Genetic abnormalities detected by comparative genomic hybridization in a human endometriosis-derived cell line

Comparative genomic hybridization (CGH) was used in parallel with fluoresce nce in-situ hybridization (FISH) and conventional karyotyping to perform a genome-wide survey of DNA gains and losses in the endometriosis-derived per manent cell line, FbEM-1. The cytogenetic analysis showed a complex karyoty pe with numerical changes and multiple chromosome aberrations, including th e der(1) complement marker exhibiting a large homogenous staining region (H SR). The chromosomal rearrangement interpreted as der(5) t(5;6)(q34;p11) wa s found in the majority of the metaphases indicating a clonal abnormality. Repeated CGH experiments demonstrated over-representation of chromosomes 1, 2, 3, 5, 6p, 7, 16, 17q, 20, 21q and 22q, while chromosomes 6q, 9, 11p, 12 , 13q, 18 and X were under-represented. Using DNA from the original endomet riotic tissues, including a peritoneal implant and ovarian endometrioma, CG H analysis revealed loss of DNA copy number on Ip, 22q and chromosome X, wh ile gain was found on chromosomal arms 6p and 17q. FISH analysis confirmed that the gain at 17q includes amplification of the proto-oncogene HER-2/neu in 16% of the FbEM-1 nuclei and in 12% of cells from the primary ovarian e ndometrioma tissue. These findings demonstrate that FbEM-1 cells share cert ain molecular cytogenetic features with the original tissue and suggest tha t chromosomal instability is important in the development of endometriosis.