miRNA-155对人乳腺癌MCF-7细胞TP53INP1表达及其增殖的影响

miRNA-155 inhibits TP53INP1 protein expression and promotes proliferation of human breast cancer MCF-7 cells

目的探讨miRNA-155对人乳腺癌MCF-7细胞TP53INP1表达及其增殖的影响。方法采用LipofectamineTM2000将miRNA-155 mimics(或带荧光无关序列阴性对照FAM-NC)转染雌激素受体(Estrogen receptor,ER)阳性人乳腺癌MCF-7细胞,并设空白对照组;RT-PCR法检测转染后miRNA-155的表达水平;CCK-8法检测miRNA-155对MCF-7细胞增殖能力的影响;流式细胞术检测MCF-7细胞的凋亡率和增殖周期;Western blot法检测TP53INP1、Caspase-3及p21蛋白的表达水平。结果与空白对照组和阴性对照组相比,转染组miRNA-155的表达量明显增高;随着时间的延长,MCF-7细胞增殖活力逐渐增加;G1期细胞明显减少,S和G2期细胞增多,凋亡率明显降低;TP53INP1、Caspase-3激活型及p21蛋白的表达水平均明显降低。结论 miRNA-155能够抑制人乳腺癌MCF-7细胞TP53INP1蛋白的表达,进而抑制肿瘤细胞凋亡、促进细胞增殖,在乳腺癌发生发展中具有重要作用。

Objective To investigate the effects of miRNA-155 on expression of TP53INPI protein and proliferation of human breast cancer MCF-7 cells. Methods Estrogen receptor （ER） positive MCF-7 cells were transfected with miRNA-155 mimics in mediation of LipofectamineTM2000, using those untransfected as blank control and those transfected with FAM- NC as negative control, and determined for expression level of miRNA-155 by RT-PCR, while the proliferation level by CCK8 method, the apoptosis rate and cell cycle of by flow cytometry, and the expression levels of TP53INP1, Caspase-3 and p21 protein by Western blot. Results The expression level of miR-155 in MCF-7 cells transfected with miRNA-155 mimics was significantly higher than those in blank and negative control groups. The proliferation activity of MCF-7 cells increased with the increasing hours after transfection, while the cells at G1 phase decreased, and those at S and G2 phases increased, and the apoptosis rate of cells decreased significantly. The expression levels of TP53INP1, Caspase-3 and P21 decreased significantly. Conclusion The miRNA-155 inhibited the expression of TP53INP1 in MCF-7 cells so as to inhibit the apoptosis and promote the proliferation of tumor cells, which played an important role in the onset and progress of breast cancer.