Phellinus linteus inhibits growth and invasive behavior of breast cancer cells through the suppression of Akt signaling.

Abstract

Cancer growth and metastasis are tightly controlled processes involving cell proliferation, formation of cancer colonies, cell adhesion, cell migration and cell invasion. Experimental studies demonstrated that certain nutrients inhibit signaling pathways responsible for the proliferation of cancer cells and could prevent against cancer metastasis. Mushroom and mushroom extracts are widely used for the promotion of health and/or as alternative therapies. However, the molecular mechanism(s) of their actions in vitro is usually elusive. Phellinus linteus is an Asian medicinal mushroom (Meshimakobu in Japan, Sang-hwang in Korea), which has been used for millennia for the treatment of various diseases including cancer. In the present study we evaluated the effects of extract from P. linteus on the growth and invasive behavior of highly metastatic breast cancer cells. Here, we show that P. linteus inhibits cell proliferation and colony formation of MDA-MB-231 cells. P. linteus also suppresses cell adhesion, migration and invasion. These biological effects of P. linteus are mediated by the inhibition of phosphorylation of AKT kinase, resulting in the suppression of secretion of urokinase plasminogen activator (uPA) and down-regulation of expression of alpha-v integrin. In summary, our results suggest that P. linteus inhibits growth and invasive behavior of breast cancer cells by modulating AKT signaling.