Investigator: John Williams Jr., Rhode Island College
Scientific Theme: Cancer and Molecular Toxicology
Abstract: Arylphosphonium salts (APS) are cytotoxic lipophilic cations that can cross cell membranes. They show SAR’s for DNA binding in electrophoresis. Computational models indicate both electrostatic and intercalation binding. They are antibacterial and antifungal by unknown mechanism(s). Some are active against cancer cells in culture and in vivo. They concentrate in mitochondria and have been used as carrier molecules to deliver DNA-alkylating agents into mitochondria. They can also be conjugated with flurophores to enhance cell imaging. We have synthesized some of these compounds and observed these effects in our laboratories. Three to five step high-yield protocols developed in our laboratories using readily available reagents and microwave-assisted and/or solvent-free syntheses are employed. Selected compounds will be tested by cellometry using a MuseTM Cell Analyzer for selective toxicity against malignant (4TI) vs. normal (NMuMG) cancer cell lines. We will use a luciferase ATP assay, ATPiyte®, to probe inhibition of ATP synthesis as a specific toxic consequence of selective mitochondrial uptake. We will begin with a set of triarylcinnamyl and triaryl (alpha-toluic acid) phosphonium salts that have proven to be the most active in previous toxicity screenings and prepare modifications of these by the synthesis methods noted herein. Leads discovered in this screening will be modified to increase potency and efficacy. They will be tested for binding to both ds and G4 DNA in electrophoresis and by CD and lTC experiments. New compounds will also be screened for estrogenic activity. Up to six students can be involved directly in this project during the summers. Three to five students can continue the project during each following academic year. The overall aim of this project is to discover new selective anticancer agents and produce leads for preclinical development. This will be done by synthesis of new compounds and selection of library compounds which will be screened for mitochondrial ATP suppression, selective toxicity in cellometry experiments and DNA binding in gel electrophoresis. Eventually we intend to do preclinical trials in mice with the most promising candidates.
Human Health Relevance: Cancer therapy, early cancer diagnosis, breast cancer, cell culture, cell-imaging, cell targeting, cytometry, medicinal chemistry, computational medicinal chemistry, dsDNA toxicity, G4 DNA toxicity, selective drug uptake, blocking of DNA amplification, fluorescence labeling, ATP inhibition, mechanisms of antipoliferation agents, correlations for and predictors of anti-cancer activity, green chemistry, microwave assisted synthesis, computational screening. in vitro screening. preclinical in vivo screening.