title: Expression of 5-lipoxygenase in human colorectal cancer.
abstract: OBJECTIVE
  To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis.
  
  
  METHODS
  The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods.
  
  
  RESULTS
  There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392, P = 0.0002), depth or vessel invasion.
  
  
  CONCLUSIONS
  These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.
authors.affiliation: Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo 113-8519, Japan. soumaorol@yahoo.com
authors.forename: Labile Togba
authors.initials: LT
authors.lastname: Soumaoro
authors.forename: Satoru
authors.initials: S
authors.lastname: Iida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uetake
authors.forename: Megumi
authors.initials: M
authors.lastname: Ishiguro
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takagi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Higuchi
authors.forename: Masamichi
authors.initials: M
authors.lastname: Yasuno
authors.forename: Masayuki
authors.initials: M
authors.lastname: Enomoto
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000368:Aged; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology / Q000473:pathology; D016859:Lipoxygenase Inhibitors; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D012333:RNA, Messenger; D001094:Arachidonate 5-Lipoxygenase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human