Breast Cancer Research and Treatment

, Volume 79, Issue 3, pp 313–320

Growth and Fatty Acid Metabolism of Human Breast Cancer (MCF-7) Xenografts in Nude Rats: Impact of Constant Light-Induced Nocturnal Melatonin Suppression

  • David E. Blask
  • Robert T. Dauchy
  • Leonard A. Sauer
  • Jean A. Krause
  • George C. Brainard
Article

DOI: 10.1023/A:1024030518065

Cite this article as:
Blask, D.E., Dauchy, R.T., Sauer, L.A. et al. Breast Cancer Res Treat (2003) 79: 313. doi:10.1023/A:1024030518065

Abstract

The nocturnal melatonin (MLT) surge is a relevant oncostatic signal for a variety of experimental malignancies. Population studies support the hypothesis that exposure to light at night may represent a new risk factor for breast cancer possibly through the suppression of pineal MLT production and/or circadian disruption. We tested the ability of constant light exposure to suppress MLT production in female nude rats and stimulate the growth of tissue-isolated MCF-7 human breast cancer xenografts via increased tumor linoleic acid (LA) metabolism. Rats maintained on an alternating light/dark cycle (L:D group) exhibited a robust circadian MLT rhythm that was abolished following constant light exposure. During the exposure of animals bearing tissue-isolated human MCF-7 breast cancer xenografts to constant light, the rate of tumor growth markedly increased relative to the L:D group. Tumor LA uptake and its metabolism to the mitogen 13-hydroxyoctadecadienoic acid (13-HODE) were also substantially higher under constant light conditions. This is the first biological evidence for a potential link between constant light exposure and increased human breast oncogenesis involving MLT suppression and stimulation of tumor LA metabolism.

circadian disruption constant light fatty acids MCF-7 human breast cancer xenografts melatonin pineal gland 

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • David E. Blask
    • 1
  • Robert T. Dauchy
    • 1
  • Leonard A. Sauer
    • 1
  • Jean A. Krause
    • 1
  • George C. Brainard
    • 2
  1. 1.Laboratory of Chrono-Neuroendocrine OncologyBassett Research InstituteCooperstownUSA
  2. 2.Department of Neurology, Jefferson Medical CollegeThomas Jefferson UniversityPhiladelphiaUSA

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