title: Differential effect of retinoic acid on growth regulation by phorbol ester in human cancer cell lines.
abstract: Phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and all-trans-retinoic acid (trans-RA) are potent regulators of growth of cancer cells. In this study, we investigated the effect of TPA and trans-RA alone or their combination on proliferation of human breast cancer ZR75-1 and T47D and lung cancer H460 and H292 cell lines. trans-RA caused various degrees of growth inhibition of these cell lines. However, TPA showed inhibition of proliferation of H460 and H292 cells and induction of ZR75-1 cell growth. Although trans-RA did not significantly regulate the growth inhibitory effect of TPA, it completely prevented its growth stimulating function. The divergent effects of TPA were associated with specific disruption of cell cycle events, an induction of G(0)/G(1) arrest in H460 and H292 cells and inhibition of G(0)/G(1) arrest with increase of S phase in ZR75-1 cells. Induction of G(0)/G(1) arrest was accompanied by induction of p21(WAF1) and ERK activity, whereas inhibition of G(0)/G(1) arrest was associated with enhanced activity of JNK and AP-1 but not ERK. trans-RA did not affect TPA-induced p21(WAF1) expression. However, it inhibited TPA-induced AP-1 activity in ZR75-1 cells and the constitutive AP-1 activity in H460 and H292 cells. Thus, trans-RA modulates TPA activity through its interaction through TPA-induced JNK/AP-1 pathway but not TPA-induced ERK/p21(WAF1) pathway.
authors.affiliation: The Burnham Institute, Cancer Research Center, La Jolla, California 92037, USA.
authors.forename: A
authors.initials: A
authors.lastname: Agadir
authors.forename: G q
authors.initials: Gq
authors.lastname: Chen
authors.forename: F
authors.initials: F
authors.lastname: Bost
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: D
authors.initials: D
authors.lastname: Mercola
authors.forename: X
authors.initials: X
authors.lastname: Zhang
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D008175:Lung Neoplasms / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D018808:Transcription Factor AP-1; D014212:Tretinoin; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D013755:Tetradecanoylphorbol Acetate