DNMT2在胃癌的表达及靶向抑制  

The expression of DNMT2 in gastric cancer and its RNA interference

作　　者：何苗[1] 汤为学[2] 范晶[3] 王子卫[1] 

机构地区：[1]重庆医科大学附属第一医院普通外科,重庆400016 [2]重庆医科大学附属第一医院实验研究中心,重庆400016 [3]重庆医科大学附属第一医院急诊科,重庆400016

出　　处：《基础医学与临床》2012年第12期1465-1470,共6页Basic and Clinical Medicine

摘　　要：目的研究DNA甲基化转移酶2(DNMT2)在胃癌的表达,并分析靶向抑制DNMT2对胃癌的影响。方法免疫组化法对60例胃癌与癌旁组织,免疫荧光法对胃癌细胞SGC-7901行DNMT2表达研究。构建3个靶向抑制DNMT2的siRNA(DNMT2-siRNA-1,DNMT2-siRNA-2,DNMT2-siRNA-3)。转染DNMT2-siRNA入SGC-7901,RT-PCR及Western免疫印迹法验证DNMT2的抑制效果。噻唑蓝比色法检测SGC-7901增殖率。结果胃癌组织DNMT2表达率43.3%,显著低于癌旁组织的93.3%(P<0.05);晚期及低分化胃癌组织的DNMT2表达率更低(P<0.05)。DNMT2在胃癌细胞核表达显著。DNMT2-siRNA可成功转染SGC-7901,并成功筛选靶向抑制DNMT2的siRNA(DNMT2-siRNA-3)。发现转染DNMT2-siRNA-3后96 h与120 h,SGC-7901增值率1.138±0.110与1.078±0.060较对照增殖率1增加(P<0.05)。结论 DNMT2在胃癌表达降低,抑制DNMT2可能利于胃癌增殖。Objective To investigate expression of DNA methyltransferase 2（DNMT2） protein in gastric cancer and the proliferation of SGC-7901（gastric cancer cell） with DNMT2 inhibition treatment（RNA interference technique）.Methods Immunohistochemistry was used to detect DNMT2 expression in 60 pairs of gastric cancer and corresponding non-cancerous tissues.Immunofluorescence was used to detect DNMT2 in SGC-7901.Three siRNA（DNMT2-siRNA-1,DNMT2-siRNA-2,DNMT2-siRNA-3） targeting DNMT2 were designed.LipofectamineTM2000 was used to transfect DNMT2-siRNA to SGC-7901.RT-PCR and western blotting were used to evaluate the effect of DNMT2 inhibition.MTT assay was carried on for SGC-7901 with DNMT2 inhibition treatment.Results Expression rate of DNMT2 in gastric cancer tissues（43.3%） was lower than that in corresponding non-cancerous tissues（93.3%）（P0.05）.DNMT2 expression was significantly lower in late-stage and poor-differentiated cancerous tissues than in early-stage and well-differentiated cancerous tissues（P0.05）.DNMT2 was distributed in nucleus of gastric cancer cell.DNMT2-siRNA could be transfect to SGC-7901 perfectly,and DNMT2-siRNA-3 could inhibit DNMT2 mRNA and protein best.At last,96 h and 120 h after DNMT2-siRNA-3 transfection,cell growth rate of SGC-7901 increased compared with control（1.138±0.110 and 1.078±0.060 vs 1,P0.05）.Conclusions Gastric cancer expressed less DNMT2 protein than non-cancerous tissues.Inhibition of DNMT2 may promote proliferation of gastric cancer cell more or less.

关 键 词：DNA甲基化转移酶2 胃癌 RNA干扰 表观遗传 

分 类 号：R735.2[医药卫生—肿瘤]