myeloma, the second most common hematologic malignancy. We also present the latest advances in the development of anti-myeloma drugs targeting crucial DDR- and MAPK-associated molecular components. These data could potentially be exploited to discover new therapeutic targets and effective biomarkers, as well as for the design of novel clinical trials. Interestingly, they might provide a new approach to increase the efficacy of anti-myeloma therapy by combining drugs targeting the DDR network and the MAPK signaling pathway.

The identification of floral visitation by pollinators provides an opportunity to improve our understanding of the fine-scale ecological interactions between plants and pollinators, contributing to biodiversity conservation and promoting ecosystem health. In this review we outline the various methods which can be used to identify floral visitation, providing a comparison between molecular and non-molecular methods. We review the literature covering the ways in which DNA metabarcoding has been used to answer ecological questions relating to plant use by pollinators and discuss the findings of this research. We present detailed methodological considerations for each step of the metabarcoding workflow, from sampling through to amplification and finally bioinformatic analysis. Detailed guidance is provided to researchers for utilization of these techniques, emphasizing the importance of standardization of methods and improving the reliability of results. Future opportunities and directions of using molecular methods to analyze plant-pollinator interactions are then discussed.