Figure 3

Increased sensitivity of differentiating NB4 cells to ER stress correlates with the strength of UPR activation. (a) Quantitative reverse transcriptase-PCR (qRT-PCR) for the expression of UPR target genes from NB4 samples treated for 24 h (n=4±s.e.m.; Student’s T-test *P-value<0.05, **P-value<0.02, ***P-value<0.005; analysis of variance (ANOVA) presented in Supplementary Table 1). (b) Western blot analysis of total protein extracts from NB4 cells for CHOP and BiP proteins. Actin was used as loading control. The histogram reports the average quantification of BiP protein (n=3±s.e.m.). (c) Western blotting in non-reducing conditions of total protein extracts from NB4 cells treated for 72 h. A shorter exposure is shown on the left, a longer one on the right. The black arrowheads point to BiP complexes. GAPDH was used as loading control. (d) Growth curve and (e) propidium iodide (PI) uptake analysis of NSC and shCHOP NB4 cells (n=2±s.e.m., ANOVA analysis in Supplementary Table 1).