Enhanced killing effects of caffein post-treatment in ultraviolet-light irradiated mouse lymphoma cells: is cAMP a mediator of the effects?
Effects of post-treatment with caffein, cyclic adenosine 3':5'-monophosphate (cAMP) and N6, O2-dibutyryl cAMP (dbcAMP) were investigated in ultraviolet light (UV)-irradiated mouse lymphoma L5178Y cells. Under conditions where UV or each chemical alone caused only slight cytotoxic effects, caffein post-treatment showed clear synergistic effects in cell killing but not for cAMP or dbcAMP. Subsequently, a mutant clone resistant to cAMP was isolated. This mutant was supposed to be deficient in cAMP-mediated cellular functions. Using the mutant cells, it was found that these cells were also sensitive to caffein post-treatment as wild cells after UV-irradiation. The results imply that the enhanced killing effects by caffein post-treatment in UV irradiated cells is not mediated by cAMP.
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology / Q000502:physiology; D002110:Caffeine / Q000008:administration & dosage / Q000633:toxicity*; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured; D002999:Clone Cells; D000242:Cyclic AMP / Q000494:pharmacology / Q000502:physiology*; D007940:Leukemia L5178 / Q000473:pathology; D051379:Mice; D009154:Mutation; D014411:Neoplastic Stem Cells / Q000528:radiation effects; D011836:Radiation Tolerance; D014466:Ultraviolet Rays
D002110:Caffeine; D003994:Bucladesine; D000242:Cyclic AMP