miR-125b靶向调控HK2表达增强乳腺癌MCF-7细胞放射敏感性的研究

目的探讨miR-125b靶向调控HK2对乳腺癌MCF-7细胞放射敏感性的影响。方法将miR-125b模拟物及其阴性对照转染至乳腺癌MCF-7细胞，分别记为miR-125b组和miR-NC组，采用RT-PCR检测MCF-7细胞中miR-125b和HK2 mRNA的表达，Western blotting检测HK2蛋白的表达；双荧光素酶报告基因实验检测miR-125b和HK2的靶向关系。另外将miR-125b模拟物和pcDNA3.1-HK2质粒共转染至MCF-7细胞中，记为miR-125b+HK2组，通过克隆形成实验和流式细胞仪检测miR-NC组、miR-125b组和miR-125b+HK2组细胞的存活分数和凋亡率。结果与miR-NC组相比，转染miR-125b模拟物后MCF-7细胞中miR-125b表达升高（P < 0.01），而HK2 mRNA和蛋白的表达降低（P < 0.01）。双荧光素酶报告基因实验证实HK2是miR-125b的潜在靶基因。与miR-NC组相比，miR-125b组细胞的存活分数降低、凋亡率升高（P < 0.01）；与miR-125b组相比，miR-125b+HK2组存活分数降低明显升高而凋亡率降低（P < 0.01）。结论miR-125b可通过靶向调控HK2表达增强乳腺癌MCF-7细胞的放射敏感性。

Study on the mechanism of miR-125b targeting HK2 expression to enhance radiosensitivity of breast cancer MCF-7 cells

ObjectiveTo investigate the effects of miR-125b targeting HK2 expression on the radiosensitivity of breast cancer MCF-7 cells.MethodsThe miR-125b mimics and its negative control were transfected into breast cancer MCF-7 cells, and divided into the miR-125b group and miR-NC group, respectively.The expression levels of miR-125b and HK2 mRNA in MCF-7 cells were detected using RT-PCR, and the expression of HK2 protein was detected by Western blotting.The targeting relationship between miR-125b and HK2 was detected using double luciferase reporter gene assay.The mimic of miR-125b and pcDNA3.1-HK2 plasmid were co-transfected into MCF-7 cells(miR-125b+HK2 group), and the survival fraction and apoptotic rate of cells in three groups were detected by clone formation assay and flow cytometry.ResultsAfter transfecting miR-125b mimics, compared with the miR-NC group, the expression level of miR-125b in MCF-7 cells increased(P < 0.01), and the expression levels of HK2 mRNA and protein decreased(P < 0.01).The results of double luciferase reporter gene assay confirmed that the HK2 was a potential target gene of miR-125b.Compared with the miR-NC group, the survival fraction and apoptotic rate of cells in miR-125b group decreased and increased, respectively(P < 0.01).Compared with the miR-125b group, the survival fraction and apoptotic rate in miR-125b + HK2 group significantly increased and decreased, respectively(P < 0.01).ConclusionsMiR-125b can enhance the radiosensitivity of breast cancer MCF-7 cells by targeting HK2 expression.