Knockdown of endogenous HDAC3 in GM979 cells. (Ai) RT-PCR analysis of HDAC3 mRNA levels 24 hours after transfection of the siRNA. (Top panel) HDAC3 levels. (Bottom panel) β-actin levels. Lane 1: control (nonspecific siRNA); lane 2: siHDAC3 (exon 8); lane 3: siHDAC3 (exon 9). (Aii) (Top panel) Immunoblot showing HDAC3 levels after cells were treated with siRNA. Lane 1: control (nonspecific siRNA); lane 2: siHDAC3 (exon 8), lane 3: siHDAC3 (exon 9). (Bottom panel) Immunoblot using β-actin as a loading control. (B) Relative induction of the ^Aγ-globin gene following siHDAC3 treatment. Ratios of firefly luciferase–renilla luciferase of cells treated with siHDAC3 (exons 8 and 9), represented as a percentage of the control transfection. Results shown were an average of 2 independent experiments and were recorded either at 24 hours (checked) or 48 hours (dotted) following siRNA treatment; error bars represent the standard errors of the mean.