title: 6r, a novel oxadiazole analogue of ethacrynic acid, exhibits antitumor activity both in vitro and in vivo by induction of cell apoptosis and S-phase arrest.
abstract: This study investigated the in vitro and in vivo antitumor effects of 5-[2,3-Dichloro-4-(2-methylene-1-oxobutyl) phenoxymethyl]-3-methyl-1,2,4- oxadiazole (6r), a novel ethacrynic acid (EA) derivative. The in vitro effect of 6r on cell proliferation of human colon, leukemia, prostate, lung, breast, ovarian and cervical tumor cell lines was assessed using MTT assay and the in vivo effect was determined with an SW620 xenografts nude mice model. The effect of 6r on expressions of GST P1-1 and apoptosis-related proteins were measured by western blotting and the effect on cell apoptosis was analysed by Hoechst 33258 nuclear staining as well as by cell surface staining of annexin V/propidium iodide. The effect on cell cycle was assessed by flow cytometry. Results showed that 6r inhibit proliferation of a range of human cancer cells in vitro and growth of SW620 tumor xenografts in vivo. The anti-proliferative effect of 6r is associated with cell apoptosis as a result of increased ratio of cellular Bax/bcl-2 expression and subsequent cytochrome-c and caspase-3 activation. Unlike EA, 6r did not show any influence on cellular GST P1-1 expression and its anti-proliferative action was associated with cell cycle arrest in G1/S-phase. In conclusion, 6r has the potential to be developed as a chemotherapeutic agent by induction of cell apoptosis but not regulating GST P1-1.
authors.affiliation: Department of Pharmacology, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Xue
authors.initials: X
authors.lastname: Dong
authors.forename: Ming-Tan
authors.initials: MT
authors.lastname: Tang
authors.forename: Li-Yan
authors.initials: LY
authors.lastname: Gao
authors.forename: Gui-Sen
authors.initials: GS
authors.lastname: Zhao
authors.forename: Lu-Gang
authors.initials: LG
authors.lastname: Yu
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Guo
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D051549:Glutathione S-Transferase pi / Q000235:genetics; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010069:Oxadiazoles / Q000494:pharmacology*; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: C582370:5-(2,3-dichloro-4-(2-methylene-1-oxobutyl)phenoxymethyl)-3-methyl-1,2,4-oxadiazole; D000970:Antineoplastic Agents; D010069:Oxadiazoles; D051549:Glutathione S-Transferase pi