摘要
背景:哺乳动物雷帕霉素靶蛋白(mTOR)信号途径和DNA甲基化均参与肿瘤的发生、发展。脾酪氨酸激酶(Syk)是一种候选抑癌基因,与肿瘤发生有关。目的:研究mTOR信号通路抑制剂和DNA甲基转移酶抑制剂对人胃癌细胞株Syk表达的调控作用。方法:分别单独或联合应用mTOR抑制剂雷帕霉素(RAPA)、DNA甲基转移酶抑制剂5-氮杂-2’-脱氧胞苷(5-Aza-dC)、磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶(PI3K/Akt)抑制剂LY294002干预人胃癌细胞株MKN45和SGC7901,以细胞计数法检测细胞增殖能力,实时定量PCR法检测Syk表达情况,亚硫酸氢盐修饰后测序法检测DNA甲基化改变。结果:单独应用5-Aza-dC对细胞增殖抑制不明显,与RAPA、LY294002联合则显著抑制细胞增殖。单独应用5-Aza-dC可通过抑制DNA甲基化上调胃癌细胞的Syk表达,联合应用5-Aza-dC、RAPA和LY294002则显著上调Syk表达,但未进一步抑制DNA甲基化。结论:抑制mTOR信号通路可间接增强DNA甲基转移酶抑制剂上调Syk表达,从而抑制胃癌细胞生长。
Background： Mammalian target of rapamycin （mTOR） signaling pathway and DNA methylation play an important role in tumorigenesis, and spleen tyrosine kinase （Syk） is an anti-oncogene related to tumor development. Aims： To investigate the effects of mTOR signaling pathway inhibitor and DNA methyltransferase inhibitor on Syk expression in human gastric cancer cell lines. Methods： Human gastric cancer cell lines MKN45 and SGC7901 were treated with mTOR inhibitor rapamycin （ RAPA ）, DNA methyltransferase inhibitor 5-aza-2 ＇-deoxycytidine （ 5-Aza-dC ） and phosphatidylinositol 3 kinase/serine-threonine protein kinases （PI3K/Akt） inhibitor LY294002. Cell proliferation was determined by cell counting method. Expression of Syk was determined by real-time quantitive PCR. DNA methylation was detected by bisulfite sequencing. Results： Treated with 5-Aza-dC had no significant effect on cell proliferation, while combinedly treated with 5-Aza-dC, RAPA and LY294002 could significantly inhibit cell proliferation. Treated with 5-Aza- dC upregulated the expression of Syk by inhibiting DNA methylation, while combinedly treated with 5-Aza-dC, RAPA and LY294002 significantly upregulated the expression of Syk, but did not further inhibit the DNA methylation. Conclusions： Inhibiting roTOR signaling pathway could enhance the effect of DNA methyltransferase inhibitor for upregulating the expression of Syk and thereby inhibiting the proliferation of gastric cancer cells.
出处
《胃肠病学》
2013年第5期276-280,共5页
Chinese Journal of Gastroenterology
基金
国家自然科学基金青年科学基金项目(81001070)资助
