Effect of leptin on proliferation and apoptosis of human breast cancer cell MCF-7

Abstract

Objective To observe the effect of leptin on proliferation and apoptosis of breast cancer MCF-7 cell line,and to explore the effect of leptin on occurrence and development of breast cancer.Method The MCF-7 cell line was treated with different concentration of leptin in vitro.Cell proliferation was evaluated by MTT assay. Distribution of cell cycle was determined by flow cytomery, meanwhile the rates of apoptosis were estimated on the basis of Annexin V-FITC/PI apoptosis detection. Results When treated with different concentration of leptin for 24 h, 48 h and 72 h, they could significantly induce the proliferation of MCF-7 cells by MTT method.There was not interaction between concentration of leptin and time course (F=0.919,P=0.523).The main effect of concentration of leptin and time course was statistically significant (F=12.699,P=0.000;F=647.881, P=0.000). Compared 200 ng/ml and 400 ng/ml with the control group, we found the difference was statistically significant by multiple comparison (P=0.007,P=0.000,respectively).The difference was also statistically significant among time course by multiple comparison (P=0.000,respectively).By the flow cytometry analysis,it was found that the 100 ng/ml and 400 ng/ml leptin groups could change the distribution of cell cycle of MCF-7 cell line after 48 h. Compared with control group, the cell number decreased by 14.42 ％ in G0/G1 phase (F=10.464, P=0.044),but increased by 7.57 ％ and 22.19 ％ respectively in S phase (F=47.361,P=0.005).The difference was not statistically significant in G2/M phase (F=1.77, P=0.311).However, the effect of apoptosis inhibition was not obvious. Conclusions Leptin could stimulate the proliferation of MCF-7 cell line and change the distribution of cell cycle.But leptin could not inhibit apoptosis of MCF-7 cell line.It suggested that leptin may serve as a risk factor of breast cancer development. Key words: Breast neoplasms; Leptin; Cell proliferation; Apoptosis