[The potential of interleukin-12 for use in cancer therapy]

Interleukin-12 (IL-12) is a cytokine that exerts immunoregulatory effects on T cells and natural killer cells, playing a unique role in promoting type 1 T helper cell responses and, thereby, cell-mediated immunity. IL-12 has been shown to exert striking therapeutic effects at nontoxic doses in mouse tumor models and in mouse models of a variety of infectious diseases and airway inflammation. In mouse tumor models, the therapeutic effects of IL-12 have been shown to result from its immunoenhancing activity, requiring T cells and IFN-gamma. Administration of IL-12 can result in antiangiogenic effects that may also contribute to its antitumor activity in some models. Enhanced antitumor effects may be achieved by administering IL-12 in combination with certain other cytokines or with radiotherapy or chemotherapy. The striking therapeutic effects of IL-12 in these preclinical models have led to the initiation of clinical trials to examine the potential therapeutic activity of IL-12 in human cancer patients and in patients with human immunodeficiency virus infection or with chronic hepatitis B or C virus infections.