Localization of human BRCA1 and BRCA2 in non-inherited colorectal carcinomas and matched normal mucosas

We characterized the expression of BRCA1 and BRCA2 in 38 sporadic colorecta l carcinomas and matched normal mucosas with 9 anti-BRCA1 antibodies and 4 anti-BRCA2 antibodies, raised against several different epitopes, using imm unohistochemical technique. We demonstrated an increased BRCA1 and BRCA2 st aining in the apical cell pole of epithelial malignant cells and we also re vealed a significant increase in BRCA1 and BRCA2 nuclear foci in tumor colo rectal specimens in comparison with corresponding normal tissues. These inc reases in BRCA1 and BRCA2 expression may be explained by the fact that colo rectal tissue is subject to very active proliferation and differentiation.