BACKGROUND - mTOR signaling pathway is commonly activated in cancer. PTEN, a tumor suppressor gene, is a potent inhibitor of this pathway. To date the expression pattern of mTOR and PTEN in schistosomal bladder squamous cell carcinoma and urothelial carcinoma was not investigated.
Also, whether alterations of these proteins are associated with pathological parameters was not established.
HYPOTHESIS - We hypothesize that "expression of mTOR and/or PTEN will be altered in schistosomal-related urothelial and squamous cell carcinomas".
PATIENTS AND METH0DS - To test our hypothesis we examined the expression pattern of mTOR and PTEN in normal and hyperplastic urothelium, squamous metaplasia, schistosomal urothelial carcinomas (70 cases) and squamous cell carcinomas (47 cases) using immunohistochemical methods.
RESULTS - mTOR protein expression was absent in the normal, hyperplastic urothelium and metaplastic squamous epithelium. mTOR was over-expressed in muscle invasive urothelial and high grade squamous cell carcinomas. In contrast, PTEN protein expression was seen in the normal and hyperplastic urothelium. The expression was reduced (metaplastic squamous epithelium) or lost in muscle invasive urothelial and high grade squamous carcinomas. Alterations of these proteins were associated with some clinicopathological features. mTOR expression was negatively correlated with PTEN expression in urothelial carcinoma only.
CONCLUSIONS - We report, for the first time, altered expression of mTOR and PTEN proteins in schistosomal urothelial and squamous cell carcinomas. Alterations of these proteins may contribute to the progression and aggressive behavior of schistosomal bladder carcinoma. Targeting mTOR, may be a promising therapeutic strategy in these tumors.
Pathology, research and practice. 2016 Feb 09 [Epub ahead of print]
Rania Makboul, Abeer Refaiy, Islam F Abdelkawi, D A Hameed, Ahmad A Elderwy, Mahmoud M Shalaby, Axel S Merseburger, Mahmoud Rezk Abdelwahed Hussein
Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt., Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt., Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt.Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt., Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt., Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt., Department of Urology, Campus Lübeck University Hospital Schleswig-Holstein, Germany., Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt.