Fig. 4

PITX2C enhances the chemoresistance of HCC cells. A Cell viabilities of PITX2C- and vector-transfected cells were detected by XTT assay after treatment with 5-Fu and Sorafenib at the indicated concentration for 48 h. The apoptotic indexes of vector-, PITX2C-transfected (B) and shCtl- and shPITX2-transfected cells (C) were detected by fluorescence-activated cell sorting-based Annexin V/AAD double staining after treatment with 5-Fu or Sorafenib at the indicated concentration for 48 h. A-C Values indicate the mean ± SD of three independent experiments with three repeats (*P < 0.05, **P < 0.01, independent Student’s t-test). D The activation of caspase-9, poly (ADP ribose) polymerase were compared between PITX2C- transfected cells (top),shPITX2-transfected cells (bottom) and control cells after 5-Fu treatment for 48 h. GAPDH was used as a loading control. E Subcutaneous tumors induced by indicated cells were treated with 5-Fu. The dose of 5 mg/kg 5-Fu could effectively shrink tumour size in control cells compared to PITX2C-transfected cells. The final tumor volumes are summarized in dot chart. The average tumour volume was expressed as the mean ± SD. P values were calculated using independent Student’s t test. F Representative IHC images show that PITX2 positive cells were enriched in 5-Fu treated cells (400×, magnification)