Objective: To investigate the role of the inflammatory factor IFN-γ in the pathogenesis and development of polycystic ovary syndrome (PCOS). Methods: The peripheral blood samples with heparin anticoagulant were collected from 31 PCOS patients and 22 healthy people. Peripheral blood mononuclear cells (PBMCs)were harvested from these samples, and the proportions of IFN-γ⁺ Th1 and IL-4⁺ Th2 cells in PBMCs were analyzed. The levels of IL-4, IL-6 and IFN-γ in plasma of PCOS patients were detected by the flow cytometer CBA method. Human granulosa-like tumor cell line KGN cultured with IFN-γ in vitro,the KGN cells were divided into two groups, control group (routine culture) and IFN-γ treated group (treated with 250 ng/mL IFN-γ) . The effects of IFN-γ on the cell cycle, proliferation and apoptosis of KGN cells were analyzed using flow cytometer. Results: Compared with the healty control group, the proportion of Th1 cells in PBMCs of PCOS patients was significantly up-regulated(P<0.01). The IFN-γ level in plasma of PCOS patients was higher than that in the control group(P<0.05). After being co-cultured IFN-γ with KGN cells in vitro, the results showed that the proliferation of CFSE labeled KGN cells in the IFN-γ treated group was significantly inhibited comparing with the control group. Both the percentage of KGN cells in G₀-G₁ phase and the proportion of apoptotic KGN cells increased in the IFN-γ treaded group(P<0.01). Conclusion: The levels of IFN-γ increased in PCOS patients, and IFN-γ inhibited the proliferation, while promoted the apoptosis of KGN cells.

［Key words］polycystic ovarian syndrome； IFN-γ； proliferation； ovary granule cell； apoptosis