Fig. 2

Spheroid respond to chromatin decondensation. Spheroids were treated with 20 mM of NaBut and were kept in culture for 3 days. After collection of 5 spheroids per time point, the treatment media were replaced by the standard growth media and the remaining spheroids were maintained for additional 7 days, until the last collection on day 10. Histones were extracted from 5 spheroids and analyzed by mass spectrometry. A Workflow for spheroids treatment. B Total levels of histone peptides containing 1, 2, or 3 methylations (me1, me2, me3, respectively) or containing acetylations (ac). C Total levels of histone H4 peptides containing acetylations (1ac, 2ac, 3ac, 4ac). Unmod, unmodified peptide. * p < 0.05, ** p < 0.005, and *** p < 0.0005 when compared with the Nt group. D Relative abundance of histone H3 acetylated peptides. Data are represented as means ± SD. Nt, non-treated. E Volcano plot representing NaBut vs Nt fold change after 3 days of treatment and F Correlation coefficient (R) of histone marks between non-treated (Nt) spheroids and NaBut-treated spheroids after recovery (Day 10). Highlighted green dots correspond to acetylated histone peptides