Figure 7

IFN α activates RIG-I transcription in HNSCC cells through p-STAT1 (Tyr701). (A) HN4 and HN30 cells were treated with IFNα (0, 20, or 200 ng ml⁻¹) and fludarabine (0.5 μ M) for 48 h, and RIG-I expression was detected. Beta-actin was used as an internal control. (B) HN4 and HN30 cells were incubated with 100 ng ml⁻¹ IFNα for 48 h. The ChIP assay was performed with p-Stat 1 (Tyr701) and normal rabbit IgG antibodies. Enrichment of DDX58 promoter regions was calculated using real-time PCR (Percent input=2% × 2^{(C[T] 2%Input Sample – C[T] IP Sample)}). (C) DDX58 promoter activity was detected in HN4 and HN30 cells 24 h after stimulation with IFNα. ChIP=chromatin immunoprecipitation. **P<0.01.