Misguided Transcriptional Elongation Causes Mixed Lineage Leukemia
Figure 7
MLL-ENL-introduced chromatin modifications resist differentiation stimuli.
(A) Left panel: cells transformed by constitutive MLL-ENL. FACS analysis of gr-1 differentiation marker in cells grown in IL-3 and in G-CSF for 7 d. Right panel: cells transformed by conditional MLL-ENL-ER. Gr-1 levels before and 3 d after inactivation of MLL-ENL-ER by removal of tamoxifen (TAM). (B) Left panel: qRT-PCR analysis of Hoxa9 expression in cells transformed by constitutive MLL-ENL cultured in IL-3 or G-CSF for 7 d (light columns) and in cells transformed by conditional MLL-ENL-ER before and 3 d after tamoxifen removal (dark columns, labeled “on” and “off”). Right panel: comparison of H3K79 dimethylation status of the Hoxa9 locus in cells treated as before. Values are averages and standard deviations of a triplicate, and the experiment was done twice with comparable results.