下调lncRNA SNHG3表达对人胃癌细胞增殖、侵袭、凋亡的影响及机制

Effect of down-regulating lncRNA SNHG3 expression on proliferation,invasion and apoptosis of human gastric cancer cells and related mechanisms

目的探讨下调长链非编码RNA核仁小分子RNA宿主基因3(lncRNA SNHG3)的表达对人胃癌细胞增殖、侵袭和凋亡的影响及可能的机制。方法采用qRT-PCR法检测不同胃癌细胞株(BGC-823、MGC-803和SGC-7901)和正常胃黏膜细胞株GES-1中lncRNA SNHG3的相对表达量。选取lncRNA SNHG3表达水平最高的胃癌BGC-823细胞系,建立lncRNA SNHG3下调模型,实验分为SNHG3-siRNA组(转染lncRNA SNHG3-siRNA)、阴性对照组(转染阴性对照序列)、空白对照组(不予转染)。行CCK-8法、克隆形成实验、Transwell迁移和侵袭实验、流式细胞术检测、观察下调lncRNA SNHG3对人胃癌细胞BGC-823增殖、迁移、侵袭和凋亡的影响。Western blot法检测下调lncRNA SNHG3表达后胃癌增殖和转移相关信号传导与活化转录因子3(STAT3)、p-STAT3蛋白和细胞基质金属蛋白酶-2(MMP-2)蛋白的表达水平。结果与胃正常黏膜上皮细胞GES1相比,人胃癌细胞株BGC-823、MGC803的lncRNA SNHG3的相对表达量均明显增高(均P<0.05)。BGC-823细胞中,SNHG3-siRNA组lncRNA SNHG3相对表达量、光密度值、克隆形成率、细胞迁移数及细胞侵袭数均明显低于阴性对照组、空白对照组(均P<0.05);SNHG3-siRNA组细胞G1期百分比均明显高于空白对照组、阴性对照组(均P<0.05),3组S期细胞百分比比较差异则无统计学意义(P>0.05);SNHG3-siRNA组细胞G2期百分比均明显低于空白对照组、阴性对照组(均P<0.05);SNHG3-siRNA组细胞凋亡率均明显高于空白对照组、阴性对照组(均P<0.05)。与阴性对照组和空白对照组比较,SNHG3-siRNA组的STAT3、p-STAT3和MMP-2蛋白的表达水平均明显下降,p-STAT3/STAT3的比值明显降低(均P<0.05)。结论下调lncRNA SNHG3的表达,可抑制胃癌细胞增殖、迁移及侵袭能力,阻滞细胞周期,并诱导细胞凋亡,可能与抑制STAT3、MMP-2的表达和STAT3的磷酸化水平有关。

Objective To investigate the effect of lncRNA SNHG3 expression on the proliferation,invasion and apoptosis of human gastric cancer cells and its possible mechanism.Methods Real time quantitative RT-PCR(qRT-PCR)was used to detect the expression of lncRNA SNHG3 in gastric cancer cell lines BGC-823,MGC-803,SGC-7901 and normal gastric mucosa cell line GES-1.BGC-823 cell line with the highest lncRNA SNHG3 expression level was selected for further study.BGC-823 cells were transfected with lncRNA SNHG3-iRNA(SNHG3-siRNA group),NC-iRNA(negative control group)or not transfected(blank control group).The effects of lncRNA SNHG3 on proliferation,migration,invasion and apoptosis of BGC-823 cells were determined by CCK8,clone formation test,Transwell migration and invasion test,and flow cytometry.Western blot was used to observe the expression of STAT3、p-STAT3 and MMP2 in gastric cancer cells.Results Compared with GES1 cells,the relative expression of lncRNA SNHG3 in BGC-823 and MGC803 cells was significantly higher(all P<0.05).Compared with the negative control group and blank control group,the relative expression of lncRNA SNHG3,optical density,clone formation rate,cell migration number and cell invasion number in SNHG3-siRNA group were significantly lower(all P<0.05).In SNHG3-siRNA group,the proportion of G1 phase cells was significantly increased(all P<0.05).The proportion of S phase cells had no statistical significance(P>0.05),the proportion of G2 was significantly decreased(all P<0.05),the apoptosis rate was significantly increased(all P<0.05),the expression levels of STAT3,p-STAT3 and MMP2 protein were significantly decreased,the ratio of p-STAT3/STAT3 decreased significantly(all P<0.05).Conclusion Down-regulation of lncRNA SNHG3 expression can inhibit the proliferation,migration and invasion,block cell cycle and induce apoptosis of gastric cancer cells.The mechanism may be related to the inhibition of STAT3,MMP2 expression and phosphorylation of STAT3.