Abstract
Min(multiple intestinal neoplasia) mice carry a mutant allele of the murine Apc locus and are predisposed to adenoma formation in the intestinal tract. Tumorigenesis in Min mice is affected by various factors including genetic background and ionizing radiation. In this report, we addressed a possibility of genetic relevance between spontaneous and X-ray induced tumorigenesis in Min mice. MSM strain is highly resistant to intestinal tumorgenesis by Min mutation. QTL analysis indicated that a newly identified modifier locus Mom3 is a major determinant of the resistance, together with a resistant allele of Mom1 locus. A congenic strain of Mom 3 and a consomic strain of the chromosome in the B6-Min background resulted in more than five-fold decrease in tumor multiplicities in the intestine of Min mice. X-irradiation of the consomic mice increased their tumor incidence, almost reaching to a level in irradiated B6-Min mice. These data suggest a possibility of the crosstalk between induction by X-irradiation and suppression by Mom3 allele in the tumorigenesis in Min mice. [J Radiat Res 44:396 (2003)]
