Figure 5. Reduction of PTPN2 expression levels affects treatment response of NUP214-ABL1 dependent cells to kinase inhibitor imatinib.
- Follow up of survival of ALL-SIL cells treated with imatinib (500 nM) demonstrated decreased sensitivity due to alteration of PTPN2 expression levels. Y-axis displays cell viability (%).Open bars: siRNA PTPN2; closed bars: control siRNA
- siRNA mediated knockdown of PTPN2 in ALL-SIL cells reduced activity of imatinib as depicted by an increased IC50 value (126 nM) compared to control cells (73 nM). Untreated cells were set to 100%. Graph displays relative cell growth (%) as a function of concentrations (nM, logarithmic scale). Open circles: siRNA PTPN2, closed rectangles: siRNA control.
- Western blot analysis of ALL-SIL cells exposed to increasing concentrations of imatinib revealed a stronger activation of NUP214-ABL downstream target STAT5 in knockdown cells (left panel). Bar graph displays calculated differences in STAT5 activation level due to alterations in PTPN2 expression levels (right panel). Loading control: c-ABL; open bars: siRNA PTPN2; closed bars: control siRNA
All values represent the average ± s.e.m. of three determinations. Significant differences compared to those of control siRNA are indicated. *p<0.05 and **p<0.005