title: Inhibition of UVB-induced nonmelanoma skin cancer: a path from tea to caffeine to exercise to decreased tissue fat.
abstract: Oral administration of green tea, black tea, or caffeine (but not the decaffeinated teas) inhibited ultraviolet B radiation (UVB)-induced skin carcinogenesis in SKH-1 mice. Studies with caffeine indicated that its inhibitory effect on the ATR/Chk1 pathway is an important mechanism for caffeine's inhibition of UVB-induced carcinogenesis. The regular teas or caffeine increased locomotor activity and decreased tissue fat. In these studies, decreased dermal fat thickness was associated with a decrease in the number of tumors per mouse. Administration of caffeine, voluntary exercise, and removal of the parametrial fat pads all stimulated UVB-induced apoptosis, inhibited UVB-induced carcinogenesis, and stimulated apoptosis in UVB-induced tumors. These results suggest that caffeine administration, voluntary exercise, and removal of the parametrial fat pads inhibit UVB-induced carcinogenesis by stimulating UVB-induced apoptosis and by enhancing apoptosis in DNA-damaged precancer cells and in cancer cells. We hypothesize that tissue fat secretes antiapoptotic adipokines that have a tumor promoting effect.
authors: Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, NJ 08854, USA. aconney@pharmacy.rutgers.edu
authors: Allan H
authors: AH
authors: Conney
authors: You-Rong
authors: YR
authors: Lou
authors: Paul
authors: P
authors: Nghiem
authors: Jamie J
authors: JJ
authors: Bernard
authors: George C
authors: GC
authors: Wagner
authors: Yao-Ping
authors: YP
authors: Lu
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects*; D000284:Administration, Oral; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D009381:Neoplasms, Radiation-Induced / Q000473:pathology / Q000517:prevention & control*; D010805:Physical Conditioning, Animal; D012878:Skin Neoplasms / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D013662:Tea; D014466:Ultraviolet Rays
chemical_list: D013662:Tea; D002110:Caffeine