The development of optimal strategies for breast cancer prevention is necessary given the high incidence in China. Several prospective randomized clinical trials have investigated the effects of various pharmacologic agents on the incidence of invasive and noninvasive breast cancer. This review aimed to summarize the different approaches to reduce the incidence of breast cancer.

Objective To explore effects of paclitaxel on proliferation and migration of breast cancer Michigan Cancer Foundation-7 (MCF-7) cells via mammalian target of rapamycin (mTOR) signaling pathway.Methods The cases were randomly divided into four groups,including control group,paclitaxel low-dose group (0.25 μmol/L),paclitaxel medium-dose group (0.5 μmol/L),and paclitaxel high-dose group (1 μmol/L).The viability of MCF-7 cells was measured with methyl thiazolyl tetrazolium (MTT) assay.MCF-7 cell cycle was examined with flow cytometry.MCF-7 cell migration was tested with transwell migration assay.The levels of mTOR signalling pathway-related protein were assayed with Western blot.Results Compared to the control group,MCF-7 cell viability was significantly decreased in paclitaxel low,medium and high-dose groups (P ＜ 0.05),and the inhibitory rate was highest at 48 h (P ＜ 0.05).MCF-7 cell migration was significantly inhibited in paclitaxel low,medium and high-dose groups [(98 ± 9.78) vs (86.21 ± 6.58),(53.41 ± 3.16) and (42.00 ± 4.69),P ＜ 0.05].Moreover,compared to the control group,the number of MCF-7 cells at G1 phase was significantly increased in paclitaxel low,medium and high-dose groups [(52.14±6.13)％ vs (67.93 ±8.16)％,(72.32 ±3.67)％ and (78.53 ± 6.28)％,P ＜ 0.01],the number of MCF-7 cells at G2 phase was significantly reduced in paclitaxel low,medium and high-dose group [(13.68 ± 0.85) ％ vs (8.57 ± 1.03) ％,(5.30 ± 0.89) ％ and (3.46 ± 0.78) ％,P ＜0.01].The phosphorylations of 4E binding protein (4EBP1) and mTOR proteins as well as the expressions of cell-cycle protein D1 (Cyclin D1) and matrix metalloproteinase-9 (MMP-9) were significantly inhibited in paclitaxel low,medium and high-dose groups (P ＜ 0.01).Conclusions These results suggested paclitaxel could inhibit proliferation and migration in breast cancer MCF-7 cells,which might be related to mTOR signal pathway.