title: Polymorphic GT dinucleotide repeat in the PIK3CA gene and risk of colorectal cancer.
abstract: BACKGROUND
  Activated PI3K generate PIP3 to trigger different signaling pathways which regulate a number of cellular functions including cell survival, apoptosis, proliferation and motility. Mutations in many cancers were discovered in the gene encoding the PI3K catalytic subunit, PIK3CA.
  
  
  OBJECTIVE
  To date, there has been no report on the association between polymorphism of PIK3CA gene microsatellites and risk of colorectal cancer. In this study, we investigate the relation between the GT dinucleotide repeat in intron 1 of the PIK3CA gene and colorectal cancer risk.
  
  
  METHODS
  A case-control study of 103 colorectal cancer patients and 150 controls was conducted in Iranian people.
  
  
  RESULTS
  The results of our study demonstrate that PIK3CA gene allele distribution in Iranian population varies between 13 and 20 repeats. Here we demonstrate that individuals who carry alleles shorter than 17 GT repeat are at higher risk of developing colorectal cancer (OR = 4.0, p= 0), by contrast, those individuals with two alleles longer than 16 GT repeats are at a significantly lower risk of developing colorectal cancer (OR = 0.12, p= 0).
  
  
  CONCLUSIONS
  This result suggests polymorphic GT repeat of PIK3CA gene may be a potential predictive marker of colorectal cancer risk in Iranian population.
authors.affiliation: Department of Biology, Faculty of Sciences, University of Isfahan, Hezar-Jarib, Isfahan, Iran.
authors.forename: Soha
authors.initials: S
authors.lastname: Parsafar
authors.affiliation: Division of Oncology, Medical Sciences University of Isfahan, Isfahan, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Hematti
authors.affiliation: Department of Biology, Faculty of Sciences, University of Isfahan, Hezar-Jarib, Isfahan, Iran.
authors.forename: Fateme
authors.initials: F
authors.lastname: Ghorbani
authors.affiliation: Department of Biology, Faculty of Sciences, University of Isfahan, Hezar-Jarib, Isfahan, Iran.
authors.forename: Forousan
authors.initials: F
authors.lastname: Safari
authors.affiliation: Department of Biology, Faculty of Sciences, University of Isfahan, Hezar-Jarib, Isfahan, Iran.
authors.forename: Manoochehr
authors.initials: M
authors.lastname: Tavassoli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D058534:Class I Phosphatidylinositol 3-Kinases; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D018900:Dinucleotide Repeats / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D009154:Mutation; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human
keywords: Colorectal cancer; GT repeat; PIK3CA; polymorphism