Fluorescence in situ hybridization determination of aneusomy: criteria and technical considerations.
OBJECTIVE
To investigate a series of tissues to determine if proliferation rate can affect chromosome counts by fluorescence in situ hybridization (FISH).


METHODS
We studied 9 non-neoplastic tissues and a trisomy 7 and tetrasomy 13 cell line by FISH. For each sample, 100 cells were analyzed for chromosome 7 and 13 number and MIB-1 expression. Centrometric enumeration probe (CEP) 7 counts were correlated with proliferation index.


RESULTS
Average CEP 7 number showed a relationship to proliferation index, with higher CEP 7 averages associated with higher proliferation indices. Specimens of brain tissue demonstrated average CEP 7 counts between 1.64 and 1.75. Tissues with high proliferation indices (23-66%) demonstrated CEP 7 counts between 2.14 and 2.31. The average CEP 7 count for the trisomy 7 cell line was 2.61. The average LSI 13 count for the tetrasomy 13 cell line was 3.65.


CONCLUSIONS
Chromosome 7 FISH counts demonstrated overlap between diploid tissues with high proliferation and triploid chromosome 7 tissues. This overlap was seen when 95% CI limits were used. The trisomic 7 and tetrasomic 13 cell lines demonstrated average CEP 7 and CEP 13 levels below 3 and 4, respectively. Definitions used for determination of polysomy should take into account tissue proliferation and section thicknesses.
Chadwick
Barbara
B
Department of Pathology, University of Utah School of Medicine, 50 North Medical Drive, Salt Lake City, Utah 84132, USA.
Willmore-Payne
Carlynn
C
Holden
Joseph
J
Layfield
Lester
L
D000782:Aneuploidy; D000974:Antibodies, Antinuclear / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D002503:Centromere; D002869:Chromosome Aberrations; D002882:Chromosomes, Human, Pair 13; D002897:Chromosomes, Human, Pair 7; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D014314:Trisomy
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; C440408:MIB-1 antibody