BRCA1/2 methylation and expression dynamics in hereditary breast and ovarian cancer: insights from gene, protein, and TCGA analysis
BRCA1/2 Mutations have been linked to an inherited risk of breast and ovarian cancer. However, gene silencing by promoter methylation of BRCA1 and BRCA2 has not been studied extensively. Promoter methylation of BRCA1 and BRCA2 in the gDNA of 113 hereditary breast and ovarian cancer patients was carried out using methylation-specific qPCR. The majority of patients showed higher methylation in BRCA2 than in BRCA1 and were significantly associated with hereditary breast and ovarian cancer Moreover, BRCA2 methylation was significantly associated with BRCA2 downregulation. Additionally, protein expression analysis in a subset of 25 patients with hypermethylated demonstrated a significant negative correlation between methylation status and protein expression for both BRCA1 and BRCA2. BRCA1 and BRCA2 promoter methylation, particularly BRCA2, contributes to gene silencing and protein loss, and may act as key biomarkers for hereditary breast and ovarian cancer prognosis and therapy.