Fig. 5.

HDAC10 inhibition induces accumulation of acidic organelles. (A) BE(2)-C cells treated with class I HDAC inhibitor MS-275 and class IIb HDAC inhibitors (tubacin, tubastatin, or bufexamac) as indicated (in µM). The accumulation of acidic organelles (normalized red fluorescence) was monitored by FACS after staining with acridine orange. (B) Acetylation of histone 4 (Ac-H4) upon treatment of BE(2)-C cells with HDAC inhibitors as indicated. β-Actin served as a loading control. (C) Acetylation of tubulin upon treatment of BE(2)-C cells with MS-275 and tubacin as indicated. β-Actin served as a loading control. (D) The BE(2)-C, Kelly, and IMR32 neuroblastoma cell lines; the neural crest-derived JoMa1 cells, which can be retained in an immortalized and undifferentiated state via 4-OHT supplementation to activate MYC expression (JoMa1 plus) and in an differentiated state upon 4-OHT removal (JoMa1 minus); and untransformed astrocytes and fibroblasts were treated with 30 or 100 µM bufexamac for 24 h and then stained with acridine orange. The accumulation of acidic organelles was quantified by FACS analysis (normalized red fluorescence). Red fluorescence in treated cells was normalized to red fluorescence in untreated cells in all experiments. Bars represent means (±SEM) of at least three independent experiments. Significant differences between groups were tested using an unpaired, two-tailed t test. **P < 0.01; ***P < 0.001.