EXCEED THE SPACE PROVIDED. This project proposes the preparation and preliminary study of selenazolidine carboxylic acids as novel selenium delivery agents. Selenium is of growing importance in human health beyond its well-recognized role as a micronutrient. For example, selenium has exhibited exciting activity as a cancer chemopreventive agent against disease in several organs, caused by a variety of carcinogens. Selenium is also known for its toxicity, however, making the development of clinically valuable agents a distinct challenge that must be accomplished with extreme care and creativity. The selenazolidines represent 'prodrug' forms of L- selenocysteine. They were designed to provide a continuous supply of the amino acid (as a source of selenium) at levels high and sustained enough to have therapeutic value but not high enough to produce toxicity. The current application will accomplish four specific aims: (1) Design, synthesize, and chemically characterize carefully selected prototypes of new subclasses of selenazolidine prodrugs to allow the development of critical structure-activity relationships; (2) Understand the chemical/biochemical breakdown of the selenazolidines; (3) Undertake animal studies in the well-established A/J mouse model to study toxicity of the novel agents, as well as their effect on basic biochemical parameters; (4) Expand animal studies to: (a) investigate the cancer chemopreventive activity of the new selenazolidines against a tobacco- derived lung carcinogen; (b) explore varied administration schedules for cancer chemoprevention; (c) study selected selenazolidines in combination with vitamin E, vitamin C, or N-acetylcysteine (cysteine source) to enhance chemoprevention; and (d) study the preventive attributes of selected selenazolidines in selenium-deficient animals. These analogs are completely novel; it appears to be an entirely new approach in the selenium field and may allow the potential of selenium as a preventive and/or therapeutic agent in human disease to be clinically realized. PERFORMANCE SITE ========================================Section End===========================================
