Inhibition of IGF-1R tyrosine kinase activity induces growth inhibition and apoptosis in ALL cell lines. Cell growth (A) and level of apoptosis (C) detected in ALL CCRF-CEM and NALM6 cells treated with the IGF-1R inhibitor HNMPA(AM)3 (2 - 100 μM) and incubated for 24 h at 37°C. Proliferation (B) and level of apoptosis (D) detected in Bp-ALL subtypes NALM6, REH (t[12;21]), and SupB15 (t[9;22]) treated with HNMPA(AM)3 (10 μM) and incubated for 24 h at 37°C. The cell growth (viability) values are expressed as a percentage relative to those obtained with untreated control cells (mean ± SEM, n = 3). Annexin V-FITC/PI staining data (apoptosis) were normalized and expressed as fold induction relative to control values (mean ± SEM, n = 3) as described in Methods.