H3.3G34W generates a unique gene expression profile in a PRC2-dependent manner. (A) Heatmap displaying the expression profiles of 180 differentially expressed genes (PPDE > 0.95; fold change > 3) in mMSCs expressing H3.3 G34W relative to H3.3 WT. Unguided hierarchical clustering was used to plot the divergence between samples. Data displays two independent biological replicates for each samples. (B) Schematic displaying the effect of K36R and K27R mutations in cis with the G34W mutation. G34W mutation allows increased PRC2 activity by blocking SETD2. PRC2 does not tolerate arginine substitution at the 36th position in vitro and in vivo; therefore, G34W-K36R is unable to increase G34W-dependent PRC2 activity in cis. K27R-G34W substitution disrupts K27ac/K27me3 on G34W oncohistone, without affecting G34W-dependent changes at K36 methylation. (C) Gene set enrichment analysis of ostoblastic differentiation signature in mMSCs expressing H3.3 G34W compared to H3.3 WT. (D) Fold change in the expression of genes associated with osteoblastic (green) and adipogenic differentiation (blue) in mMSCs expressing H3.3G34W. Genes implicated in promoting cell motility and chemotaxis are shown in red. (E) Heatmap displaying the expression profiles of genes associated with adipogenic and osteoblastic differentiation in human GCTB-derived cells. (F and G) Kaplan–Meier survival curve displaying the survival of mice injected with mesenchymal stem cells overexpressing H3.3WT (n = 9, 10), H3.3G34W (n = 10, 9), or H3.3G34W;K27R (n = 5, 10) double mutant. P values for significant difference for H3.3G34W samples were determined using the log rank test with respect to WT (in blue) or G34W;K27R double mutant (in green).