Diverse regulations of albumin gene expression by hepatocyte growth factorin HepG2 human hepatoma cells and primary culture of rat hepatocytes

The effects of HGF on albumin gene expression in HepG2 human hepatoma cells and rat hepatocytes were investigated. HGF reduced the levels of albumin m RNA in HepG2 cells but the level was augmented in rat hepatocytes. By the t rans-fection assay, HGF stimulated albumin promoter activity but repressed cc-fetoprotein (AFP) enhancer activity regulating both AFP and albumin prom oters in HepG2 cells. In contrast, HGF stimulated albumin promoter and AFP enhancer activities in rat hepatocytes. These results suggest that HGF elic its diverse responses of albumin gene expression in HepG2 cells and rat hep atocytes through the different biological actions on AFP enhancer in these cells.