Fig. 4. Upregulation of GP73 promotes cell invasion.

a H&E staining of lung metastases in metastatic tumors from nude mice (scale bar: 1 mm). The lung metastases from the lungs of nude mice were counted and are shown as scatter diagrams. b HepG2 cells were transfected with siRNAs and vectors as described. Six hours after transfection, 100,000 cells from each group were subjected to Matrigel Transwell assays (scale bar: 100 μm). c MHCC-97H cells in the hypoxia group were cultured in a hypoxic chamber containing 2% oxygen, and cells in the control group were cultured in hypoxic chambers containing 21% oxygen. Each group was cultured for 6 h before the samples were harvested. The levels of the indicated proteins were determined by immunoblotting. d HepG2 cells were transfected with 2 μg pCMV-c-Myc, pCMV-GP73 or pCMV vector. MHCC-97H cells were transfected with a specific siRNA against c-Myc or GP73 or with a control siRNA. Samples were harvested 48 h after transfection. The mRNA level of MMP-7 was determined by qRT-PCR, and the levels of the indicated proteins were determined by immunoblot. e HepG2 cells were transfected with 2 μg pCMV-c-Myc, pCMV-GP73 or pCMV vector. MHCC-97H cells were transfected with c-Myc, GP73-specific siRNAs or control siRNAs. Cell culture supernatant was collected 48 h after transfection. The level of MMP-7 was determined by ELISA. f MHCC-97H and HepG2 cells were transfected with siRNAs and vectors as described. Six hours after transfection, 100,000 cells of each group were subjected to Matrigel Transwell assays (scale bar: 100 μm). Data in a, d and e are the mean ± s.e.m. and data represent three independent experiments. A two-tailed Student’s t-test was used for statistical analysis