Gene-expression profiles of IFN-gamma-affected HOSE cells

The source of IFN-γ in ovarian cancer microenvironment and its biological effect to the tumor cells is unclear. The immortalized human ovarian surface epithelial cell line, HOSE-E7/hTERT (HOSE) was treated with IFN-γ and expression microarray analysis was performed, and probes showing significantly higher values in IFN-γ-added group were termed “IFN-γ signature genes (295 probes)”. We then applied this signature to our ovarian cancer microarray data, which included 75 ovarian cancer clinical samples, by means of ss-GSEA. IFN-γ signature score was strongly correlated to the number of infiltrating CD4-positive or CD8-positive lymphocytes in the tumors. These data suggest that the IFN-γ in the ovarian cancer microenvironment is derived from lymphocytes, and an IFN-γ-rich microenvironment is strongly correlated to a lymphocyte-rich microenvironment. HOSE cells were incubated in 8 separate culture dishes, 4 dishes with and 4 dishes without 500 IU/ml recombinant human IFN-γ (R&D Systems) in the culture medium for 6 hours prior to the analysis.