The antagonizing effects of N-acetyl-cysteine on prolactin induced proliferation of human breast cancer cells

Breast cancer is a hormone dependent disease and the role of prolactin in its pathogenesis and progression has been the subject of considerable debate. Thiol antioxidants including N-Acetyl-L-cysteine (NAC) are among the many substances that have been used in experimental and epidemiological studies for cancer prevention. In this study we examined the effects of prolactin (PRL) and NAC on the growth of MCF-7 human breast cancer cells and the influence of NAC on PRL-induced cell proliferation when both substances were added simultaneously to the culture medium. According to our results, NAC alone at concentrations above 4mM caused a gradual decrease in cell proliferation which was statistically significant at concentrations above 6 mM. Prolactin significantly increased cell proliferation and when PRL and NAC were added simultaneously to the culture medium an inhibitory effect on PRL-induced MCF-7 proliferation was observed at concentrations of 5 and 6 mM NAC. The higher the NAC concentration, the greater the reduction was.