William B. Parker, Ph.D.

Biography

Dr. Parker obtained a Ph.D. in Pharmacology in 1984 from George Washington University and received further post-doctoral research training at The University of North Carolina at Chapel Hill with Dr. Yung-chi Cheng. He joined Southern Research in 1988 where he is currently a Senior Research Scientist and Director of the Biochemistry and Molecular Biology Department. Throughout his career Dr. Parker has concentrated his research efforts on understanding the mechanism of action of purine and pyrimidine antimetabolites that are used in the treatment of cancer and infectious diseases to aid in the development of new drugs to treat these diseases.

Since 1989 his research has been funded by eleven investigator-initiated research grants from the National Institutes of Health. This work has led to a total of 62 publications in peer-reviewed journals, eight book chapters and reviews, and eight patents. In addition to grant-based research, Dr. Parker also contracts with pharmaceutical companies to aid them in their research efforts. He is frequently asked to serve on peer review panels for the National Institutes of Health to review grant applications that involve research into the development of new anti-AIDS and anticancer drugs. Through these efforts Dr. Parker has gained world-wide recognition as an expert on the development of nucleoside analogs for the treatment of cancer and viral infections.

Laboratory Focus: Drug Development based on Purine and Pyrimidine Biochemistry

Purine and pyrimidine antimetabolites are an important class of drugs that are used in the treatment of cancers and viral infections. Dr. Parker is an expert in the evaluation of the effect of these agents and their metabolites on enzymes involved in nucleic acid synthesis in humans and pathogenic organisms. Biochemical studies are conducted in cell-free assays, intact cells, and in animals in order to gain a complete understanding of the mechanism of action of these agents. The laboratory currently has four research projects to develop new drugs for the treatment of cancer, viral infections, or bacterial infections.

Since 1988, Dr. Parker has been part of a research team at Southern Research that designs, synthesizes, and evaluates nucleoside analogs in an effort to create new anticancer compounds. A new drug resulting from these efforts, clofarabine, was approved by the FDA in 2004 for the treatment of childhood acute lymphocytic leukemia, and another agent, 4'-thio-arabinofuranosyl cytosine, is currently being evaluated for antitumor activity in clinical trials.

Dr. Parker has also been involved in the development of a gene therapy strategy to treat solid tumors that exploits the substrate differences between human and E. coli purine nucleoside phosphorylase to selectively generate toxic purine analogs in tumor cells. This gene therapy strategy for the treatment of solid tumors has recently led to the creation PNP Therapeutics Inc.

Another project in the laboratory evaluates purine metabolic enzymes in Mycobacterium tuberculosis. Currently little is known about purine metabolism in mycobacteria and it is hoped that with further study differences in utilization of substrates by the enzymes involved in purine salvage could be discovered leading to the creation of new agents to selectively treat Mycobacterium tuberculosis infections.

Dr. Parker is also involved with a project to design, synthesize, and evaluate analogs of ribavirin in an attempt to identify new agents that could be useful in the treatment of hantavirus infections.