Elevated in vivo frequencies of mutant T cells with altered functional expression of the T-cell receptor or hypoxanthine phosphoribosyltransferase genes in p53-deficient mice
T. Suzuki et al., Elevated in vivo frequencies of mutant T cells with altered functional expression of the T-cell receptor or hypoxanthine phosphoribosyltransferase genes in p53-deficient mice, MUT RES-F M, 483(1-2), 2001, pp. 13-17
Citations number
21
Categorie Soggetti
Molecular Biology & Genetics
Journal title
MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS
We have studied the effects of a defect in the p53 gene on spontaneous and
radiation-induced somatic mutation frequencies in vivo by measuring T-cell
receptor (TCR) and hypoxanthine phosphoribosyltransferase (HPRT) mutant fre
quencies (MFs) in p53 deficient mice both before and after exposure to X-ir
radiation. In the absence of irradiation, the TCR and HPRT mutant frequenci
es were roughly two-fold higher in p53 null (-/-) mice than in wild-type (/+) mice. Unexpectedly, the TCR and HPRT MFs were slightly lower in heteroz
ygote p53 (+/-) than in wild-type (+/+) mice., however. After 2 weeks 2 Gy
whole body irradiation the TCR and HPRT MFs were about two-fold higher in t
he p53 null (-/-) and p53 (+/-) mice than in the wild-type. Taken together,
these findings suggest that a defect in the p53 gene may lead to TCR and H
PRT mutants being recovered at higher frequencies in both irradiated and un
irradiated mice, but it should be emphasized that the effects we have obser
ved are not particularly strong, albeit that they are statistically signifi
cant. Interestingly, several of the highest TCR MF values that we observed
in the course of our experiments were recorded in p53 (-/-) animals that ha
d developed thymomas and hence appeared to be cancer prone. (C) 2001 Elsevi
er Science B.V. All rights reserved.