title: No association between germline allele-specific expression of TGFBR1 and colorectal cancer risk in Caucasian and Ashkenazi populations.
abstract: BACKGROUND
  Germline allele-specific expression (ASE) of the TGFBR1 gene has been reported as a strong risk factor for colorectal cancer (CRC) with an odds ratio close to 9. Considering the potential implications of the finding, we undertook the task of validating the initial results in this study.
  
  
  METHODS
  Allele-specific expression was measured using the highly quantitative and robust technique of pyrosequencing. Individuals from two different populations were studied, one Caucasian-dominated and the other of Ashkenazi Jewish descent, with different sources of non-tumoral genetic material in each.
  
  
  RESULTS
  Our results showed no statistically significant differences in the degree of ASE between CRC patients and controls, considering ASE as either a quantitative or a binary trait. Using defined cutoff values to categorise ASE, 1.0% of blood lymphocytes from informative Israeli cases (total n=96) were ASE positive (median 1.00; range 0.76-1.31) and 2.2% of informative matched controls (total n=90) were ASE positive (median 1.00; range 0.76-1.87). Likewise, normal mucosae from Spanish patients (median 1.03; range: 0.68-1.43; n=75) did not show significant differences in the degree of ASE when compared with the Israeli patients or controls.
  
  
  CONCLUSIONS
  Taken together, these results suggest that ASE of TGFBR1 does not confer an increased risk of CRC.
authors.affiliation: Translational Research Laboratory, Catalan Institute of Oncology, IDIBELL, Hospitalet de Llobregat, Av. Gran Vía 199-203, Barcelona 08908, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Seguí
authors.forename: K N
authors.initials: KN
authors.lastname: Stevens
authors.forename: E
authors.initials: E
authors.lastname: Guinó
authors.forename: L S
authors.initials: LS
authors.lastname: Rozek
authors.forename: V R
authors.initials: VR
authors.lastname: Moreno
authors.forename: G
authors.initials: G
authors.lastname: Capellá
authors.forename: S B
authors.initials: SB
authors.lastname: Gruber
authors.forename: L
authors.initials: L
authors.lastname: Valle
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000483:Alleles; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D005838:Genotype; D018095:Germ-Line Mutation; D006801:Humans; D007557:Israel / Q000208:ethnology; D007585:Jews / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D012307:Risk Factors; D044465:White People / Q000235:genetics*
chemical_list: D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human