Fig. 5

The AIM2-triggered IL-1β secretion positively regulates STAT1/NF-κB activation, irradiation resistance, cellular migration ability and PD-L1 expression in OSCC cells. A Dot blot (upper) of three independent experiments (Exp) and histograms (lower) of ELISA results for the IL-1β protein levels in the culture media from HSC4 (left) and SAS (right) cell variants. B Western blot analyses for phosphorylated STAT1/NF-κB, total STAT1/NF-κB and GAPDH protein levels (upper) and histograms for DNA-binding activity of STAT1/NF-κB in luciferase reporter assays (lower) against the AIM2-overexpressing SAS cells treated without or with IL-1β-neutralizing or isotype antibody (Ab, 10 μg/ml of each). C–H Crystal violet staining (upper)/histogram (lower) for colony formation post-treatment without or with irradiation at 4 Gy, Giemsa staining (upper)/histogram (lower) for the migrated cells and RT-PCR/Western blot analyses for the mRNA/protein levels of PD-L1 and GAPDH (upper)/histograms for PD-L1 transcriptional activity in luciferase assays (lower) against the AIM2-overexpressing SAS cells cultivated in the absence or presence of IL-1β-neutralizing/isotype antibody (C–E) and NF-κB inhibitor SN50 at the indicated concentrations (F–H). In B, E and H, GAPDH was used as an internal control of experiments. The symbol “***” and different alphabets represent p < 0.001 and p < 0.05, respectively