BACKGROUND： Increasing evidence indicates that down- regulation of cell adhesion molecule 1 （CADM1） contributes to tumorigenesis in various cancers. The present study was undertaken to investigate the CADM1 express...BACKGROUND： Increasing evidence indicates that down- regulation of cell adhesion molecule 1 （CADM1） contributes to tumorigenesis in various cancers. The present study was undertaken to investigate the CADM1 expression pattern in human hepatocellular carcinoma （HCC）, and to elucidate the mechanism underlying CADMl-mediated tumor suppression.展开更多
目的探讨CADM1在大肠癌细胞系中的表达及与启动子甲基化的关系。方法用RT-PCR法检测大肠癌细胞系中CADM1基因m RNA表达水平,Western blot法检测细胞系CADM1蛋白表达情况,BSP法和MSP法检测CADM1基因启动子甲基化状态。结果 CADM1 m RNA在...目的探讨CADM1在大肠癌细胞系中的表达及与启动子甲基化的关系。方法用RT-PCR法检测大肠癌细胞系中CADM1基因m RNA表达水平,Western blot法检测细胞系CADM1蛋白表达情况,BSP法和MSP法检测CADM1基因启动子甲基化状态。结果 CADM1 m RNA在24%大肠癌细胞系表达缺失,在50%细胞系中CADM1 m RNA表达减少。75%大肠癌细胞系检测到CADM1基因启动子甲基化阳性,且表达缺失。结论 CADM1基因启动子甲基化与大肠癌的发生发展有密切关系,该基因的甲基化检测可作为癌症早期筛选、监测预后的肿瘤标志物。展开更多
A tumor suppressor gene, CADM1, encoding an immunoglobulin superfamily cell adhesion molecule, is inactivated in various cancers, including non-small-cell lung cancer (NSCLC). Although promoter methylation is one of t...A tumor suppressor gene, CADM1, encoding an immunoglobulin superfamily cell adhesion molecule, is inactivated in various cancers, including non-small-cell lung cancer (NSCLC). Although promoter methylation is one of the mechanisms to suppress CADM1 expression, about half of tumors lacking CADM1 expression do not show methylation of the gene promoter. We herein investigated the possible involvement of microRNA (miRNA) in the down-regulation of CADM1. Using computational algorithms, miR-214 and miR-375 were identified as candidate miRNAs targeting CADM1. A luciferase reporter assay demonstrated that miR-214 and miR-375 repressed the promoter activity through 3’-UTR of CADM1. Quantitative RT-PCR analysis demonstrated that miR-214 and miR-375 was highly expressed in 21 (62%) and 17 cases (50%) of 34 primary NSCLCs. Notably, increased expression of miR-214 was preferentially observed in tumors with advanced pathological stages and in those lacking CADM1 expression but were not associated with the promoter methylation, suggesting that miR-214-mediated silencing would be another mechanism to suppress CADM1 expression. On the other hand, introduction of miR-214 or miR-375 into NSCLC cells decreased CADM1 protein expression. Furthermore, overexpression of miR-214 enhanced anchorage-independent growth of NSCLC cells, A549, whereas transfection of miRNA inhibitor, miR-214 or miR-375, significantly suppressed the in vitro wound healing activity of HCC827 cells. These findings suggest that overexpression of miR-214 and miR-375 could participate in the malignant features of NSCLC through down-regulating CADM1 and would provide a potential target for the treatment of a subset of NSCLC.展开更多
Objective: Targeting mutated EGFR by EGFR-tyrosine kinase inhibitors (EGFR-TKI) is a potent approach to a subset of non-small cell lung cancer (NSCLC). However, the response to EGFR-TKI varies in individual cases even...Objective: Targeting mutated EGFR by EGFR-tyrosine kinase inhibitors (EGFR-TKI) is a potent approach to a subset of non-small cell lung cancer (NSCLC). However, the response to EGFR-TKI varies in individual cases even among tumors carrying the same?EGFR?mutation, suggesting the involvement of modifying factors. To characterize possible modifiers, we examined mutation state of the?EGFR?and the?KRAS?genes in Japanese NSCLC and compared them with the methylation state of lung tumor suppressors, the?CADM1 and?4.1B,?whose products have potentials to modify the functions of EGFR or KRAS. Materials and methods: A total of 103 Japanese NSCLC and 11 NSCLC cell lines were examined. Genomic DNA of exons 18–21 of the?EGFR?and exons 1 and 2 of the?KRAS?were amplified by polymerase chain reaction (PCR), followed by single-strand conformation polymorphism analysis and direct sequencing. Methylation status of gene promoters in NSCLC cells were examined by methylation-specific PCR. Results: Mutations of the?EGFR?and?KRAS?were detected mutually exclusively in 27 and 11 out of 103 NSCLC cases, respectively.?EGFR?mutations were observed exclusively in adenocarcinoma (27 of 69, 41%) and preferentially in tumors from female and non-smokers (p < 0.00001). Eight (30%) and 12 (44%) of 27 tumors carrying mutated?EGFR?and 4 (36%) and 8 (73%) of 11 tumors carrying mutated?KRAS?showed methylation of the?CADM1 and 4.1B, respectively.?EGFR-mutated tumors with methylation of either?CADM1 or 4.1B?showed more malignant features than those with unmethylated?CADM1 and 4.1B?(p < 0.05). Conclusion: Methylation state of the?CADM1 and?4.1B?are independent of the mutation status of the?EGFR?or?KRAS?but play roles in the malignant progression of NSCLC. Integration of epigenetic information would be useful for identifying possible modifiers to predict the response or recurrence of lung adenocarcinoma to the EGFR-TKI therapy.展开更多
基金supported by grants from the National S&T Major Project(2012ZX10002-017)National Natural Science Foundation of China(81201944)+1 种基金Health Science and Technology Program of Zhejiang Province(2013KYB083)Education Department of Zhejiang Province Scientific Research Project(Y201430751)
文摘BACKGROUND： Increasing evidence indicates that down- regulation of cell adhesion molecule 1 （CADM1） contributes to tumorigenesis in various cancers. The present study was undertaken to investigate the CADM1 expression pattern in human hepatocellular carcinoma （HCC）, and to elucidate the mechanism underlying CADMl-mediated tumor suppression.
文摘目的探讨CADM1在大肠癌细胞系中的表达及与启动子甲基化的关系。方法用RT-PCR法检测大肠癌细胞系中CADM1基因m RNA表达水平,Western blot法检测细胞系CADM1蛋白表达情况,BSP法和MSP法检测CADM1基因启动子甲基化状态。结果 CADM1 m RNA在24%大肠癌细胞系表达缺失,在50%细胞系中CADM1 m RNA表达减少。75%大肠癌细胞系检测到CADM1基因启动子甲基化阳性,且表达缺失。结论 CADM1基因启动子甲基化与大肠癌的发生发展有密切关系,该基因的甲基化检测可作为癌症早期筛选、监测预后的肿瘤标志物。
文摘A tumor suppressor gene, CADM1, encoding an immunoglobulin superfamily cell adhesion molecule, is inactivated in various cancers, including non-small-cell lung cancer (NSCLC). Although promoter methylation is one of the mechanisms to suppress CADM1 expression, about half of tumors lacking CADM1 expression do not show methylation of the gene promoter. We herein investigated the possible involvement of microRNA (miRNA) in the down-regulation of CADM1. Using computational algorithms, miR-214 and miR-375 were identified as candidate miRNAs targeting CADM1. A luciferase reporter assay demonstrated that miR-214 and miR-375 repressed the promoter activity through 3’-UTR of CADM1. Quantitative RT-PCR analysis demonstrated that miR-214 and miR-375 was highly expressed in 21 (62%) and 17 cases (50%) of 34 primary NSCLCs. Notably, increased expression of miR-214 was preferentially observed in tumors with advanced pathological stages and in those lacking CADM1 expression but were not associated with the promoter methylation, suggesting that miR-214-mediated silencing would be another mechanism to suppress CADM1 expression. On the other hand, introduction of miR-214 or miR-375 into NSCLC cells decreased CADM1 protein expression. Furthermore, overexpression of miR-214 enhanced anchorage-independent growth of NSCLC cells, A549, whereas transfection of miRNA inhibitor, miR-214 or miR-375, significantly suppressed the in vitro wound healing activity of HCC827 cells. These findings suggest that overexpression of miR-214 and miR-375 could participate in the malignant features of NSCLC through down-regulating CADM1 and would provide a potential target for the treatment of a subset of NSCLC.
文摘Objective: Targeting mutated EGFR by EGFR-tyrosine kinase inhibitors (EGFR-TKI) is a potent approach to a subset of non-small cell lung cancer (NSCLC). However, the response to EGFR-TKI varies in individual cases even among tumors carrying the same?EGFR?mutation, suggesting the involvement of modifying factors. To characterize possible modifiers, we examined mutation state of the?EGFR?and the?KRAS?genes in Japanese NSCLC and compared them with the methylation state of lung tumor suppressors, the?CADM1 and?4.1B,?whose products have potentials to modify the functions of EGFR or KRAS. Materials and methods: A total of 103 Japanese NSCLC and 11 NSCLC cell lines were examined. Genomic DNA of exons 18–21 of the?EGFR?and exons 1 and 2 of the?KRAS?were amplified by polymerase chain reaction (PCR), followed by single-strand conformation polymorphism analysis and direct sequencing. Methylation status of gene promoters in NSCLC cells were examined by methylation-specific PCR. Results: Mutations of the?EGFR?and?KRAS?were detected mutually exclusively in 27 and 11 out of 103 NSCLC cases, respectively.?EGFR?mutations were observed exclusively in adenocarcinoma (27 of 69, 41%) and preferentially in tumors from female and non-smokers (p < 0.00001). Eight (30%) and 12 (44%) of 27 tumors carrying mutated?EGFR?and 4 (36%) and 8 (73%) of 11 tumors carrying mutated?KRAS?showed methylation of the?CADM1 and 4.1B, respectively.?EGFR-mutated tumors with methylation of either?CADM1 or 4.1B?showed more malignant features than those with unmethylated?CADM1 and 4.1B?(p < 0.05). Conclusion: Methylation state of the?CADM1 and?4.1B?are independent of the mutation status of the?EGFR?or?KRAS?but play roles in the malignant progression of NSCLC. Integration of epigenetic information would be useful for identifying possible modifiers to predict the response or recurrence of lung adenocarcinoma to the EGFR-TKI therapy.
