[Effect of RNA interference targeting HIF-1α gene on biological behavior of human esophageal squamous cell carcinoma and gastric adenocarcinoma cells in vitro].

OBJECTIVE: To investigate the effect of hypoxia inducible factor-1α (HIF-1α) on the proliferation, migration and vasculogenic mimicry(VM) in human esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 in vitro. METHODS: The recombinant plasmid pGCsi-shHIF-1α was transfected into Eca-109 and SGC-7901 cells by Lipofectamine(TM) 2000. The inhibitory effect of HIF-1α was measured at protein level by Western blot under normoxia and hypoxia. The cell proliferation was detected by colony formation and MTT assays. The migration of transfected cells was assayed using Transwell chambers. Whether Eca-109 and SGC-7901 cells could form the capillary tube-like structures (TLSs) was observed by 3-dimensional culture, and the tube formation of transfected cells was detected by tube-like structure formation assay. RESULTS: The expression of HIF-1α protein in each group of transfected cells was significantly suppressed under normoxia and hypoxia (Eca-109: 0.00, 0.74 ± 0.05; 0.00, 1.11 ± 0.06; SGC-7901: 0.00, 0.60 ± 0.05; 0.00, 0.96 ± 0.07, P < 0.01). Colony formation and MTT assays showed that the cell proliferation of the pGCsi-shHIF-1α transfected cells was slower than that of the control groups (104.7 ± 9.6, 151.7 ± 4.5; 88.3 ± 5.1, 128.3 ± 6.7, P < 0.05). The migration of the recombinant plasmid-transfected cells was significantly suppressed compared with that of cells transfected with empty vector (55.5 ± 11.2, 121.9 ± 17.3; 64.7 ± 10.8, 132.3 ± 16.0, P < 0.01). Both the Eca-109 and SGC-7901 cells could form TLSs when cultured on matrigel, and the number of tubules was significantly increased under hypoxia (30.8 ± 3.9, 34.3 ± 3.4; 26.2 ± 3.4, 30.1 ± 4.1, P < 0.05), the tubule-forming ability of transfected groups was significantly inhibited under normoxia and hypoxia (Eca-109: 3.7 ± 2.8, 30.8 ± 3.9; 3.9 ± 2.7, 34.3 ± 3.4; SGC-7901: 4.9 ± 3.5, 26.2 ± 3.4; 5.3 ± 3.6, 30.1 ± 4.1, P < 0.01). CONCLUSIONS: Both the esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 are capable of forming vasculogenic mimicry structures in vitro. The recombinant plasmid pGCsi-shHIF-1α can efficiently suppress their proliferation, migration and vasculogenic mimicry formation.