Additive effects of medroxyprogesterone acetate and 5-fluorouracil derivative on 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors

Abstract

Chronic oral administration of 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil suppressed thymidylate synthetase (TS) gene expression followed by reduction of TS activity in rat mammary tumors induced with 7,12-dimethylbenz[a]anthracene. Addition of medroxyprogesterone acetate (MPA) to the anticancer drug caused an additional decrease in TS and thymidine kinase activities in the tumor growth and restoration of bone loss. These results suggest that the simultaneous administration of MPA and anticancer drugs causes increased inhibition of mammary tumor growth and also diminishes the bone loss.