[Role of clock proteins in skin carcinogenesis in 14-month-old SHR mice maintained under disrupted light regimen]

Circadian rhythm disturbance promotes of carcinogenesis and is associated with changes in clock genes and proteins expression. In the current study we observed that continu- ous light exposure potentiated skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene and 12-0-tetradecanoylphor- bol-13-acetate while melatonin had opposite effect. Carcinogenic exposure decreased BMAL1 and CRYI- expression in the skin, CLOCK expression was upregulated and CRYl downregulated in tumor compared to normal skin. BMAL1 expression increased under disrupted light regimen; melatonin treatment affected CLOCK expression in tumors and CRYI in skin at the carcinogens application sites.