Interferon-gamma (IFN-γ)의 신세포암 세포주에 대한 직접 세포독성 조사

Abstract

Purpose: Interferon-gamma (IFN-γ), a cytokine meditating cellular immune response, has been reported to have antiproliferative and cytotoxic effects on tumor cells in vitro. IFN-γ is also capable enhancing immune responses against tumor cells by increasing the expression of MHC class I and II molecules and tumor markers on cell surfaces. The present study focuses on the direct antitumor effects of IFN-γ on Reca cell line. Materials and Methods: Direct antiproliferative and cytotoxic effects of IFN-γ were investigated in Renca cells by viable cell count using Trypan blue dye exclusion. BrdU cell proliferation ELISA and LDH cytotoxicity detection assays were performed in order to determine which effect was dominant by the IFN-γ treatment. DNA fragmentation assay showed that IFN-γ induced apoptotic cell death in Renca. Results: The number of Renca cells attached to the culture plates reached only 61.5% that of untreated cells on the second day of incubation with 150U/ml of IFN-γ. Renca detachment began to increase after six days of culture. Trypan Blue dye exclusion showed the attached or detached cell populations mostly comprised of live or dead cells, respectively. It was observed that IFN-γ had a dose-dependent antiproliferative effect on Renca. Cytotoxicity measured by LCH secretion into the culture supernatant was not prominent, but assay for DNA fragmentation revealed apoptosis-associated nucleosomal ladders in IFN-γ treated Renca. Conclusions: These results indicate that IFN-γ by playing antiproliferative roles in early phase and inducing apoptosis-mediated cell death in the later phase could perform direct inhibitory effects on the Renca cell line. Key word : IFN-γ, Proliferation, Cytotoxisity, Apoptosis