Expression of BRCA1 and BRCA2 in different tumor cell lines with various growth status.

BRCA1 and BRCA2 are breast cancer susceptibility genes. Recent studies suggest that BRCA1 interacts with a great variety of proteins, including BRCA2, cell-cycle regulators, transcriptional activators and repressors. We investigated the expression of both BRCA1 and BRCA2 during the progression of the cell cycle of human tumor cell lines from different origins (MCF7, MDA-MB231, PA1 and CCL221) in two growth status (60% and 100% of confluency).,First, the growth status was characterized by determination of the cell cycle by flow cytometry analysis. At the same time, immunohistochemistry was performed to follow BRCA1 and BRCA2 protein expression and then, quantification of BRCA1 and BRCA2 transcripts was realized using real-time quantitative RT-PCR.,We reported in studied tumor cell lines with 60% of confluency by comparison with 100% of confluency, an increase in the BRCA1 and BRCA2 expression at the level of proteins and transcripts.,Therefore, the expression of both BRCA1 and BRCA2 genes at the protein and mRNA levels appear to be up-regulated after cell proliferation in human tumor cell lines from different origins.