R. Stephen Lloyd, Ph.D.
- Professor, Oregon Institute of Occupational Health Sciences
- Professor of Molecular and Medical Genetics, School of Medicine
- Associate Director for Basic Research, Oregon Institute of Occupational Health Sciences
- Molecular and Medical Genetics Graduate Program, School of Medicine
- Graduate Program in Biomedical Sciences, School of Medicine
- Cancer Biology Graduate Program, School of Medicine
Biography
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 CROET faculty at OHSU. Together they have both separate and joint research projects in the research areas described below.
Education and training
-
Degrees
- B.S., 1975, Florida State University
- Ph.D., 1979, University of Texas Houston Graduate School of Biomedical Sciences
Memberships and associations:
- American Association for the Advancement of Science (AAAS)
- Environmental Mutagenesis & Genomics Society
- Federation of the American Societies of Experimental Biology
Areas of interest
- Strategies to prevent sunlight-induced skin cancer via the topical introduction of repair enzymes into human cells
- The mechanisms by which the loss of a DNA repair enzyme can lead to the clinical manifestations of Metabolic Syndrome - a constellation of diseases (obesity, fatty liver disease, insulin resistance and hypertension) that affect >45 million Americans
- Mutagenic potential of alkyl-substituted and unsubstituted Fapy-dG adducts
- Molecular mechanisms for the repair and replication of DNA-protein crosslinks
- Replication bypass of DNAs containing interstrand DNA crosslinks
Additional information
Honors and awards
- Awards: Editor’s Choice Award for Environmental and Molecular Mutagenesis for Sha Y, Minko IG, Malik CK, Rizzo CJ, Lloyd RS. Error-prone replication bypass of the imidazole ring-opened formamidopyrimidine deoxyguanosine adduct. Environ Mol Mutagen. 2017 May;58(4):182-189. PMID:28436537 PMCID: PMC5476229
Publications
Selected publications
- Tomar R, Minko IG, Kellum AH Jr, Voehler MW, Stone MP, McCullough AK, Lloyd RS. DNA Sequence Modulates the Efficiency of NEIL1-Catalyzed Excision of the Aflatoxin B1-Induced Formamidopyrimidine Guanine Adduct. Chem Res Toxicol. 2021 Mar 15;34(3):901-911. PMCID: in progress
- Owen N, Minko IG, Moellmer SA, Cammann SK, Lloyd RS, McCullough AK. Enhanced cytarabine-induced killing in OGG1-deficient acute myeloid leukemia cells. Proc Natl Acad Sci U S A. 2021 Mar 16;118(11):e2016833118. PMCID: in progress
- Kant M, Tahara YK, Jaruga P, Coskun E, Lloyd RS, Kool ET, Dizdaroglu M. Inhibition by Tetrahydroquinoline Sulfonamide Derivatives of the Activity of Human 8-Oxoguanine DNA Glycosylase (OGG1) for Several Products of Oxidatively induced DNA Base Lesions. ACS Chem Biol. 2021 Jan 15;16(1):45-51. PMCID: in progress
- Paluri SL, Burak M, Senejani AG, Levinson M, Rahim T, Clairmont K, Kashgarian M, Alvarado-Cruz I, Meas R, Cardó-Vila M, Zeiss C, Maher S, Bothwell ALM, Coskun E, Kant M, Jaruga P, Dizdaroglu M, Lloyd RS, Sweasy JB. DNA glycosylase deficiency leads to decreased severity of lupus in the Polb-Y265C mouse model. DNA Repair (Amst). 2021 Jun 24;105:103152. PMCID: in progress
- Minko IG, Vartanian VL, Tozaki NN, Coskun E, Coskun SH, Jaruga P, Yeo J, David SS, Stone MP, Egli M, Dizdaroglu M, McCullough AK, Lloyd RS. Recognition of DNA adducts by edited and unedited forms of DNA glycosylase NEIL1. DNA Repair (Amst). 2020 Jan;85:102741 PMCID: PMC7069121
- McCullough, AK, I. G. Minko, IG, A. Nilsen, A, S. Nagarajan, S, and Lloyd, RS (2020) Modulation of DNA Glycosylase Activities via Small Molecules. Chapter 14 in DNA Damage, DNA Repair and Disease, (Eds Miral Dizdaroglu and R. Stephen Lloyd) Royal Society of Chemistry, United Kingdom
- Sampath, H and Lloyd, RS. Roles of OGG1 in transcriptional regulation and maintenance of metabolic homeostasis. DNA Repair (Amst). 2019 Sep;81:102667 PMCID: PMC6939861.
- McCullough AK, Lloyd RS. Mechanisms underlying aflatoxin-associated mutagenesis - Implications in carcinogenesis. DNA Repair (Amst). 2019 May;77:76-86 PMCID:PMC6959417
- Minko IG, Christov PP, Li L, Stone MP, McCullough AK, Lloyd RS. Processing of N5-substituted formamidopyrimidine DNA adducts by DNA glycosylases NEIL1 and NEIL3. DNA Repair (Amst). 2019 Jan;73:49-54 PMCID: PMC6588396
- Minko IG, Vartanian VL, Tozaki NN, Linde OK, Jaruga P, Coskun SH, Coskun E, Qu C, He H, Xu C, Chen T, Song Q, Jiao Y, Stone MP, Egli M, Dizdaroglu M, McCullough AK, Lloyd RS. Characterization of rare NEIL1 variants found in East Asian populations. DNA Repair (Amst). 2019 May 3;79:32-39 PMCID: PMC6677271
Publications
The Distinct Roles of NEIL1 and XPA in Limiting Aflatoxin B1–Induced Mutagenesis in Mice
Molecular Cancer ResearchFunctional characterization of single nucleotide polymorphic variants of DNA repair enzyme NEIL1 in South Asian populations
DNA RepairInteraction of mitoxantrone with abasic sites - DNA strand cleavage and inhibition of apurinic/apyrimidinic endonuclease 1, APE1
DNA RepairMass Spectrometry-Based Method to Measure Aflatoxin B1 DNA Adducts in Formalin-Fixed Paraffin-Embedded Tissues
Chemical Research in ToxicologyThe aflatoxin B1-induced imidazole ring-opened guanine adduct
Environmental and Molecular MutagenesisBase excision repair of the N-(2-deoxy-d-erythro-pentofuranosyl)-urea lesion by the hNEIL1 glycosylase
Nucleic acids researchFunctional analyses of single nucleotide polymorphic variants of the DNA glycosylase NEIL1 present in sub-Saharan African populations
DNA RepairSpontaneous allelic variant in deafness–blindness gene Ush1g resulting in an expanded phenotype
Genes, Brain and BehaviorSynthesis and Characterization of 15N5-Labeled Aflatoxin B1-Formamidopyrimidines and Aflatoxin B1-N7-Guanine from a Partial Double-Stranded Oligodeoxynucleotide as Internal Standards for Mass Spectrometric Measurements
ACS OmegaPolymorphic variant Asp239Tyr of human DNA glycosylase NTHL1 is inactive for removal of a variety of oxidatively-induced DNA base lesions from genomic DNA
DNA RepairDNA glycosylase deficiency leads to decreased severity of lupus in the Polb-Y265C mouse model
DNA RepairDNA Sequence Modulates the Efficiency of NEIL1-Catalyzed Excision of the Aflatoxin B1-Induced Formamidopyrimidine Guanine Adduct
Chemical Research in ToxicologyEnhanced cytarabine-induced killing in OGG1-deficient acute myeloid leukemia cells
Proceedings of the National Academy of Sciences of the United States of AmericaInhibition by Tetrahydroquinoline Sulfonamide Derivatives of the Activity of Human 8-Oxoguanine DNA Glycosylase (OGG1) for Several Products of Oxidatively induced DNA Base Lesions
ACS chemical biologyMaternal Transmission of Human OGG1 Protects Mice Against Genetically- and Diet-Induced Obesity Through Increased Tissue Mitochondrial Content
Frontiers in Cell and Developmental BiologyExosomal miR-221 derived from hydroquinone-transformed malignant human bronchial epithelial cells is involved in cell viability of recipient cells
Journal of Applied ToxicologyExosomes derived from normal human bronchial epithelial cells down-regulate proliferation and migration of hydroquinone-transformed malignant recipient cells via up-regulating PTEN expression
ChemosphereOGG1 deficiency alters the intestinal microbiome and increases intestinal inflammation in a mouse model
PloS oneRecognition of DNA adducts by edited and unedited forms of DNA glycosylase NEIL1
DNA RepairAflatoxin-Guanine DNA Adducts and Oxidatively Induced DNA Damage in Aflatoxin-Treated Mice in Vivo as Measured by Liquid Chromatography-Tandem Mass Spectrometry with Isotope Dilution
Chemical Research in ToxicologyCharacterization of rare NEIL1 variants found in East Asian populations
DNA RepairProcessing of N5-substituted formamidopyrimidine DNA adducts by DNA glycosylases NEIL1 and NEIL3
DNA RepairModulation of UVB-induced Carcinogenesis by Activation of Alternative DNA Repair Pathways
Scientific ReportsThe DNA Repair Protein OGG1 Protects Against Obesity by Altering Mitochondrial Energetics in White Adipose Tissue
Scientific Reports8-oxoguanine DNA glycosylase (OGG1) deficiency elicits coordinated changes in lipid and mitochondrial metabolism in muscle
PloS oneError-prone replication bypass of the imidazole ring-opened formamidopyrimidine deoxyguanosine adduct
Environmental and Molecular MutagenesisMutagenic potential of nitrogen mustard-induced formamidopyrimidine DNA adduct
Journal of Biological Chemistry