![]() |
6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A066
Aim: Quantitative and qualitative changes in p53 may lead to an accumulation
of genetic aberrations in the cells affected. At a certain degree those
aberrations are detectable cytometrically as DNA aneuploidy. The study was
aimed at the analysis of numerical aberrations of the p53 gene locus in
relation to the centromere of chromosome 17 and the DNA ploidy of the tumor
as to study the heterogeneity of p53 changes in that cancer type. Methods:
Tumor imprints of 35 breast cancers (8 peridiploid, 8 peritetraploid, 18
aneuploid) were subjected to a two-color FISH technique with DNA probes for
the centromere 17 and the p53 gene locus. FISH spots were counted in at least
120 tumor cells and up to 10 lymphocytes in each imprint. The DNA ploidy of
the tumors was detected by Feulgen DNA image cytometry, the expression of p53,
Ki-67, and WAF-1 was studied by immunohistochemistry. By means of SSCP
mutations were searched in the exons 5 to 8 of the p53 gene. Results &
Conclusions: In peritetraploid and aneuploid tumors numerous p53
aberrations were found, accompanied by a strong intratumoral heterogeneity
of the aberration pattern in the single cells. Besides deletions gains of
gene loci were found in those tumors, too. However, in p53 expression and
in the proliferation rate the peritetraploid tumors were not different from
the peridiploid ones. An evolution from the peridiploid to the peritetraploid
and aneuploid tumors seems to be obvious, in which the p53 plays an important
but not the decisive role.
NUMERICAL ABERRATIONS OF THE P53-GENE IN BREAST TUMOR CELLS WITH DIFFERENT
DNA CONTENT
Haroske G, Friedrich K, Dimmer V, Illmer T*, Kunze KD
Institute of Pathology, * Department of Internal Medicine, Dresden University
of Technology, Germany