Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 36 4 2014 10 05 Association between the Expression of Tap73 and Δnp73 Variants and Breast Cancer in Patients of North-West of Iran 30 37 EN Mohammad Ali Hosseinpourfeizi Aida Sedaie Bonab Reyhaneh Ravanbakhsh Nasser Pouladi Maryam Moradi Nasab Parvin Azarfam Vahid Montazeri Ashraf Fakhrjou Journal Article 2013 09 07 2013 11 04 Background and Objectives: Breast cancer is the most common malignancy; meanwhile, finding molecular markers to identify it in the early stages, might be helpful in this regard. Overexpression of TP73 gene is frequent in cancers. TP73 is expressed in multiple variants with either tumor suppressor or oncogenic function. This study was performed to evaluate the association between the expression of tumor suppressor TAp73 and oncogenic ΔNp73 variants and breast tumorigenesis. Materials and Methods: In this experimental study, 60 specimens (30 tumoral and 30 marginal tissues) were examined by RT-PCR technique and the semi-quantitative data were converted to quantitative data using UV-tech software. Results: Overexpression of TAp73 and ΔNp73 was observed in 80% and 43.3% of tumors, respectively. A direct significant correlation was found between the expression level of both variants in tumors (P=0.01) that indicates co-upregulation of them in tumor tissues. A significant difference was found in the expression level of TAp73 between tumor and marginal tissues (P=0.001) but the difference in the expression level of ΔNp73, was not significant (P=0.92). There was not any significant difference in the expression level of studied variants between the early and the late stage tumors (P>0.05). Conclusion: Overexpression of TAp73 is a marker for the detection of malignant breast tumors. Co-upregulation of TAp73 and ΔNp73 is also a hallmark of malignant epithelial cells of the breast. Overexpression of TAp73 is involved in tumorigenesis via the overexpression of ΔNp73. So, overexpression of tumor suppressor TAp73 can indirectly cause breast tumorigenesis.