Fig. 4: The cytoplasmic IRF3 in resting state inhibits the cell proliferation and Wnt/β-catenin pathway in HCT116 and H1299 cell lines.
From: IRF3 prevents colorectal tumorigenesis via inhibiting the nuclear translocation of β-catenin
a, b Proliferation of the IRF3+/+ and IRF3−/− HCT116 (a) and H1299 (b) cells. c Colony formation experiment of the IRF3+/+ and IRF3−/− HCT116 and H1299 cells. d Proliferation of the HCT116 cells with Wnt signaling inhibitor ICG-001 (50 μM) or DMSO treatment. e, f Representative images of tumors from subcutaneous tumor formation assay in nude mice (e). Subcutaneous tumor formation assay in nude mice with 2 × 106 IRF3+/+ or IRF3−/− HCT116 cells per mouse. After 1 week of the injection, PBS or ICG-001 treatment (200 mg/kg, i.v., once daily) was applied in mice until the end of the model. Tumor weight for each group (n = 4) was plotted (f) at day 21 after injection. g Immunohistochemical analysis for ki67 in tumors from e. h Proliferation of β-catenin-wild type (Ctnnb1+/+) and β-catenin-knockout (Ctnnb1−/−) HCT116 cells treated with siNC or siIRF3. i, j Proliferation of the IRF3+/+ and IRF3−/− HCT116 (i) and H1299 (j) cells transfected with the indicated plasmids expressing backbone, IRF3, IRF3-ΔnDB, IRF3-ΔNLS, or IRF3-5D. k Real time qPCR analysis for the Wnt target, and associated genes in IRF3+/+ and IRF3−/− HCT116 cells transfected with the indicated plasmids expressing backbone, IRF3, IRF3-ΔnDB, IRF3-ΔNLS, or IRF3-5D. l, m The stable expression control plasmid, Flag-tagged IRF3, -IRF3-ΔnDB, -IRF3-ΔNLS, and IRF3-5D mutations IRF3+/+ or IRF3−/− HCT116 cells were applied to subcutaneous tumor formation assay in nude mice with 2 × 106 cells/group per mouse for 21 days. Images of tumor grafts from these cells at day 21 (l). Tumor weight for each group (n = 4) was plotted in m. Each symbol represents one mouse (m). *P < 0.05; **P < 0.01; ***P < 0.001; NS not statistically significant by two-tailed t test (a–m). Data represent two (e–g, l, m) or three independent experiments (a–d, h–k) and are presented as mean ± s.e.m. in a–m. See also Supplementary Fig. S4.
