Figure 2

Modulation of Wnt/β-catenin activation by HBx, ctHBx or BAMBI. (a) HepG2 cells were transfected with either mock (LacZ), HBx, ctHBx or BAMBI plasmids alone or in combination with pTOP-Flash and pFOP-Flash reporter plasmids. After 48 h of culture, luciferase activity was measured. The values represent the mean±s.d. from three independent experiments. *P<0.01. (b) Subcellular localization of HBx and ctHBx proteins. HepG2 cells were transiently transfected with GFP-tagged HBx or ctHBx, fixed in 0.4% paraformaldehyde and subsequently processed for indirect immunofluorescence with antibodies against BAMBI (TRITC, red). Nuclei were stained with Hoechst 33258 (blue), and the cells were subsequently examined using confocal microscopy (Trans, transmission; bar, 20 μm). (c) Subcellular localization of β-catenin by HBx or ctHBx. β-Catenin expression was determined via immunoblot analysis in nuclear or cytoplasmic fractions of the stable transfectants expressing HBx or ctHBx. (d) Increased BAMBI promoter activity induced by mutant β-catenin. ALX and HepG2 cells were transfected with either wild-type or mutant β-catenin expression plasmids. After 48 h of culture, luciferase activity was measured. The values represent the mean±s.d. from three independent experiments. **P<0.01. (e) Modulation of wild-type or mutant BAMBI promoter activity by TCF-1 or TCF-4 in ALX and HepG2 cells. The values represent the mean±s.d. from three independent experiments. **P<0.01.