MicroRNA-494对胃癌细胞增殖、细胞周期及凋亡的影响

MiR-494 arrests gastric cancer proliferation and cell cycle progression through down-regulating CyclinD1

目的探讨microRNA-494(miR-494)对胃癌细胞增殖、细胞周期及凋亡的影响。方法选取2015年1月—2018年1月被陕西省肿瘤医院收治并行手术切除的60例患者的胃癌组织及对应癌旁组织(距肿瘤边缘>2 cm)标本。将胃癌细胞MGC803分为miR-494组和对照组。采用PCR检测胃癌组织及体外培养细胞中的miR-494表达水平。在MGC803细胞中过表达miR-494,采用MTT法检测细胞增殖,流式细胞术检测细胞周期及细胞凋亡。PCR及Western blotting检测miR-494潜在靶点Cyclin D1的表达变化。结果癌旁组织miR-494相对表达量较胃癌组织高(P<0.05)。不同肿瘤直径、TNM分期miR-494相对表达量比较,差异有统计学意义(P<0.05)。对照组MGC803细胞miR-494相对表达量较miR-494组低(P<0.05)。miR-494组OD值较对照组低(P<0.05)。对照组CyclinD1 mRNA和蛋白相对表达量较miR-494组高(P<0.05)。miR-494与CyclinD1免疫组织化学评分呈负相关(r=-0.469,P<0.05)。结论胃癌组织中miR-494表达水平降低,过表达miR-494能通过下调Cyclin D1的表达发挥抑制胃癌细胞增殖和细胞周期进展的作用。

Objective To investigate the role of miR-494 in gastric cancer proliferation,cell cycle progression and apoptosis.Methods The gastric cancer and corresponding adjacent tissues(at least 2 cm away from the tumor margins)were surgically removed from 60 patients admitted to our hospital from January 2015 to January 2018.The gastric cancer MGC803 cells were divided into miR-494 group and control group.The expression of miR-494 in gastric cancer tissues and the cultured cells in vitro was detected by PCR.MTT assay and flow cytometry assay were used to detect cell proliferation,cell cycle and apoptosis.PCR and immunoblotting were used to detect CyclinD1 expression.Results The miR-494 expression was down-regulated in gastric cancer tissues(t=5.421,P<0.001)and associated with large tumor size(>3 cm,t=1.844,P=0.041)and advanced TNM stage(III+IV,t=1.969,P=0.028).Up-regulation of miR-494 inhibited proliferation(t=3.868,P=0.022)and cell cycle progression(t=3.721,P=0.023),but had no effect on apoptosis(t=1.034,P=0.063)in MGC803 cells.The expression of CyclinD1 was impaired due to the overexpression of miR-494 in vitro(P<0.05).Moreover,the negative relationship between CyclinD1 IHC scores and miR-494 levels was confirmed in clinical samples(r=-0.469,P=0.009).Conclusions The expression of miR-494 was down-regulated in gastric cancer tissues.Up-regulation of miR-494 could inhibit gastric tumor cell proliferation and cell cycle progression through inhibiting CyclinD1.