Effects of epidermal growth factor on growth control and signal transduction pathways in different human hepatoma cell lines.

The roles of epidermal growth factor (EGF) on cell growth control and phosphatidylinositol signal transduction pathway in human hepatoma cell lines with different differentiated states were evaluated. Ligand binding study showed that only one receptor type with similar affinity was found in all three cell lines. Under serum-free conditions, EGF (10(-8)-10(-11) M) enhanced DNA synthesis and cell proliferation of the three cell lines in a dose-dependent manner. The response of the poorly differentiated HA22T/VGH hepatoma cells was most obvious whereas much smaller effects were found in Hep3B and Chang liver cells. The metabolism of phosphoinositides also increased in HA22T/VGH cells as compared with both Hep3B and Chang liver cells under basal and EGF-treated conditions. Our data indicated that EGF had different effects on different human hepatoma cell lines and its role might be more important in poorly differentiated hepatoma cells than in well differentiated ones.