The Lloyd & McCullough Laboratory

Lab Group July 2015
Lab Members July 2015


The Lloyd-McCullough lab combines the research interests of Dr. Amanda McCullough and Dr. R. Stephen Lloyd in the field of DNA damage, replication and repair.  Our interests cover a wide variety of topics that range from the biochemical basis of DNA repair to the effects of oxidative stress on metabolism.

Dr. Amanda McCullough

Amanda Mccullough

Dr. McCullough received her doctoral degree in Cellular and Molecular Biology from the University of Vermont.  She completed postdoctoral training at Oregon Health & Science University and the University of Texas Medical Branch in Galveston Texas.  She was an Assistant Professor in the Department of Human Biological Chemistry and Genetics at the University of Texas before moving to Oregon Health & Science University in 2003.  She is currently an Associate Professor in the Department of Molecular & Medical Genetics and the Oregon Institute of Occupational Health Sciences.  In addition she is also President and CEO of Restoration Genetics, Inc. (RGI), an Oregon-based biotechnology development company working with OHSU to develop cancer therapeutics. 

email me - publication history

Dr. R. Stephen Lloyd

Stephen Lloyd

Dr. R. Stephen Lloyd received his BS in Biology from Florida State University in 1975, majoring in marine pollution biology. His research interests turned to cancer chemotherapy and in 1979, he earned his Ph.D. in Molecular Biology from the University of Texas Graduate School of Biomedical Sciences in Houston, TX. After learning about mechanisms by which DNA can be damaged, he began his career in DNA repair as a postdoctoral fellow at Stanford University in the laboratory of Dr. Philip Hanawalt. Following two years at Stanford, he worked for two more years for a genetic engineering company, before joining the Biochemistry Department at Vanderbilt University in 1983. In his ten-year stay at Vanderbilt, Dr. Lloyd rose through the ranks to Full Professor, and his research focused on both DNA repair and molecular mutagenesis. He was then recruited to the Center for Molecular Science at the University of Texas Medical Branch in which the faculty exclusively specialized in DNA repair mechanisms. During his twelve years at UTMB, he also became the Director of two Centers in Environmental Toxicology. In August 2003, he, along with his wife, Dr. Amanda K. McCullough was recruited to join the Institute's faculty at OHSU. Together they have both separate and joint research projects in the research areas described below.

email me - publication history

Group Members

Our group members have a wide variety of interests inside and outside the laboratory.  Some individuals have links to additional information.


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.

Current Projects: