Detection of amplified dna sequences in human tumor cell lines by fluorescence in situ hybridization

✍ Scribed by Irit Bar-Am; Orna Mor; Yosef Shiloh; Lydia Avivi; Herman Yeger

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 761 KB
• Volume: 4
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.2870040407

✦ Synopsis

An unambiguous and rapid characterization of amplified DNA sequences in tumor cells is important for the understanding of neoplastic progression. This study was conducted t o evaluate the potential of fluorescence in situ hybridization (FISH) t o identify such amplified DNA sequences in human tumor cell lines. Applying this technique, we followed the metaphase location and interphase position of amplified DNA sequences corresponding t o the SAMK, MYC, and MYCN genes in four cell lines derived from human tumors: two gastric carcinoma lines (KATO 111 and SNU-I6), a neuroblastoma (NUBJ), and a neuroepithelioma (NUB-20) line. In metaphase cells of KATO 111, NUB-7, and NUB-20 lines, the amplified regions were clearly visible and easily identified at an intrachrornosornal location: in KATO 111 and NUB-7 at a terminal position and in NUB-20 at an interstitial position. In SNU-16, on the other hand, the amplified SAMK and MYC sequences were identified in extrachromoso-ma1 double minute chromosomes (DMs). In this line, the SAMK and MYC sequences were coamplified in the same cells and were colocated on the same DMs. FISH also allowed the identification of amplified DNA sequences in nondividing cells, enabling us t o distinguish, at interphase, whether the amplification gave rise t o intrachromosomal amplified regions (IARs) o r to extrachromosomal DMs. The FISH technique also allowed us t o determine at metaphase as well as at interphase the extent of amplification and the size of the IARs. Genes Chrorn Cancer 4:314-320 (1992). @ 1992 WiIey-Lirs, Inc.