Expression of MSX2. (A) RT-PCR analysis indicates MSX2 expression in T-ALL cell lines. Expression of TEL serves as positive control. NTC: no template control. (B) Western blot analysis demonstrates MSX2 protein expression in PEER and JURKAT cells. Expression of ERK1/2 serves as loading control performed on a separate gel. (C) Immunocytological analysis in JURKAT cells. DAPI staining (blue) illustrates the nucleus. MSX2 staining (green) demonstrates a speckled distribution within the nucleus. The speckled pattern of PML staining (red) differs from that of MSX2. The scale bar represents 10 μm. (D) MOLT-4 cells were transfected by electroporation with expression construct pMSX2-EGFP. The fusion protein MSX2-EGFP (green) shows a speckled distribution within the nucleus (blue), resembling that of endogenous MSX2. (E) Quantitative expression analysis of MSX2 by real-time PCR in primary hematopoietic cells (CD34+, CD3+, PBC) and 23 T-ALL cell lines revealed striking differences. MSX2 expression levels are shown in relation to that of CD34+ cells which was set to 1. Expression of TBP served as endogenous control. Bars show standard deviations. (F) Western blot analysis demonstrates MSX2 protein expression in primary CD34+ and CD3+ cells. ERK1/2 serves as loading control, indicating higher amounts of MSX2 protein in CD34+ cells.