MONDAY, Mar. 2 (HealthDay News) -- Caffeine causes skin cells damaged by ultraviolet light to self-destruct by blocking a cellular pathway involved in regulating the cell cycle, which may explain why tea and coffee consumption is associated with lower rates of non-melanoma skin cancer, according to the results of a study published online Feb. 26 in the Journal of Investigative Dermatology.
Timothy P. Heffernan, Ph.D., from Harvard Medical School in Boston, and colleagues investigated which of the known effects of caffeine might explain the lower rates of skin cancer associated with tea and coffee consumption after treating human keratinocytes with caffeine and ultraviolet-B light.
The investigators found that blocking expression of the ataxia-telangiectasia and Rad3-related (ATR) gene doubled apoptosis, but only in cells treated with ultraviolet light. Caffeine had no additional effect on apoptosis if ATR was depleted. Inhibiting a target of ATR, checkpoint kinase 1 (Chk1), using an inhibitor or by blocking its expression also increased apoptosis induced by ultraviolet radiation, the researchers report.
"These data suggest that topical application of caffeine or another ATR-Chk1 pathway inhibitor, perhaps in a sunscreen or after-sun preparation, could be investigated as an approach to minimize or reverse the effects of ultraviolet damage in human skin," Heffernan and colleagues conclude.
Two co-authors are employed by Pfizer and Cylene Pharmaceuticals.
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