Localization of a Target Region of Allelic Loss to a 1‐cM Interval on Chromosome 16p.13.13 in Hepatocellular Carcinoma

To identify the location of the putative tumor suppressor gene on chromosome 16p that may be involved in hepatocellular carcinoma (HCC), we examined 96 primary HCCs and evaluated their patterns of allelic loss at 10 microsatellite marker loci distributed along this chromosome arm. Allelic loss at one or more loci was observed in 46 (48%) of these tumors. Through detailed deletion mapping of tumors having partial or interstitial deletions, we identified a commonly deleted region at a 1‐cM interval, flanked by D16S519 and D16S3078 at 16p13.13, defining the location of a putative tumor suppressor gene for HCC. This region contains the gene for JAB (JAK‐binding protein), which is responsible for negative‐feedback regulation of the JAK‐STAT pathway induced by cytokine stimulation, raising the possibility that inactivation of this gene may participate in hepatocarcinogenesis via genetic and/or epigenetic changes.