GO-203 induces death of MOLM-13 cells resistant to FLT3 inhibitors. (A) MOLM-13 cells were treated with the indicated concentrations of GO-203 for 72 hours. Cell number (mean ± SD of 3 determinations) was determined by trypan blue staining. (B) MOLM-13 cells were left untreated (control) or treated with (1) 50 nM PKC412, (2) 10 nM HG-7-85-01 (HG), and (3) 2 μM GO-203 for 72 hours. Percentage cell death (mean ± SD of 3 determinations) was determined by PI staining and flow cytometry. (C) MOLM-13/PKC412 cells were treated with the indicated concentrations of GO-203 for 72 hours. Cell number (mean ± SD of 3 determinations) was determined by trypan blue staining. (D) MOLM-13/PKC412 cells were left untreated (control) or treated with (1) 5 nM PKC412 and (2) 3 μM GO-203 for 72 hours. Percentage cell death (mean ± SD of 3 determinations) was determined by PI staining and flow cytometry. (E) MOLM-13/HG cells were left untreated (control) or treated with (1) 10 nM HG-7-85-01 (HG) and (2) 3 μM GO-203 for 72 hours. Percentage cell death (mean ± SD of 3 determinations) was determined by PI staining flow cytometry.