ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of esophageal cancer related gene 4 (ECRG4) in human hepatocellular carcinoma and the role of ECRG4 in proliferation, apoptosis and migration of hepatoma cells.</p><p><b>METHODS</b>ECRG4 expression was investigated in normal or tumor liver cell lines including QSG7701 and HepG2 cells, and in 24 pairs of fresh samples of hepatocellular carcinoma by quantitative real-time PCR or Western blot. ECRG4-pcDNA3.1 expressing plasmid was transfected into HepG2 cells, of which cellular proliferation, apoptosis and migration were documented.</p><p><b>RESULTS</b>ECRG4 mRNA expression was reduced or absent in most primary hepatocellular carcinoma samples (95.8%, 23 out of 24 hepatocellular carcinoma samples) compared to their paired normal liver samples (P < 0.01). ECRG4 mRNA was significantly lower in HepG2 cells than QSG7701 cells (P < 0.05) along with decreased ECRG4 protein expression. HepG2 cells overexpressing ECRG4 showed decreased proliferation, increased apoptosis and reduced migration as compared with control cells (P < 0.05).</p><p><b>CONCLUSIONS</b>ECRG4 expression is frequently down-regulated in hepatocellular carcinoma. Overexpression of ECRG4 inhibits the proliferation and migration but promotes apoptosis of HepG2 cells, suggesting that ECRG4 is a candidate tumor suppressor gene in hepatocellular carcinoma and therefore may serve as a novel target for precision therapy.</p>