X-F Guo1, A-Y Wang, J Liu. 1. Department of Infectious Liver Diseases, Zaozhuang Municipal Hospital, Zaozhuang, Shandong, China. junliu80s@outlook.com.
Abstract
OBJECTIVE: In this study, we investigated whether miR-33a downregulation in HCC is a result of hypoxia-inducible factors (HIFs) overexpression. Then, we further studied the regulative effects of miR-33a on Twist1 and their regulation in HCC cell invasiveness. MATERIALS AND METHODS: Human hepatocellular cancer (HCC) cell lines (HepG2 and BEL-7402) were transfected with miR-33a mimics, HIFs siRNA or Twist1 siRNA. MiR-33a level was measured using QRT-PCR. The binding between miR-33a and Twist1 3'UTR was verified using Western blot analysis and dual luciferase assay. E-cadherin and N-cadherin expression levels were detected by western blot analysis. Tumor cell invasion was assessed using transwell assay. RESULTS: MiR-33a downregulation in HCC cells is hypoxia-induced and is a result of HIFs upregulation. HIF-1α and HIF-2α suppression partly rescued miR-33a expression under hypoxia. Both HepG2 and BEL-7402 cells with miR-33a overexpression had significantly decreased E-cadherin expression and increased N-cadherin level. Transwell analysis confirmed that miR-33a overexpression significantly suppressed the tumor cell invasion capability. Twist1 is a direct target of miR-33a in HCC. HepG2 cells with Twist1 knockdown had significantly increased E-cadherin, decreased N-cadherin and suppressed invasion capability. CONCLUSIONS: MiR-33a downregulation in HCC cells is hypoxia-induced and is a result of HIFs upregulation. MiR-33a can modulate EMT and invasion of hepatocellular cancer cells at least partly via downregulating Twist1.
OBJECTIVE: In this study, we investigated whether miR-33a downregulation in HCC is a result of hypoxia-inducible factors (HIFs) overexpression. Then, we further studied the regulative effects of miR-33a on Twist1 and their regulation in HCC cell invasiveness. MATERIALS AND METHODS:Humanhepatocellular cancer (HCC) cell lines (HepG2 and BEL-7402) were transfected with miR-33a mimics, HIFs siRNA or Twist1 siRNA. MiR-33a level was measured using QRT-PCR. The binding between miR-33a and Twist1 3'UTR was verified using Western blot analysis and dual luciferase assay. E-cadherin and N-cadherin expression levels were detected by western blot analysis. Tumor cell invasion was assessed using transwell assay. RESULTS:MiR-33a downregulation in HCC cells is hypoxia-induced and is a result of HIFs upregulation. HIF-1α and HIF-2α suppression partly rescued miR-33a expression under hypoxia. Both HepG2 and BEL-7402 cells with miR-33a overexpression had significantly decreased E-cadherin expression and increased N-cadherin level. Transwell analysis confirmed that miR-33a overexpression significantly suppressed the tumor cell invasion capability. Twist1 is a direct target of miR-33a in HCC. HepG2 cells with Twist1 knockdown had significantly increased E-cadherin, decreased N-cadherin and suppressed invasion capability. CONCLUSIONS:MiR-33a downregulation in HCC cells is hypoxia-induced and is a result of HIFs upregulation. MiR-33a can modulate EMT and invasion of hepatocellular cancer cells at least partly via downregulating Twist1.