MicroRNA-10b调控乳腺癌细胞生长增殖与凋亡的研究

MicroRNA-10b regulates proliferation,cell cycle and apoptosis in human breast cancer cells

研究MicroRNA-10b(miR-10b)对乳腺癌细胞MCF-7、MDA-MB-231的生长增殖和凋亡的调控作用。采用能模拟内源miR-10b的miR-10b模拟物以及能特异靶向敲除内源miR-10b的miR-10b抑制剂分别转染乳腺癌细胞MCF-7和MDA-MB-231。RT-PCR测定转染后细胞中miR-10b的表达水平,MTT检测miR-10b对细胞增殖活力的影响,流式细胞仪检测miR-10b对细胞周期和凋亡的影响。生物信息学软件预测miR-10b潜在的靶基因,3'UTR荧光素酶报告法验证其靶向性,Western blot检测caspase-3、P21的蛋白表达水平。研究证实,miR-10b模拟物上调乳腺癌中miR-10b的表达水平,与对照组相比,细胞增殖能力提高,细胞周期加速,细胞凋亡率降低;反之miR-10b抑制剂能显著下调miR-10b的表达,与对照组相比,细胞增殖能力降低,细胞周期阻滞,细胞凋亡率上调。初步探讨miR-10b的作用机制可能是通过靶向作用于TP53INP1,抑制细胞周期与凋亡关键蛋白caspase-3、P21的表达水平,从而促进乳腺癌的发生发展。

To investigate the effects of miRNA-10b（miR-lOb） on breast cancer proliferation and apoptosis in MCF-7 and MDA-MB-231, the miR-10b mimics used to increase the endogenous expression of miR-10b, and miR-10b inhibitor used to decrease the endogenous expression of miR-10b, were stably transfected into MCF-7 and MDA-MB-231 breast cancer ceils. The expression level of miR-10b was determined by real-time PCR. The effects of miR-10b on proliferation were evaluated by MTT assay, while cell cycle assay and the apoptosis rate were measured by flow cytometry. Bioinformatic software was used to predict the potential targets of miR-10b, and 3＇UTR luciferase reporter and qRT-PCR assay were used to verify a direct target of miR-10b. The expression levels of caspase-3 and p21 protein were measured by Western blot. Results confirmed that over-expression of miR-10b could promote the proliferation of breast cancer cells and inhibit the apoptosis by up-regulating the endogenous miR-10b, while the miR-10b inhibitor could restrain the proliferation of breast cancer cells and increase the apoptosis by reducing the endogenous miR-10b. In conclusion, miR-10b could negatively regulate the expression of caspase-3 and p21 by targeting TP53INP1, hence highlighting its potential as an oncogene in breast cancer cells.