Co-overexpression of EpCAM and c-myc genes in malignant breast tumors

Purpose:The overexpression of epithelial cell adhesion molecule (EpCAM) proto-oncogene affects progression, treatment, and diagnosis of many adenocarcinomas. C-myc has been shown to be a downstream target of EpCAM and is also one of the most important proto-oncogenes routinely overexpressed in breast cancer. However, co-overexpression of EpCAM and c-myc genes has not been investigated in breast cancer tissues, particularly in Iranian population. Objectives: The aim of this study was to assess the expression of EpCAMand c-myc genes in malignant breast cancer tissues using RT-qPCR, followed by analyses of the association between the outcomes. Methods: To this purpose, 122 fresh tissues including 104 malignant and 18 benign samples were disrupted by mortar and pestle and RNA was then isolated from the samples and converted to cDNA. The relative expression levels of EpCAM and c-myc genes were measured by2 method using RTqPCR method. EpCAM protein level was also assessed in 66 cases using western blot technique. Results:Our results showed that EpCAMwas overexpressed in 48% of malignant and 11.1% of benign samples, using RT-qPCR method.Evaluating EpCAM protein overexpression in a portion of samples depicted the fully concordance rate between Western blot and RT-qPCR techniques. C-myc expression was first evaluated by RT-qPCR method, showing the overexpression rate of 39% and 28% in malignant and benign samples respectively. These data were also quite concordant with the clinically available IHC reports of the same samples studied in this study. Importantly, overexpression of EpCAM and c-myc was significantly associated and showed theagreement of 57.3%. Conclusion:This study demonstrated the co-overexpression of EpCAM and c-myc in breast tumors collected from breast cancer patients of theIranian population.EpCAM and c-myc positive cases were significantly associated with reduced and enhanced risk of ER/PR positivity respectively. However, they both were associated with grade III of breast cancer.