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Zhang Y, Calado R, Rao M, Hong JA, Meeker AK, Dumitriu B, Atay S, McCormick PJ, Garfield SH, Wangsa D, Padilla-Nash HM, Burkett S, Zhang M, Kunst TF, Peterson NR, Xi S, Inchauste S, Altorki NK, Casson AG, Beer DG, Harris CC, Ried T, Young NS, Schrump DS. Telomerase variant A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal carcinomas. PLoS One 2014; 9:e101010. [PMID: 24983628 PMCID: PMC4077737 DOI: 10.1371/journal.pone.0101010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 06/02/2014] [Indexed: 12/24/2022] [Imported: 05/06/2024] Open
Abstract
BACKGROUND Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas. METHODS Sequencing techniques were used to evaluate mutational status of telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC) in neoplastic and adjacent normal mucosa from 143 esophageal cancer (EsC) patients. MTS, flow cytometry, time lapse microscopy, and murine xenograft techniques were used to assess proliferation, apoptosis, chemotaxis, and tumorigenicity of EsC cells expressing either wtTERT or TERT variants. Immunoprecipitation, immunoblot, immunofluorescence, promoter-reporter and qRT-PCR techniques were used to evaluate interactions of TERT and several TERT variants with BRG-1 and β-catenin, and to assess expression of cytoskeletal proteins, and cell signaling. Fluorescence in-situ hybridization and spectral karyotyping techniques were used to examine telomere length and chromosomal stability. RESULTS Sequencing analysis revealed one deletion involving TERC (TERC del 341-360), and two non-synonymous TERT variants [A279T (2 homozygous, 9 heterozygous); A1062T (4 heterozygous)]. The minor allele frequency of the A279T variant was five-fold higher in EsC patients compared to healthy blood donors (p<0.01). Relative to wtTERT, A279T decreased telomere length, destabilized TERT-BRG-1-β-catenin complex, markedly depleted β-catenin, and down-regulated canonical Wnt signaling in cancer cells; these phenomena coincided with decreased proliferation, depletion of additional cytoskeletal proteins, impaired chemotaxis, increased chemosensitivity, and significantly decreased tumorigenicity of EsC cells. A279T expression significantly increased chromosomal aberrations in mouse embryonic fibroblasts (MEFs) following Zeocin™ exposure, as well as Li Fraumeni fibroblasts in the absence of pharmacologically-induced DNA damage. CONCLUSIONS A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal cancer cells. These findings warrant further analysis of A279T expression in esophageal cancers and premalignant esophageal lesions.
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Zhang Y. Epidemiology of esophageal cancer. World J Gastroenterol 2013; 19:5598-5606. [PMID: 24039351 PMCID: PMC3769895 DOI: 10.3748/wjg.v19.i34.5598] [Citation(s) in RCA: 695] [Impact Index Per Article: 63.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/13/2013] [Accepted: 07/19/2013] [Indexed: 02/06/2023] [Imported: 05/06/2024] Open
Abstract
Esophageal cancer (EsC) is one of the least studied and deadliest cancers worldwide because of its extremely aggressive nature and poor survival rate. It ranks sixth among all cancers in mortality. In retrospective studies of EsC, smoking, hot tea drinking, red meat consumption, poor oral health, low intake of fresh fruit and vegetables, and low socioeconomic status have been associated with a higher risk of esophageal squamous cell carcinoma. Barrett’s esophagus is clearly recognized as a risk factor for EsC, and dysplasia remains the only factor useful for identifying patients at increased risk, for the development of esophageal adenocarcinoma in clinical practice. Here, we investigated the epidemiologic patterns and causes of EsC. Using population based cancer data from the Surveillance, Epidemiology and End Results Program of the United States; we generated the most up-to-date stage distribution and 5-year relative survival by stage at diagnosis for 1998-2009. Special note should be given to the fact that esophageal cancer, mainly adenocarcinoma, is one of the very few cancers that is contributing to increasing death rates (20%) among males in the United States. To further explore the mechanism of development of EsC will hopefully decrease the incidence of EsC and improve outcomes.
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Zhang M, Mathur A, Zhang Y, Xi S, Atay S, Hong JA, Datrice N, Upham T, Kemp CD, Ripley RT, Wiegand G, Avital I, Fetsch P, Mani H, Zlott D, Robey R, Bates SE, Li X, Rao M, Schrump DS. Mithramycin represses basal and cigarette smoke-induced expression of ABCG2 and inhibits stem cell signaling in lung and esophageal cancer cells. Cancer Res 2012; 72:4178-92. [PMID: 22751465 PMCID: PMC6261440 DOI: 10.1158/0008-5472.can-11-3983] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] [Imported: 05/06/2024]
Abstract
Cigarette smoking at diagnosis or during therapy correlates with poor outcome in patients with lung and esophageal cancers, yet the underlying mechanisms remain unknown. In this study, we observed that exposure of esophageal cancer cells to cigarette smoke condensate (CSC) led to upregulation of the xenobiotic pump ABCG2, which is expressed in cancer stem cells and confers treatment resistance in lung and esophageal carcinomas. Furthermore, CSC increased the side population of lung cancer cells containing cancer stem cells. Upregulation of ABCG2 coincided with increased occupancy of aryl hydrocarbon receptor, Sp1, and Nrf2 within the ABCG2 promoter, and deletion of xenobiotic response elements and/or Sp1 sites markedly attenuated ABCG2 induction. Under conditions potentially achievable in clinical settings, mithramycin diminished basal as well as CSC-mediated increases in AhR, Sp1, and Nrf2 levels within the ABCG2 promoter, markedly downregulated ABCG2, and inhibited proliferation and tumorigenicity of lung and esophageal cancer cells. Microarray analyses revealed that mithramycin targeted multiple stem cell-related pathways in vitro and in vivo. Collectively, our findings provide a potential mechanistic link between smoking status and outcome of patients with lung and esophageal cancers, and support clinical use of mithramycin for repressing ABCG2 and inhibiting stem cell signaling in thoracic malignancies.
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Preoperative taxane-based chemotherapy and celecoxib for carcinoma of the esophagus and gastroesophageal junction: results of a phase 2 trial. J Thorac Oncol 2011; 6:1121-7. [PMID: 21532508 PMCID: PMC7457227 DOI: 10.1097/jto.0b013e31821529a9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] [Imported: 05/06/2024]
Abstract
PURPOSE The primary objective of this study was to determine the rate of pathological response after preoperative celecoxib and concurrent taxane-based chemotherapy in patients with cancer of the esophagus and gastroesophageal junction. METHODS Thirty-nine patients were enrolled in this single-arm, phase II clinical trial. Patients were administered daily celecoxib in combination with two to three cycles of carboplatin and paclitaxel with preoperative intent. Levels of cyclooxygenase (COX)-2 expression in resected tumors were analyzed by immunohistochemistry and correlated with clinical outcome measures. Postoperatively, patients were administered daily celecoxib for 1 year or until documented tumor recurrence. RESULTS All patients received two to three cycles of chemotherapy plus celecoxib 800 mg/d. Toxicities were as expected. A major clinical response (complete response + partial response) was noted in 22 patients (56%); six patients (15%) had a complete clinical response. Thirty-seven patients underwent esophagectomy. Five patients had a major pathological response (12.8%). Four-year overall and disease-free survivals were 40.9% and 30.3%, respectively. Patients with tumors expressing COX-2 demonstrated a higher likelihood of a major clinical response response (62% versus 50%) and an improved overall survival, compared with patients with COX-2-negative tumors. CONCLUSIONS Preoperative celecoxib with concurrent chemotherapy demonstrated sufficient effect on pathologic response to warrant further study. Patients with tumors expressing COX-2 demonstrated trends toward improved response to preoperative therapy and improved overall survival compared with nonexpressors.
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Rao M, Chinnasamy N, Hong JA, Zhang Y, Zhang M, Xi S, Liu F, Marquez VE, Morgan RA, Schrump DS. Inhibition of histone lysine methylation enhances cancer-testis antigen expression in lung cancer cells: implications for adoptive immunotherapy of cancer. Cancer Res 2011; 71:4192-204. [PMID: 21546573 PMCID: PMC3116976 DOI: 10.1158/0008-5472.can-10-2442] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] [Imported: 05/06/2024]
Abstract
Cancer-testis antigens (CTA), such as NY-ESO-1, MAGE-A1, and MAGE-A3, are immunogenic proteins encoded by genes, which are normally expressed only in male germ cells but are activated by ill-defined epigenetic mechanisms in human tumors, including lung cancers. Previously, we reported induction of these CTAs in cancer cells, but not normal cells, by DNA-demethylating agents and histone deacetylase inhibitors using clinically achievable exposure conditions. In the present study, we evaluated chromatin alterations associated with repression/activation of cancer-testis genes in lung cancer cells to further develop gene-induction regimens for cancer immunotherapy. Repression of NY-ESO-1, MAGE-A1, and MAGE-A3 coincided with DNA hypermethylation, recruitment, and binding of polycomb-group proteins, and histone heterochromatin modifications within the promoters of these genes. Derepression coincided with DNA demethylation, dissociation of polycomb proteins, and presence of euchromatin marks within the respective promoters. Short hairpin RNAs were used to inhibit several histone methyltransferases (KMT) and histone demethylases (KDM) that mediate histone methylation and repress gene expression. Knockdown of KMT6, KDM1, or KDM5B markedly enhanced deoxyazacytidine (DAC)-mediated activation of these cancer-testis genes in lung cancer cells. DZNep, a pharmacologic inhibitor of KMT6 expression, recapitulated the effects of KMT6 knockdown. Following DAC-DZNep exposure, lung cancer cells were specifically recognized and lysed by allogeneic lymphocytes expressing recombinant T-cell receptors recognizing NY-ESO-1 and MAGE-A3. Combining DNA-demethylating agents with compounds, such as DZNep, that modulate histone lysine methylation may provide a novel epigenetic strategy to augment cancer-testis gene expression as an adjunct to adoptive cancer immunotherapy.
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Liu F, Killian JK, Yang M, Walker RL, Hong JA, Zhang M, Davis S, Zhang Y, Hussain M, Xi S, Rao M, Meltzer PA, Schrump DS. Epigenomic alterations and gene expression profiles in respiratory epithelia exposed to cigarette smoke condensate. Oncogene 2010; 29:3650-64. [PMID: 20440268 PMCID: PMC6329296 DOI: 10.1038/onc.2010.129] [Citation(s) in RCA: 210] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 02/03/2010] [Accepted: 03/17/2010] [Indexed: 12/19/2022] [Imported: 05/07/2024]
Abstract
Limited information is available regarding epigenomic events mediating initiation and progression of tobacco-induced lung cancers. In this study, we established an in vitro system to examine epigenomic effects of cigarette smoke in respiratory epithelia. Normal human small airway epithelial cells and cdk-4/hTERT-immortalized human bronchial epithelial cells (HBEC) were cultured in normal media with or without cigarette smoke condensate (CSC) for up to 9 months under potentially relevant exposure conditions. Western blot analysis showed that CSC mediated dose- and time-dependent diminution of H4K16Ac and H4K20Me3, while increasing relative levels of H3K27Me3; these histone alterations coincided with decreased DNA methyltransferase 1 (DNMT1) and increased DNMT3b expression. Pyrosequencing and quantitative RT-PCR experiments revealed time-dependent hypomethylation of D4Z4, NBL2, and LINE-1 repetitive DNA sequences; up-regulation of H19, IGF2, MAGE-A1, and MAGE-A3; activation of Wnt signaling; and hypermethylation of tumor suppressor genes such as RASSF1A and RAR-beta, which are frequently silenced in human lung cancers. Array-based DNA methylation profiling identified additional novel DNA methylation targets in soft-agar clones derived from CSC-exposed HBEC; a CSC gene expression signature was also identified in these cells. Progressive genomic hypomethylation and locoregional DNA hypermethylation induced by CSC coincided with a dramatic increase in soft-agar clonogenicity. Collectively, these data indicate that cigarette smoke induces 'cancer-associated' epigenomic alterations in cultured respiratory epithelia. This in vitro model may prove useful for delineating early epigenetic mechanisms regulating gene expression during pulmonary carcinogenesis.
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Gronich N, Kumar A, Zhang Y, Efimov IR, Soldatov NM. Molecular remodeling of ion channels, exchangers and pumps in atrial and ventricular myocytes in ischemic cardiomyopathy. Channels (Austin) 2010; 4:101-7. [PMID: 20090424 PMCID: PMC2891309 DOI: 10.4161/chan.4.2.10975] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] [Imported: 05/06/2024] Open
Abstract
Existing molecular knowledge base of cardiovascular diseases is rudimentary because of lack of specific attribution to cell type and function. The aim of this study was to investigate cell-specific molecular remodeling in human atrial and ventricular myocytes associated with ischemic cardiomyopathy. Our strategy combines two technological innovations, laser-capture microdissection of identified cardiac cells in selected anatomical regions of the heart and splice microarray of a narrow catalog of the functionally most important genes regulating ion homeostasis. We focused on expression of a principal family of genes coding for ion channels, exchangers and pumps (CE&P genes) that are involved in electrical, mechanical and signaling functions of the heart and constitute the most utilized drug targets. We found that (1) CE&P genes remodel in a cell-specific manner: ischemic cardiomyopathy affected 63 CE&P genes in ventricular myocytes and 12 essentially different genes in atrial myocytes. (2) Only few of the identified CE&P genes were previously linked to human cardiac disfunctions. (3) The ischemia-affected CE&P genes include nuclear chloride channels, adrenoceptors, cyclic nucleotide-gated channels, auxiliary subunits of Na(+), K(+) and Ca(2+) channels, and cell-surface CE&Ps. (4) In both atrial and ventricular myocytes ischemic cardiomyopathy reduced expression of CACNG7 and induced overexpression of FXYD1, the gene crucial for Na(+) and K(+) homeostasis. Thus, our cell-specific molecular profiling defined new landmarks for correct molecular modeling of ischemic cardiomyopathy and development of underlying targeted therapies.
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Tiwari S, Zhang Y, Heller J, Abernethy DR, Soldatov NM. Atherosclerosis-related molecular alteration of the human CaV1.2 calcium channel alpha1C subunit. Proc Natl Acad Sci U S A 2006; 103:17024-9. [PMID: 17071743 PMCID: PMC1636572 DOI: 10.1073/pnas.0606539103] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] [Imported: 05/06/2024] Open
Abstract
Atherosclerosis is an inflammatory process characterized by proliferation and dedifferentiation of vascular smooth muscle cells (VSMC). Ca(v)1.2 calcium channels may have a role in atherosclerosis because they are essential for Ca(2+)-signal transduction in VSMC. The pore-forming Ca(v)1.2alpha1 subunit of the channel is subject to alternative splicing. Here, we investigated whether the Ca(v)1.2alpha1 splice variants are affected by atherosclerosis. VSMC were isolated by laser-capture microdissection from frozen sections of adjacent regions of arteries affected and not affected by atherosclerosis. In VSMC from nonatherosclerotic regions, RT-PCR analysis revealed an extended repertoire of Ca(v)1.2alpha1 transcripts characterized by the presence of exons 21 and 41A. In VSMC affected by atherosclerosis, expression of the Ca(v)1.2alpha1 transcript was reduced and the Ca(v)1.2alpha1 splice variants were replaced with the unique exon-22 isoform lacking exon 41A. Molecular remodeling of the Ca(v)1.2alpha1 subunits associated with atherosclerosis caused changes in electrophysiological properties of the channels, including the kinetics and voltage-dependence of inactivation, recovery from inactivation, and rundown of the Ca(2+) current. Consistent with the pathophysiological state of VSMC in atherosclerosis, cell culture data pointed to a potentially important association of the exon-22 isoform of Ca(v)1.2alpha1 with proliferation of VSMC. Our findings are consistent with a hypothesis that localized changes in cytokine expression generated by inflammation in atherosclerosis affect alternative splicing of the Ca(v)1.2alpha1 gene in the human artery that causes molecular and electrophysiological remodeling of Ca(v)1.2 calcium channels and possibly affects VSMC proliferation.
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MESH Headings
- Aged
- Alternative Splicing
- Amino Acid Sequence
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Base Sequence
- Calcium Channels, L-Type/chemistry
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Cell Proliferation
- DNA Primers/genetics
- Exons
- Humans
- Kinetics
- Models, Molecular
- Molecular Sequence Data
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- RNA, Messenger/genetics
- Sequence Homology, Amino Acid
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Abstract
Regenerating gene (Reg or REG) family, within the superfamily of C-type lectin, is mainly involved in the liver, pancreatic, gastric and intestinal cell proliferation or differentiation. Considerable attention has focused on Reg family and its structurally related molecules. Over the last 15 years, 17 members of the Reg family have been cloned and sequenced. They have been considered as members of a conserved protein family sharing structural and some functional properties being involved in injury, inflammation, diabetes and carcinogenesis. We previously identified Reg IV as a strong candidate for a gene that was highly expressed in colorectal adenoma when compared to normal mucosa based on suppression subtractive hybridization (SSH), reverse Northern blot, semi-quantitative reverse transcriptase PCR (RT-PCR) and Northern blot. In situ hybridization results further support that overexpression of Reg IV may be an early event in colorectal carcinogenesis. We suggest that detection of Reg IV overexpression might be useful in the early diagnosis of carcinomatous transformation of adenoma. This review summarizes the roles of Reg family in diseases in the literature as well as our recent results of Reg IV in colorectal cancer. The biological properties of Reg family and its possible roles in human diseases are discussed. We particularly focus on the roles of Reg family as sensitive reactants of tissue injury, prognostic indicators of tumor survival and early biomarkers of carcinogenesis. In addition to our current understanding of Reg gene functions, we postulate that there might be relationships between Reg family and microsatellite instability, apoptosis and cancer with a poor prognosis. Investigation of the correlation between tumor Reg expression and survival rate, and analysis of the Reg gene status in human maliganancies, are required to elucidate the biologic consequences of Reg gene expression, the implications for Reg gene regulation of cell growth, tumorigenesis, and the progression of cancer. It needs to be further attested whether Reg gene family is applicable in early detection of cancer and whether Reg and Reg-related molecules can offer novel molecular targets for anticancer therapeutics. This has implications with regard to prognosis, such as in monitoring cancer initiation, progression and recurrence, as well as the design of chemotherapeutic drugs.
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Zhang Y, Lai M, Lv B, Gu X, Wang H, Zhu Y, Zhu Y, Shao L, Wang G. Overexpression of Reg IV in colorectal adenoma. Cancer Lett 2003; 200:69-76. [PMID: 14550954 DOI: 10.1016/s0304-3835(03)00460-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] [Imported: 05/06/2024]
Abstract
Identification of molecular markers associated with colorectal adenoma may uncover critical events involved in the initiation and progression of colorectal cancer. Our previous studies, mainly based on suppression subtractive hybridization, have identified Reg IV as a strong candidate for a gene that is highly expressed in colorectal adenoma when compared to normal mucosa. In this study, we sought to determine the mRNA expression of Reg IV in colorectal adenoma, in comparison with normal colorectal mucosa and carcinoma in multiple samples. Semi-quantitative RT-PCR was performed in 12 colorectal adenomas and 10 concurrent carcinomas. Reg IV mRNA level was higher in all adenomas (12/12) (p=0.001) and in 9/10 concurrent colorectal carcinoma (p=0.021) when compared to paired normal colorectal mucosa. Northern blot analysis further confirmed these results. In situ hybridization with digoxigenin (DIG)-labeled cRNA was performed in 32 colorectal adenomas with varying degree of dysplasia. Compared with paired normal tissues, Reg IV was overexpressed in 74% (14/19) adenomas with mild or moderate dysplasia and 100% (13/13) cases of adenoma with severe dysplasia. In addition, higher levels of Reg IV mRNA was consistently scored in regions with more severe dysplasia within the same adenoma sample displaying varying degree of dysplasia. The strongest staining was seen within carcinomoutous areas of the 12 adenoma cases (p=0.002). Our results support that overexpression of Reg IV may be an early event in colorectal carcinogenesis. Detection of Reg IV overexpression may be useful in the early diagnosis of carcinomatous transformation of adenoma.
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Zhang Y, Lai M, Gu X, Luo M, Shao L. Reg IV, a differentially expressed gene in colorectal adenoma. Chin Med J (Engl) 2003; 116:918-22. [PMID: 12877807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] [Imported: 05/06/2024] Open
Abstract
OBJECTIVE To discover and identify differentially expressed genes associated with colorectal adenoma formation and the role of RegIV in colorectal adenoma differentiation. METHODS A subtracted cDNA library was constructed with cDNAs that were isolated from either the normal mucosa or adenoma tissue of a single patient. Suppressive subtractive hybridization (SSH) combined with virtual northern blotting was used to characterize differentially expressed genes and contigs were assembled by electronic cloning (in silico cloning) with the EST database. Semi-quantitative RT-PCR was performed in 9 colorectal adenomas. RESULTS The amino acid sequence was determined with open reading frame (ORF) prediction software and was found to be 100% homologous to the protein product of RegIV (a novel gene isolated from a large inflammatory bowel disease library). RegIV was found to be highly expressed in all of the adenoma samples (9/9) compared with the normal mucosa samples, while 5/6 cases showed RegIV to be more strongly expressed in adenocarcinoma. CONCLUSION RegIV may play an important role in the initiation of colorectal adenoma differentiation, and its detection may be useful in the early diagnosis of colorectal adenoma formation.
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Mao-de L, Yu-wei Z, Yu-tong G, Chao H. Microsatellite alteration and its characteristics in colorectal carcinoma. JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE A 2001; 2:94-99. [DOI: 10.1631/bf02841184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2000] [Accepted: 10/25/2000] [Indexed: 05/06/2024] [Imported: 05/06/2024]
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Zhang Y, Lai M. [Microsatellite alterations on chromosome 9p21-22 in sporadic colorectal cancer]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 1999; 28:418-21. [PMID: 11869554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] [Imported: 05/06/2024]
Abstract
OBJECTIVE To study whether alteration of p16 plays an important role in the development of colorectal carcinomas and the relationship between the molecular changes of 9p21-22 chromosome subregion in sporadic colorectal cancers. METHODS To detect microsatellite instability (MSI) and loss of heterozygosity (LOH) by PCR, denatured-polyacrylamide gel-electrophoresis and silver staining (microsatellite DNA-PCR-silver staining method) and to compare the results with the clinopathological parameters. RESULTS Between MSI positive and negative cases and the clinopathological findings, some evidences found in the MSI positive group were as follows: (1) tendency towards younger patients (usually < 50 years in age, P < 0.05); (2) more frequently seen in mucoid carcinomas (P < 0.01). CONCLUSIONS Microsatellite DNA-PCR-silver staining method is very sensitive in detecting even a tiny change of a single base. MSI occured in the selected microsatellite loci of different subregions and different chromosomes might be different in significance, therefore, a right choice of the suitable loci for studying the microsatellite changes is important. Since the frequency of loss of heterozygosity at 9p21-22 is low (merely 8.42%), it is considered that p16 is not closely associated with the development of sporadic colorectal cancer.
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