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Degrees: 1980 - PhD - University of California Davis - Biochemistry 1974 - BS - University of California Berkeley - Chemistry Awards: 2001 Klaus Schwartz Commemorative Medal from the International Association of Bioinorganic Scientists for Outstanding Achievement in Biological Trace Element Research for the discovery of selenocysteine transfer RNA and its role in selenoprotein biosynthesis. Department and Center Affiliations: USDA-ARS Western Human Nutrition Research Center Genome Center Professional Societies: American Chemical Society American Society for Nutritional Sciences American Association for the Advancement of Science Publications: Hawkes, W. C., Association of glutathione peroxidase activity with insulin resistance and dietary fat intake during normal pregnancy. Journal of Clinical Endocrinology and Metabolism 89, 4772-4773; author reply 4773-4774 (2004). Hawkes, W.C., Kelley, D.S. and Taylor, P.C., The effects of dietary selenium on the immune system in healthy men. Biol Trace Elem Res, 81, 189 (2001). Hawkes, W.C., Alkan, Z., Lang, K. and King, J.C., Plasma selenium decrease during pregnancy is associated with glucose intolerance, Biological Trace Element Research, 100, 19-30 (2004). Hawkes, W.C. and Keim, N. L., Dietary selenium intake modulates thyroid hormone and energy metabolism in men, Journal of Nutrition, 133, 3443-3448 (2003). Hawkes, W.C., Alkan, F. Z., and Oehler, L. Absorption, distribution and excretion of selenium from beef and rice in healthy North American men, Journal of Nutrition, 133, 3434-3442 (2003). Hawkes, W.C and Turek, P.J., The effects of dietary selenium on sperm motility in healthy men. J. Andrology, 22, 764 (2001). Hawkes, W. C., Wilhelmsen, E. C., and Tappel, A. L., Abundance and tissue distribution of selenocysteine-containing proteins in the rat, J Inorg Biochem, 23, 77 (1985). Hawkes, W. C., Lyons, D. E., and Tappel, A. L., Identification of a selenocysteine-specific aminoacyl transfer RNA from rat liver, Biochim Biophys Acta, 699, 183 (1982). Research Interests: Our laboratory investigates the biochemical functions of the trace element selenium. Our research is focused on the gene-nutrient interactions underlying selenium's protective effect against cancer and the functions of selenocysteine-containing proteins. We use animal and cell culture models and genomic tools to develop and test dietary interventions for cancer prevention in collaboration with the UC Davis Cancer Center in Sacramento. We have recently completed a two-year study demonstrating the safety of high-selenium yeast supplements and have begun a pilot study to use them for prevention of breast cancer in women with proliferative breast disease that places them at high risk. Our current research goals are: 1. Identify potential molecular targets for chemoprevention with selenium in cultured human cells. Messenger RNA profiles are measured on DNA microarrays to identify cancer-associated genes regulated by selenium. Changes in gene expression are validated with quantitative real-time RT-PCR assays specific for each gene product. 2. Modulate expression of potential molecular targets of selenium and test effects on selenium chemoprevention. Cells are transfected with siRNA or extra copies of the target gene bearing strong promoters to modulate expression of targets in cultured cells. Effects of modified target expression are assessed by changes in mRNA profiles and changes in tumorigenic potential of xenografted cells into immunodeficient mice. Transgenic mice overexpressing or underexpressing targets will be created and tested for susceptibility to chemical carcinogenesis and response to selenium chemoprevention 3. Conduct human trails to test high-selenium yeast supplements for prevention of breast and prostate cancer. Preliminary tests of efficacy will follow cancer biomarkers and selenium targets in small numbers of volunteers at high risk for cancer. Our laboratory is equipped for ultra-sensitive selenium analysis, glutathione peroxidase and protein assays, high-performance liquid chromatography, nucleic acid purification, RT-PCR, analytical and preparative gel electrophoresis, and ultraviolet-visible spectroscopy. http://www.whnrc.usda.gov/chawkes/chawkes.html |