MLL-AF4 depletion facilitates hematopoietic differentiation. (A) Reduction of CD133 mRNA levels upon MLL-AF4 suppression. Total RNAs were isolated 24 hours after the third electroporation of SEM cells with 500 nM of the indicated siRNA and were analyzed by real-time RT-PCR. The columns represent the averages of 2 independent experiments with 3 replicates each. (B) MLL-AF4 siRNAs diminish CD133 surface expression. Three days after the third electroporation with 500 nM of the indicated siRNA, SEM cells were analyzed by flow cytometry. One of 2 experiments yielding similar results is shown. Gray peak indicates mock-transfected cells; broken line, siMM-transfected cells; solid line, siMA6-transfected cells; dotted line, isotype control.