ABSTRACT
PURPOSE: We have previously cloned three enhancer factor genes encoding proteins that bind to long terminal repeats (LTRs) of Rous sarcoma virus. Among these genes, RSV- EF-I gene is expressed in rat hepatoma tissues and several proliferating cell lines but not in normal rat liver tissues. We have isolated the human homologue of RSV-EF-I gene and examined its expression in human hepatocellular carcinoma tissues. MATERIALS AND METHODS: We have screened the human genomic library and cDNA library of Hep G2 cell line derived from human hepatocellular carcinoma to isolate the human homologue of RSV-EF-I gene. RESULTS: We have isolated one cDNA clone containing about 1.5 kb insert and sequenced. Sequence analysis reveals that this human homologue of RSV-EF-I gene has a high similarities to human YB-1 mRNA, human DNA-binding protein B (dbpB) gene and other Y-box protein genes. It is expressed in human hepatocellular carcinoma but very slightly in normal human liver tissues in Northern blot analysis. CONCLUSION: Our data suggest that the human homologue of RSV-EF-I gene presumably belongs to Y-box protein family genes and plays a role in the transformation of the human hepatoma cells.