The IL-1β signaling cascade is further propagated by fibroblasts. (A) Cytokine array analysis of the normal IMR90 human fibroblast secretome after retroviral transfection with an IL-1A–expressing plasmid. The top ten secreted cytokines are displayed relative to their level in the secretome of normal IMR90 human fibroblasts transfected with control vector. Values represent a mean of two independent experiments. (B) Western blot analysis of p65, pp65, IL-6, IL-8, and GROα expression in HFF cells treated with 100 ng/ml IL-1β for the stated time points. Data are representative of three independent experiments. (C) Western blot analysis of IL-6, IL-8, and GROα expression in HFF cells cultured in conditioned media (CM) taken from NHM macrophage (NHM-Mφ), WM266-4–Mφ, WM164-Mφ, and MM485-Mφ, with 1 µg/ml normal goat IgG control or 1 µg/ml IL-1β neutralizing antibody (IL1βnAb). Data are representative of three independent experiments. (D) Sections from tumors isolated from Il-1r1^fl/fl and Il-1r1^−/− mice stained for GROα and SMA expression as indicated by the labels. (iii) Arrowheads indicate cells that are clearly double stained. Bars: (i and ii)100 µm; (iii) 33 µm. Images are representative of three independent tumors. (E) Real-time qPCR analysis of Groα expression in tumors isolated from Il-1r1^−/− mice (n = 3) relative to expression in tumors isolated from Il-1r1^fl/fl mice (n = 3), at day 28 after injection. Data are represented as mean ± SEM. *, P < 0.05; Mann-Whitney test.