PS2 EXPRESSION INDUCED BY AMERICAN GINSENG IN MCF-7 BREAST-CANCER CELLS

Background: Alternative medicines are frequently used by patients with breast cancer for general health benefits. American ginseng, an herba l remedy, purportedly alleviates treatment-induced postmenopausal symp toms. Methods: Estrogenic potential of American ginseng root extract t o induce the expression of pS2, an estrogen-regulated gene, was evalua ted in breast cancer cell lines MCF-7, T-47D, and BT-20 by Northern an d Western blot analysis. Competitive studies were performed with ginse ng in combination with tamoxifen. Cell proliferation assays were perfo rmed using the tetrazolium dye procedure and direct cell count. Result s: Ginseng and estradiol induce the expression of pS2 RNA and protein in MCF-7 cells, whereas tamoxifen suppresses expression. Neither ginse ng nor estradiol induced increased pS2 expression in T-47D or BT-20 ce ll lines. Although estradiol exhibited a proliferative effect and tamo xifen had an inhibitory effect, ginseng demonstrated no significant ef fect on cell proliferation. Conclusions: The results of this study sug gest that ginseng may exhibit estrogenlike effects on estrogen recepto r-positive breast cancer cells by inducing pS2 expression and that the effect of ginseng may be mediated in part through the estrogen recept or. Because ginseng does not exhibit a proliferative effect, it may pl ay a protective role against breast cancer rather than serve as a mito gen.