Fig. 3.

Combined effects of bortezomib and mitotane treatment on markers of ER-stress in adrenocortical tumour cells. Concomitant treatment for 24 h with different concentrations of bortezomib and mitotane result in a concentration dependent increase in XBP1 mRNA splicing (a) and specific changes in expression of marker proteins (b), compared to treatment with the two substances alone. M, molar concentration; μM, concentration in micromoles/litre; CHOP, C/EBP homologous protein; eIF2α, eukaryotic translation initiation factor 2 A; P-eIF2α, phosphorylated eIF2α; HIF1α, hypoxia inducible factor 1; XBP1-s, X-Box binding protein 1, encoded by the spliced mRNA; GRP78, 78 kDa glucose-regulated protein; ***, p < 0.001 compared to reference treatment; experiments were performed in biological triplicates