title: Evaluation of serum and tissue levels of VAP-1 in colorectal cancer.
abstract: BACKGROUND
  The endothelial adhesion molecule, vascular adhesion protein-1 (VAP-1, AOC3) promotes lymphocyte recruitment to tumours, although the contribution that VAP-1 makes to lymphocyte recruitment in human colorectal cancer (CRC) is unknown. VAP-1 exists in circulating soluble form (sVAP-1). A previous study demonstrated elevated sVAP-1 levels in CRC patients. The aim of this study was to confirm this finding and study the differences in tissue VAP-1 expression between CRC and healthy tissues.
  
  
  METHODS
  sVAP-1 levels were measured in the serum of 31 patients with CRC and 31 age- and sex-matched controls. Tissue VAP-1 levels were measured by immunohistochemistry, quantitative real-time PCR and Western blotting.
  
  
  RESULTS
  The mean sVAP-1 level ± SD was significantly lower in the CRC group compared with the control group (399 ± 138 ng/ml versus 510 ± 142 ng/ml, P = 0.003). Tissue VAP-1 protein and mRNA levels were significantly lower in CRC compared with normal colon tissue. VAP-1 immunostaining was practically absent from CRC.
  
  
  CONCLUSIONS
  VAP-1 is downregulated in human CRC and although the molecular basis of this down regulation is not yet known, we suggest it may be part of a mechanism used by the tumour to prevent the recruitment of anti-tumour immune cells. Our data contradicts the findings of others with regard sVAP-1 levels in patients with CRC. Possible reasons for this are discussed.
authors.affiliation: Centre for Liver Research & NIHR Birmingham Biomedical Research Unit, Level 5 Institute for Biomedical Research, University of Birmingham, Vincent Drive, Birmingham, B15 2TT, UK. drsteveward@yahoo.com.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Ward
authors.affiliation: Centre for Liver Research & NIHR Birmingham Biomedical Research Unit, Level 5 Institute for Biomedical Research, University of Birmingham, Vincent Drive, Birmingham, B15 2TT, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Weston
authors.affiliation: Centre for Liver Research & NIHR Birmingham Biomedical Research Unit, Level 5 Institute for Biomedical Research, University of Birmingham, Vincent Drive, Birmingham, B15 2TT, UK.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Shepherd
authors.affiliation: Department of Colorectal Surgery, Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham, B15 2GW, UK.
authors.forename: Rahul
authors.initials: R
authors.lastname: Hejmadi
authors.affiliation: Department of Colorectal Surgery, Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham, B15 2GW, UK.
authors.forename: Tariq
authors.initials: T
authors.lastname: Ismail
authors.affiliation: Centre for Liver Research & NIHR Birmingham Biomedical Research Unit, Level 5 Institute for Biomedical Research, University of Birmingham, Vincent Drive, Birmingham, B15 2TT, UK.
authors.forename: David H
authors.initials: DH
authors.lastname: Adams
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; D012333:RNA, Messenger; C076668:AOC3 protein, human; D006631:Amine Oxidase (Copper-Containing)