title: A novel MEK1/2 inhibitor induces G1/S cell cycle arrest in human fibrosarcoma cells.
abstract: Blockade of the ERK pathway has antitumor effects against malignant tumor cells. In this study, we investigated the antitumor activity of JTP-70902, a novel specific MEK inhibitor, against human fibrosarcoma cells in which the ERK pathway is constitutively activated. JTP-70902 was synthesized at Japan Tabacco. Human fibrosarcoma HT1080 cells were cultured. JTP-70902 was added at various concentrations. The number of viable cells was counted employing a trypan blue dye exclusion test. Unsynchronized cells were exposed to JTP-70902 for 24 h. The nuclei were stained with propidium iodide. The DNA content was measured using a FACSCalibur flow cytometer. Protein extraction and Western blot analysis were performed. (1) A dose-dependent inhibition of cell growth was observed at concentrations of 10 nM or more. Forty-eight hours after the treatment, the growth of HT1080 cells was completely inhibited by 200 nM JTP-70902. (2) FACS analysis revealed that a 24-h exposure to JTP-70902 increased the population of G1/S phase cells in a dose-dependent manner. (3) The phosphorylation of ERK was inhibited by JTP-70902. Furthermore, after the treatment with JTP-70902, p21WAF1/CIP1 and p27KIP1 protein expression increased and the phosphorylation of RB was reduced. Our results showed that JTP-70902 inhibits cell growth and induces cell cycle arrest in human Ras mutant fibrosarcoma cells. These results indicate that JTP-70902 might be an attractive compound for molecular-targeting chemotherapy for malignant soft tissue tumors with the activation of the Ras-MEK-ERK pathway.
authors.affiliation: Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Matsui
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Murata
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sowa
authors.forename: Tomoya
authors.initials: T
authors.lastname: Sakabe
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Koto
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Horie
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Tsuji
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sakai
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kubo
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D005354:Fibrosarcoma / Q000473:pathology*; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors*; D048370:MAP Kinase Kinase 2 / Q000037:antagonists & inhibitors*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011744:Pyrimidinones / Q000494:pharmacology; D016196:S Phase / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D047428:Protein Kinase Inhibitors; D011744:Pyrimidinones; D013449:Sulfonamides; D050760:Cyclin-Dependent Kinase Inhibitor p27; C482128:MAP2K2 protein, human; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; C553329:N-(3-(5-(4-bromo-2-fluorophenylamino)-3-cyclopropyl-8-methyl-2,4,7-trioxo-3,4,7,8-tetrahydro-2H-pyrido(2,3-d)pyrimidin-1-yl)phenyl)methanesulfonamide