Modulation of mitogen-activated protein kinases by 6-nitro-7-hydroxycoumarin mediates apoptosis in renal carcinoma cells.
6-Nitro-7-hydroxycoumarin has previously been shown to be a selective anti-proliferative agent capable of activating p38, stress-activated protein kinase (SAPK) and mitogen-activated protein (MAP) kinase in the human renal cell carcinoma cell line, A-498. Here, the role of p38 MAP kinase was further investigated in relation to its participation in 6-nitro-7-hydroxycoumarin induced apoptosis. 6-Nitro-7-hydroxycoumarin was shown to alter cell cycle progression, leading to the appearance of a sub-G(1) peak, containing hypodiploid DNA, accompanied by increases in both poly(ADP-ribose)polymerase cleavage and decreased expression of cyclin D1. Drug treatment also lead to a rise in the expression in the cyclin-dependent kinase inhibitor, p21(WAF1/CIP1), and the appearance of inter-nucleosomal DNA cleavage and morphological changes, consistent with apoptotic cell death. Using a p38 MAP kinase inhibitor, SB203580, caused expression of p21(WAF1/CIP1) to be suppressed and both cleaved poly(ADP-ribose)polymerase and the numbers of apoptotic cells were decreased. In summary, this study shows the participation of p38 MAP kinase in 6-nitro-7-hydroxycoumarin induced apoptosis of A-498 cells and suggests that targeting of p38 may represent a novel mechanism to inhibit renal cell carcinoma and that coumarin type drugs require further investigation as potential anticancer agents directed against renal cell carcinoma.
Finn
Gregory
G
Department of Applied Science, National Centre for Sensor Research, School of Science, Institute of Technology, Tallaght, Dublin 24, Ireland.
Creaven
Bernadette
B
Egan
Denise
D
D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002292:Carcinoma, Renal Cell / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology*; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D014468:Umbelliferones / Q000494:pharmacology* / Q000627:therapeutic use; D048051:p38 Mitogen-Activated Protein Kinases
D014468:Umbelliferones; C031477:7-hydroxycoumarin; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases