Nonrandom chromosomal imbalances in human ovarian surface epithelial cells immortalized by HPV16-E6E7 viral oncogenes

We had previously immortalized human ovarian surface epithelial (HOSE) cells using HPV16E6E7 ORFs. In order to identify crucial genetic events involved during cell immortalization, the genomic profile of immortalization of five HOSE cell lines was analyzed by comparative genomic hybridization. Our results showed that chromosomal imbalance was common in HOSE cells after immortalization. The common chromosomal imbalances identified in immortal HOSE cells are: +19q13.1 (5/5 lines), −13q12∼qter (4/5 lines), +5q15∼q33 (3/5 lines), +20q11.2∼q13.2 (3/5 lines) and −22q11.2∼qter (3/5 lines). Other chromosomal imbalances, which were detected in two of the five immortal HOSE cell lines, included gains on chromosome 1 and 11q12∼q13, and losses on 2p, 4q, 8p, 10p and 11q14∼qter. The chromosomal imbalances observed in HOSE cells before immortalization include −8pter∼p11.2, −11q23∼qter, −13q12∼qter and +19 which may represent early genetic events during cell immortalization. The genomic profile was examined in one HOSE cell line (HOSE 6-3) at various stages of immortalization. The genomic profiles of HOSE 6-3 cells after crisis were largely stable. A few additional chromosomal imbalances were detected in the immortalized HOSE cells after an extensive culture period including +11pter∼q23, −15q23∼qter, and +17q12∼qter. Identification of nonrandom chromosomal imbalance in immortalized HOSE cells may facilitate the identification of specific chromosomes harboring genes involved in the immortalization of human ovarian surface epithelial cells.