
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.
Pathogenesis/Carcinogenesis of Tumors
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Darlene Dixon, D.V.M., Ph.D., D.A.C.V.P.
Acting Chief, Mechanistic Toxicology Branch -
Tel 984-287-3848
[email protected] -
P.O. Box 12233Mail Drop B3-06Durham, NC 27709
Research Summary
The Molecular Pathogenesis Group has focused on defining the pathogenesis/carcinogenesis of tumors affecting the reproductive tract of rodents and humans, and assessing the role of environmental and endogenous hormonal factors in the growth of these tumors.
The group has used cell lines, archival mouse tissue and human clinical samples to investigate the influence of growth factors/receptors and their signaling pathways on uterine leiomyoma (fibroid) growth. The clinical tissues used are leiomyoma and patient-matched myometrial samples taken from cycle-staged, premenopausal women that are part of the NIEHS/George Washington University Fibroid Study. The rodent tissue samples are from either in-house studies or the archives of the NTP.
By understanding the basic mechanisms of disease, therapeutic interventions can be developed that will help spawn alternative non-invasive treatments for clinical fibroids and other diseases.
Major areas of research:
- Determination of the role of growth factors/receptors and their signaling pathways in regulating uterine fibroid growth
- Investigation of the effects of endogenous and environmental hormones on uterine fibroid growth
- Characterization of in vitro and animal models for studying the pathogenesis of uterine fibroids
Current projects:
- Animal models of human disease
- Effects of bromoethane in the uterus of ovariectomized B6C3F1 mice
- Induction of telomerase activity in human uterine leiomyoma cell lines
- Role of growth factors in the pathogenesis of uterine leiomyoma growth in women
Darlene Dixon, D.V.M., Ph.D., leads the Molecular Pathogenesis Group within the NTP Laboratory. She earned her Doctor of Veterinary Medicine (D.V.M.) degree in 1982 at Tuskegee University School of Veterinary Medicine and her Ph.D. in 1985 at Michigan State University. She served as a Postdoctoral Fellow at The Rockefeller University before joining NIEHS in 1987. She is a Diplomate in the American College of Veterinary Pathologists (ACVP board certified in 1987).
Recent Publications
- Ooka M, Zhao J, Zhang L, Huang R, Sakamuru S, TeKrony C, Hsieh J, Collins B, Dunnick J, Dixon D, Xia M. Profiling of Environmental Mixtures Containing Metals for Their Toxicity Pathways and Mechanism of Action. Environmental science & technology. 2025 Mar 18;59(10):4778-4787. [ AbstractOoka M, Zhao J, Zhang L, Huang R, Sakamuru S, TeKrony C, Hsieh J, Collins B, Dunnick J, Dixon D, Xia M. Profiling of Environmental Mixtures Containing Metals for Their Toxicity Pathways and Mechanism of Action. Environmental science & technology. 2025 Mar 18 ]
- Wu X, Kreutz A, Dixon D, Tokar E. Engineering human cerebral organoids to explore mechanisms of arsenic-induced developmental neurotoxicity. Toxicology and applied pharmacology. 2025 Mar;496:117230. [ AbstractWu X, Kreutz A, Dixon D, Tokar E. Engineering human cerebral organoids to explore mechanisms of arsenic-induced developmental neurotoxicity. Toxicology and applied pharmacology. 2025 Mar ]
- Smarr M, Rappazzo K, Dixon D. Editorial: Environmental impacts on women's health disparities and reproductive health: advancing environmental health equity in clinical and public health practice. Frontiers in reproductive health. 2024;6:1484406. [ AbstractSmarr M, Rappazzo K, Dixon D. Editorial: Environmental impacts on women's health disparities and reproductive health: advancing environmental health equity in clinical and public health practice. Frontiers in reproductive health. 2024 ]
- Liu J, Yu L, Castro L, Yan Y, Bushel P, Scappini E, Dixon D. Induction of fibrosis following exposure to bisphenol A and its analogues in 3D human uterine leiomyoma cultures. Journal of hazardous materials. 2024 Sep 05;476:134772. [ AbstractLiu J, Yu L, Castro L, Yan Y, Bushel P, Scappini E, Dixon D. Induction of fibrosis following exposure to bisphenol A and its analogues in 3D human uterine leiomyoma cultures. Journal of hazardous materials. 2024 Sep 05 ]
- Mark Z, Yu L, Castro L, Gao X, Rodriguez N, Sutton D, Scappini E, Tucker C, Wine R, Yan Y, Motley E, Dixon D. Tobacco Smoke Condensate Induces Morphologic Changes in Human Papillomavirus-Positive Cervical Epithelial Cells Consistent with Epithelial to Mesenchymal Transition (EMT) with Activation of Receptor Tyrosine Kinases and Regulation of TGFB. International journal of molecular sciences. 2024 Apr 30;25(9):. [ AbstractMark Z, Yu L, Castro L, Gao X, Rodriguez N, Sutton D, Scappini E, Tucker C, Wine R, Yan Y, Motley E, Dixon D. Tobacco Smoke Condensate Induces Morphologic Changes in Human Papillomavirus-Positive Cervical Epithelial Cells Consistent with Epithelial to Mesenchymal Transition (EMT) with Activation of Receptor Tyrosine Kinases and Regulation of TGFB. International journal of molecular sciences. 2024 Apr 30 ]
NTP Reports
- CLARITY-BPA Research Program. NTP Research Report on the Consortium Linking Academic and Regulatory Insights on Bisphenol A Toxicity (CLARITY-BPA): A Compendium of Published Findings: Research Report 18 NTP Research Reports. 2021 Oct [Epub ahead of print]. [ AbstractCLARITY-BPA Research Program. NTP Research Report on the Consortium Linking Academic and Regulatory Insights on Bisphenol A Toxicity (CLARITY-BPA): A Compendium of Published Findings: Research Report 18 NTP Research Reports. 2021 Oct ]