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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
