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NCTR Research Highlights

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Current Highlight from September 5, 2014

Dissecting Tamoxifen Toxicity

Tamoxifen is:

  • clinically invaluable to prevent recurrence of breast cancer, or occurrence of breast cancer in high risk populations
  • noted to increase incidence of endometrial cancer and Non-Alcoholic Fatty Liver Disease (NAFLD) in humans
  • a well-established liver carcinogen in rats, but it is not thought to be a liver carcinogen in mice
  • known to cause both genetic and epigenetic changes in rats; and NAFLD changes are present

The current studies conducted at NCTR demonstrate that tumorigenic dose treatments in mice produce the same levels of genetic damage observed in rats, but epigenetic and NAFLD-associated injuries are not present; and may explain the variability of tamoxifen toxicity.  These results provide additional evidence that carcinogenesis requires both genotoxic and non-genotoxic alterations and highlights the role of epigenetic alterations in carcinogenesis. (Toxicology, http://dx.doi.org/10.1016/j.tox.2014.08.004disclaimer icon). 

For additional information, please contact Igor Pogribny, Ph.D., Division of Biochemical Toxicology, FDA/NCTR.


Contact FDA

National Center for Toxicological Research

Food and Drug Administration

3900 NCTR Road

Jefferson, AR 72079

Page Last Updated: 09/08/2014
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