miR-520c-3p靶向MEX3A调控肺癌细胞增殖、凋亡的分子机制

为研究miR-520c-3p对肺癌细胞增殖和凋亡的影响及其潜在的作用机制,用实时定量RT-PCR检测肺癌细胞H1299、NCI-H460、A549和正常肺上皮细胞BEAS-2B中miR-520c-3p和MEX3同源物A(MEX3 homolog A,MEX3A)的表达水平。将miR-NC、miR-520c-3p、si-NC、si-MEX3A、anti-miR-NC、anti-miR-520c-3p转染至H1299细胞后,用细胞计数试剂盒8(cell counting kit 8,CCK-8)法检测细胞增殖,流式细胞术检测细胞凋亡,Western blotting检测蛋白表达,双荧光素酶报告基因检测实验检测细胞的荧光活性。结果显示,与正常肺上皮细胞BEAS-2B比较,肺癌细胞H1299、NCI-H460、A549中miR-520c-3p的表达水平均显著降低(P<0.05),MEX3A mRNA和蛋白的表达水平显著升高(P<0.05)。miR-520c-3p过表达、MEX3A抑制表达均可抑制H1299细胞的增殖活力,促进细胞凋亡;miR-520c-3p过表达抑制CyclinD1、Bcl-2蛋白的表达,促进p21、Cleaved Caspase-3、Bax蛋白的表达;MEX3A抑制表达抑制CyclinD1、Bcl-2蛋白的表达,促进p21、Bax蛋白的表达。miR-520c-3p可靶向调控MEX3A的表达;MEX3A过表达逆转了miR-520c-3p过表达对肺癌细胞H1299的增殖抑制和凋亡促进作用。提示miR-520c-3p可抑制肺癌细胞H1299的增殖,促进其凋亡,其机制可能与靶向MEX3A有关,这将为肺癌的预防和治疗提供新靶点。

Molecular mechanism of miR-520c-3p targeting MEX3A in regulating proliferation and apoptosis of lung cancer cells

To investigate the effect of miR-520 c-3 p on proliferation and apoptosis of lung cancer cell and its mechanism,real-time quantitative RT-PCR was used to detect the expression of miR-520 c-3 p and MEX3 homolog A(MEX3 A)in lung cancer cells H1299,NCI-H460,A549 and normal lung epithelial cell BEAS-2 B.After miR-NC,miR-520 c-3 p,si-NC,si-MEX3 A,anti-miR-NC,anti-miR-520 c-3 p were transfected into H1299 cells,the cell proliferation was detected by cell counting kit 8(CCK-8)method;the apoptosis was detected by flow cytometry;the protein expression was detected by Western blotting;fluorescence activity of cells was detected by dual luciferase reporter assay.The results showed that,compared with the normal lung epithelial cell BEAS-2 B,the expression of miR-520 c-3 p in lung cancer cells H1299,NCI-H460 and A549 was significantly decreased(P<0.05),in the contrast,the expression of MEX3A mRNA and protein were significantly increased(P<0.05).Overexpression of miR-520 c-3 p and decreased expression of MEX3 A inhibited the proliferation,and promoted apoptosis of H1299 cells.Overexpression of miR-520 c-3 p inhibited the expressions of CyclinD1 and Bcl-2 proteins,and promoted the expressions of p21,Cleaved Caspase-3 and Bax proteins;inhibition of MEX3 A inhibited the expressions of CyclinD1 and Bcl-2 proteins,and promoted the expressions of p21 and Bax proteins.miR-520 c-3 p can specifically regulate the expression of MEX3 A;MEX3 A overexpression reversed the effect of overexpressed miR-520 c-3 p on proliferation inhibition and apoptosis promotion of lung cancer cells H1299.Taken together,these results indicate that miR-520 c-3 p could inhibit the proliferation and promote the apoptosis of lung cancer cell H1299 by targeting MEX3 A.These findings will provide a new target for the prevention and treatment of lung cancer.