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Topology of double minutes (dmins) and homogeneously staining regions (HSRs) in nuclei of human neuroblastoma cell lines
Author(s) -
Solovei Irina,
Kienle Dirk,
Little Graham,
Eils Roland,
Savelyeva Larissa,
Schwab Manfred,
Jäger Willi,
Cremer Christoph,
Cremer Thomas
Publication year - 2000
Publication title -
genes, chromosomes and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.754
H-Index - 119
eISSN - 1098-2264
pISSN - 1045-2257
DOI - 10.1002/1098-2264(2000)9999:9999<::aid-gcc1046>3.0.co;2-h
Subject(s) - chromatin , interphase , chromosome , biology , microbiology and biotechnology , amplicon , chromosome conformation capture , gene , fluorescence in situ hybridization , topology (electrical circuits) , transcription factor , genetics , polymerase chain reaction , mathematics , enhancer , combinatorics
Abstract Amplification of the MYCN gene is a characteristic feature of many neuroblastomas and is correlated with aggressive tumor growth. Amplicons containing this gene form either double minutes (dmins) or homogeneously staining regions (HSRs). To study the nuclear topology of these tumor‐specific and transcriptionally active chromatin structures in comparison to chromosome territories, we performed fluorescence in situ hybridization with a MYCN probe and various chromosome paint probes, confocal laser scanning microscopy, and quantitative three‐dimensional image analysis. The dmins formed dot‐like structures in interphase nuclei and were typically located at the periphery of complexly folded chromosome territories; dmins noted in the chromosome territory interior were often detected within an invagination of the territory surface. Interphase HSRs typically formed extremely expanded structures, which we have never observed for chromosome territories of normal and tumor cell nuclei. Stretches of HSR‐chromatin often extended throughout a large part of the cell nucleus, but appeared well separated from neighboring chromosome territories. We hypothesize that dmins are located within the interchromosomal domain (ICD) space and that stretches of HSR‐chromatin align along this space. Such a topology could facilitate access of amplified genes to transcription and splicing complexes that are assumed to localize in the ICD space. © 2000 Wiley‐Liss, Inc.