Shawn Wnek, PhD, DABT
Senior Toxicologist
Dr. Wnek’s background includes a B.S. in Biology from Baldwin-Wallace College in Berea, Ohio with coursework focusing on microbiology, immunology, biochemistry, gross anatomy, physiology, and genetics. Upon graduation from Baldwin Wallace, he worked at Wil Research Laboratories in Ashland, Ohio as a biologist in the necropsy department. He was involved in conducting all teratology and pathology phases of reproductive and toxicological studies. This work experience sparked his interest in the field of toxicology; which is why he decided to attend The University of Arizona to complete a Ph.D. in the field of Pharmacology and Toxicology. His graduate research focused on the mechanism of arsenic-induced bladder cancer following chronic, low-level exposure to the arsenic metabolite, monomethylarsonous acid. In particular, he has investigated the role of chronic arsenic exposure and mechanisms of carcinogenesis as a result of arsenical-induced oxidative stress and protein oxidation, genotoxicity, alteration of DNA repair enzymes and site-specific interaction of arsenic at targeted proteins within cellular systems.
As a senior toxicologist at CTEH®, Dr. Wnek specializes in toxicology, risk assessment, toxicity evaluations, and emergency response toxicology. He is a responding toxicologist in the CTEH® Toxicology Emergency Response Program (TERP®). Dr. Wnek participates in a variety of projects, including evaluating the relationship between chemical exposure and disease, participating in the formulation of emergency response guides, and involvement in environmental contamination and toxic tort litigation. He is a member of the Society of Toxicology and is certified as a Diplomate of the American Board of Toxicology.
Education
- Ph.D., Pharmacology & Toxicology, University of Arizona, Tucson, AZ
- B.S., Biology, Baldwin-Wallace College, Berea, OH
Past or Current Professional Affiliations
- Society of Toxicology
Publications
- P.T. Hazards after the Storm: Floodwater Drainage Pump Stations and Exposure to Hydrogen Sulfide
- Toxicology of Metals
- Petroleum smoke incident support: the composition and adverse health effects of petroleum fire smoke
- Strategies for Assessing Human Health Impacts of Crude Oil Releases
- Global gene expression changes in human urothelial cells exposed to low-level monomethylarsonous acid
- Interdependent genotoxic mechanisms of monomethylarsonous acid: Role of ROS-induced DNA damage and poly(ADP-ribose) polymerase-1 inhibition in the malignant transformation of urothelial cells
- Monomethylarsonous acid produces irreversible events resulting in malignant transformation of a human bladder cell line following 12 weeks of low-level exposure
- Low level exposure to monomethylarsonous acid-induced the over-production of inflammation-related cytokines and the activation of cell signals associated with tumor progression in a urothelial cell model
- Arsenicals produce stable and progressive changes in DNA methylation patterns that are linked to malignant transformation of immortalized urothelial cells
- Persistence of DNA damage following exposure of human bladder cells to chronic monomethylarsonous acid
- Epigenetic mediated transcriptional activation of WNT5A participates in arsenical-associated malignant transformation
- Reactive oxygen species regulate properties of transformation in UROtsa cells exposed to monomethylarsonous acid by upregulation of MAPK signaling cascade