title: Isoliquiritigenin inhibits proliferation and induces apoptosis of U87             human glioma cells in vitro.
abstract: Isoliquiritigenin (ISL), a member of the flavonoids, has been demonstrated to possess antitumor activity in various cancer cell lines in vitro and in vivo. In this study, we investigated the antitumor effects of ISL on U87 glioma cells in vitro. As determined by MTT assay, ISL inhibited the proliferation of U87 cells in a time-dependent and dose-dependent manner. The results of fluorescence-activated cell sorting (FACS) analysis suggested that ISL induced the apoptosis of the U87 cells and blocked cell cycle progression at the S and G2/M phases. Moreover, it was identified that ISL induced the apoptosis of the U87 cells in a caspase-dependent manner. Although treatment with the pan-caspase inhibitor Z-VAD-FMK efficiently blocked the ISL-induced caspase activation, it did not eliminate the ISL-induced cell death. Further examination using western blot analysis revealed that ISL upregulated p21/WAF1 and p27. These results indicate that cell cycle arrest and the caspase-mediated apoptosis pathway may participate in the antiproliferative activity of ISL in U87 cells by regulating the expression of specific molecules.
authors.affiliation: Neurosurgery Department, The First Affiliated Hospital of Zhengzhou                     University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: Guo-Sheng
authors.initials: GS
authors.lastname: Zhou
authors.forename: Lai-Jun
authors.initials: LJ
authors.lastname: Song
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000737:chemistry / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D047188:Chalcones / Q000737:chemistry / Q000633:toxicity*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005910:Glioma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D047188:Chalcones; D050759:Cyclin-Dependent Kinase Inhibitor p21; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D050760:Cyclin-Dependent Kinase Inhibitor p27; C040920:isoliquiritigenin; D020169:Caspases