Figure 6.

Inhibition of IGF-1 R activity or IGFBP7 cooperates with chemotherapy in the inhibition of AML cell viability. (a) Cell viability of Kasumi-1 cells incubated with various concentrations of NVP-AEW541 (left panel) and cytarabine (right panel). (b) Kasumi-1 cells incubated with a combination of NVP-AEW541 and cytarabine. The combination index (CI) of the indicated drug combinations (right panel) were calculated using the Calcusyn software.³⁸ Defined CI values: ±(0.90–1.10), ++ (0.70–0.85), +++ (0.3–0.7). (c) Cell viability of NB4 cells with or without the overexpression of IGFBP7 and incubated with doxorubicin, cytarabine and etoposide (left panel) and K562 treated with doxorubicin (right panel). (d) Cell viability of NB4 and K562 cells in the presence of rhIGFBP7 (20 μg/ml in the case of NB4 and 300 μg/ml in the case of K562) with various concentrations of cytarabine (left panel) or doxorubicin (right panel) measured by the MTT assay. All bars represent the average cell viability and error bars show the S.D. of a triplicate. One-way ANOVA analysis was used in combination with a post hoc Tukey test to calculate the P-value *P≤0.05, **P≤0.01, ***P≤0.001. (e) NB4 cells were cultured in Opti-Mem reduced serum medium with 1% FSC in the presence of 0.04 μM doxorubicin, 0.5 μM NVP-AEW541 or the combination of doxorubicin and NVP-AEW541 or the combination of doxorubicin, NVP-AEW541 and 20 μg/ml rhIGFBP7