title: PKCdelta and MAPK mediate G(1) arrest induced by PMA in SKBR-3 breast cancer cells.
abstract: The effects of activating endogenous protein kinase C (PKC) on cell proliferation and the cell cycle were investigated by treating the breast cancer cell line SKBR-3 with phorbol 12-myristate 13 acetate (PMA). This inhibited cell growth in a concentration-dependent manner, causing a marked arrest of cells in G(1). Pre-treatment with GF109203X completely blocked the antiproliferative effect of PMA, and pre-treatment with the PKCdelta inhibitor rottlerin partially blocked it. Infecting SKBR-3 cells with an adenovirus vector containing wild-type PKCdelta, WTPKCdeltaAdV, had similar effects on PMA. Infecting the cells with a dominant-negative PKCdeltaAdV construct blocked the growth inhibition induced by PMA. Downstream of PKC, PMA treatment inhibited extracellular signal-regulated kinase mitogen-activated protein kinase phosphorylation, up-regulated c-jun NH(2)-terminal kinase phosphorylation, and inhibited retinoblastoma (Rb) phosphorylation. These results strongly implicated PKC (mainly PKCdelta) in the G(1) arrest induced by PMA and suggested PKC as a target for breast cancer treatment.
authors.affiliation: Department of Surgery, Kurume University School of Medicine, 67 Asahimachi, Fukuoka 830-0011, Japan.
authors.forename: Goro
authors.initials: G
authors.lastname: Yokoyama
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Fujii
authors.forename: Kosuke
authors.initials: K
authors.lastname: Tayama
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamana
authors.forename: Michihiko
authors.initials: M
authors.lastname: Kuwano
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shirouzu
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005260:Female; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D051745:Protein Kinase C-delta; D012175:Retinoblastoma / Q000188:drug therapy / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D013755:Tetradecanoylphorbol Acetate