title: Gene expression in colorectal neoplasia: modifications induced by tissue ischaemic time and tissue handling protocol.
abstract: OBJECTIVE
  The heterogeneity within individual distinct cancer types in terms of behaviour, response to therapy and prognosis is well recognized. A major goal of translational research projects has therefore been to define clinically significant subgroups of individual tumour types by analysis of mRNA as well as protein expression. An essential premise of such investigations is that expression of these key molecules is a true reflection of conditions present within the neoplastic cells in vivo. The aim was to investigate the effect of methods of tissue handling and storage on expression of mRNA.
  
  
  RESULTS
  mRNA expression in 60 biopsy samples obtained from 10 patients with colorectal tumours was examined. The mRNA expression profile and the level of expression of specific mRNA species were significantly affected by the procedures used for collection and storage of tissue samples. Significant variation in the level of expression (both increased and decreased) of transcripts was detectable after 15 min, and by 120 min there was a fourfold increase in the number of genes with a more than twofold change in the level of expression.
  
  
  CONCLUSIONS
  Reliable interpretation of results of gene expression at the mRNA level requires standardized protocols for tissue procurement.
authors.affiliation: Department of Surgery & Molecular Oncology, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Bray
authors.forename: Fiona E M
authors.initials: FE
authors.lastname: Paulin
authors.forename: Siew Chinn
authors.initials: SC
authors.lastname: Fong
authors.forename: Lee
authors.initials: L
authors.lastname: Baker
authors.forename: Frank A
authors.initials: FA
authors.lastname: Carey
authors.forename: David A
authors.initials: DA
authors.lastname: Levison
authors.forename: Robert J C
authors.initials: RJ
authors.lastname: Steele
authors.forename: Neil M
authors.initials: NM
authors.lastname: Kernohan
mesh_terms: D001706:Biopsy; D015179:Colorectal Neoplasms / Q000098:blood supply / Q000235:genetics* / Q000473:pathology; D015925:Cryopreservation / Q000379:methods; D005260:Female; D005615:Freezing; D020869:Gene Expression Profiling; D006801:Humans; D007511:Ischemia; D008297:Male; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D015203:Reproducibility of Results; D013997:Time Factors; D016707:Tissue Fixation / Q000379:methods; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D012334:RNA, Neoplasm