FREQUENT LOSS OF HETEROZYGOSITY AND 3 CRITICAL REGIONS ON THE SHORT ARM OF CHROMOSOME-8 IN OVARIAN ADENOCARCINOMAS

Many chromosomal regions undergo loss of heterozygosity (LOH) in ovari an adenocarcinomas but few of the target regions have been finely mapp ed. One of the chromosome arms likely to harbour one or more tumour su ppressor genes inactivated in ovarian cancer is the short arm of chrom osome 8 which is frequently deleted in many other solid tumours, We ha ve examined a large panel of microsatellite markers on 8p for LOH in 5 3 ovarian adenocarcinomas. LOH was observed in 27 tumours (51%), with a significant trend towards a higher frequency of LOH in more advanced tumours, Detailed examination of nine tumours with partial deletions defined three regions of overlap, two in 8p23 and one in 8p22, which s uggests that there might be as many as three tumour or metastasis supp ressor genes on 8p which are inactivated during ovarian tumorigenesis. LOH on 8p was significantly associated with 9p LOH which suggests tha t inactivation of target genes on these chromosomes may be cooperative events.