Allelic Loss Analysis of Lymphomas Induced in Fas-Heterozygous Deficient Mice

Abstract

Mutations of Fas (CD95/Apo-1) gene have been reported in various malignancies and therefore the Fas gene has been considered to be a tumor suppressor gene. To examine an involvement of Fas gene as a tumor suppressor gene in radiation lymphomagenesis, we examined the loss of heterozygosity (LOH) in lymphomas from (MSM/Ms x MRL-MpJ/Fas ^lpr) F₁ and (BALB/cHeA × MRL-MpJ/Fas ^lpr) F₁ hybrid mice. Lymphoma development by X-irradiation was efficiently observed in both F₁ hybrids. Frequent LOH was found on chromosomes 12 and 4 in the tumors from both F₁ mice, but no allelic loss on chromosome 19 containing Fas locus was found, and no wild-type allele of the Fas gene was lost in 51 lymphomas. Therefore, the putative tumor-suppressor gene regions responsible for lymphomagenesis might not considerably differ due to the Fas gene status.