MPNST cell lines validate the changes observed in human tumors and allow
for more precise quantification of changes is H3 PTMs. A,
Correlation between changes in histone PTMs as a function of PRC2 status in cell
lines (x-axis) and human tumors (y-axis) for peptides with
significant changes in either comparison. P values for Pearson
correlation are shown. B, Quantitative comparison of H3K27me2
levels between PRC2LOSS (12 replicates) and PRC2RET (10
replicates) samples. Two-tailed t test; ****,
P< 0.0001. Using DIA acquisition, H3K27me2/1 and
H3K36me3 could be distinguished, enabling more precise quantification of
H3K27me2 levels. Error bars, ± SD. C, IHC for histone
H3K27me2 in representative MPNST cases: PRC2LOSS (left) and
PRC2RET (right). D, Quantitative comparison of
H3K36me2 levels between PRC2LOSS (left) and PRC2RET
(right) samples. The peptide quantifications are represented as stacked bar
plots, with each level of methylation colored according to the schematic
depicted at right, where higher levels of methylation at K27 lead to
progressively darker red colors. Unpaired t test,
P < 0.0001 for pairwise peptide comparisons at the
same level of methylation. Error bars, ± SD.