Objective: To investigate effect of interferon-gamma (IFN-gamma) on Fas expression and Fas-mediated apoptosis in tumor cell lines.
Methods: Fas expression was detected by flow cytometry, and the tumor cell apoptosis evaluated by enzyme-linked immunosorbent assay and AnnexinV staining assay.
Results: All the 4 tumor cell lines used in this study, e.g. gastric cancer cell lines Kato-III AGS, lung cancer cell line A549 and laryngeal cancer cell line Hep-2, expressed Fas protein to varied degrees. Fas expression was up-regulated by IFN-gamma (P<0.05), which alone was enough to induce apoptosis in tumor cells and increase the susceptibility of them to anti-Fas antibodies. IFN-gamma induced Fas expression up-regulation and tumor cell apoptosis in a time-dependent manner.
Conclusion: Fas-mediated apoptosis is one of the mechanisms for IFN-gamma to exercise its anti-tumor effect.