Effects of interferon-α and γ on development of LAK activity from mononuclear cells in breast cancer patients

We examined the effect of recombinant IFN-α and IFN-γ on induction of LAK cells from peripheral blood mononuclear cells (PBMNCs) in 7 pre-operative breast cancer patients and 4 healthy volunteers. Significant LAK activity was developed from PBMNCs of pre-operative breast cancer patients and healthy volunteers after incubation for 4 days with IL-2 (presence of IL-2 vs. absence of IL-2). Incubation of PBMNCs of pre-operative breast cancer patients with 1000 U/ml of IFN-α for 4 days suppressed the LAK activity significantly (P<0.05). By contrast, incubation of PBMNCs of pre-operative patients with 1000 U/ml of IFN-γ for 4 days increased the LAK activity significantly (P<0.05). Significant cytotoxicity againstMCF-7 cells (estrogen receptor positive human breast cancer cell line) was developed from PBMNCs of pre-operative breast cancer patients at 20:1and 40:1E/T ratios after incubation for 4days with IL-2 (absence of IL-2vs. 20:1or40:1, P<0.05, P<0.05), whereas PBMNCs of healthy volunteers did not. Stimulation of LAK cells with IFN-γ produced a significant augmentation of cytotoxic activity against MCF-7 (P<0.05), while IFN-α suppressed the cytotoxicity significantly (P<0.05). These findings suggested that combined stimulation by IFN-γ and IL-2 might be a reasonable treatment for breast cancer patients.