Loss of heterozygosity in the RAD51 and BRCA2 regions in breast cancer

Background: Loss of heterozygosity (LOH) in the 15q14-21 and 13q12-13 regions can contribute to the inactivation of RAD51 and BRCA2 genes implicated in the pathogenesis of breast cancer. We investigated allelic losses in microsatellites in the RAD51 and BRCA2 regions, and their association with clinicopathological parameters in breast cancer. Methods: The LOH analysis was performed by amplifying DNA by PCR, using D15S118, D15S214, D15S1006 polymorphic markers in the 15q14-21 region and D13S260, D13S290 polymorphic markers in the 13q12-13 region in 36 sporadic breast cancer cases. Results: LOH in the RAD51 region ranged from 29% to 46% and in the BRCA2 region from 38% to 43% of informative cases. Eleven percent of the breast cancer cases displayed LOH for at least one studied marker in the RAD51 region exclusively. On the other hand, 44% of cases manifested statistically significant LOH for at least one microsatellite marker concomitantly in the RAD51 and BRCA2 regions. LOH in the RAD51 region similarly as in the BRCA2 region appeared to correlate with steroid receptors content and lymph node status. Discussion: The obtained results indicate that alteration in RAD51 region may contribute to the disturbances of DNA repair involving RAD51 and/or BRCA2 penetration and thus enhance the risk of breast cancer development.