Extended Data Fig. 7.

a-b Representative images and quantifications of immunostaining for H3K27me3 (a) and BMI (b) in WT and MLL4^Q4092X MSCs untreated or treated with TSA (1.5 μM for 8h). Scale bar, 20 μm. Box plots indicate the median (middle line), the first and third quartiles (box), and the 10th and 90th percentile (error bars) of the normalized fluorescence intensity. The number of analyzed nuclei is reported in figure as n; unpaired two-tailed Student’s t-test was applied for statistical analysis (****P<0.0001).

c Representative images and quantification of immunostaining for H3K27me3 in WT, MLL4^Q4092X or MLL4^Q4092X MSCs expressing either H3.3^WT or H3.3^K27M. Scale bar, 20 μm. Box plots indicate the median (middle line), the first and third quartiles (box), and the 10th and 90th percentile (error bars) of the normalized fluorescence intensity. The number of analyzed nuclei is reported in figure as n; unpaired two-tailed Student’s t-test was applied for statistical analysis (****P<0.0001).

d Representative maps of stiffness distribution in WT, MLL4^Q4092XMSCs, MLL4^Q4092X MSCs expressing H3.3^K27M or MLL4^Q4092X MSCs treated with TSA for 24h; Scale bars, 10 μm. Bar plot representing nuclear Brillouin shift in the different conditions. Data are means + SEM (n=4 independent experiments); unpaired two-tailed Student’s t-test was applied for statistical analysis (****P<0.0001).