Molecular definition of a small amplification domain within 3q26 in tumorsof cervix, ovary, and lung

A common amplification target encompassing chromosome region 3q25 to q27 ha s been identified by comparative genomic hybridization analyses in tumors o f the cervix, ovary, endometrium, lung,: and head and neck. Because this se gment spans at least 30 megabases, rye undertook a molecular analysis of co py number to more precisely define the amplification domain. Our Southern b lot and fluorescence in situ hybridization results with the use of 17 marke rs confirmed the presence of low-level 3q amplification events in cervical, ovarian, and variant SCLC: tumors. Most of the tumor types studied appeare d to have similar, broad amplification domains centered within 3q26.2, sugg esting that the same target is being affected in all. The ovarian carcinoma cell line NIH:OVCAR3 had a highly restricted amplification domain spanned by four overlapping YAC clones, suggesting a small target. The region of hi gh est amplification included the gene for the RNA component of telomerase (hTR), sup porting it as a potential target. Although the importance of low -level amplification is unknown, the consistent and reproducible nature of this event in a variety of carcinomas suggests that 3q26.2 harbors an oncog ene whose low-level amplification has a significant influence on tumor biol ogy. (C) Elsevier Science Inc., 2000. All rights reserved.