Figure 6

miR-26b sensitizes tumor cells to the doxorubicin-induced apoptosis. (A) Introduction of miR-26b sensitized HCC cells to the doxorubicin-induced apoptosis. Nontransfected (cell) or NC- or miR-26b-transfected HCC cells were treated with the indicated concentrations of doxorubicin (DOX) for 48 hours before apoptosis analysis by DAPI staining. (B) miR-26b expression increased the cleavage of pro-caspase-3. Nontransfected (cell) or NC- or miR-26b-transfected HCC cells were treated with doxorubicin for 48 hours before immunoblotting. (C) Antagonism of miR-26b desensitized tumor cells to the doxorubicin-induced apoptosis. QGY-7703 cells transfected with anti-NC or anti-miR-26b were treated with doxorubicin for 48 hours before apoptosis analysis by DAPI staining. (D) Knockdown of TAK1 or TAB3 sensitized HCC cells to the doxorubicin-induced apoptosis. QGY-7703 cells transfected with the indicated siRNA duplexes were treated with doxorubicin for 48 hours before apoptosis analysis by DAPI staining. (E) miR-26b expression is positively correlated with the rate of apoptosis in HCC tissues. The level of miR-26b was examined by real-time qPCR and normalized to RNU6B expression. Apoptosis was analyzed using TUNEL staining. The correlation between miR-26b levels and apoptosis rates in 20 HCC tissues was determined using Spearman’s correlation coefficient. **, P < 0.01; ***, P < 0.001.