ISOLATION AND CHARACTERIZATION OF NEW MICROSATELLITES AT THE NM23-H1 AND NM23-H2 GENE LOCI AND APPLICATION FOR LOSS OF HETEROZYGOSITY (LOH)ANALYSIS

The nm23-H1 gene has been suggested to be a metastasis suppressor gene . Studies about the events of loss of heterozygosity (LOH) at the nm23 locus and its correlation to metastasis are controversially discussed . To optimize detection of LOH at the nm23 locus, we screened two P1 c lones for additional microsatellites. Tumor and normal DNA from 37 col orectal, 16 gastric, and 8 germ cancer patients were examined for LOH. We found two new CA repeats, one 5' to nm23-H1 and another 3' to nm23 -H2. Using these nm23 locus-specific CA repeats and five other chromos ome 17 loci (D17S1522, D17S1566, D17S855, D17S515, and TP53), allele l oss was observed in 4/32 (12.5%) patients with colon cancer, 2/14 (14. 3%) with gastric cancer, and 1/7 (14%) with germ cancer. No isolated L OH of the nm23 region was observed.