DELETION MAPPING OF CHROMOSOME 8P IN COLORECTAL-CARCINOMA AND DYSPLASIA ARISING IN ULCERATIVE-COLITIS, PROSTATIC-CARCINOMA, AND MALIGNANT FIBROUS HISTIOCYTOMAS

Short tandem repeat polymorphism markers on the short arm of chromosom e 8 were used to search for loss of heterozygosity (LOH) in colorectal carcinoma and dysplasia complicating ulcerative colitis, in prostatic carcinoma, and in malignant fibrous histiocytoma (MFH). Fifty percent of prostatic carcinomas (13/26), 44% of carcinomas or dysplasias aris ing in ulcerative colitis (7/16), and 30% (4/12) of MFH cases showed L OH for markers on 8p. Detailed mapping demonstrated variability is the size of the chromosomal region showing LOH; however, the data suggest a common 30-centimorgan region of LOH on chromosome 8p between the LP L locus and pter in colorectal and prostatic cancers. In addition, LON was observed on 8p in both high-grade and low-grade dysplasia in ulce rative colitis, indicating that LON off 8p may occur at as early stage of neoplastic development in this disorder. In contrast, MFH cases ex hibited LOH for marker D8S87, which has been identified as being near the putative Werner's syndrome locus. These results suggest that a tum or suppressor gene, located on the distal portion of chromosome 8p, ex ists in common for prostatic and colorectal carcinomas, and a second t umor suppressor gene may exist linked to the Werner's syndrome locus.