title: Increased mRNA expression levels of ERCC1, OGG1 and RAI in colorectal adenomas and carcinomas.
abstract: BACKGROUND
  The majority of colorectal cancer (CRC) cases develop through the adenoma-carcinoma pathway. If an increase in DNA repair expression is detected in both early adenomas and carcinomas it may indicate that low repair capacity in the normal mucosa is a risk factor for adenoma formation.
  
  
  METHODS
  We have examined mRNA expression of two DNA repair genes, ERCC1 and OGG1 as well as the putative apoptosis controlling gene RAI, in normal tissues and lesions from 36 cases with adenomas (mild/moderat n = 21 and severe n = 15, dysplasia) and 9 with carcinomas.
  
  
  RESULTS
  Comparing expression levels of ERCC1, OGG1 and RAI between normal tissue and all lesions combined yielded higher expression levels in lesions, 3.3-fold higher (P = 0.005), 5.6-fold higher (P < 3.10-5) and 7.7-fold higher (P = 0.0005), respectively. The levels of ERCC1, OGG1 and RAI expressions when comparing lesions, did not differ between adenomas and CRC cases, P = 0.836, P = 0.341 and P = 0.909, respectively. When comparing expression levels in normal tissue, the levels for OGG1 and RAI from CRC cases were significantly lower compared to the cases with adenomas, P = 0.012 and P = 0.011, respectively.
  
  
  CONCLUSIONS
  Our results suggest that increased expression of defense genes is an early event in the progression of colorectal adenomas to carcinomas.
authors.affiliation: Telemark University College, Faculty of Arts and Sciences, Department of Environmental and Health Studies, Hallvard Eikas plass, N-3800 Bø i Telemark, Norway. mona.sabo@hit.no
authors.forename: Mona
authors.initials: M
authors.lastname: Saebø
authors.forename: Camilla Furu
authors.initials: CF
authors.lastname: Skjelbred
authors.forename: Bjørn Andersen
authors.initials: BA
authors.lastname: Nexø
authors.forename: Håkan
authors.initials: H
authors.lastname: Wallin
authors.forename: Inger-Lise
authors.initials: IL
authors.lastname: Hansteen
authors.forename: Ulla
authors.initials: U
authors.lastname: Vogel
authors.forename: Elin H
authors.initials: EH
authors.lastname: Kure
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000378:metabolism*; D045647:DNA Glycosylases / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018450:Disease Progression; D004720:Endonucleases / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins
chemical_list: D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C119612:PPP1R13L protein, human; D012333:RNA, Messenger; D012097:Repressor Proteins; C071447:ERCC1 protein, human; D004720:Endonucleases; D045647:DNA Glycosylases; C479058:oxoguanine glycosylase 1, human