Targeting acute myeloid leukemia cells with cytokines

AML is a hematologic malignancy that represents 15-20% of all childhood acute leukemias and is responsible for more than one-half of pediatric leukemic deaths. The bulk tumor is continuously regenerated and sustained by rare leukemic ICs that proliferate slowly, thus resulting refractory to chemotherapeutic agents targeting highly proliferating cells within the tumor. Therefore, a complete eradication of the bulk tumor may depend on efficacy of therapies that target IC. In spite of the improvements in the treatment of AML, the difficulty to eradicate completely the disease incites research for innovative therapeutic approaches. In this regard, the role of cytokines in the treatment of AML has been investigated for many years, and some of them have been tested in clinical trials as a result of their immunomodulatory properties. Furthermore, recent preclinical studies highlighted the ability of the IL-12 superfamily cytokines as potent antileukemic agents that act directly on tumor cells and on leukemic IC, thus opening new perspectives for leukemic patient treatment. Here, we review the current knowledge about the antileukemic effects of cytokines, documented in preclinical and clinical studies, discussing their potential clinical application. J. Leukoc. Biol. 92: 567-575; 2012.