(A) High MXD3 protein expression in a series of primary preB ALL samples. Ten primary preB ALL samples showed high MXD3 protein expression relative to Reh cells. Jurkat cells and normal CD34+HSCs showed low expression. Boxes represent MXD3 protein levels in individual cells relative to those in Reh cells, measured by MFI. Bars indicate mean and whiskers 10–90 percentile represented as individually plotted points.
(B) MXD3 knockdown in a primary leukaemia sample treated with the MXD3 siRNA-αCD22 Ab-SPIO NPs at 4 h after treatment. Cells that were treated with the control siRNA-αCD22 Ab-SPIO NPs did not exhibit the same level of MXD3 knockdown. For each image, protein level was measured by MFI in each cell in the field and the average MFI is shown in the right lower corner of each MXD3 image.
(C) The MXD3 protein level measured by MFI. The cells treated with MXD3 siRNA-αCD22 Ab-SPIO NPs showed significantly decreased MXD3 protein expression compared with the cells treated with the control siRNA-αCD22 Ab-SPIO NPs or untreated cells. Each point represents the average MFI of all measured cells per treatment type, in 3 independent experiments. Untreated vs. MXD3 siRNA-αCD22 Ab-SPIO NPs (**) p = 0.00735, control vs. MXD3 siRNA-αCD22 Ab-SPIO NPs (*) p = 0.03108
(D) Accelerated cell death in the primary leukaemia cells treated with the MXD3 siRNA-αCD22 Ab-SPIO NPs. Data points indicate mean values of independent cell count in triplicates from 3 independent experiments. Live cell count was measured at 4, 8, 24, 48 and 72 h after single treatment with the MXD3 or control siRNA-αCD22 Ab-SPIO NPs. Untreated cells were also used as a control. Data as mean ± SD. Untreated vs. MXD3 siRNA-αCD22 Ab-SPIO NPs (****) p< 0.00001, untreated vs. control siRNA-αCD22 Ab-SPIO NPs (****) p = 0.000035, control vs. MXD3 siRNA-αCD22 Ab-SPIO NPs (****) p < 0.00001.
αCD22 Ab, anti-CD22 antibody; SPIO, superparamagnetic iron oxide; NP, nanoparticle; siRNA, small interfering RNA; MFI, mean fluorescence intensity; SD, standard deviation.