Promoter Methylation Status of Breast Cancer Susceptibility Gene 1 and 17 Beta Hydroxysteroid Dehydrogenase Type 1 Gene in Sporadic Breast Cancer Patients

Epigenetic modifications are involved in breast carcinogenesis. Identifying genes that are epigenetically silenced via methylation could select target patients for diagnostic as well as therapeutic potential. We assessed promoter methylation of breast cancer susceptibility gene 1 (BRCA1) and 17 Beta Hydroxysteroid Dehydrogenase Type 1 (17βHSD-1) in normal and cancer breast tissues of forty sporadic breast cancer (BC) cases using restriction enzyme based methylation-specific PCR (REMS-PCR). In cancerous tissues,BRCA1and17βHSD-1were methylated in 42.5% and 97.5%, respectively, while normal tissues had 35% and 95% methylation, respectively.BRCA1methylation in normal tissues was 12.2-fold more likely to associate with methylation in cancer tissues (p<0.001). It correlated significantly with increased age at menopause, mitosis, the negative status of Her2, and the molecular subtype “luminal A” (p=0.048,p=0.042,p=0.007, andp=0.049, resp.). Methylation ofBRCA1and17βHSD-1related to luminal A subtype of breast cancer. Since a small proportion of normal breast epithelial cells hadBRCA1methylation, our preliminary findings suggest that methylation ofBRCA1may be involved in breast tumors initiation and progression; therefore, it could be used as a biomarker for the early detection of sporadic breast cancer. Methylation of17βHSD-1in normal and cancer tissue could save patients the long term use of adjuvant antiestrogen therapies.