MicroRNA-21靶向PDCD4对胃癌细胞增殖及凋亡的影响

目的探讨MicroRNA-21对胃癌细胞中PDCD4表达、细胞增殖与凋亡的影响。方法将MGC-803人胃癌细胞分为5组,分别为空白对照组(不转染)、阴性对照组(转染不相关siRNA)、mir 21组(转染miRNA-21质粒)、mir 21 Inhibitor组(转染miRNA-21抑制物)、PDCD4 siRNA组(转染PDCD4 siRNA)。分别于转染后36、48、72小时收集细胞,采用实时定量PCR及细胞爬片免疫组织化学检测细胞中PDCD4基因及蛋白水平,运用MTS法检测细胞增殖情况,流式细胞仪检测细胞凋亡。结果与空白、阴性对照组比较,mir 21组PDCD4表达量下降,细胞增殖能力增强(均P<0.05);mir 21 Inhibitor组PDCD4表达量增多(P<0.05),细胞增殖受到抑制(P<0.01),细胞总凋亡比例增高(P<0.05);PDCD4 siRNA组PDCD4表达几乎完全被抑制,细胞增殖能力增强(均P<0.01),36小时时细胞总凋亡比例减少(P<0.05)。而阴性和空白对照组比较,细胞PDCD4表达量、细胞增殖与凋亡都无明显差异(P>0.05)。结论 MicroRNA-21能靶向调控PDCD4,抑制胃癌细胞MicroRNA-21的表达后可上调PDCD4表达,发挥抑制细胞增殖并诱导细胞凋亡的作用。

Effect of PDCD4 targeting microRNA-21 on proliferation and apoptosis of gastric cancer cells

Objective To investigate the effect of regulating nficroRNA-21 on the expression of PDCD4 and the proliferation and apoptosis of gastric cancer cells. Methods Human gastric cancer MGC-803 cells were divided into 5 groups ： blank control group （ not transfected ）, negative control group （transfected with non-related siRNA）, mir 21 group （transfected with miRNA-21 plasnfids ）, mir 21 inhibitor group （transfected with miRNA-21 inhibitors） and PDCD4 siRNA group （transfected with PDCD4 siRNA）. The cells were collected after being transfected for 36,48 and 72 h. The level of PDCD4 gene and protein in MGC-803 cells were detected by real-time qualitative PCR,creep plates IHC. Cell proliferation was assessed by MTS assay and cell apoptosis was detected by flow cytometry （FCM）. Results Compared with blank control and negative control groups, the expression of PDCIM in mir 21 group was down- regulated,and cell proliferation significantly increased （both P 〈 0.05）;the expression of PDCD4 in mir 21 inhibitor group was significantly up-regulated （ P 〈 0.05 ）, and cell proliferation was inhibited significantly （ P 〈 0.01 ） and total apoptosis rate was significantly increased （ P 〈 0.05 ）. The expression of PDCD4 in PDCD4 siRNA group was almost inhibited completely （ P 〈 0.01 ）. Compared to blank control group, cell proliferation in PDCD4 siRNA group significantly increased （P 〈 0.01 ） and apoptosis rate significantly decreased after 36 h transfection （ P 〈 0.05 ）. There were no significant differences in the expression of PDCD4, cell proliferation and apoptosis between blank control group and negative control group. Conclusion MicroRNA-21 can induce proliferation and inhibit apoptosis of human gastric cancer MGC-803 cells, which is associated with the down-regulation of PDCD4.