ABSTRACT
The NADPH oxidases (NOXs) play a recognized role in the development and progression of inflammation-associated disorders, as well as cancer. To date, several NOX inhibitors have been developed, through either high throughput screening or targeted disruption of NOX interaction partners, although only a few have reached clinical trials. To improve the efficacy and bioavailability of the iodonium class NOX inhibitor diphenylene iodonium (DPI), we synthesized 36 analogs of DPI, focusing on improved solubility and functionalization. The inhibitory activity of the analogs was interrogated through cell viability and clonogenic studies with a colon cancer cell line (HT-29) that depends on NOX for its proliferative potential. Lack of altered cellular respiration at relevant iodonium analog concentrations was also demonstrated. Additionally, inhibition of ROS generation was evaluated with a luminescence assay for superoxide, or by Amplex Red® assay for H2O2 production, in cell models expressing specific NOX isoforms. DPI and four analogs (NSCs 740104, 751140, 734428, 737392) strongly inhibited HT-29 cell growth and ROS production with nanomolar potency in a concentration-dependent manner. NSC 737392 and 734428, which both feature nitro functional groups at the meta position, had >10-fold higher activity against ROS production by cells that overexpress dual oxidase 2 (DUOX2) than the other compounds examined (IC50≈200-400nM). Based on these results, we synthesized and tested NSC 780521 with optimized potency against DUOX2. Iodonium analogs with anticancer activity, including the first generation of targeted agents with improved specificity against DUOX2, may provide a novel therapeutic approach to NOX-driven tumors.
Subject(s)
Cell Proliferation/drug effects , Enzyme Inhibitors/pharmacology , NADH, NADPH Oxidoreductases/antagonists & inhibitors , Onium Compounds/pharmacology , Thiophenes/pharmacology , Cell Survival/drug effects , Dose-Response Relationship, Drug , Dual Oxidases , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , HT29 Cells , Humans , Molecular Structure , NADH, NADPH Oxidoreductases/genetics , NADPH Oxidases/antagonists & inhibitors , NADPH Oxidases/genetics , Onium Compounds/chemical synthesis , Onium Compounds/chemistry , Oxygen Consumption/drug effects , Reactive Oxygen Species/antagonists & inhibitors , Thiophenes/chemical synthesis , Thiophenes/chemistryABSTRACT
First synthesis of gemcitabine triphosphate (dFdCTP) as a tris(triethylammonium) salt is reported.
Subject(s)
Antimetabolites, Antineoplastic/pharmacology , Deoxycytidine/analogs & derivatives , Polyphosphates/pharmacology , Quaternary Ammonium Compounds/pharmacology , Salts/pharmacology , Tromethamine/pharmacology , Antimetabolites, Antineoplastic/chemical synthesis , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Deoxycytidine/chemical synthesis , Deoxycytidine/pharmacology , Humans , Models, Chemical , Polyphosphates/chemical synthesis , Quaternary Ammonium Compounds/chemistry , Salts/chemistry , Tromethamine/chemistry , Tumor Cells, Cultured/drug effects , GemcitabineABSTRACT
Castrate-resistant prostate cancer (CRPC) continues to be dependent on the androgen receptor (AR) for disease progression. We have synthesized and evaluated a novel compound that is a conjugate of colchicine and an AR antagonist (cyanonilutamide) designed to inhibit AR function in CRPC. A problem in multifunctional AR-binding compounds is steric hindrance of binding to the embedded hydrophobic AR ligand-binding pocket. Despite the bulky side chain projecting off of the AR-binding moiety, this novel conjugate of colchicine and cyanonilutamide binds to AR with a K(i) of 449 nmol/L. Structural modeling of this compound in the AR ligand-binding domain using a combination of rational docking, molecular dynamics, and steered molecular dynamics simulations reveals a basis for how this compound, which has a rigid alkyne linker, is able to bind to AR. Surprisingly, we found that this compound also binds to tubulin and inhibits tubulin function to a greater degree than colchicine itself. The tubulin-inhibiting activity of this compound increases cytoplasmic AR levels in prostate cancer cells. Finally, we found that this compound has greater toxicity against androgen-independent prostate cancer cells than the combination of colchicine and nilutamide. Together, these data point to several ways of inhibiting AR function in CRPC.
Subject(s)
Antineoplastic Agents/pharmacology , Colchicine/pharmacology , Imidazolidines/pharmacology , Receptors, Androgen/metabolism , Cell Death/drug effects , Cell Line, Tumor , Colchicine/chemistry , Cytoplasm/drug effects , Humans , Male , Protein Structure, Secondary , Receptors, Androgen/chemistryABSTRACT
Biotin conjugates are of considerable value in investigating the mode of action of biologically active compounds. Two biotin conjugates related to the antifungal compound cymoxanil [1-(2-cyano-2-methoximinoacetyl)-3-ethyl urea] were prepared as the first step in an effort to employ display cloning to identify the compound's target site. In the first conjugate, prepared in five steps, the biotin moiety was attached at the position occupied by the ethyl group in cymoxanil. In the second conjugate, prepared in four steps, the biotin moiety was attached through the oxime functional group.
