FLUORESCENCE IN-SITU HYBRIDIZATION ANALYSIS USING COSMID PROBES TO DEFINE CHROMOSOME 6Q ABNORMALITIES IN OVARIAN-CARCINOMA CELL-LINES

Deletion of as is a frequent finding in ovarian carcinoma, which would suggest that this region contains one or more putative tumor suppress or genes. Chromosome 6q abnormalities in six ovarian carcinoma cell li nes were analyzed by G-banding and fluorescence in situ hybridization (FISH). Using a variety of probes, including a chromosome 6 paint, a p robe specific for the chromosome 6 centromere, and cosmids that map to q24 (cCI6-115), q25 (cCI6-4), q26 (cCI6-91, cCI6-119), and q27 (cCI6- 13, cCI6-24, and cCIG-111), abnormalities of 6q were found in three ce ll lines. In cell line OAW42 (hypotetraploid), the sequences complemen tary to cCI6-119, cCI6-91, and cCI6-13 probes were lost in two homolog ues of chromosome 6, which indicates the deletion of genetic material from bands q26-27. The same bands were translocated in cell line PEO1 (hypertriploid). The probes from this region were absent on two copies of chromosome 6, but hybridized to two or three markers. In cell line 59M (hyperdiploid) an interstitial deletion proximal to q24 was detec ted in one chromosome 6. We conclude that it is very likely that a gen e or genes localized in bands 6q26-27, and perhaps in the region proxi mal to 6q24, play a critical role in the development or progression of ovarian carcinoma.