Figure 1.

T₃ positively regulates mRNA and protein levels of ISG20 and effects of T₃ and ISG20 on angiogenesis in hepatoma cells. (A) ISG20 mRNA and (B) protein expression in TR stable cell lines (HepG2-TRα1, HepG2-TRβ1, HepG2-neo control or SK-Hep1) incubated for 12, 24 or 48 h in the absence or presence of T₃ (10 or 100 nM). Total RNA or protein was isolated and analyzed via qRT-PCR and western blot, respectively. (C) HepG2-TRα1 cells were incubated with T₃ (10 nM) for 24 h, and conditional medium (CM) was collected. HUVECs were incubated with CM for 16 h, and cell capillary-like structure formation was photographed and counted. (D) HepG2-TRα1-shCtrl and HepG2-TRα1-shISG20 cells were incubated with T₃ (10 nM) for 24 h, and CMs were collected. HUVECs were incubated with CM for 16 h, and cell capillary-like structure formation was photographed and counted. (E) HUVECs were incubated with CM collected from SK-Hep1- and J7-ISG20 and control cells, and cell capillary-like structure formation in HUVECs was photographed and counted. Data are presented as means ± SD from three independent experiments, each performed in triplicate (*p < 0.05; **p < 0.01).