title: Differential anti-tumor activity of coriolus versicolor (Yunzhi) extract through p53- and/or Bcl-2-dependent apoptotic pathway in human breast cancer cells.
abstract: Coriolus versicolor (CV), also called Yunzhi, has been demonstrated to exert anti-tumor effects on various types of cancer cells, but the underlying mechanism has not been fully elucidated. The present study aimed to evaluate the in vitro anti-tumor activity of a standardized aqueous ethanol extract prepared from CV on four breast cancer cell lines using MTT assay, and test whether the mechanism involves apoptosis induction and modulation of p53 and Bcl-2 protein expressions using cell death detection ELISA, p53 and Bcl-2 ELISAs respectively. Our results demonstrated that the CV extract dose-dependently suppressed the proliferation of three breast tumor cell lines, with ascending order of IC50 values: T-47D, MCF-7, MDA-MB-231, while BT-20 cells were not significantly affected. Tumoricidal activity of the CV extract was found to be comparable to a chemotherapeutic anti-cancer drug, mitomycin C. Nucleosome productions in apoptotic MDA-MB-231, MCF-7 and T-47D cells were significantly augmented in a time-dependent manner and paralleled the anti-proliferative activity of CV extract. Expression of p53 protein was significantly upregulated only in T-47D cells treated with the CV extract in a dose- and time-dependent fashion, but not in MCF-7 (except at 400 mug/ml after 16 h) and MDA-MB-231 cells. The CV extract significantly induced a dose-dependent downregulation of Bcl-2 protein expression in MCF-7 and T-47D cells, but not in MDA-MB-231 cells. These results suggested that apoptosis induction, differentially dependent of p53 and Bcl-2 expressions, might be the possible mechanism of CV extract-mediated cytotoxicity in human breast cancer cells in vitro.
authors.affiliation: School of Pharmacy, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Cheong-Yip
authors.initials: CY
authors.lastname: Ho
authors.forename: Chi-Fai
authors.initials: CF
authors.lastname: Kim
authors.forename: Kwok-Nam
authors.initials: KN
authors.lastname: Leung
authors.forename: Kwok-Pui
authors.initials: KP
authors.lastname: Fung
authors.forename: Tak-Fu
authors.initials: TF
authors.lastname: Tse
authors.forename: Helen
authors.initials: H
authors.lastname: Chan
authors.forename: Clara Bik-San
authors.initials: CB
authors.lastname: Lau
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology; D020072:Polyporales / Q000737:chemistry*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53