Induction of cytochrome P450IA1 gene expression in rat epidermis and human keratinocytes by. beta. -napthoflavone and benzanthracene
Imran Khan, Hasan Mukhtar, David R. Bickers, Tariq M. Haqqi · FASEB Journal (Federation of American Societies for Experimental Biology); (United States) · 1991
Cytochrome P450IA1 (P450IA1) plays a major role in the bioactivation of procarcinogens in various tissues including skin. However, factors controlling the expression of P450IA1 gene message in mammalian skin are unknown. In this study, the polymerase chain reaction (PCR) using specific primers was employed to study the expression of P450IA1 mRNA transcripts in rat epidermis and human keratinocytes (HK) treated with {beta}-napthoflavone ({beta}NF) and benzanthracene (BA). Total RNA was extracted from the epidermis of control and inducer-treated 4-day-old and adult Sprague Dawley rats, and from control and inducer-treated HL. cDNAs were synthesized using random primers and reverse transcriptase. PCR products were analyzed on agarose gel and quantitated by densitometry. Inducer treatment of rats and HK resulted in several-fold increases in aryl hydrocarbon hydroxylase (AHH) activity. The level of P450IA1 gene message increased 2-5-fold in treated animals as compared to controls; higher basal level and inducibility in adult than in 4-day-old rats. This induction occurred as early as 4 h after {beta}NF application, reached a maximum at 16 h and returned to basal levels by 36 h. Exposure to {beta}NF and BA resulted in 2-3-fold increase in gene message in HK. Northern blot analysis complemented PCR data. These results indicate thatmore » in mammalian skin P450IA1 gene expression is increased by the inducers of epidermal AHH activity.« less