Fig. 4

STAT3 regulates the nuclear localization of METTL3 via WTAP. A Western blotting analysis of METTL3 in the whole-cell lysate (WCL), cytoplasmic (Cyto), and nuclear (Nuc) fractions from the HCCLM3 (MOCK), HCCLM3-knockdown-control (Control), and HCCLM3-STAT3-knockdown (KD-STAT3) cells. β-actin and Lamin B1 were used as cytoplasmic and nuclear markers, respectively. The right panel shows the quantification of the intensity relative to β-actin or Lamin B1. B Immunofluorescence analysis of METTL3 (green), STAT3 (red) and DAPI (blue) in HCCLM3-STAT3-knockdown and HCCLM3-control cells. Scale bar, 10 μm. C qRT-PCR analysis of STAT3, WTAP, and ZC3H13 in MHCC97L cells transfected with the indicated plasmids. D qRT-PCR analysis of STAT3, WTAP and ZC3H13 in STAT3 knockdown and control MHCC97H cells, STAT3 knockdown and control HCCLM3 cells. E Western blotting analysis of WTAP and STAT3 in MHCC97L cells transfected with the indicated plasmids. F Western blotting analysis of WTAP, ZC3H13, and STAT3 in STAT3 knockdown and control MHCC97H cells, STAT3 knockdown and control HCCLM3 cells. G Western blotting analysis of METTL3 in the whole-cell lysate (WCL), cytoplasmic (Cyto), and nuclear (Nuc) fractions from the HCCLM3-knockdown-control, HCCLM3-STAT3-knockdown, and HCCLM3-STAT3-knockdown-WTAP-overexpression cells. β-actin and Lamin B1 were used as cytoplasmic and nuclear markers, respectively. The right panel shows the quantification of the intensity relative to β-actin or Lamin B1. H, I Immunofluorescence analysis of METTL3 (green), STAT3 (red) and DAPI (blue) in the indicated cells. Scale bar, 10 μm. (I) shows the quantification of nuclear fluorescence intensity of anti-METTL3 cell. All experiments were repeated at least three times. Error bars represent mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001 by 2-tailed Student’s t-test