Expression of miR-150 targets GAB1 or FOXP1 affects BCR signaling. (A) The Raji cell line was transfected with artificial miR-150 (miR-150, 100 nM), control miRNA (miR negative control [Neg. Ctrl], 100 nM), siRNA against GAB1 (siGAB1, 100 nM) or FOXP1 (siFOXP1, 100 nM), and control siRNA (siRNA Neg. Ctrl, 100nM). The band intensities observed in immunoblot analysis were measured using ImageJ 1.42q, and the GAB1/β-actin and FOXP1/β-actin ratio in control was arbitrarily set at 1. The FOXP1/β-actin ratios for the 2 major isoforms of FOXP1 are provided (ratio for larger and smaller variant is separated by a slash). GAB1 and FOXP1 protein levels were analyzed 48 hours posttransfection and β-actin was used as a loading control (representative example of an immunoblot). (B-C) The effect of Raji cell transfection with siRNA against GAB1 (siGAB1, 100 nM) or FOXP1 (siFOXP1, 100 nM) or control siRNA (siNEG CTRL, 100 nM) on calcium influx after anti-μ stimulation (10 μg/mL; indicated by a black arrow). (D) The effect of Raji cell transfection with artificial miR-150 (miR-150 MIMIC, 100 nM) or control miRNA (miR NEG CTRL, 100 nM) on calcium influx after anti-μ stimulation (10 μg/mL; indicated by a black arrow). The calcium influx (FLUO-4 fluorescence intensity) in panels B-D were analyzed continuously for 120 seconds. The acquisition of background fluorescence (30 seconds) was followed by adding anti-μ (final concentration 10 μg/mL; indicated by a black arrow), and data at 6-second intervals were visualized as peak intensity. Error bars represent standard error of the mean of at least 2 independent experiments. Differences were statistically analyzed by 2-way analysis of variance.