Figure 7

A: Transfection with HuR overexpressing plasmid. Western blotting on whole cell lysates from parental (MCF-7) and doxorubicin resistant MCF-7 (MCF-7/DoxorR) cells, mock transfected, to detect the HuR expression level also in the presence (+) of HuR overexpressing plasmid. Beta tubulin was used as loading control. B. Caspase 7 activation in MCF-7/DoxoR. Western blotting on whole cell lysates from parental (MCF-7) and doxorubicin resistant MCF-7 (MCF-7/DoxorR), mock transfected, to detect caspase 7 activation in the presence of doxo C. HuR revert MCF-7 doxorubicin resistance. Sigmoidal inhibition curves of MCF-7 wild type (WT), doxorubicin-resistant (MCF-7/DoxoR), and MCF-7/DoxoR trasfected with a plasmid containing the coding sequence of HuR (MCF-7/DoxoR + HuR). Cells were exposed to different concentration of doxorubicin for 24 h before being assayed. As demonstrated by the dashed line, the doxo toxic effect on HuR transiently transfected-DoxoRes cells was similar to the one exerted on MCF-7.