Suppression of sodium arsenite-potentiated cytotoxicity of ultraviolet light by cycloheximide in Chinese hamster ovary cells.
Post-treatment with sodium arsenite synergistically increased the cytotoxicity of ultraviolet (UV) light. The potentiation of UV cytotoxicity by sodium arsenite was apparently suppressed by cycloheximide (CHM), a protein synthesis inhibitor. The protective effect of CHM against sodium arsenite-potentiated UV cytotoxicity was well correlated to its activity in inhibiting the synthesis of stress proteins, particularly a small polypeptide with a molecular weight of 8500 dalton. This small stress protein was demonstrated as ubiquitin by immunoprecipitation. Our results also showed that neither ubiquitin induction nor potentiation of UV cytotoxicity by post-treatment with sodium arsenite was observed in the stationary cells. Thus, we suggested that ubiquitin is possibly involved in the action of arsenite in potentiating UV-induced cell killing.
Lee
T C
TC
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China.
Kao
S L
SL
Yih
L H
LH
D000818:Animals; D001151:Arsenic / Q000633:toxicity*; D018053:Arsenites; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002869:Chromosome Aberrations; D006224:Cricetinae; D003513:Cycloheximide / Q000494:pharmacology*; D004260:DNA Repair; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D017670:Sodium Compounds; D014466:Ultraviolet Rays / Q000009:adverse effects*
D018053:Arsenites; D006360:Heat-Shock Proteins; D017670:Sodium Compounds; C017947:sodium arsenite; D003513:Cycloheximide; D001151:Arsenic