Skip Navigation

Your Environment. Your Health.

Robert Sills, D.V.M., Ph.D.

Molecular Pathology Group

Robert C. Sills, D.V.M., Ph.D.
Robert C. Sills, D.V.M., Ph.D.
Chief, Cellular & Molecular Pathology Branch and Acting Molecular Pathology Group Leader
Tel (919) 541-0180
P.O. Box 12233
Mail Drop B3-06
Research Triangle Park, NC 27709

Delivery | Postal
Delivery Instructions 

Robert Sills, D.V.M., Ph.D., is a pathologist and Chief of the Cellular and Molecular Pathology Branch (CMPB) in the Division of the National Toxicology Program at the National Institute of Environmental Health Sciences. His branch is responsible for overseeing all pathology data generated by NTP toxicity and carcinogenicity studies.

Additionally, Sills is an adjunct professor in the Department of Toxicology at the University of North Carolina School of Medicine at Chapel Hill, North Carolina, and in the Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University.

His research activities include the study of molecular mechanisms of chemical carcinogenesis with focus on protooncogenes and tumor suppressor genes, neuropathology, and the inclusion of biologic based interdisciplinary research in NTP studies. He is a member of the American College of Veterinary Pathologists (ACVP), American Association of Cancer Research (AACR), Society of Toxicologic Pathology (STP), and the American Veterinary Medical Association (AVMA). He presently serves on the Executive Council for the Society of Toxicologic Pathology and is the associate editor for the environmental pathobiology section of Veterinary Pathology.

Sills has served on the editorial board of Toxicologic Pathology. He chaired STP annual meeting sessions on the human genome, implications for toxicologic pathology and carcinogenesis, and the session on cellular and molecular neurocarcinogenesis, toxicologic pathology of the nervous system. Also, he co-chaired the International Life Sciences Institute (ILSI) seminar series on current issues in neuropathology.

Sills received his Doctor of Veterinary Medicine degree from Tuskegee University (1984) and completed an internship in anatomical pathology from Tuskegee University (1985) and a combined residency/Ph.D. in toxicologic pathology from Michigan State University (1991). He is certified as a veterinary pathologist by the American College of Veterinary Pathologists.

Selected Publications

Genetic Alternations in Animal Models of Cancer

  1. Rao DB, Jortner BS, Sills RC. Animal models of peripheral neuropathy due to environmental toxicants. ILAR journal / National Research Council, Institute of Laboratory Animal Resources 2014 54(3):315-323.[Abstract]
  2. Cesta MF, Malarkey DE, Herbert RA, Brix A, Hamlin MH 2nd, Singletary E, Sills RC, Bucher JR, Birnbaum LS. The National Toxicology Program Web-based nonneoplastic lesion atlas: a global toxicology and pathology resource. Toxicologic pathology 2014 42(2):458-460. [Abstract]
  3. Koivisto C, Flake GP, Kolenda-Roberts H, Masinde T, Kissling GE, Sills RC, Hoenerhoff MJ. Immunohistochemical investigation of F344/N rat islet cell tumors from national toxicology program studies. Toxicologic pathology 2012 40(5):751-63.[Abstract]
  4. Merrick BA, Auerbach SS, Stockton PS, Foley JF, Malarkey DE, Sills RC, Irwin RD, Tice RR. Testing an aflatoxin B1 gene signature in rat archival tissues. Chemical research in toxicology. 25(5):1132-44, 2012.[Abstract]
  5. Rao, D.B., Little, P.B., Malarkey, D.E., Herbert, R.A., Sills, R.C. Histopathological Evaluation of the Nervous System in Routine National Toxicology Program Rodent Studies: A Modified Approach. Toxicologic Pathology. 39(3):463-470, 2011.[Abstract]
  6. Goodman, J.I., Augustine, K.A., Cunnningham, M.L., Dixon, D., Dragan, Y.P., Falls, G., Rasoulpour, R.J., Sills, R.C., Storer, R.D., Wolf, D.C., Pettit, S.D.: What Do We Need To Know Prior To Thinking About Incorporating An Epigenetic Evaluation Into Safety Assessments? A Report Based On An International Life Sciences Institute, Health And Environmental Sciences Institute (HESI) Workshop On State Of The Science: Evaluating Epigenetic Changes. Toxicological Sciences. 116(2): 375-381, 2010.[Abstract]  
  7. Wei B.R., Edwards J.B., Hoover S.B., Tillman H.S., Reed L.T., Sills R.C., Simpson R.M.: Altered {beta}-catenin accumulation in hepatocellular carcinomas of diethynitrosamine-exposed rhesus macaques. Toxicologic pathology, 36(7):972-980, 2008.[Abstract]  
  8. Takatoshi, K., Ton, T.T, Lahousse, S.A., Hong, H.L., Wakamatsu, N., Sills, R.C.: K-ras cancer gene mutations in lung tumors from female Swiss (CD-1) mice exposed transplacentally to 3’-azido-3’-deoxythymidine. Environ. Mol. Mutagenesis. In Press, 2008.[Abstract]  
  9. Wei, B.H., Edwards, J.B., Hoover, S.B., Sheppard H.W., Reed, L.T., Sills, R.C., Simpson, R.M.: Altered beta-catenin accumulation in hepatocelular carcinomas of diethynitrosamine-exposed rhesus macaques. Toxicologic Pathology. In Press, 2008.  
  10. Wakamatsu, N., Collins, J.B., Parker, J.S., Tessema, M., Clayton, N.P., Ton, T.V., Hong, H.H., Belinsky, S., Devereux, T.R., Sills ,R.C., Lahoousse, S.A.: Gene expression studies demonstrate that the K-ras/Erk MAP kinase signal transduction pathway and other novel pathways contribute to the pathogenesis of cumene-induced lung tumors. Toxicologic Pathology, 36: 743, 2008.[Abstract]  
  11. Hong H.H., Ton T.T., Kim Y., Wakamatsu N., Clayton N.P., Chan P.C., Sills R.C., Lahousse S.A.: Genetic alterations in K-ras and p53 cancer genes in lung neoplasms from B6C3F1 mice exposed to cumene. Tox. Path. 36: 720, 2008.[Abstract]  
  12. Wakamatsu, N., Hong, H.L., Devereux, T.R., Sills, R.C.: Overview of the molecular carcinogenesis of mouse lung tumor models of human lung cancer. Tox. Path. 35: 75, 2007.[Abstract]
  13. Hong, H.L., Houle, C.D., Ton, T.T., Sills, R.C.: K-ras mutations in lung tumors and tumors from other organs are consistent with a common mechanism of ethylene oxide tumorigenesis in the B6C3F1 mouse. Tox. Path. 35: 81, 2007.[Abstract]  
  14. Hong, H.H., Dunnick, J., Herbert, R., Devereux, T.R., Kim, Y., Sills, R.C.: Genetic alterations in K-ras and p53 cancer genes in lung neoplasms of Swiss (CD-1) male mice exposed transplacentally to AZT. Environmental and Molecular Mutagenesis. 48: 299, 2007.[Abstract]  
  15. Houle, C.D., Ton, T., Clayton, N., Huff, J., Hong, H.L., Sills, R.C.: Frequent p53 and H-ras mutations in benzene- and ethylene oxide-induced mammary carcinomas from B6C3F1 mice. Tox. Path. 34: 752, 2006.[Abstract]  
  16. Ton, T., Hong, H.H., Devereux, T.R., Melnick, R.L., Sills, R.C., Kim Y.: Evaluation of genetic alterations in cancer-related genes in lung and brain tumors from B6C3F1 mice exposed to 1,3-butadiene or chloroprene. Chem Biol Interactions. 166: 112, 2006.[Abstract]  
  17. Kim, Y., Ton, T.V., DeAngello, T., Morgan, K., Devereux, T.R., Anna, C., Collins, J.B., Paules, R.S., Crosby, L.M., Sills, R.C.: Major carcinogenic pathways and genes identified by gene expression analysis of peritoneal mesotheliomas following chemical treatment in F344 rats. Toxicol Appl Pharmacol. 214: 144, 2006.[Abstract]  
  18. Lambertini, L., Surin, K., Ton, T.V., Clayton, N., Dunnick, J.K., Kim, Y., Hong, H.H., Devereux, T.R., Sills, R.C.: Analysis of p53 tumor suppressor gene, H-ras protooncogene and proliferating cell nuclear antigen (PCNA) in squamous cell carcinomas of HRA/Skh mice following exposure to 8-methoxypsoralen (8-MOP) and UVA radiation (PUVA therapy). Tox. Path. 33: 292, 2005.[Abstract]  
  19. Kim, Y., Hong, H.H., Lachat, Y., Clayton, N.P., Devereux, T.R., Melnick, R.L., Hegi, M.E., Sills, R.C.: Genetic alterations in brain tumors following 1,3-butadiene exposure in B6C3F1 mice. Tox. Path. 33: 307, 2005.[Abstract]  
  20. Iida, M., Anna, C.H., Holliday, W.M., Collins, J.B., Cunningham, M.L., Sills, R.C., Devereux, T.R.: Unique patterns of gene expression changes in liver after treatment of mice for 2 weeks with different known carcinogens and non-carcinogens. Carcinogenesis. 26: 689, 2005.[Abstract]  
  21. Sills, R.C., Hong, H.L., Flake, G., Moomaw, C., Clayton, N., Boorman, G.A., Dunnick, J., Devereux, T.R.: O-Nitrotoluene-induced large intestinal tumors in B6C3F1 mice model human colon cancer in their molecular pathogenesis. Carcinogenesis. 25: 605, 2004.[Abstract]


Neuropathology Research in Animal Models

  1. Kaufmann W., Bolon B., Bradley A., Butt M., Czasch S., Garman R.H., George C., Groters S., Krinke G., Little P., McKay J., Narama I., Rao D., Shibutani M., Sills, R. Proliferative and nonproliferative lesions of the rat and mouse central and peripheral nervous systems. Toxicologic pathology 40(4 Suppl):87S-157S, 2012.[Abstract]
  2. Hoenerhoff MJ, Hong HH, Ton T, Lahousse SA, Sills RC. A Review of the Molecular Mechanisms of Chemically Induced Neoplasia in Rat and Mouse Models in National Toxicology Program Bioassays and Their Relevance to Human Cancer. Toxicologic pathology. 37(7):835-48, 2009.[Abstract]
  3. Bolon, B., Anthony D.C., Butt, M., Dorman, D., Green, M.V., Little, P., Valentine, W.M., Weinstock, D., Yan, J., Sills, R.C.:“Current Pathology Techniques” symposium review: advances and issues in neuropathology. Toxicologic Pathology. 36: 871, 2008.[Abstract]  
  4. Moser, V., Phillips, P.M., McDaniel, K.L., Sills, R.C.: Neurotoxicological evaluation of two disinfection by-products, bromodichloromethane and dibromoacetonitrile in rats. Toxicology. 230: 137, 2007.[Abstract]  
  5. Herr, D.W., Graff, J.E., Moser, V.C., Crofton, K.M., Little, P.B., Morgan, D.L., Sills, R.C.: Inhalational exposure to carbonyl sulfide (COS) produces altered brainstem auditory (BAER) and somatosensory (SEP) evoked potentials in F344 rats. Toxicological Sciences. 95: 118, 2007.[Abstract]
  6. Cesta, M.F., Mozzachio, P., Little, P.B., Olby, N.J., Sills, R.C., Brown T.T.: Neuronal ceriod lipofuscinosis in a vietnamese pot-bellied pig (Sus Scrofa). Vet Pathol. 43: 556, 2006.[Abstract]  
  7. Sills, R.C., Harry, G.J., Valentine, W.M., Morgan, D.L.: Interdisciplinary neurotoxicity inhalation studies: Carbon disulfide and carbonyl sulfide research in F344 rats. Toxicol Appl Pharmacol, 207 (2 Suppl): 245, 2005.[Abstract]  
  8. Sills, R.C., Morgan, D.L., Herr, D.W., Little, P.B., George, N.M., Ton, T.V., Love, N.E., Maronpot, R.R., Johnson, G.A.: Contribution of magnetic resonance microscopy in the 12-week neurotoxicity evaluation of carbonyl sulfide in Fischer 344 rats. Tox. Path. 32: 501, 2004.[Abstract]  
  9. Morgan, D.L., Little, P.B., Herr, D.W., Moser, V.C., Collins, B., Herbert, R., Johnson, G.A., Maronpot, R.R., Harry, G.J., Sills, R.C.: Neurotoxicity of carbonyl sulfide in F344 rats following inhalation exposure for up to 12 weeks. Toxicol Appl Pharmacol. 200: 131, 2004.[Abstract]  
  10. Moser, V.C., Phillips, P.M., Levine, A.B., McDaniel, K.L., Sills, R.C., Jortner, B.S., Butt, M.T.: Neurotoxicity produced by dibromoacetic acid in drinking water of rats. Toxicol Sci. 79: 112, 2004.[Abstract]  
  11. Sills, R.C., Valentine, W.M., Moser, V., Graham, D.G., Morgan, D.L.: Characterization of carbon disulfide neurotoxicity in C57BL6 mice: Behavioral, morphological and molecular effects. Tox. Path., 28: 142, 2000.[Abstract]  
  12. Sills, R.C., Hailey, J.R., Neal, J., Boorman, G.A., Haseman, J.K., Melnick, R.L.: Examination of low incidence brain tumor responses in F344 rats following chemical exposures in National Toxicology Program Studies. Tox. Path., 27: 589, 1999.[Abstract]

Back to Top

Share This Page:

Page Options:

Request Translation Services