title: ALKBH3 contributes to survival and angiogenesis of human urothelial carcinoma cells through NADPH oxidase and tweak/Fn14/VEGF signals.
abstract: OBJECTIVE
  The role and function of a novel human AlkB homologue, ALKBH3, in human urothelial carcinoma development were examined.
  
  
  METHODS
  Biologic roles of ALKBH3 were examined by gene silencing analysis using in vitro and in vivo siRNA transfection. Immunohistochemical analyses of ALKBH3 and the related molecules using human bladder cancer samples were conducted to estimate the association with clinicopathologic or prognostic parameters.
  
  
  RESULTS
  ALKBH3 knockdown induced cell cycle arrest at the G1 phase through downregulation of NAD(P)H oxidase-2 (NOX-2)-mediated generation of reactive oxygen species (ROS). ALKBH3 knockdown reduced VEGF expression by reducing expression of tumor necrosis factor-like weak inducer of apoptosis (Tweak) and its receptor, fibroblast growth factor-inducible 14 (Fn14). Silencing of ALKBH3 or Tweak significantly suppressed invasion and angiogenesis of urothelial carcinoma in vivo as assessed both by a chorioallantoic membrane assay and in an orthotopic mouse model. Interestingly, not only urothelial carcinoma cells but also vascular endothelial cells within cancer foci expressed Fn14, which was strongly reduced by ALKBH3 and Tweak knockdown in vivo, suggesting that ALKBH3-dependent expression of Tweak stabilizes Fn14. Immunohistochemical examination showed high expression of ALKBH3, Tweak, and Fn14 in urothelial carcinoma, especially in high-grade, superficially, and deeply invasive carcinomas; moreover, Fn14-positive vessel counts within cancer foci were increased in invasive phenotypes.
  
  
  CONCLUSIONS
  ALKBH3 contributes to development of urothelial carcinomas by accelerating their survival, angiogenesis, and invasion through NOX-2-ROS and Tweak/Fn14-VEGF signals.
authors: Department of Pathology and Urology, Nara Medical University School of Medicine, Shijo-cho, Kashihara, Japan.
authors: Keiji
authors: K
authors: Shimada
authors: Tomomi
authors: T
authors: Fujii
authors: Kazutake
authors: K
authors: Tsujikawa
authors: Satoshi
authors: S
authors: Anai
authors: Kiyohide
authors: K
authors: Fujimoto
authors: Noboru
authors: N
authors: Konishi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; D000818:Animals; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics*; D000074049:Cytokine TWEAK; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D055806:Microvessels / Q000378:metabolism; D008875:Middle Aged; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D015398:Signal Transduction; D000074050:TWEAK Receptor; D048069:Tumor Necrosis Factors / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019459:Urothelium / Q000378:metabolism / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D000074049:Cytokine TWEAK; D008562:Membrane Glycoproteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D018124:Receptors, Tumor Necrosis Factor; C000613297:TNFRSF12A protein, human; C109743:TNFSF12 protein, human; D000074050:TWEAK Receptor; C000613299:Tnfrsf12a protein, mouse; D048069:Tumor Necrosis Factors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D049308:Dioxygenases; C486439:ALKBH3 protein, human; D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D045643:DNA Repair Enzymes