1: Mol Carcinog. 1999 Nov;26(3):157-62. 

Accumulation of aberrant Y chromosomes in gamma-ray-induced thymic lymphomas
lacking p53.

Chou D, Matsuki J, Saitou Y, Kosugi SI, Shinbo T, Gejyo F, Niwa O, Kominami R.

Department of Biochemistry, Niigata University School of Medicine, Niigata,
Japan.

Male F(1) hybrids between MSM mice carrying a deficient p53 allele and BALB/c
mice were irradiated with gamma-rays, and 80 thymic lymphomas were obtained, 46
of which developed in mice carrying the deficient p53 allele. Because the Y
chromosome contributes little to cellular function, the stability of the Y
chromosome in the tumors was assessed by polymerase chain reaction by examining
three genes: Smcy and Sry on the short arm and Sts in the pseudoautosomal region
of the long arm of the Y chromosome. Twenty-one lymphomas had lost one or two
genes, probably as a result of mitotic recombination or interstitial deletion,
whereas no lymphomas had lost all three genes. The p53 status of the lymphomas
was determined by genotyping and allelic loss analysis; 34 had retained two
wild-type p53 alleles, suggesting normal function; 34 had lost both alleles,
indicating loss of function; and the other 12 had at least one wild-type p53
allele, so their p53 status was unclear. Compilation of these data revealed that
changes in the Y chromosome were detected in only two of the 34 lymphomas
retaining functional p53 but in 18 of the 34 lymphomas lacking p53 function,
suggesting that p53 deficiency leads to an increase in the accumulation of
radiation-induced aberrant chromosomes. This is consistent with our previous
result from analysis of the inactive X chromosome. In contrast, a decrease in
the fidelity of mitotic transmission in p53-deficient lymphomas was not noted
for the Y chromosome. Copyright 1999 Wiley-Liss, Inc.

PMID: 10559790 [PubMed - indexed for MEDLINE]


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