DETECTION OF NUMERIC ABNORMALITIES OF CHROMOSOME-17 AND P53 DELETIONSBY FLUORESCENCE IN-SITU HYBRIDIZATION IN PLEOMORPHIC ADENOMAS AND CARCINOMAS IN PLEOMORPHIC ADENOMA - CORRELATION WITH P53 EXPRESSION
Xw. Li et al., DETECTION OF NUMERIC ABNORMALITIES OF CHROMOSOME-17 AND P53 DELETIONSBY FLUORESCENCE IN-SITU HYBRIDIZATION IN PLEOMORPHIC ADENOMAS AND CARCINOMAS IN PLEOMORPHIC ADENOMA - CORRELATION WITH P53 EXPRESSION, Cancer, 79(12), 1997, pp. 2314-2319
BACKGROUND. A fluorescence in situ hybridization (FISH) technique usin
g specific DNA probes allows for the detection of chromosomal aberrati
ons and gene deletions and gains, even in interphase nuclei in human s
olid tumors. A high frequency of aberrations of chromosome 17 and muta
tion of the p53 gene have been reported in some human tumors. The corr
elation of p53 expression with abnormalities of chromosome 17 and p53
gene deletion in salivary gland tumors has not yet been investigated.
METHODS. The authors analyzed the numeric aberrations of chromosome 17
and p53 gene deletions in 11 paraffin embedded pleomorphic adenomas (
PA) and 9 carcinomas in pleomorphic adenoma (CIPA), using FISH techniq
ues. The centromere specific DNA probe for chromosome 17 and p53 cosmi
d DNA probe was used. The aberrations of chromosome 17 and p53 deletio
ns were correlated with immunohistochemical detection of p53 protein.
RESULTS. Monosomy 17 was detected in 30.8% of CIPA cells and 29.6% of
PA cells, and polysomy 17 was detected in 19.6% of CIPA cells and 9.6%
of PA cells. p53 protein expression was observed in 6 of 9 CIPA speci
mens (66.7%) and 2 of 75 PA specimens (2.7%). Deletion of the p53 gene
was frequent in p53 protein positive specimens. A statistically signi
ficant correlation existed between p53 protein expression and polysomy
17 (P = 0.0417). CONCLUSIONS. It was observed that loss of chromosome
17 may occur in PA before its transformation to carcinoma. p53 expres
sion was frequently associated with deletion of the p53 gene as detect
ed by FISH. Polysomy 17 was more frequent in CIPA than PA and was asso
ciated with mutation of p53. (C) 1997 American Cancer Society.