Role of Oxidative Stress in Non—genotoxic Carinogenesis with Special Reference to Liver Tumors Induced by Peroxisome Proliferators

Peroxisome proliferators(POPs),such as hypolipidemic drugs or industrial phthalate ester plasticizers,are widely known as non-genotoxic hepatocarcinogens in rodents.As one of the possible mechanisms of POP-induced carcinogenesis,the“Oxidative Stress” theory has bee postulated.In this review,in order to reconsider the significance of “Oxidative Stress”to POP-induced carcinogenesis,we focus on in vivo studies examining formation of 8-hydroxydeoxyguanosine(8-OH-dG),a marker of oxidative DNA damage with mutagenic potential,after treatment of rodents with POPs.Some studies clearly demonstrated that 8-OH-dG levels in the liver DNA were increased by OPO-treatments.Thee findings suggest that“Oxidative Stress could contribute as one factor to POP-induced carcinogenesis.Furthermore,we refer to other multiple biological changes caused by POP-treatment presumably contributing to the carcinogenic mechanisms,and consider possible roles of “Oxidative Stress” in the carcinogenesis process.