RT Journal Article SR Electronic T1 Topoisomerase I Deficiency Results in Chromosomal Alterations in Cervical Cancer Cells JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 3257 OP 3265 VO 30 IS 9 A1 EIGIL KJELDSEN A1 DAVID TORDRUP A1 GERDA M. HÜBNER A1 BIRGITTA R. KNUDSEN A1 FELICIE F. ANDERSEN YR 2010 UL http://ar.iiarjournals.org/content/30/9/3257.abstract AB Human topoisomerase I has been suggested to be implicated in the maintenance of genomic stability via its ability to regulate genome topology during transcription and replication. In the present study, we demonstrate by whole-genome array comparative genomic hybridization (aCGH) and fluorescence in situ hybridisation (FISH) analysis that topoisomerase I deficiency results in chromosome 5p gain in the cervical cancer cell line, HeLa-CCL2. In contrast, chromosome 5p copy number remained unaffected by topoisomerase I down-regulation in the non-cancer cell line HEK293T, as demonstrated by FISH analysis. Chromosome 5p gain is the most frequent genetic alteration in invasive cervical cancer, which leads to overexpression of genes involved in proliferation and occurs primarily at late stages in cancer development. The amplification of this region upon topoisomerase I down-regulation specifically in HeLa-CCL2 cells may indicate an important role of topoisomerase I in preventing malignant progression of precancerous lesions in the cervix.