DOI: 10.36347/sajb.2016.v04i12.011

Pages: 1121-1127

Epigenetics has emerged as one of the most-exciting frontiers in the study of the human carcinogenesis. Promoter CpG islands (CGIs) hypermethylation is an important epigenetic change associated with silencing the DNA transcription and has a role in tumour suppressor genes inactivation in many types of cancer. Here, we have investigated aberrant methylation of two tumour suppressor genes (RAR2: retinoic acid receptor gene and 3-OST-2: heparan sulphate D-glucosaminyl 3-Osulphotransferase-2 gene) which are early markers for breast cancer. A total of 178 individuals was enrolled in this study; they were divided into breast- cancer patients (n=93), patients with benign breast tumour (n=55), and healthy individuals (n=30). Using the relative quantitative methylation specific PCR (RQ-MSP) technique, the methylations of RAR2 and 3-OST-2 genes were analysed in the serum samples and compared with traditional tumour markers and clinicopathological factors. The methylat ions of RARβ2 and 3-OST-2 – which are tumour suppressor genes –were significantly higher in breast-cancer patients than in the benign and control individuals (p0.0001). Methylated genes were not significantly related to clinicopathological factors apart from pathological types. Both methylated genes were found in all different tumours regardless the grades and stages. Sensitivities and specificities for the candidate genes were together superior to other tumour markers in the detection of early- stage and low-grade breast cancer..