title: Modulation of L-Arginine-Arginase Metabolic Pathway Enzymes: Immunocytochemistry and mRNA Expression in Peripheral Blood and Tissue Levels in Head and Neck Squamous Cell Carcinomas in North East India.
abstract: BACKGROUND
  Arginine may play important roles in tumor progression by providing ornithine for polyamine biosynthesis, required for cell growth. The aim of this work was to determine the expression of arginine metabolic pathway enzymes in head and neck squamous cell carcinoma (HNSCC) in northeast India.
  
  
  METHODS
  The expressions of arginase isoforms (ARG1 and ARG2), ornithine aminotransferase (OAT) and ornithine decarboxylase (ODC) were examined in fifty paired HNSCC and adjacent non-tumor tissues by immunohistochemistry. Immunocytochemistry, semiquantitative reverse transcription sq-PCR and quantitative real-time qPCR were used to assess protein and mRNA expressions in peripheral blood of fifty HNSCC patients and hundred controls.
  
  
  RESULTS
  ARG1 and ODC protein and mRNA were strongly expressed in peripheral blood from HNSCC patients. No ARG2 expression was observed. In vivo, expression of ARG1, ARG2 and ODC was significantly higher in tumor than in non-tumor tissues. Most tumors expressed low levels of OAT, with no difference in tissues or blood, compared to controls. The absolute extent of maximal ARG1 upregulation with qPCR showed 6.23 fold increase in HNSCC.
  
  
  CONCLUSIONS
  These findings strongly suggest that in HNSCCs, the ARG1 pathway is stimulated leading to the formation of polyamines as indicated by higher ODC expression, which promote tumor growth.
authors.affiliation: Molecular Medicine Laboratory, Department of Biotechnology, Assam University, Silchar, Assam, India E-mail : drsankarghosh@gmail.com.
authors.forename: Shilpee
authors.initials: S
authors.lastname: Srivastava
authors.forename: Sankar Kumar
authors.initials: SK
authors.lastname: Ghosh
mesh_terms: D000328:Adult; D001119:Arginase / Q000032:analysis / Q000097:blood* / Q000235:genetics; D001120:Arginine / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000201:enzymology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000201:enzymology*; D006801:Humans; D007120:Immunochemistry; D007194:India; D008297:Male; D053858:Metabolic Networks and Pathways; D008875:Middle Aged; D009955:Ornithine Decarboxylase / Q000032:analysis / Q000097:blood* / Q000235:genetics; D009953:Ornithine-Oxo-Acid Transaminase / Q000032:analysis / Q000097:blood* / Q000235:genetics; D020033:Protein Isoforms / Q000097:blood / Q000235:genetics; D012333:RNA, Messenger / Q000097:blood*
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D001120:Arginine; D009953:Ornithine-Oxo-Acid Transaminase; C574619:ARG1 protein, human; C477631:ARG2 protein, human; D001119:Arginase; D009955:Ornithine Decarboxylase