title: Alterations of mTOR and PTEN protein expression in schistosomal squamous cell carcinoma and urothelial carcinoma.
abstract: 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.
  
  
  OBJECTIVE
  We hypothesize that "expression of mTOR and/or PTEN will be altered in schistosomal-related urothelial and squamous cell carcinomas".
  
  
  METHODS
  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.
authors.affiliation: Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Rania
authors.initials: R
authors.lastname: Makboul
authors.affiliation: Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Abeer
authors.initials: A
authors.lastname: Refaiy
authors.affiliation: Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt. Electronic address: Islamfaa@yahoo.com.
authors.forename: Islam F
authors.initials: IF
authors.lastname: Abdelkawi
authors.affiliation: Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: D A
authors.initials: DA
authors.lastname: Hameed
authors.affiliation: Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Ahmad A
authors.initials: AA
authors.lastname: Elderwy
authors.affiliation: Department of Urology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Shalaby
authors.affiliation: Department of Urology, Campus Lübeck University Hospital Schleswig-Holstein, Germany.
authors.forename: Axel S
authors.initials: AS
authors.lastname: Merseburger
authors.affiliation: Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Mahmoud Rezk Abdelwahed
authors.initials: MR
authors.lastname: Hussein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D012552:Schistosomiasis / Q000378:metabolism* / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology; D019459:Urothelium / Q000378:metabolism* / Q000473:pathology
chemical_list: C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D051059:PTEN Phosphohydrolase
keywords: MTOR; PTEN; Squamous cell carcinoma; Urothelial carcinoma