Abstract: Objective Our study aims to investigate the inhibition effects of miR-124 on the growth of breast cancer cell MCF-7 induced by paclitaxel. Methods MTT was used to detect the growth inhibition of MCF-7 induced by paclitaxel. Flow cytometry was used to detect the effect of paclitaxel on cell cycle. Real-time quantitative PCR(qRT-PCR) was used to detect the expression level of miR-124, while MCF-7 celss were treated with paclitaxel. MiR-124 inhibitor was transfected into MCF-7 breast cancer cells, and growth inhibition was detected by MTT. Results The results showed that paclitaxel could significantly inhibit the growth of breast cancer cell line MCF-7 by blocking the G2 phase. The results from qRT-PCR showed that the relative expression of miR-124 was increased when the dosage of paclitaxel was increased. When the expression of miR-124 was inhibited, the cell growth inhibition caused by paclitaxel was also prominent decreased. Conclusion The higher expression of miR-124 in MCF-7 induced by paclitaxel was dose dependent. And miR-124 inhibitor can significant influence the cell growth inhibition caused by paclitaxel. These results indicated that miR-124 plays an important role in paclitaxel-induced chemotherapy drug resistance, and provides a new direction to solve the problem.

Key words: miR-124 , Paclitaxel , Breast cancer