Whey acidic protein inhibits mammary cancer cellk proliferation via cell cycle arrest. - GreenMedInfo Summary
Whey acidic protein (WAP) depresses the proliferation of mouse (MMT) and human (MCF-7) mammary tumor cells.
J Reprod Dev. 2005 Oct;51(5):649-56. Epub 2005 Jul 27. PMID: 16046839
Laboratory of Applied Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan. firstname.lastname@example.org
We previously reported that the enforced expression of exogenous whey acidic protein (WAP) significantly inhibited the proliferation of mouse mammary epithelial cells (HC11 and EpH4/H6 cells). This paper presents the first evidence that WAP also depresses the proliferation of mammary tumor cells from mouse (MMT cells) and human (MCF-7 cells). We established WAP-clonal MMT and MCF-7 cell lines, and confirmed the secretion of WAP from the WAP-clonal cells into culture medium. The enforced expression of WAP significantly inhibited the proliferation of MMT and MCF-7 cells in in vitro culture. FACScan analyses revealed that G0/G1 phase cell-cycle progression was disordered and elongated in the WAP-clonal MMT and MCF-7 cells compared to that of the control cells. The expression of cyclin D1 was significantly decreased in the WAP-clonal MMT and MCF-7 cells, suggesting that progression from the G1 to the S phase was delayed in the WAP-clonal cells. The present results indicate that WAP plays a negative regulatory role in the cell-cycle progression of mammary tumor cells via a paracrine mechanism.