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Much of the work carried out by DTT is in support of the National Toxicology Program (NTP), an interagency partnership of the Food and Drug Administration, National Institute for Occupational Safety and Health, and NIEHS.

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Mechanistic Toxicology Branch

Erik Tokar, Ph.D.
Erik Tokar, Ph.D.
Staff Scientist
Tel 984-287-4173
[email protected]
P.O. Box 12233
Mail Drop E1-07
Durham, NC 27709

Selected Publications

  1. Wu X, Chen Y, Luz A, Hu G, Tokar EJ. 2022. Cardiac development in the presence of cadmium: An in vitro study using human embryonic stem cells and cardiac organoids. Environ Health Perspect. 130(11):117002. [Abstract Wu X, Chen Y, Luz A, Hu G, Tokar EJ. 2022. Cardiac development in the presence of cadmium: An in vitro study using human embryonic stem cells and cardiac organoids. Environ Health Perspect. 130(11):117002.]
  2. Escudero-Lourdes C, Alvarado-Morales I, Tokar EJ. 2022. Stem cells as target for prostate cancer therapy: Opportunities and challenges. Stem Cell Rev Rep. 18(8):2833-2851. [Abstract Escudero-Lourdes C, Alvarado-Morales I, Tokar EJ. 2022. Stem cells as target for prostate cancer therapy: Opportunities and challenges. Stem Cell Rev Rep. 18(8):2833-2851.]
  3. Alvarado-Morales I, Olivares-Illana V, Arenas-Huertero C, Reynaga-Hernández E, Layseca-Espinosa E, Tokar EJ, Escudero-Lourdes C. 2021. Human prostate epithelial cells and prostate-derived stem cells malignantly transformed in vitro with sodium arsenite show impaired Toll like receptor -3 (TLR3)-associated anti-tumor pathway. Toxicol Lett. 350:185-193. [Abstract Alvarado-Morales I, Olivares-Illana V, Arenas-Huertero C, Reynaga-Hernández E, Layseca-Espinosa E, Tokar EJ, Escudero-Lourdes C. 2021. Human prostate epithelial cells and prostate-derived stem cells malignantly transformed in vitro with sodium arsenite show impaired Toll like receptor -3 (TLR3)-associated anti-tumor pathway. Toxicol Lett. 350:185-193.]
  4. Xu Y, Tokar EJ, Pi J. 2021. Arsenic as an environmental toxicant and a therapeutic agent: Foe and friend. Toxicol Appl Pharmacol; doi: 10.1016/j.taap.2021.115438 [Online 15 March 2021]. [Abstract Xu Y, Tokar EJ, Pi J. 2021. Arsenic as an environmental toxicant and a therapeutic agent: Foe and friend. Toxicol Appl Pharmacol; doi: 10.1016/j.taap.2021.115438 [Online 15 March 2021].]
  5. Upson K, O’Brien K, Hall J, Tokar EJ, and Baird D. Cadmium Exposure and Ovarian Reserve in Women Ages 35-49 Years: The Impact of Urinary Creatinine Adjustment Approach to Correct for Urinary Dilution on Results (In Press, Am J Epidemiol)
  6. Merrick BA, Phadke DP, Bostrom MA, Shah RR, Wright GM, Wang X, Gordon O, Auerbach SS, Paules RS, DeVito MJ, Waalkes MP, and Tokar EJ. Arsenite malignantly transforms human prostate epithelial cells in vitro by gene amplification of mutated KRAS. PLoS One 14(4):e0215504, 2019. [Abstract Merrick BA, Phadke DP, Bostrom MA, Shah RR, Wright GM, Wang X, Gordon O, Auerbach SS, Paules RS, DeVito MJ, Waalkes MP, and Tokar EJ. Arsenite malignantly transforms human prostate epithelial cells in vitro by gene amplification of mutated KRAS. PLoS One 14(4):e0215504, 2019.]
  7. Gwinn WM, Bell M, Tokar EJ, Dixon D, Crizer D, Urbano N, Roberts GK, Masten, S, DeVito M. NTP Research Report on Synthetic Turf/Recycled Tire Crumb Rubber: Characterization of the Leachability and Cytotoxicity of Crumb Rubber In Vitro. NTP RR 12. Research Triangle Park, NC: National Toxicology Program. (12): 1-11, 2019. [Abstract Gwinn WM, Bell M, Tokar EJ, Dixon D, Crizer D, Urbano N, Roberts GK, Masten, S, DeVito M. NTP Research Report on Synthetic Turf/Recycled Tire Crumb Rubber: Characterization of the Leachability and Cytotoxicity of Crumb Rubber In Vitro. NTP RR 12. Research Triangle Park, NC: National Toxicology Program. (12): 1-11, 2019.]
  8. Nachman KE, Punshon T, Rardin L, Signes‐Pastor AJ, Murray CJ, Jackson BP, Guerinot ML, Burke TA, Chen CY, Tokar EJ, Karagas MR. Opportunities and Challenges for Dietary Arsenic Intervention. Environ. Health Perspect. 126(8): 84503, 2018. [Abstract Nachman KE, Punshon T, Rardin L, Signes‐Pastor AJ, Murray CJ, Jackson BP, Guerinot ML, Burke TA, Chen CY, Tokar EJ, Karagas MR. Opportunities and Challenges for Dietary Arsenic Intervention. Environ. Health Perspect. 126(8): 84503, 2018.]
  9. Luz AL, Wu X, Tokar EJ. Toxicology of Inorganics, Chapter 1; in Fishbein, J. (Ed): Advances in Molecular Toxicology, 2018. Vol. 12, Elsevier. (In Press)
  10. Ngalame NNO, Luz A, Makia NL, and Tokar EJ. Arsenic Alters Exosome Quantity and Cargo to Mediate Stem Cell Recruitment into a Cancer Stem Cell-like Phenotype. Toxicological Sciences. 2018. (In Press) doi: 10.1093/toxsci/kfy176
  11. Luz AL, Tokar EJ. Pluripotent Stem Cells in Developmental Toxicity Testing: A Review of Methodological Advances. Toxicological Sciences. 2018. (In Press) doi: 10.1093/toxsci/kfy174 (In Press)
  12. Ren NSX, Ji M, Tokar EJ, Busch E, Xu X, Lewis D, Xu Q, Li X, Wu WKK, Fargo DC, Keku T, Sandler R, and Li X: Haploinsufficiency of SIRT1 enhances glutamine metabolism and promotes cancer development. Current Biol. 27(4): 483-494, 2017. [Abstract Ren NSX, Ji M, Tokar EJ, Busch E, Xu X, Lewis D, Xu Q, Li X, Wu WKK, Fargo DC, Keku T, Sandler R, and Li X: Haploinsufficiency of SIRT1 enhances glutamine metabolism and promotes cancer development. Current Biol. 27(4): 483-494, 2017.]
  13. Ganini D, Leinisch F, Kumar A, Jiang JJ, Tokar EJ, Malone CC, Petrovich RM, and Mason RP. Fluorescent proteins such as eGFP lead to catalytic oxidative stress in cells. Redox Biol. 12:462-468, 2017. [Abstract Ganini D, Leinisch F, Kumar A, Jiang JJ, Tokar EJ, Malone CC, Petrovich RM, and Mason RP. Fluorescent proteins such as eGFP lead to catalytic oxidative stress in cells. Redox Biol. 12:462-468, 2017.]
  14. Morgan DL, Dixon D, King DH, Travlos GS, Herbert RA, French JE, Tokar EJ, Waalkes MP, Jokinen M P. NTP Research Report on Absence of Formaldehyde-Induced Neoplasia in Trp53 Haploinsufficient Mice Exposed by Inhalation. NTP RR 3. Research Triangle Park, NC: National Toxicology Program. (3): 1-30, 2017. [Abstract Morgan DL, Dixon D, King DH, Travlos GS, Herbert RA, French JE, Tokar EJ, Waalkes MP, Jokinen M P. NTP Research Report on Absence of Formaldehyde-Induced Neoplasia in Trp53 Haploinsufficient Mice Exposed by Inhalation. NTP RR 3. Research Triangle Park, NC: National Toxicology Program. (3): 1-30, 2017.]
  15. Tokar EJ, Waalkes MP. Cancer Induced by Exposure to Arsenicals in Animals, Chapter 19; In; States, J. C. (Ed): Arsenic: Exposure Sources, Health Risks and Mechanisms of Toxicity, John Wiley & Sons, Inc. pp. 441-452, 2016.
  16. Tokar EJ, Xu Y, Waalkes MP. Stem Cell Targeting and Alteration by Arsenic, Chapter 17; In; States, J. C. (Ed): Arsenic: Exposure Sources, Health Risks and Mechanisms of Toxicity, John Wiley & Sons, Inc., pp. 397-420, 2016.
  17. Bailey KA, Smith AH, Tokar EJ, Graziano JH, Kim KW, Navasumrit P, Ruchirawat M, Thiantanawat A, Suk WA, Fry RC. Mechanisms underlying disease risk associated with early-life arsenic exposure: current research trends and scientific gaps. Environmental Health Perspectives 124(2):170–175, 2016. [Abstract Bailey KA, Smith AH, Tokar EJ, Graziano JH, Kim KW, Navasumrit P, Ruchirawat M, Thiantanawat A, Suk WA, Fry RC. Mechanisms underlying disease risk associated with early-life arsenic exposure: current research trends and scientific gaps. Environmental Health Perspectives 124(2):170–175, 2016.]
  18. Ngalame NNO, Makia NL, Waalkes MP, and Tokar EJ. Mitigation of arsenic-induced acquired cancer phenotype in prostate cancer stem cells by miR-143 restoration. Toxicology and applied pharmacology 312: 11-18, 2016. [Abstract Ngalame NNO, Makia NL, Waalkes MP, and Tokar EJ. Mitigation of arsenic-induced acquired cancer phenotype in prostate cancer stem cells by miR-143 restoration. Toxicology and applied pharmacology 312: 11-18, 2016.]
  19. Tokar, EJ. MicroRNAs: Small molecules with big effects. Toxicology and applied pharmacology 312: 1–2, 2016 [Special Issue Guest Editorial].
  20. Kumar A, Ehrenshaft M, Tokar EJ, Mason RP, and Sinha BK. Nitric oxide inhibits Topoisomerase II activity and induces resistance to Topoisomerase II-poisons in human tumor cells. Biochimica et Biophysica Acta 1860(7): 1519-1527, 2016. [Abstract Kumar A, Ehrenshaft M, Tokar EJ, Mason RP, and Sinha BK. Nitric oxide inhibits Topoisomerase II activity and induces resistance to Topoisomerase II-poisons in human tumor cells. Biochimica et Biophysica Acta 1860(7): 1519-1527, 2016.]
  21. Carlin DJ, Naujokas MF, Bradham K, Cowden J, Heacock M, Henry H, Lee J, Thomas DJ, Thompson C, Tokar FJ, Waalkes MP, Birnbaum LS, and Suk WA. Arsenic and Environmental Health: State of the Science and Future Research Opportunities. Environmental Health Perspectives 124(7): 890-899, 2016.
  22. Ngalame NO, Waalkes MP, Tokar EJ. Silencing KRAS Overexpression in Cadmium-Transformed Prostate Epithelial Cells Mitigates Malignant Phenotype. Chemical research in toxicology 29(9): 1458-1467, 2016. [Abstract Ngalame NO, Waalkes MP, Tokar EJ. Silencing KRAS Overexpression in Cadmium-Transformed Prostate Epithelial Cells Mitigates Malignant Phenotype. Chemical research in toxicology 29(9): 1458-1467, 2016.]
  23. Pelch KE, Tokar EJ, Merrick BA, and Waalkes MP. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium. Toxicology and applied pharmacology 286(3):159-167, 2015. [Abstract Pelch KE, Tokar EJ, Merrick BA, and Waalkes MP. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium. Toxicology and applied pharmacology 286(3):159-167, 2015.]
  24. Tokar EJ, Person RJ, Ngalame NN, Qu W, Waalkes, MP. Oxidative Stress and the Inorganic Carcinogens, Chapter 16; In Kehrer, Roberts, Klotz (Eds): Oxidative Stress in Applied Basic Research and Clinical Practice, Springer (Humana Press), pp. 323-334, 2015.
  25. Sharma NK, Kumar A, Kumari A, Tokar EJ, Waalkes MP, Bortner CD, Williams J, Mason RP, Sinha BK. Nitric Oxide Down-Regulates Topoisomerase I and Induces Camptothecin Resistance in Human Breast MCF-7 Tumor Cells. PloS one 10(11):- , 2015. [Abstract Sharma NK, Kumar A, Kumari A, Tokar EJ, Waalkes MP, Bortner CD, Williams J, Mason RP, Sinha BK. Nitric Oxide Down-Regulates Topoisomerase I and Induces Camptothecin Resistance in Human Breast MCF-7 Tumor Cells. PloS one 10(11):- , 2015.]
  26. Person RJ, Olive Ngalame NN, Makia NL, Bell MW, Waalkes MP, Tokar EJ. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells.Toxicology and applied pharmacology  286(1):36-43, 2015. [Abstract Person RJ, Olive Ngalame NN, Makia NL, Bell MW, Waalkes MP, Tokar EJ. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells.Toxicology and applied pharmacology  286(1):36-43, 2015.]
  27. Xu Y, Tokar EJ, Waalkes MP. Arsenic-induced transformation of human breast epithelia is estrogen receptor-independent but involves aromatase activation. Arch Toxicol 88(2): 263-274, 2014. [Abstract Xu Y, Tokar EJ, Waalkes MP. Arsenic-induced transformation of human breast epithelia is estrogen receptor-independent but involves aromatase activation. Arch Toxicol 88(2): 263-274, 2014.]
  28. Ngalame NN, Tokar EJ, Person RJ, Xu Y, Waalkes MP. Aberrant microRNA expression likely controls RAS oncogene activation during malignant transformation of human prostate epithelial and stem cells by arsenic. Toxicol. Sci. 138(2): 268-277, 2014. [Abstract Ngalame NN, Tokar EJ, Person RJ, Xu Y, Waalkes MP. Aberrant microRNA expression likely controls RAS oncogene activation during malignant transformation of human prostate epithelial and stem cells by arsenic. Toxicol. Sci. 138(2): 268-277, 2014.]
  29. Waalkes MP, Qu W, Tokar EJ, Kissling GE, Dixon D. Lung tumors in mice induced by "whole life" inorganic arsenic exposure at human relevant doses. Arch. Toxicol. 88(8): 1619-1629, 2014. [Abstract Waalkes MP, Qu W, Tokar EJ, Kissling GE, Dixon D. Lung tumors in mice induced by "whole life" inorganic arsenic exposure at human relevant doses. Arch. Toxicol. 88(8): 1619-1629, 2014.]
  30. Ngalame NN, Tokar EJ, Person RJ, Waalkes MP. Silencing KRAS overexpression in arsenic-transformed prostate epithelial and stem cells partially mitigates malignant phenotype. Toxicol. Sci. 142(2): 489-496, 2014 [Abstract Ngalame NN, Tokar EJ, Person RJ, Waalkes MP. Silencing KRAS overexpression in arsenic-transformed prostate epithelial and stem cells partially mitigates malignant phenotype. Toxicol. Sci. 142(2): 489-496, 2014]
  31. Tokar EJ, Kojima C, Waalkes MP. Methylarsonous acid causes oxidative DNA damage in cells independent of the ability to biomethylate inorganic arsenic. Archives of Toxicology, 88(2):249-261, 2014. [Abstract Tokar EJ, Kojima C, Waalkes MP. Methylarsonous acid causes oxidative DNA damage in cells independent of the ability to biomethylate inorganic arsenic. Archives of Toxicology, 88(2):249-261, 2014.]
  32. Tokar EJ, Boyd W, Freedman JH, Waalkes MP. Toxic Effects of Metals, Chapter 23; In: Klaassen, C. D. (Ed): Casarett and Doull's Toxicology: The Basic Science of Poisons, 8th Edition, McGraw-Hill Medical, New York, 2013.
  33. Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Coordinate H3K9 and DNA methylation silencing of ZNFs in toxicant-induced malignant transformation. Epigenetics 8(10): 1080-1088, 2013 [Abstract Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Coordinate H3K9 and DNA methylation silencing of ZNFs in toxicant-induced malignant transformation. Epigenetics 8(10): 1080-1088, 2013]
  34. Tokar EJ, Person RJ, Sun Y, Perantoni AO, Waalkes MP. Chronic exposure of renal stem cells to inorganic arsenic induces a cancer phenotype. Chemical research in toxicology, 26(1):96-105, 2013. [Abstract Tokar EJ, Person RJ, Sun Y, Perantoni AO, Waalkes MP. Chronic exposure of renal stem cells to inorganic arsenic induces a cancer phenotype. Chemical research in toxicology, 26(1):96-105, 2013.]
  35. Person RJ, Tokar EJ, Xu Y, Orihuela R, Ngalame NN, Waalkes MP. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells. Toxicology and Applied Pharmacology 273(2):281-8, 2013. [Abstract Person RJ, Tokar EJ, Xu Y, Orihuela R, Ngalame NN, Waalkes MP. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells. Toxicology and Applied Pharmacology 273(2):281-8, 2013.]
  36. Xu Y, Tokar EJ, Person RJ, Orihuela RG, Ngalame NN, Waalkes MP. Recruitment of normal stem cells to an oncogenic phenotype by noncontiguous carcinogen-transformed epithelia depends on the transforming carcinogen. Environmental health perspectives 121(8):944-950, 2013. [Abstract Xu Y, Tokar EJ, Person RJ, Orihuela RG, Ngalame NN, Waalkes MP. Recruitment of normal stem cells to an oncogenic phenotype by noncontiguous carcinogen-transformed epithelia depends on the transforming carcinogen. Environmental health perspectives 121(8):944-950, 2013.]
  37. Chatterjee S, Ganini D, Tokar EJ, Kumar A, Das S, Corbett J, Kadiiska M, Waalkes M, Diehl AM, Mason RP. Leptin is key to peroxynitrite-mediated oxidative stress and Kupffer cell activation in experimental non-alcoholic steatohepatitis. Journal of hepatology 2013 58(4):778-784. [Abstract Chatterjee S, Ganini D, Tokar EJ, Kumar A, Das S, Corbett J, Kadiiska M, Waalkes M, Diehl AM, Mason RP. Leptin is key to peroxynitrite-mediated oxidative stress and Kupffer cell activation in experimental non-alcoholic steatohepatitis. Journal of hepatology 2013 58(4):778-784.]
  38. Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Agglomerates of aberrant DNA methylation are associated with toxicant-induced malignant transformation. Epigenetics: official journal of the DNA Methylation Society 7(11):1238-1248, 2012. [Abstract Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Agglomerates of aberrant DNA methylation are associated with toxicant-induced malignant transformation. Epigenetics: official journal of the DNA Methylation Society 7(11):1238-1248, 2012.]
  39. Xu Y, Tokar EJ, Sun Y, Waalkes MP. Arsenic-transformed malignant prostate epithelia can convert noncontiguous normal stem cells into an oncogenic phenotype. Environmental health perspectives. 120(6):865-71, 2012. [Abstract Xu Y, Tokar EJ, Sun Y, Waalkes MP. Arsenic-transformed malignant prostate epithelia can convert noncontiguous normal stem cells into an oncogenic phenotype. Environmental health perspectives. 120(6):865-71, 2012.]
  40. Tokar EJ, Diwan BA, Thomas DJ, Waalkes MP. Tumors and proliferative lesions in adult offspring after maternal exposure to methylarsonous acid during gestation in CD1 mice. Archives of toxicology  86(6):975-82, 2012. [Abstract Tokar EJ, Diwan BA, Thomas DJ, Waalkes MP. Tumors and proliferative lesions in adult offspring after maternal exposure to methylarsonous acid during gestation in CD1 mice. Archives of toxicology  86(6):975-82, 2012.]
  41. Qu W, Tokar EJ, Kim AJ, Bell MW, Waalkes MP. Chronic cadmium exposure in vitro causes acquisition of multiple tumor cell characteristics in human pancreatic epithelial cells. Environmental health perspectives.  120(9):1265-71, 2012. [Abstract Qu W, Tokar EJ, Kim AJ, Bell MW, Waalkes MP. Chronic cadmium exposure in vitro causes acquisition of multiple tumor cell characteristics in human pancreatic epithelial cells. Environmental health perspectives.  120(9):1265-71, 2012.]
  42. Sun Y, Tokar EJ, Waalkes MP. Overabundance of Putative Cancer Stem Cells in Human Skin Keratinocyte Cells Malignantly Transformed by Arsenic. Toxicological Sciences 125(1):20-29, 2012. [Abstract Sun Y, Tokar EJ, Waalkes MP. Overabundance of Putative Cancer Stem Cells in Human Skin Keratinocyte Cells Malignantly Transformed by Arsenic. Toxicological Sciences 125(1):20-29, 2012.]
  43. Tokar, E.J., Benbrahim-Tallaa, L., and Waalkes, M. P.: Metal ions in human cancer development.  Met Ions Life Sci. 8: 375-401, 2011. [Abstract Tokar, E.J., Benbrahim-Tallaa, L., and Waalkes, M. P.: Metal ions in human cancer development.  Met Ions Life Sci. 8: 375-401, 2011.]
  44. Tokar, E. J., Qu, W., and Waalkes, M. P.: Arsenic, stem cells, and the developmental basis of adult cancer.  Toxicol Sci. 120 Suppl 1: S192-203, 2011. [Abstract Tokar, E. J., Qu, W., and Waalkes, M. P.: Arsenic, stem cells, and the developmental basis of adult cancer.  Toxicol Sci. 120 Suppl 1: S192-203, 2011.]
  45. Tokar, E.J., Diwan, B.A., Ward, J.M., Delker, D.A., and Waalkes, M.P.: Carcinogenic effects of "whole-life" exposure to inorganic arsenic in CD1 mice.  Toxicol Sci. 119: 73-83, 2011. [Abstract Tokar, E.J., Diwan, B.A., Ward, J.M., Delker, D.A., and Waalkes, M.P.: Carcinogenic effects of "whole-life" exposure to inorganic arsenic in CD1 mice.  Toxicol Sci. 119: 73-83, 2011.]
  46. Tokar, E. J., Benbrahim-Tallaa, L., Ward, J.M., Lunn, R., Sams, R. L., 2nd, and Waalkes, M. P.: Cancer in experimental animals exposed to arsenic and arsenic compounds.  Crit Rev Toxicol. 40: 912-927, 2010. [Abstract Tokar, E. J., Benbrahim-Tallaa, L., Ward, J.M., Lunn, R., Sams, R. L., 2nd, and Waalkes, M. P.: Cancer in experimental animals exposed to arsenic and arsenic compounds.  Crit Rev Toxicol. 40: 912-927, 2010.]
  47. Tokar, E. J., Diwan, B. A., and Waalkes, M. P.: Early life inorganic lead exposure induces testicular teratoma and renal and urinary bladder preneoplasia in adult metallothionein-knockout mice but not in wild type mice.  Toxicology. 276: 5-10, 2010. [Abstract Tokar, E. J., Diwan, B. A., and Waalkes, M. P.: Early life inorganic lead exposure induces testicular teratoma and renal and urinary bladder preneoplasia in adult metallothionein-knockout mice but not in wild type mice.  Toxicology. 276: 5-10, 2010.]
  48. Tokar, E. J., Diwan, B.A., and Waalkes, M.P.: Arsenic exposure in utero and nonepidermal proliferative response in adulthood in Tg.AC mice.  Int J Toxicol. 29: 291-296, 2010. [Abstract Tokar, E. J., Diwan, B.A., and Waalkes, M.P.: Arsenic exposure in utero and nonepidermal proliferative response in adulthood in Tg.AC mice.  Int J Toxicol. 29: 291-296, 2010.]
  49. Tokar, E. J., Qu, W., Liu, J., Liu, W., Webber, M. M., Phang, J., and Waalkes, M. P.: Arsenic-specific stem cell selection during malignant transformation.  J. Natl. Cancer Inst. 102: 638-649, 2010. [Abstract Tokar, E. J., Qu, W., Liu, J., Liu, W., Webber, M. M., Phang, J., and Waalkes, M. P.: Arsenic-specific stem cell selection during malignant transformation.  J. Natl. Cancer Inst. 102: 638-649, 2010.]
  50. Tokar, E. J., Diwan, B. A., and Waalkes, M. P.: Arsenic exposure transforms human epithelial stem/progenitor cells into a cancer stem-like phenotype.  Envron. Health Perspect. 118: 108-115, 2010. [Abstract Tokar, E. J., Diwan, B. A., and Waalkes, M. P.: Arsenic exposure transforms human epithelial stem/progenitor cells into a cancer stem-like phenotype.  Envron. Health Perspect. 118: 108-115, 2010.]
  51. Benbrahim-Tallaa, L., Tokar, E. J., Diwan, B. A., Dill, A. L., Coppin, J. F., and Waalkes, M. P.: Cadmium malignantly transforms normal human breast epithelial cells into a basal-like phenotype. Envron. Health Perspect. 117: 1847-1852, 2009. [Abstract Benbrahim-Tallaa, L., Tokar, E. J., Diwan, B. A., Dill, A. L., Coppin, J. F., and Waalkes, M. P.: Cadmium malignantly transforms normal human breast epithelial cells into a basal-like phenotype. Envron. Health Perspect. 117: 1847-1852, 2009.]
  52. Kojima, C., Ramirez, D. C., Tokar, E. J., Himeno, S., Drobná, Z., Stýblo, M., Mason, R. P., and Waalkes, M. P.: Requirement of arsenic biomethylation for oxidative DNA damage.  J. Natl. Cancer Inst. 101: 1670-1681, 2009. [Abstract Kojima, C., Ramirez, D. C., Tokar, E. J., Himeno, S., Drobná, Z., Stýblo, M., Mason, R. P., and Waalkes, M. P.: Requirement of arsenic biomethylation for oxidative DNA damage.  J. Natl. Cancer Inst. 101: 1670-1681, 2009.]
  53. Sun, Y., Pi, J., Wang, X., Tokar, E. J., Liu, J., and Waalkes, M. P.: Aberrant cytokeratin expression during arsenic-induced acquired malignant phenotype in human HaCaT keratinocytes consistent with epidermal carcinogenesis.  Toxicology. 262: 162-170, 2009. [Abstract Sun, Y., Pi, J., Wang, X., Tokar, E. J., Liu, J., and Waalkes, M. P.: Aberrant cytokeratin expression during arsenic-induced acquired malignant phenotype in human HaCaT keratinocytes consistent with epidermal carcinogenesis.  Toxicology. 262: 162-170, 2009.]
  54. Waalkes, M. P., Liu, J., Germolec, D. R., Trempus, C. S., Cannon, R. E., Tokar, E. J., Tennant, R. W., Ward, J. M., and Diwan, B. A.: Arsenic exposure in utero exacerbates skin cancer response in adulthood with contemporaneous distortion of tumor stem cell dynamics. Cancer Res. 68: 8278-8285, 2008. [Abstract Waalkes, M. P., Liu, J., Germolec, D. R., Trempus, C. S., Cannon, R. E., Tokar, E. J., Tennant, R. W., Ward, J. M., and Diwan, B. A.: Arsenic exposure in utero exacerbates skin cancer response in adulthood with contemporaneous distortion of tumor stem cell dynamics. Cancer Res. 68: 8278-8285, 2008.]