INHIBITION OF BENZOYL PEROXIDE-INDUCED TUMOR PROMOTION AND PROGRESSION BY COPPER(II)(3,5-DIISOPROPYLSALICYLATE)2

The ability of a biomimetic superoxide dismutase agent, copper(II)(3,5 -diisopropylsalicylate)2 CuDIPS), to modulate benzoyl peroxide (BzPo)- induced tumor promotion and progression in mouse skin multistage carci nogenesis was evaluated. The results showed a significant inhibition o f tumor incidence by CuDIPS pretreatment during promotion-progression. Different types of tumors were developed: papillomas, keratoacanthoma s and squamous cell carcinomas. There was a significant increase in th e keratoacanthoma-papilloma ratio when the period of treatment with Bz Po was prolonged, which was inhibited by CuDIPS pretreatment. CuDIPS i nduced a significant inhibition of malignant conversion. Our results s uggest that reactive oxygen species could be important in BzPo-induced promotion and progression.