title: Anticarcinogenic effect of FTY720 in human prostate carcinoma DU145 cells: modulation of mitogenic signaling, FAK, cell-cycle entry and apoptosis.
abstract: Despite the high frequency of prostate cancer, therapeutic options for advanced disease are limited to chemotherapy, radiation or hormonal therapy and eventually fail in all patients. Therefore, alternative approaches need to be developed. We previously reported that FTY720, a metabolite from Isaria sinclarii, is a unique antitumor agent for an androgen-independent prostate cancer cell line and requires caspase-3 activation in apoptosis. In our study, we have evaluated the effect of FTY720 on a family of mitogen-activated protein kinases (MAPKs), focal adhesion kinase (FAK), mitochondrial transmembrane potential, caspase-9 and caspase-8 and analyzed the expression of some cell-cycle regulator proteins in DU145 cells in order to understand the various antitumor effects of FTY720. Apoptosis was quantified by phosphatidylserine exposure. Activation of MAPKs, cleavage of caspase-9 and caspase-8, status of cyclin-dependent kinases (CDKs) and Cip1/p21, a cyclin-dependent kinase inhibitor, were evaluated by Western blot analysis, in addition to FAK and phospho-FAK immunoprecipitation and cell-cycle analysis by FACScan. We found that in DU145 cells, 40 microM FTY720 caused activation of p38 MAPK and the upstream kinase MKK3/MKK6 but not SAPK/JNK. Mitochondrial transmembrane potential, FAK and ERK1/2 were reduced while caspase-9 and caspase-8 were cleaved. The p38-specific inhibitor had no effect on apoptosis induced by FTY720, whereas z-VAD.FMK, a broad-spectrum caspase inhibitor, did not inhibit the p38 MAPK activation. An amount of 20 microM FTY720 resulted in G(1) arrest and a decrease of CDK2 as well as CDK4, whereas it induced Cip1/p21. FTY720 may exert anticarcinogenic effects against prostate cancer cells possibly involving modulation of mitogenic signaling, cell-cycle regulators, induction of G(1) arrest and apoptotic death in DU145 cells.
authors.affiliation: Department of Urology, Osaka University Medical School, Suita-city, Osaka, Japan.
authors.forename: Sompol
authors.initials: S
authors.lastname: Permpongkosol
authors.forename: Jing-Ding
authors.initials: JD
authors.lastname: Wang
authors.forename: Shiro
authors.initials: S
authors.lastname: Takahara
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Matsumiya
authors.forename: Norio
authors.initials: N
authors.lastname: Nonomura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nishimura
authors.forename: Akira
authors.initials: A
authors.lastname: Tsujimura
authors.forename: Apichat
authors.initials: A
authors.lastname: Kongkanand
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okuyama
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D017209:Apoptosis; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000068876:Fingolimod Hydrochloride; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D007700:Kinetics; D048371:MAP Kinase Kinase 3; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology; D011409:Propylene Glycols / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D061945:Caspase Inhibitors; D018797:Cell Cycle Proteins; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D008934:Mitogens; D011409:Propylene Glycols; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048371:MAP Kinase Kinase 3; C482530:MAP2K3 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D020169:Caspases; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine