title: Polymorphisms in the insulin like growth factor 1 and IGF binding protein 3 genes and risk of colorectal cancer.
abstract: BACKGROUND
  The insulin-like growth factor1 (IGF1) pathway plays a significant role in both the normal and malignant cell growth. IGF1 binds to the IGF1 receptor and starts a signaling cascade that regulates cell proliferation, differentiation, and apoptosis. The bioavailability of IGF1 is regulated by the binding protein IGFBP3. A CA repeat polymorphism, in the IGF1 gene, which is located 969 bp upstream from the transcription start site and the rs2854744 and rs2854746 single nucleotide polymorphisms (SNPs) in the IGFBP3 gene have been associated with the serum levels of the respective proteins and colorectal cancer (CRC), but the results are inconsistent. We wanted to study if these polymorphisms or any haplotypes of the IGF1 and the IGFBP3 genes are associated with CRC.
  
  
  METHODS
  High linkage disequilibrium was seen in these gene regions. Therefore, the CA repeat along with two SNPs in the IGF1 gene, and rs2854744 (A-202C), rs2854746 (Ala32Gly) and two additional SNPs in the IGFBP3 gene were selected to cover the whole gene regions. A case-control study was carried out using 661 German CRC cases and 607 matched controls.
  
  
  RESULTS
  We did not find any association between the CA repeat length or any of the SNPs in the IGF1 and the IGFBP3 genes and the risk of CRC. Nor did the haplotypes of these genes affect the risk of CRC.
  
  
  CONCLUSIONS
  Our study suggests no major role of the assessed genetic variation within the IGF1 and the IGFBP3 genes in CRC risk.
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany.
authors.forename: Sonali
authors.initials: S
authors.lastname: Pechlivanis
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wagner
authors.forename: Jenny
authors.initials: J
authors.lastname: Chang-Claude
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmeister
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
authors.forename: Asta
authors.initials: A
authors.lastname: Försti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I