High expression of cytochrome P450 2a-5 (coumarin 7-hydroxylase) in mouse hepatomas.
A high level of Cyp2a-5 was found in spontaneous and transplanted mouse hepatomas compared with normal liver. Increased expression of Cyp2a-5 was associated with an increase in coumarin 7-hydroxylation, a marker activity of Cyp2a-5, and the corresponding mRNA, suggesting that regulation of Cyp2a-5 in hepatomas is pretranslational. In contrast, the total P450 content and arylhydrocarbon hydroxylase and amidopyrene demethylase activities decreased. Pyrazole, a strong inducer of Cyp2a-5 in normal mouse livers, also increases this isozyme in hepatomas. A parallel increase in the corresponding mRNA suggests that pyrazole, like the formation of hepatomas, affects the regulation of Cyp2a-5 pretranslationally.
Kobliakov
V
V
Institute of Carcinogenesis of Cancer Research Center, Moscow, Russia.
Kulikova
L
L
Samoilov
D
D
Lang
M A
MA
D000633:Aminopyrine N-Demethylase / Q000378:metabolism; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D015153:Blotting, Western; D002251:Carbon Tetrachloride / Q000633:toxicity; D065637:Cytochrome P-450 CYP2A6; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism*; D015870:Gene Expression; D007527:Isoenzymes / Q000096:biosynthesis* / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology*; D051379:Mice; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D011720:Pyrazoles / Q000633:toxicity; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism
D007527:Isoenzymes; D011720:Pyrazoles; D012333:RNA, Messenger; C031280:pyrazole; D003577:Cytochrome P-450 Enzyme System; D002251:Carbon Tetrachloride; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; D065637:Cytochrome P-450 CYP2A6; D000633:Aminopyrine N-Demethylase