5-氮杂-2'-脱氧胞苷和曲古菌素A对胰腺癌Panc-1细胞系TFPI-2基因甲基化水平及表达的影响

摘要

Objective To investigate effects of 5-aza-2'-deoxycytidine(5-Aza-dC)and trichostatin A(TSA)on the methylation and expression of TFPI-2 gene in pancreatic cancer Panc-1 cells.Methods We treated pancreatic cancer Panc-1 cells with 5-Aza-dC and TSA alone or combined.TFPI 2 gene's DNA,mRNA and protein were determined by MSP,RT-PCR and Western blot.Results The hypermethylation of TFPI-2 gene in Panc-1 cells was reversed after treated with 5 Aza-dC alone or in combination with TSA.The re-introduction or raised expression of TFPI-2 mRNA and protein was detected in Panc-1 cells after treated with 5 Aza dC alone or in combination.However,we did not see the hypermethylation of TFPI 2 gene reversed nor detected TFPI 2 gene mRNA and protein after treated with TSA alone.Conclusions The methylation of the promoter region for the TFPI-2 gene is a main cause for its transcriptional activation in Panc-1 cells.The hypermethylation of TFPI-2 gene in Panc-1 cell was reversed and the expression of TFPI-2 gene mRNA and protein was detected after trea ted with 5-Aza-dC alone or in combination with TSA.Treatment of TSA alone does not have significant effect on TFPI-2 gene reexpression.%目的 探讨甲基化酶抑制剂5-氮杂2'-脱氧胞苷(5-Aza-dC)及组蛋白去乙酰化酶抑制剂曲古菌素A(TSA)对胰腺癌Panc-1细胞系中TFPI-2基因甲基化水平及基因表达的影响.方法 单独或联合应用5-Aza-dC及TSA处理Panc-1细胞,应用甲基化特异性聚合酶链反应、逆转录聚合酶链反应及蛋白印迹实验检测药物处理前后Panc-1细胞TFPI-2基因启动子区甲基化状态、mRNA及蛋白表达情况.结果 经5-Aza-dC单独处理或5-Aza-dC及TSA联合处理Panc-1细胞后,TFPI-2基因启动子区高甲基化状态得到逆转,表现为非甲基化,原本不表达的TFPI-2基因mRNA及蛋白重新表达,两组作用效果相似.经TSA单独处理的Panc-1细胞TFPI-2基因启动子区仍为异常高甲基化状态,原本不表达的TFPI-2基因未见重新表达.结论 胰腺癌Panc-1细胞系中TFPI-2基因启动子区高甲基化可能是导致该基因失活的主要原因,5-Aza-dC单独作用或与TSA联合作用均能逆转TFPI-2基因的高甲基化状态,使该基因重新表达,TSA对受抑制的TFPI-2基因重新表达作用不明显.