Mutations in the human APC gene cause various familial colon cancer syndromes. The Multiple intestinal neoplasia (Min) mouse provides an excellent model for familial colon cancer: it carries a mutant mouse Apc gene and develops many intestinal adenomas. Here, we analyze how this tumor phenotype is dramatically modified by genetic background. We report the genetic mapping of a locus that strongly modifies tumor number in Min/+ animals. This gene, Mom-1 (Modifier of Min-1), maps to distal chromosome 4 and controls about 50% of genetic variation in tumor number in two intraspecific backcrosses. The mapping is supported by a LOD score exceeding 14. Interestingly, Mom-1 lies in a region of synteny conservation with human chromosome 1p35-36, a region of frequent somatic loss of heterozygosity in a variety of human tumors, including colon tumors. These results provide evidence of a major modifier affecting expression of an inherited cancer syndrome.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)