A Bacterial Metabolite, Compound K, Induces Programmed Necrosis in MCF-7 Cells via GSK3beta
Ginsenosides, the major active component of ginseng, are traditionally used to treat various diseases, including cancer, inflammation, and obesity. Among these, compound K (CK), an intestinal bacterial metabolite of the ginsenosides Rb1, Rb2, and Rc from Bacteroides JY-6, is reported to inhibit cancer cell growth by inducing cell-cycle arrest or cell death, including apoptosis and necrosis. However, the precise effect of CK on breast cancer cells remains unclear. MCF-7 cells were treated with CK (0-70 micrometer) for 24 or 48 h. Cell proliferation and death were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Changes in downstream signaling molecules involved in cell death, including glycogen synthase kinase 3beta (GSK3beta), GSK3beta, beta-catenin, and cyclin D1, were analyzed by western blot assay. To block GSK3beta signaling, MCF-7 cells were pretreated with GSK3beta inhibitors 1 h prior to CK treatment. Cell death and the expression of beta-catenin and cyclin D1 were then examined. CK dose- and time-dependently inhibited MCF-7 cell proliferation. Interestingly, CK induced programmed necrosis, but not apoptosis, via the GSK3beta signaling pathway in MCF-7 cells. CK inhibited GSK3beta phosphorylation, thereby suppressing the expression of beta-catenin and cyclin D1. Our results suggest that CK induces programmed necrosis in MCF-7 breast cancer cells via the GSK3beta signaling pathway.
|ISBN||1738-8872 (Electronic) 1017-7825 (Linking)|
|Authors||Kwak, C. W.; Son, Y. M.; Gu, M. J.; Kim, G.; Lee, I. K.; Kye, Y. C.; Kim, H. W.; Song, K. D.; Chu, H.; Park, B. C.; Lee, H. K.; Yang, D. C.; Sprent, J.; Yun, C. H.;|
|Responsible Garvan Author|
|Publisher Name||JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/pubmed/26032359|
|OpenAccess link to author's accepted manuscript version||https://publications.gimr.garvan.org.au/open-access/13208|