To investigate a possible role of cytokines in parvovirus-mediated suppression of tumorigenesis, we tested in cell culture whether parvoviruses are able to induce interferon (IFN)-beta, tumor necrosis factor (TNF)-alpha or interleukin-6 (IL-6). Infection of rodent or human cells with the parvoviruses minute virus of mice (MVM), H-1 or adeno-associated virus (AAV) types 2 or 5 failed to induce expression of the luciferase or beta-galactosidase reporter genes transfected into these cells as constructs containing an IFN-beta promoter. Parvoviruses did weakly induce synthesis of TNF-alpha and of IL-6 in cell culture and could slightly enhance synthesis of these cytokines when induced by other agents. These in vitro data suggest that the rather unspecific tumor-suppressive properties of parvoviruses are unlikely to be attributable to stimulation of the synthesis of IFN, TNF or IL-6.