Fig. 6. Gain of K36me2 in H3K27M DIPG.
(A) H3K36me2 levels are significantly higher in H3K27M DIPG (n = 2 for H3.1K27M and n = 2 for H3.3K27M) than in WT DIPG/GLIOMA (n = 4 for H3K27WT cortical glioma and n = 2 for H3K27WT DIPG), as revealed by MS (see fig. S7). Data are plotted as means ± SD. (B) H3K36me2 ChIP-seq performed with glioma cell lines bearing either WT histone H3 (n = 2 total) or H3K27M, as indicated (n = 2; see table S1 for details). Left: The trend plot was generated by first identifying genes that displayed significant H3K36me2 enrichment above input for the H3K27M-bearing DIPG XIII cell line (1727 genes). Subsequently, average H3K36me2 levels were plotted for each glioma cell line across those genes (transcriptional start to end site). Right: As a control, H3K36me2 was plotted over all genes in the genome. Combined, H3K36me2-enriched genes in the H3K27M DIPG showed overall higher levels of H3K36me2 relative to glioma with WT histone H3. (C) Representative ChIP-seq tracks show generally elevated levels of H3K36me2 across these genes in H3K27M DIPG. Variations of the effect can be seen in these gliomas: Some genes are devoid of H3K36me2 in H3WT gain H3K36me2 in H3K27M, while others contain H3K36me2 in both H3WT and H3K27M glioma, yet the levels in the H3K27M cell lines are generally higher. TSS, transcriptional start site; TES, transcriptional end site.