ABSTRACT
Structural analogues of JS-K, an anti-cancer lead compound, were prepared and their in vitro anti-leukemic activity was determined. The rate of nitric oxide release from the corresponding diazeniumdiolate anions did not appear to affect the anti-leukemic activity of the prodrug forms. Two compounds with potent inhibitory activity and a potentially favorable toxicological profile were identified.
Subject(s)
Antineoplastic Agents , Azo Compounds , Glutathione Transferase/metabolism , Piperazines , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Azo Compounds/chemical synthesis , Azo Compounds/chemistry , Azo Compounds/pharmacology , Combinatorial Chemistry Techniques , Glutathione/metabolism , HL-60 Cells , Humans , Leukemia/metabolism , Models, Molecular , Molecular Structure , Nitric Oxide Donors/chemistry , Nitric Oxide Donors/pharmacology , Piperazines/chemical synthesis , Piperazines/chemistry , Piperazines/pharmacology , Prodrugs/pharmacologyABSTRACT
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 R(2)N-N(O)=NO-Ar for which R(2)N 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 O(2)-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 IC(50) value of the N-(ethoxycarbonyl)piperazine byproduct of NO release suggests a role for the R(2)N moiety. In addition to the above-mentioned in vivo activities, JS-K is shown here to be carcinostatic in a rat liver cancer model.
Subject(s)
Antineoplastic Agents/chemical synthesis , Azo Compounds/chemical synthesis , Piperazines/chemical synthesis , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Azo Compounds/chemistry , Azo Compounds/pharmacology , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Liver Neoplasms, Experimental/drug therapy , Liver Neoplasms, Experimental/pathology , Male , Neoplasm Transplantation , Piperazines/chemistry , Piperazines/pharmacology , Rats , Rats, Inbred F344 , Transplantation, HeterologousABSTRACT
Nitric oxide (NO) induces differentiation and apoptosis in acute myelogenous leukemia (AML) cells. The NO prodrug O2-(2,4-dinitrophenyl)1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate, or JS-K, has potent antileukemic activity. JS-K induces apoptosis in HL-60 cells by a caspase-dependent mechanism. The purpose of this study was to determine the pathway through which JS-K induces apoptosis. We show that JS-K alters mitochondrial membrane potential (DeltaPsim) and induces cytochrome c release from mitochondria into the cytoplasm. Treatment with JS-K resulted in activation of Caspase (Casp) 9, Casp 3 and Casp 8. JS-K constitutes a promising lead for a new class of anti-leukemic agents.
Subject(s)
Apoptosis/drug effects , Azo Compounds/pharmacology , Caspases/metabolism , Nitric Oxide Donors/pharmacology , Piperazines/pharmacology , Cytochromes c/analysis , HL-60 Cells , Humans , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mitochondrial Membranes/drug effects , Mitochondrial Membranes/physiologyABSTRACT
Intracellular calcium [Ca(2+)](i) is mobilized in many cell types in response to activation of phosphoinositide (PIP(n)) signaling pathways involving PtdIns(4,5)P(2) or PtdIns(3,4,5)P(3). To further explore the relationship between increases in intracellular PIP(n) concentrations and mobilization of [Ca(2+)](i), each of the seven phosphorylated phosphoinositides (PIP(n)s) were delivered into cells and the metabolism and physiological effects of the exogenously administered PIP(n)s were determined. The efficient cellular delivery of fluorophore-tagged and native PIP(n)s was accomplished using histone protein, neomycin, and dendrimeric polyamines. PtdIns(4,5)P(2) fluorophore-tagged analogs with short- and long-acyl chains were substrates for cellular enzymes in vitro and for phospholipases in stimulated fibroblasts. PtdIns(4)P, PtdIns(3,4)P(2) and PtdIns(4,5)P(2), each induced calcium mobilization rapidly after exogenous addition to fibroblasts. PtdIns(3,4,5)P(3) induced a significant, but smaller increase in intracellular calcium. These observations suggest that PIP(n)s other than PtdIns(4,5)P(2) or PtdIns(3,4,5)P(3) may have direct roles in signaling involving [Ca(2+)](i).
