In vitro effects of insulin-like growth factor-1 (IGF-1) on proliferation and constitutive cytokine secretion by acute myelogenous leukemia blasts

The effects of insulin-like growth factor 1 (IGF-1) on autonomous prolifera tion, cytokine-dependent proliferation and constitutive cytokine secretion by acute myelogenous leukemia (AML) blasts were investigated using serum-fr ee in vitro conditions. IGF-1 enhanced AML blast proliferation independent of the presence of other exogenous cytokines only for 2 of 21 patients, but for 10 additional patients IGF-1 altered blast proliferation in the presen ce of certain exogenous cytokines or cytokine combinations. IGF-1 had minor effects on AML blast cytokine secretion only for a subset of the patients (decreased levels for 1 patient, increased levels for 7 patients). Our in v itro observations indicate that IGF-1 can modulate AML blast proliferation and/or cytokine secretion for a subset of patients.