Identification and characterization of a transcriptional silencer upstreamof the human BRCA2 gene

Expression of the breast cancer susceptibility tumor-suppressor protein BRC A2, a protein potentially involved in DNA recombination repair, is tightly regulated throughout development. We have identified a transcriptional sile ncer at the distal end of the human BRCA2 gene promoter. This silencer is i nvolved in the negative regulation of the expression of this gene in breast cell lines tested but not in HeLa or HepG2 cells. The 221-base-pair silenc er region is characterized by a full-length Alu-repeat, Presence of specifi c BRCA2 silencer-binding proteins in the breast cell extracts indicates the potential regulation of BRCA2 gene expression by these proteins. (C) 1999 Academic Press.