title: Inhibition of cell growth and induction of G1-phase cell cycle arrest in hepatoma cells by steroid extract from Meretrix meretrix.
abstract: In this study, we report that the steroid extract 5alpha, 8alpha-epidioxycholest-6-ene-3beta-ol (MME) from Meretrix meretrix has the ability to inhibit growth of hepatoma cells and to induce G1-phase cell cycle arrest in two human hepatoma cell lines, HepG2 and Hep3B. HepG2 cells were more sensitive than Hep3B to MME. The extract markedly up-regulated the expression of p53 and p21WAF1/CIP1 in HepG2, suggesting that MME-induced G1 phase cell cycle arrest in HepG2 might be p53-dependent. Therefore, the up-regulation of p27KIP1and p16INK4A in both cell lines indicates that a p53-independent pathway might be involved in the mechanism of MME inducing cell cycle arrest. In conclusion, MME induces G1 phase cell cycle arrest via both p53-dependent and p53-independent pathways.
authors.affiliation: Laboratory of Marine Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Ting-He
authors.initials: TH
authors.lastname: Wu
authors.forename: Ruo-Lin
authors.initials: RL
authors.lastname: Yang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Xie
authors.forename: Hong-Zhong
authors.initials: HZ
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Shuyi
authors.initials: S
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Rong-Qing
authors.initials: RQ
authors.lastname: Zhang
mesh_terms: D049872:Bivalvia / Q000737:chemistry*; D006528:Carcinoma, Hepatocellular / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000032:analysis; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000032:analysis; D016193:G1 Phase / Q000187:drug effects*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis; D008113:Liver Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology; D013256:Steroids / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D019014:fas Receptor / Q000032:analysis
chemical_list: C493956:CDKN1A protein, human; C436291:CDKN1B protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D047908:Intracellular Signaling Peptides and Proteins; D013256:Steroids; D016159:Tumor Suppressor Protein p53; D019014:fas Receptor; D050760:Cyclin-Dependent Kinase Inhibitor p27