Breast Cancer1 (BRCA1) Protein Expression in Epithelial Ovarian Tumours

Abstract

BRCA 1 is a tumor suppressor gene that is mutated in high percentage of hereditary breast and ovarian cancers as well as in some sporadic cases. The human BRCA I gene has been mapped to chromosome 17q21 and encodes a protein of 1863 amino acid residues. Studies over the last few years have suggested that BRCAI may function as a scaffold in the assembly of a multi-protein complex, which plays a role in gene transcription, DNA damage• repair, cell cycle checkpoint regulator, regulation of centrosome duplication, and apoptotic regulator.

This work aimed at evaluation of BRCA I expression and its correlation with established clinicopathological parameters, in order to evaluate its prognostic effect on ovarian carcinoma, and its effect on the patient survival.

The material of this study consisted of archival paraffin blocks of fifty­ two cases, five were normal ovary (control), five were functional cysts, eleven were benign tUJ11_or (5 serous, 5 mucinous, and 1 Brenner), four were borderline (2 serous', and 2 mucinous), and thirty-seven were malignant (23 ' serous, II mucinod, 1 Brenner, 1 endometrioid, and I undifferentiated).

1: Clinicopathological data and survival analysis were done for the available ,[ cases. From each paraffin block, sections were stained with the following: H&E to re-evaluate tumor type, grade, and calculation of mitotic and apoptotic indexes, arid immunohistochemical staining using BRCA I mouse monoclonal antibJdy (Ab 4), utilizing the streptavidine-biotin immunoperoxidase tequnique with antigen retrival protocol.

BRCAI positive cases contain more than 5% positive nuclear staining of strong or moderatintensity, and weighted score more than or equal 6. in the tissue section.