Antitumor Activity of JS-K [O2-(2,4-Dinitrophenyl) 1-[(4-Ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate] and Related O2-Aryl Diazeniumdiolates in Vitro and in Vivo

Abstract

The literature provides evidence that metabolic nitric oxide (NO) release mediates the cytotoxic activities (against human leukemia and prostate cancer xenografts in mice) of JS-K, a compound of structure R₂N−N(O)NO−Ar for which R₂N is 4-(ethoxycarbonyl)piperazin-1-yl and Ar is 2,4-dinitrophenyl. Here we present comparative data on the potencies of JS-K and 41 other O²-arylated diazeniumdiolates as inhibitors of HL-60 human leukemia cell proliferation, as well as in the NCI 51-cell-line screen for six of them. The data show JS-K to be the most potent of the 42 in both screens and suggest that other features of its structure and metabolism besides NO release may contribute importantly to its activity. Results with control compounds implicate JS-K's arylating ability, and the surprisingly low IC₅₀ value of the N-(ethoxycarbonyl)piperazine byproduct of NO release suggests a role for the R₂N moiety. In addition to the above-mentioned in vivo activities, JS-K is shown here to be carcinostatic in a rat liver cancer model.