Fig. 5.

The NQO1 short 3’UTR isoform has oncogenic function and increases aggressiveness in liver cells. a Schematic illustration of the NQO1 isoform with long or short 3’UTR. Positions of the binding sites of miRNA were indicated by yellow horizontal lines. The activity of short 3’UTR (3’UTR-S) and long 3’UTR (3’UTR-L) of NQO1 after enforced expression of the specific miRNAs was examined using luciferase reporter assay in HL-7702 (b) and Huh-7 (c) cells. d Luciferase expression from a reporter containing the short 3’UTR of NQO1, as compared to that from the reporter containing the long 3’UTR of NQO1 in 4 liver cell lines. e The protein levels of NQO1 in HL-7702 cells stably transfected with NQO1-overexpressing plasmids were assessed by western blotting. β-actin was used as internal control. f Proliferation curves of HL-7702 cells stably transfected with NQO1-overexpressing plasmids or control (Ctrl) were shown. g The cell viability of HL-7702-NQO1-OE and HL-7702-Ctrl cells was examined by MTT assay. h Colony formation analysis of HL-7702-NQO1-OE and HL-7702-Ctrl cells. i Transwell analysis of the migration ability of HL-7702 cells. j Transwell analysis of the invasion ability of HL-7702 cells. k HL-7702 xenograft tumor growth with or without overexpression of different NQO1 isoforms. l The weight of HL-7702 tumors at the end point was shown. m IHC analysis of NQO1 and Ki67 expression in tumors. Scale bars, 100 μm. n Representative pictures of H&E staining of lungs and incidence of lung metastasis from mice inoculated with HL-7702 cells. Black arrows indicate the lung metastases. **p < 0.001, Student’s t test