【摘要】 目的:探讨肿瘤细胞降钙素(calcitoninCT)基因甲基化模式及其与DNA甲基转移酶(methyltransferaseMTase)活性变化的关系。方法:以6种实体肿瘤细胞系和2种白血病细胞系为研究对象,采用设有内、外参照的多聚酶链反应(polymerasechainreactionPCR),结合限制性内切酶和激光扫描技术,检测CT基因5′端甲基化率(methylationrateof5′regionofCTgeneCTMR);采用同位素示踪微量分析法检测MTase活性。结果:肿瘤细胞系和白血病细胞系的CTMR及MTase活性均显著高于正常对照细胞;CTMR增高与MTase活性增高具有相关性。结论:在恶性肿瘤细胞中普遍存在CT基因高甲基化及MTase活性增高。MTase活性增高为CT基因高甲基化形成的可能机制之一。更多还原

【Abstract】 Objective:The current study was designed to investigate the relationship between t he pattern of methylation of calcitonin(CT)gene and the activity of DNA methyltr ansferase(MTase).Methods:The methylation rate of 5’ region of CT gene(CTMR)and the activity of MTase in 6solid tu mor cell lines and 2leukemia cell lin es were determined.CTMR was detected by polymerase chain reaction(PCR)with inter and external references i n combination with restriction endonuclease and laser scan technique.MTase activity was e xamined by isotope labeled microass ay.Results:Both CTMR and MTase activity in all tumor c ell lines were significantly higher than that of control cells.The incre ased MTase activity was relative to elevated CTMR.Conclusion:There is prevalence of hypermethyla tion of CT gene and elevated activity of MTase in malignant cells.The increased MTase activity is one of the possible reasons for CT gene hypermethylation in tumor cells.更多还原