The Lloyd & McCullough Laboratory

Steven Lloyd and Amanda McCullough labs
Lab Members August 2018


Dr. Amanda McCullough

Amanda McCullough

Dr. McCullough earned her PhD in Cellular and Molecular Biology from the University of Vermont. She completed postdoctoral training in the Division of Hematology & Medical Oncology at Oregon Health & Science University and in the Department of Human Biological Chemistry & Genetics at the University of Texas Medical Branch. She is currently an Associate Professor in the Department of Molecular & Medical Genetics and the Oregon Institute of Occupational Health Sciences. Dr. McCullough serves as the co-Director of the Molecular & Medical Genetics Graduate Program.. 

email me - publication history


Dr. R. Stephen Lloyd

R. Stephen Lloyd

R. Stephen Lloyd earned his PhD in molecular biology at the University of Texas, MD Anderson Hospital and Tumor Institute in Houston and carried out postdoctoral training at Stanford University. Following employment with a genetic engineering company, he has been a faculty member at three US medical schools, including Vanderbilt University, University of Texas Medical Branch (UTMB) at Galveston, and Oregon Health & Science University (OHSU). During his career in academia, he has served as the Principal Investigator of a National Institute of Environmental Health Sciences (NIEHS) Center (UTMB), the Director of the Center in Environmental Health & Medicine (UTMB), and the Director of the Center for Research in Occupational and Environmental Toxicology (OHSU). Dr. Lloyd has authored 219 peer-reviewed publications and 27 review articles. His laboratoryan American Cancer Society Faculty Research Award, a Faculty Research Award from the Graduate School of Biomedical Sciences, UTMB, and an Outstanding Achievement Award in Research at OHSU.

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Group Members


The research within our laboratories is concentrated in three major areas that have as a central theme, the biochemical mechanisms of DNA repair and replication in response to environmental toxicant exposures.  These systems are directly germane to human cancers, metabolic syndrome, and aging.  First, we are interested in understanding the cellular pathways for the tolerance, mutagenesis, and repair of alkylated, ring-fragmented purines (Fapy-dG adducts), DNA interstrand crosslinks, and DNA-protein crosslinks.  These DNA adducts are formed as a consequence of environmental exposure to reactive aldehydes and as a result of endogenous metabolism.  Second, we are investigating the biochemical mechanisms and therapeutic applications of ultraviolet (UV) light-induced DNA damage-specific glycosylases for the prevention of skin cancer and UV-induced immunosuppression.  Third, we are using biochemical, cellular and animal models to investigate repair of oxidatively-induced DNA damage that is initiated by either NEIL1 or OGG1 DNA glycosylases.  Defects in these pathways contribute to lung and liver cancers and the absence of these enzymes can lead to the development of many of the symptoms of metabolic disease.  See our current projects.