Figure 4

Fbxw7 regulates the stability of the YAP protein in HCC cells. A) HepG2 and Hep3B cells that were transfected with Flag-Fbxw7 and Fbxw7-shRNA, respectively, and subjected to Western blotting for Fbxw7, c-Myc, Cyclin E and YAP. Fbxw7 overexpression decreased c-Myc, Cyclin E and YAP protein levels in HepG2 cells, whereas Fbxw7 knockdown led to c-Myc, Cyclin E and YAP accumulation in Hep3B cells. Data are representative of multiple repeats with similar results. B) HepG2 cells transfected with EV or Flag-Fbxw7 and Hep3B cells transfected with non-targeting (NT)-shRNA or Fbxw7-shRNA were harvested for RNA extraction and real time RT-PCR. Fbxw7 overexpression or knockdown did not change YAP mRNA levels. n = 3 independent experiment; Values are depicted as the Mean ± SEM. C) HCC cells that were treated as above were subjected to IF for YAP. Quantification of YAP immunofluorescence revealed that the average level of YAP in the control cells was significantly higher than that in the Fbxw7 overexpressing HepG2 cells and lower than that in the Fbxw7 shRNA transfected Hep3B cells. Scale bar: 20 μm, n = 6; Values are depicted as the Mean ± SEM; **P < 0.01 by t test.