Lentivirus-Mediated siRNA Targeting ER-α Inhibits Tumorigenesis and Induces Apoptosis in Hepatocarcinoma Cells

BACKGROUND AND OBJECTIVES Estrogen receptor-α (ER-α) plays important roles in hepatocarcinogenesis. Recent studies have shown that ER-α could lead to cell cycle progression or inhibition of apoptosis. To better understand the role of ER-α, RNA interference (RNAi) was used to inhibit ER-α expression in the human hepatocellular carcinoma (HCC) cells. METHODS Lentivirus-mediated ER-α small interfering RNA (siRNA) was transfected into HCC cells Hep3B. ER-α expression was monitored by real-time polymerase chain reaction (PCR) and western blot. Cell proliferation, apoptosis, and invasion were examined by methyl thiazol tetrazolium (MTT), flow cytometry (FCM), and invasion assay, respectively. RESULTS ER-α siRNA efficiently downregulated the expression of ER-α in Hep3B cells at both mRNA and protein levels in a time-dependent manner. ER-α siRNA also inhibited cell proliferation and reduced cell invasion (compared with other groups, P < 0.05, resp.). Furthermore, knockdown of ER-α slowed down the cell population at S phase and increased the rate of apoptosis (P < 0.05, resp.). CONCLUSION ER-α knockdown suppressed the growth of HCC cells. Thus, ER-α may play a very important role in carcinogenesis of HCC and its knockdown may offer a new potential gene therapy approach for human liver cancer in the future.