Combination of lamin immunocytochemistry and in situ hybridization for the analysis of chromosome copy numbers in tumor cell areas with high nuclear density
✍ Scribed by Jos Herbergs; Ernst J. M. Speel; Frans C. S. Ramaekers; Adriaan P. de Bruïne; Jan-Willem Arends; Anton H. N. Hopman
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 711 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0196-4763
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✦ Synopsis
We describe the application of lamin immunocytochemistry (ICC) and single-or double-target fluorescence in situ hybridization (FISH) on 4 pm thick frozen tissue sections as a method to facilitate scoring of aberrant chromosome copy numbers in colonic tumors. Analysis of FISH signals in colon tissue sections is often hampered by overlap and truncation of epithelial nuclei, due to the density of the epithelial cells. Furthermore, on the basis of nuclear staining it is often difficult to determine whether or not nuclei are overlapping, or adjoining. Therefore, reliable evaluation of (F)ISH signals to screen for genomic changes was until now mainly restricted to isolated nuclei obtained from relatively thick tissue sections.
In this study the applicability of lamin ICC, to stain the nuclear periphery and to distinguish indi- vidual nuclei, combined with the FISH procedure is explored to solve this problem for colon epithe-lium. For ICC we applied the alkaline phosphatase (APase)-Fast Red detection method, since the fluorescent precipitate of this reaction resists extensive proteolytic digestion as needed for efficient FISH on tissue sections.
Chromosome copy numbers could easily be determined in 4 pm thick frozen tissue sections by combining lamin ICC and FISH. The ratio of the copy numbers of the chromosomes 7 and 17 could be determined in frozen tissue sections after combined lamin ICC and double-target FISH.
It is concluded that the combination of lamin ICC and FISH improves chromosome copy number anal- ysis and can be used to investigate genomic changes in Merent tumor compartments in t h i n frozen tissue sections. o 1996 Wuey-Liss, I ~C .