Radio-Adaptive Response and Breast Cancer
Final rept. 15 Sep 2010-14 Sep 2011
CALIFORNIA PACIFIC MEDICAL CENTER RESEARCH INST SAN FRANCISCO
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Hormesis describes a phenomenon where low doses of toxic substances or radiation stimulate responses that might counteract the harmful effects of a subsequent high level of stress. We hypothesized that low doses of radiation received through mammography could be beneficial for patients. We therefore treated human breast epithelial cells with X-rays at low doses, high doses, or at low doses followed by high doses. We then scored cells for the effects of these various doses on the number of DNA damage 53BP1 foci and on the ability to trigger cell senescence. Based on the results we have obtained so far, there was no significant change in the amount of DNA damage foci generated nor in the induction of senescence when cells were pre-treated with low doses of ionizing radiation and subsequently challenged by a high dose of ionizing radiation. Moreover, there was no effect on chromatin modifications in mammary epithelial cells, whereas low doses of radiation appeared to have some effects in human fibroblasts. In conclusion, our data suggest that low doses of radiation are not protective, nor detrimental, in mammary epithelial cells, whereas in other cell types, such as fibroblasts, these low doses of radiation appear to be protective.
- Anatomy and Physiology
- Medicine and Medical Research