title: Purvalanol A, a CDK inhibitor, effectively suppresses Src-mediated transformation by inhibiting both CDKs and c-Src.
abstract: The nonreceptor tyrosine kinase c-Src is frequently over-expressed or hyperactivated in various human cancers and contributes to cancer progression in cooperation with up-regulated growth factor receptors. However, Src-selective anticancer drugs are still in clinical trials. To identify more effective inhibitors of c-Src-mediated cancer progression, we developed a new screening platform using Csk-deficient cells that can be transformed by c-Src. We found that purvalanol A, developed as a CDK inhibitor, potently suppressed the anchorage-independent growth of c-Src-transformed cells, indicating that the activation of CDKs contributes to the c-Src transformation. We also found that purvalanol A suppressed the c-Src activity as effectively as the Src-selective inhibitor PP2, and that it reverted the transformed morphology to a nearly normal shape with less cytotoxicity than PP2. Purvalanol A induced a strong G2-M arrest, whereas PP2 weakly acted on the G1-S transition. Furthermore, when compared with PP2, purvalanol A more effectively suppressed the growth of human colon cancer HT29 and SW480 cells, in which Src family kinases and CDKs are activated. These findings demonstrate that the coordinated inhibition of cell cycle progression and tyrosine kinase signaling by the multi-selective purvalanol A is effective in suppressing cancer progression associated with c-Src up-regulation.
authors.affiliation: Department of Oncogene Research, Research Institute of Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hikita
authors.forename: Chitose
authors.initials: C
authors.lastname: Oneyama
authors.forename: Masato
authors.initials: M
authors.lastname: Okada
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000081247:CSK Tyrosine-Protein Kinase; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D003106:Colon / Q000166:cytology / Q000187:drug effects*; D003110:Colonic Neoplasms; D019073:HT29 Cells / Q000187:drug effects; D006801:Humans; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology; D011687:Purines / Q000494:pharmacology*; D019061:src-Family Kinases
chemical_list: C471843:6-((3-chloro)anilino)-2-(isopropyl-2-hydroxyethylamino)-9-isopropylpurine; D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011687:Purines; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D016203:CDC2 Protein Kinase