Epirubicin inhibits proliferation of breast cancer cells through upregulating p 21 cip 1 expression

Increasing evidence suggested that epirubicin possess antitumor effect, and could be used in cancer chemotherapy. However, the role of epirubicin in breast cancer remains unclear. Therefore, in this context, the present study investigated the effects of epirubicin on breast cancer cell lines (MCF-7 and T47D) proliferation, apoptosis, as well as the underlying mechanism. Our results showed that epirubicin inhibited the proliferation of both MCF-7 and T47D breast cancer cells, with timeand concentration-dependent manners. Specifically, we observed that MCF-7cell lines treatment with epirubicin had an obvious cell-cycle arrest at the G0/G1 phase (P < 0.01), although it has no effect on apoptosis. Furthermore, we investigated the effect of epirubicin on p21cip1 expressionin MCF-7 and T47D cells, and found that epirubicin increased the expression of p21cip1 at both mRNA and protein levels. Moreover, we demonstrated that knockdown of p21cip1 significantly reversed epirubicin-inhibited cell proliferation in breast cancer cells, as compared with the control group, and also reversed epirubicin-inhibited cell cycle arrest the G0/G1 phase in breast cancer cell lines. Taken together, it is, therefore, concluded that epirubicin inhibits proliferation of breast cancer cells through upregulating p21cip1 expression. Therefore, epirubicin may represent a chemopreventive and/or therapeutic agent in the prevention of breast cancer. However, further more studies need to be carried out to verify this point.