Int J Biol Sci 2019; 15(7):1358-1367. doi:10.7150/ijbs.27360 This issue
Breast Disease Center, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, China
Triple negative breast cancer (TNBC) is a highly aggressive cancer and lack of targeting therapies. It is believed that the breast cancer stem cells (BCSCs) are responsible for the aggressive characteristics of TNBC. Hence, developing BCSC-targeting agents may provide new therapeutic strategies for the patients. Huaier polysaccharide (HP), an active ingredient extracted from the mushroom Trametes robiniophila Murr, has been widely used in clinical anti-cancer treatments in China. Here we demonstrated that HP could target BCSCs in TNBC cells, resulting in decreased mammosphere formation, downregulated expression of stem-related genes and reduced proportion of aldehyde dehydrogenase positive cells in vitro, and inhibited xenograft tumor formation in vivo. Mechanically, HP markedly reduced the expression of estrogen receptor α-36 (ERα-36), a recently identified subtype of estrogen receptor α, and attenuated ERα-36-mediated activation of AKT/β-catenin signaling in ERα-36high TNBC cells. This study provides a new insight into the mechanism of HP on BCSC-targeting therapy and new ideas for comprehensive treatment strategies for TNBC.
Keywords: Huaier, ERα-36, Triple negative breast cancer, Cancer stem cells