Localization of a novel tumor suppressor locus on human chromosome 3q important in osteosarcoma tumorigenesis

Mitotic recombination or nondysjunction are common mechanisms for tumor- specific loss of constitutional heterozygosity (LOH) and tumor suppressor allelic inactivation and can be useful in localizing new putative tumor suppressor genes. In osteosarcoma, the highest frequencies of LOH have been reported for chromosomes 3q, 13q, 17p, and 18q. The high incidence of LOH on chromosome 3q suggests the presence of a novel tumor suppressor gene. To localize this putative tumor suppressor gene, we have used polymorphic markers on chromosome 3q to define the minimal region in which mitotic recombination or deletion results in LOH, which should contain the tumor suppressor gene. This putative tumor suppressor has been localized to a region between 3q26.2-3q26.3 of less than 1 cM between the polymorphie loci D3S1212 and D3S1246.