Characterization of chromosome 9 deletions in transitional cell carcinoma by microsatellite assay

A panel of 18 superficial or Invasive transitional cell carcinomas (TCCs) was analyzed for chromosome 9 deletions by performing a high-density loss of heterozygosity (LOH) analysis. Twenty-five microsatellite loci were assayed by the polymerase chain reaction (PCR) and 7 restriction fragment length polymorphism (RFLP) loci were analyzed by Southern biotting. Concordant results were obtained with these methods, Including direct comparisons at 2 locl. Chromosome 9 LOH was observed In 13 (72%) of 18 Informative cases, including 10 superficial lesions. In contrast, LOH on chromosomes 10, 15, 20 and 21 was ≤8%. Evidence for missing copies of chromosome 9 was observed in 7 of 13 LOH cases. Comparison of cases with subchromosomal LOH Implicated the region between the D9S55 locus on 9p12 and the argininosucclnate synthetase (ASS) locus on 9q34.1 as the location of a tumor suppressor gene relevant to TCC.