Bmi-1与miR-221-3P在乳腺癌组织和细胞中的表达及相互调控关系

Study on the expression of Bmi-1 and miR-221-3P in breast cancer and their regulation relationship

目的:探讨Bmi-1与miR-221-3P在乳腺癌组织及细胞中的表达水平及相互调控关系。方法:运用RT-PCR检测Bmi-1与miR-221-3P在乳腺癌组织、癌旁组织及MCF-7、MCF-10a细胞中的相对表达水平。运用统计学方法探讨两者的相关性。运用Targetscan软件分析Bmi-1与miR-221-3P存在的结合位点,构建双荧光报告基因载体验证Bmi-1与miR-221-3P的相互结合作用。Western-blotting检测乳腺癌组织及细胞中Bmi-1蛋白的相对表达水平。结果:Bmi-1在乳腺癌组织及MCF-7细胞中呈高表达,而miR-221-3P的表达水平明显下调,两者呈负相关性,相关系数为r=-0.826。在转染克隆有Bmi-1基因3'UTR质粒的实验中,miR-221-3P组与空白组、miR-221-3P抑制剂组、NC组、NC抑制剂相比较,P<0.05,差异极显著。降低Bmi-1的表达水平之后,miR-221-3P的表达水平显著上调。结论:Bmi-1在乳腺癌组织和细胞中呈高表达,miR-221-3P在乳腺癌组织和细胞中呈低表达,miR-221-3P负性调控Bmi-1的表达,为阐明乳腺癌的发病机制指明方向。

Objective： To investigate the expression level of Bmi-1 and miR-221-3 P in breast cancer tissues and cells and regulatory interaction. Methods： The relative expression levels of Bmi-1 and miR-221-3 P in breast cancer tissues,adjacent tissues and MCF-7,MCF-10 a cells were detected by RT-PCR. Use the statistical methods to explore their correlation. The binding sites between Bmi-1 and miR-221-3 P were analyzed by argetscan software. Constructe the luciferase vector to verifiy the interaction between Bmi-1 and miR-221-3 P. The relative expression level of protein in breast cancer tissues and cells were detected by Western-blotting. Results： The expression of Bmi-1 in breast cancer tissue and MCF-7 cells was high,and the expression level of miR-221-3 P decreased significantly. There was a negative correlation between miR-221-3 P and Bmi-1,the correlation coefficient was r =-0. 826. The co-transfection of MCF-7 cells with miR-221-3 P mimics and psi CHECK-2-Bmi-1 3＇UTR significantly inhibited luciferase activity（ P＜0. 05）,when compared with control,miR-221-3 P inhibitor,negative control,NC inhibitor group. After decreasing the expression level of Bmi-1,the expression level of miR-221-3 P increased significantly. Conclusion： The expression of Bmi-1 in breast cancer was high,the expression of miR-221-3 P was low in breast cancer,the miR-221-3 P negatively regulates the expression of Bmi-1,which indicates the direction for clarifying the pathogenesis of breast cancer.