Abstract A22: Association of breast cancer risk and concentrations of tissue estrogens to single strand breaks in DNA

Conclusions: The most likely mechanism by which 4-OHE2 or 2-OHE1 could protect against formation of SSBs in the breast is by their antioxidative properties. 4-OHE2 and other catechol estrogens are capable of undergoing redox reactions, cycling between the catechol structure, semiquinone radical, and o-quinone. They are also capable of forming metal complexes, sequestering metals, preventing them from undergoing redox reactions. In addition, 4-OHE2 has a binding affinity relative to that of estradiol of 1.51; that of 2-OHE1 is 1.02 Therefore, the catechol estrogens have activity similar to or greater than that of estradiol in terms of activation of NRF-1 and Mn SOD, both of which were elevated in association with lower SSB levels. We conclude that SSBs measured by the nick translation procedure are associated with, but not redundant with, measures of breast cancer risk and with deficiencies of both DNA damage responses and antioxidant mechanisms. Concentrations of 4-hydroxyestradiol in breast tissue may serve an antioxidant function and may be protective.Citation Format: Mathavi Sahadevan, Oukseub Lee, Miguel Muzzio, Belinda Phan, Lisa Jacobs, Nagi Khouri, Jun Wang, Hong Hu, Vered Stearns, Robert T. Chatterton. Association of breast cancer risk and concentrations of tissue estrogens to single strand breaks in DNA. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philad...
Source: Cancer Epidemiology Biomarkers and Prevention - Category: Cancer & Oncology Authors: Tags: Improving Cancer Risk Prediction for Prevention and Early Detection: Poster Presentations - Proffered Abstracts Source Type: research