Gu Xi, Li Jian-Yi, Guo Jiao, Li Pi-Song, Zhang Wen-Hai
Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
Med Sci Monit. 2015 Oct 30;21:3291-7. doi: 10.12659/msm.894475.
This study aimed to investigate the potential influence of microRNA-451 (miR-451) in drug resistances of the Paclitaxel-resistant breast cancer cell line by transfecting miR-451 mimics and miR-451 inhibitors to MCE-7, MCF-7/EPI, and MCF-7/DOC.
Real-time quantitative PCR (qRT-PCR) was performed for detecting whether transfected miR-451 mimics and miR-451 inhibitors could regulate the expression of miR-451 effectively. The apoptosis of the 3 cell lines was measured by applying Annexin V-APC/PI staining. Western blot was used for the detection of the protein expression of Bcl-2 and Caspase 3 after the transfection of miR-451 mimics /inhibitors. Bioinformatics analysis demonstrated that Bcl-2 protein is a potential target gene for miR-451.
In comparison to the control group, after transfection with miR-451 mimics, there was a significant increase in miR-451 expression in MCF-7, MCF-7/EPI, and MCF-7/DOC. Cells in the three cell lines had increased apoptosis, Bcl-2 protein expression decreased significantly, and Caspase protein expression increased obviously. After the transfection with miR-451 inhibitors, miR-451 expression was significantly decreased and apoptosis in the 3 cell lines had no significant decrease compared with the control group.
Increased miR-451 expression may negatively regulate Bcl-2 mRNA and protein expression, followed by affecting the protein expression of caspase 3, and accelerate the apoptosis in breast cancer, indicating that miR-451 might influence the drug resistances of the Paclitaxel-resistant breast cancer cell line.
本研究旨在通过将微小RNA - 451（miR - 451）模拟物和miR - 451抑制剂转染至MCE - 7、MCF - 7/EPI和MCF - 7/DOC细胞，研究miR - 451对耐紫杉醇乳腺癌细胞系耐药性的潜在影响。
采用实时定量聚合酶链反应（qRT - PCR）检测转染的miR - 451模拟物和miR - 451抑制剂是否能有效调节miR - 451的表达。应用膜联蛋白V - APC/PI染色检测3种细胞系的凋亡情况。转染miR - 451模拟物/抑制剂后，采用蛋白质印迹法检测Bcl - 2和半胱天冬酶3的蛋白表达。生物信息学分析表明Bcl - 2蛋白是miR - 451的潜在靶基因。
与对照组相比，转染miR - 451模拟物后，MCF - 7、MCF - 7/EPI和MCF - 7/DOC细胞中miR - 451表达显著增加。三种细胞系的细胞凋亡增加，Bcl - 2蛋白表达显著降低，半胱天冬酶蛋白表达明显增加。转染miR - 451抑制剂后，miR - 451表达显著降低，与对照组相比，三种细胞系的凋亡无显著下降。
miR - 451表达增加可能负向调节Bcl - 2 mRNA和蛋白表达，进而影响半胱天冬酶3的蛋白表达，加速乳腺癌细胞凋亡，表明miR - 451可能影响耐紫杉醇乳腺癌细胞系的耐药性。
