增强miR-146b-3p表达对胰腺癌细胞增殖和凋亡的影响

Effects of Up-regulated Expression of miR-146b-3p on Proliferation and Apoptosis of Pancreatic Cancer Cell Lines

目的探讨增强miR-146b-3p表达对胰腺癌细胞增殖和凋亡的影响。方法 Real time PCR检测miR-146b-3p在6种人胰腺癌细胞系(MIA PaCa-2、BxPC-3、AsPC-1、PANC-1、SW1990、PC-3)和手术切除的12对胰腺癌/癌旁组织中的表达。将Pre-miR-hsa-miR-146b-3p Precursor转染MIA PaCa-2细胞,Real time PCR检测转染后miR-146b-3p的表达变化,四甲基偶氮唑蓝(MTT)法检测细胞增殖能力,流式细胞仪检测细胞凋亡率,免疫印迹法(Western blot)检测凋亡相关蛋白Bcl-2、Bax、Caspase-3、Caspase-8的表达变化。结果与正常胰腺组织相比,miR-146b-3p在6种胰腺癌细胞系中均呈低表达,以MIA PaCa-2细胞最为明显;12对胰腺组织中,癌组织miR-146b-3p表达水平均低于癌旁组织。同阴性对照组比较,转染前体组的MIA PaCa-2细胞,miR-146b-3p表达增强383.25倍,细胞增殖能力下降,细胞凋亡率增加,蛋白Bcl-2表达降低(50.0%),Bax表达升高(4.29倍)。结论 miR-146b-3p在胰腺癌细胞系和癌组织中低表达;上调胰腺癌细胞MIA PaCa-2中miR-146b-3p的表达,能够抑制增殖和诱导细胞凋亡,其机制可能与下调Bcl-2表达,上调Bax的表达有关。

Objective To investigate the effects of the up-regulated miR-146b-3p on proliferation and apoptosis of pancreatic cancer cells.Methods The expression of miR-146b-3p in 6 pancreatic cancer cell lines and 12 matched pancreatic cancer and adjacent non-tumorous tissues were detected by real time PCR.Pre-miR-hsa-miR-146b-3p precursor was transfected into MIA PaCa-2 cells with transfection agent.The miR-146b-3p expression was detected by real time PCR.The cellular growth activity was assayed by MTT assay,and the apoptosis was tested by flow cytometry.The apoptosis-related proteins Bcl-2,Bax,Caspase-3 and Caspase-8 were measured by Western blot.Results Real time PCR showed that the expression of miR-146b-3p was lower in 6 pancreatic cancer cell lines than in normal pancreatic tissues,especially in MIA PaCa-2.The miR-146b-3p expression level in 12 pancreatic cancer tissues was all lower than that in matched adjacent non-tumor tissues.Compared with negative control group,the miR-146b-3p expression level in MIA PaCa-2 cells transfected with miR-146b-3p precursor was increased by 383.25 fold,the cellular growth activity decreased,the apoptosis rate increased,and the expression level of Bcl-2 protein significantly reduced by 50.0%,and that of Bax protein markedly increased by 4.29 fold.Conclusion The expression of miR-146b-3p is down-regulated in pancreatic cancer cells and pancreatic cancer tissues.With up-regulation of miR-146b-3p expression in pancreatic cancer cell line MIA PaCa-2,cell proliferation can be inhibited and cell apoptosis can be increased,which may be related to down-regulation of the Bcl-2 expression and up-regulation of the Bax expression.