FIGURE 2.

Ubiquitin‐specific protease 28 (USP28) positively regulates Wnt signaling through transcription factor 7‐like 2 (TCF7L2). (A) Western blot analysis of TCF/LEF family transcription factors in HepG2 cells. (B) Western blot analysis of TCF7L2 in HepG2 cells depleted of USP28 by shRNA‐mediated knockdown followed the overexpression of TCF7L2. (C) TOPFlash reporter assay in HepG2 cells depleted of USP28 by two independent shRNAs followed the overexpression of TCF7L2. All data were normalized to shNC in the RFP control group. (D) Cell viability of HepG2 cells depleted of USP28 by two independent shRNAs followed the overexpression of TCF7L2 determined using MTS assay. (E, F) Western blot and quantitative RT‐PCR analyses of TCF7L2, AXIN2, and CCND1 expression in HepG2 (E) and HuH6 (F) cells depleted of USP28 by two independent shRNAs. All data are representative of three independent experiments (mean ± SEM). Two‐tailed Student's t‐tests were used to examine statistical significance. **p < 0.01; ***p < 0.001; ****p < 0.0001