Genome-wide association and fine mapping of genetic loci predisposing to colon carcinogenesis in mice

Pengyuan Liu, Yan Lu, Hongbo Liu, Weidong Wen, Dongmei Jia, Yian Wang, Ming You

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

To identify the genetic determinants of colon tumorigenesis, 268 male mice from 33 inbred strains derived from different genealogies were treated with azoxymethane (AOM; 10 mg/kg) once a week for six weeks to induce colon tumors. Tumors were localized exclusively within the distal colon in each of the strains examined. Inbred mouse strains exhibit a large variability in genetic susceptibility to AOM-induced colon tumorigenesis. The mean colon tumor multiplicity ranged from 0 to 38.6 (mean = 6.5 ± 8.6) and tumor volume ranged from 0 to 706.5mm 3 (mean = 87.4 ± 181.9) at 24 weeks after the first dose of AOM. AOM-induced colon tumor phenotypes are highly heritable in inbred mice, and 68.8% and 71.3% of total phenotypic variation in colon tumor multiplicity and tumor volume, respectively, are attributable to strain-dependent genetic background. Using 97,854 single-nucleotide polymorphisms, we carried out a genome-wide association study (GWAS) of AOM-induced colon tumorigenesis and identified a novel susceptibility locus on chromosome 15 (rs32359607, P = 6.31 × 10 -6). Subsequent fine mapping confirmed five (Scc3, Scc2, Scc12, Scc8, and Ccs1) of 16 linkage regions previously found to be associated with colon tumor susceptibility. These five loci were refined to less than 1 Mb genomic regions of interest. Major candidates in these loci are Sema5a, Fmn2, Grem2, Fap, Gsg1l, Xpo6, Rabep2, Eif3c, Unc5d, and Gpr65. In particular, the refined Scc3 locus shows high concordance with the human GWAS locus that underlies hereditary mixed polyposis syndrome. These findings increase our understanding of the complex genetics of colon tumorigenesis, and provide important insights into the pathways of colorectal cancer development and might ultimately lead to more effective individually targeted cancer prevention strategies.

Original languageEnglish (US)
Pages (from-to)66-74
Number of pages9
JournalMolecular Cancer Research
Volume10
Issue number1
DOIs
StatePublished - Jan 2012

ASJC Scopus subject areas

  • Molecular Biology
  • Oncology
  • Cancer Research

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