Fig. 3

Screening of different HDACi on IGR-NB8 cells and effect of CUDC-907 on mIBG internalization. A mIBG internalization in IGR-NB8 cells incubated with different HDACi for 48 h. Results are expressed as fold of increase in mIBG internalization compared with non-incubated cells. B and C Dose response studies for CUDC-907 and sodium-4-P. D Determination of the affinity of IGR-NB8 cells toward mIBG with or without CUDC-907 treatment. Cells were incubated with DMSO or CUDC-907 0.1 µM for 48 h and then with mIBG at increasing concentrations for 10 min (X-axis). Results were normalized by a BCA test and performed three times in duplicates, with the mean values of each series shown. Non-linear regression was drawn using GraphPad Prism’s Michaelis–Menten interpolation. E Extracellular and intracellular mIBG concentration in IGR-NB8 cells treated with CUDC-907 over time. Y-axis on the left corresponds to intracellular mIBG concentration and is expressed as pmol of mIBG per mg of protein. Y-axis on the right corresponds to extracellular mIBG concentration and is expressed as nmol of mIBG per liter. F mIBG internalization in SK-N-Be2C, LAN1 and PC12 cells incubated with different concentrations of CUDC-907 for 48 h. For the experiments A, B, C, E, and F results were normalized by a BCA test and performed three times in duplicates. Statistical analysis was performed through the unpaired t-test between the control and condition tested. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001