Figure 4. JNK is involved in the enhancement of ATRA-induced differentiation of neuroblastoma cells by bortezomib.

A: WB was used to detect the expression of pJNK, RARα, RARβ, pERK and pp38 after SP600125 treatment. B: CHP126 cells were treated with 5.0 nM bortezomib, 10.0 nM ATRA and 5.0 nM bortezomib plus 10.0 nM ATRA in the presence of SP600125, as well as under control conditions. The morphology of cells was observed by microscopy at the same magnification. The microphotographs shown are representative of three different experiments. The images were analyzed with the Leica software to determine the relative lengths of the neurites (C). Data are shown as the means ± SE (n = 3). D. WB was used to detect the expression of tau and β tubulin III with or without SP600125 treatment. BTZ = bortezomib.