药物调控对喉癌细胞系中抑癌基因表达的影响

Effect of drug regulation on tumor suppressor gene expression in Hep-2 cell line

目的探讨甲基化转移酶抑制剂5-氮杂-2'-脱氧胞苷(5-aza-2'-deoxycytidine,5-Aza-dC)对喉癌细胞系中抑癌基因错配修复基因(O6-methylguanine-DNA methyltransferase,MGMT)和Ras相关区域家族1A基因(ras association domain family1A,RASSF1A)甲基化水平及基因表达的影响。方法 5-Aza-dC处理体外培养的喉癌Hep-2细胞(简称Hep-2细胞),应用实时荧光定量逆转录PCR(realtime fluro-genetic quantitative reverse transcription PCR)方法 及甲基化特异性PCR(MSP)方法 分别检测药物干预前后细胞中抑癌基因MGMT和RASSF1A表达及甲基化情况。结果①在Hep-2细胞中未经药物干预前抑癌基因MGMT和RASSF1A表现为甲基化,抑癌基因MGMT和RASSF1A弱表达。②在5-Aza-dC的作用下,Hep-2细胞系中MGMT和RASSF1A基因的甲基化状态得到了逆转,MGMT和RASSF1A基因表达上调。结论 Hep-2细胞中抑癌基因MGMT和RASSF1A启动子甲基化可能是导致其基因失活的主要原因。应用5-Aza-dC能够通过逆转抑癌基因MGMT和RASSF1A的DNA甲基化水平从而使基因表达得到了增强。

OBJECTIVE To investigate the effect of 5-Aza-dC on tumor suppressor gene MGMT and RASSF1A expression and methylation level in Hep-2 cell line.METHODS Hep-2 cell line was cultured in vitro and treated with 5-Aza-dC.MGMT and RASSF1A expression and methylation level before and after intervention with drug were detected using realtime PCR and MSP.RESULTS ①Before intervention with drug,tumor suppressor gene MGMT and RASSF1A was weakly expressed and methylated in Hep-2 cell line.② With the effect of 5-Aza-dC,the methylation of MGMT and RASSF1A gene was reversed.The expression of MGMT and RASSF1A was enhanced.CONCLUSION In Hep-2 cell line,Promoter methylation of tumor suppressor MGMT and RASSF1A may play a very important role in loss of gene expression.5-Aza-dC can improve MGMT and RASSF1A expression by reversing DNA methylation.