miR-145对人乳腺癌MCF-7/ADR细胞耐药逆转的作用机制研究

Mechanism of miR-145 on regulating adriamycin resistance of human breast cancer cell line MCF-7/ADR

目的:探讨miR-145对人乳腺癌阿霉素耐药细胞株MCF-7/ADR阿霉素耐药的影响及可能的作用机制。方法:采用实时定量PCR方法检测miR-145在乳腺癌细胞株MCF-7及MCF-7/ADR中的表达差异;脂质体转染法将构建好的miR-145 mimics,miR-145inhibitor成功转染进MCF-7/ADR细胞中,MTT法检测转染后MCF-7/ADR细胞对阿霉素的敏感性,流式细胞仪检测耐药细胞对阿霉素诱导凋亡的影响,Western blot检测转染前后抗凋亡蛋白Bcl-2、多药耐药基因MDR1表达蛋白P-gp的表达差异。结果:miR-145在人乳腺癌细胞株MCF-7/ADR中表达下降;上调miR-145可以增强MCF-7/ADR细胞对阿霉素的敏感性,显著抑制MCF-7/ADR细胞增殖,并促进阿霉素诱导的细胞凋亡,同时显著抑制了耐药细胞中Bcl-2和P-gp的表达。结论:miR-145通过抑制Bcl-2和P-gp蛋白的表达来增加MCF-7/ADR细胞对阿霉素的敏感性和凋亡。

Ob je c t iv e ：T o in v es tig ate wh e th e r miR-145 could mo du la te th e ad riamy cin re s is ta n c e of th e h uman breast cancer cell line MCF-7/ADR, and to explore the probable mechanism. Methods： miR-145 ex p re s s io n was measured by quantitative real-time PCR. Transient transfection was used in MCF-7 and MCF-7/ADR cell lines. MTT was used to detect the cell viability. Flow cytometry was used to testify the adriamycin-induced cell apoptosis. Pro-tein expressions of BCL-2 and P-gp were measured by western blot. Results：We found that miR-145 was down-reg-ulated while Bcl-2 and P-gp were up-regulated in MCF-7/ADR cells compared with the parental MCF-7 cells. In vitro drug sensitivity assay demonstrated that the over-expression of miR-145 sensitized MCF-7/ADR cells to adria-mycin. Enforced miR-145 expression reduced the protein level of Bcl-2 and P-gp and sensitized MCF-7/ADR cells to adriamycin-induced apoptosis. Conclusion：Our study demonstrated that hsa-miR-145 can modulate adriamycin resist-ance in breast cancer cell line and induce cell apoptosis partly via targeting Bcl-2 and P-gp.Key words