Radiation-Induced Apoptosis in Breast Cancer Cells
Final rept. 29 Aug 94-28 Aug 98
MASSACHUSETTS GENERAL HOSPITAL BOSTON
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This project was designed to study the role of apoptosis in breast cancer cells exposed to ionizing radiation and hormonal manipulation in vitro and to investigate the potential for using these manipulations to enhance tumor cell killing, thus improving radiotherapy of breast cancer. Several new, and potentially important, observations are reported herein. First, breast cancer cell lines in vitro generally do not appear to be particularly sensitive to induction of apoptosis, and even when they do undergo apoptosis in response to some treatments, do not fragment their DNA to oligonucleosomal sized pieces. Second, breast cancer cell lines in vitro appear to be resistant to radiation-induced apoptosis. At this time, the reasons for this observation and its potential clinical significance are not clear, but the finding clearly deserves further investigation because of its potential clinical importance. Third, in some breast cancer cell lines tamoxifen treatment prior to irradiation does not alter the radiation response, but in others tamoxifen pre-treatment causes radiation sensitization. On the other hand, some published data have shown radiation protection by tamoxifen. Since this is clearly a clinically important issue, attempts should be made to clarify the discrepancies.
- Medicine and Medical Research