Extended Data Fig. 7: P38α expression in fibroblasts is critical for the generation of pre-metastatic.
a. Representative western blot analysis of p38α protein level in the isolated lung fibroblasts from tamoxifen-treated Mapk14fl/flCol1a2-CreER- (Mapk14fl/fl) and Mapk14fl/flCol1a2-CreER+ (Mapk14ΔFib, p38α knock out specific in fibroblasts) mice. b. A representative flow cytometry gating and histogram of IFNAR1 level in the lung fibroblasts of Mapk14fl/fl and Mapk14ΔFib mice injected with SFM, B16F10 TCM, or MH6499c4 TCM. c. Representative flow cytometry analysis of neutrophils in the lung tissues of Mapk14fl/fl and Mapk14ΔFib mice injected with SFM, B16F10 TCM, MH6499c4 TCM. d. qPCR analysis of the indicated chemokines in the lung tissues of Mapk14fl/fl and Mapk14ΔFib mice pretreated with SFM, B16F10 TCM, or MH6499c4 TCM followed by intravenous injection of 5*105 B16F10-TdTomato cells. Data shown as mean±SEM (n=4 mice for SFM treated Mapk14ΔFib group, n=5 mice for all the other groups). Two-way ANOVA and Tukey’s multiple comparisons test were performed. e. Representative flow cytometry analysis (left) and the quantification of percent and absolute number (right) of neutrophils in the lung tissues of Mapk14fl/fl and Mapk14ΔFib mice pretreated with SFM, B16F10 TCM, MH6499c4 TCM followed by intravenous injection of 5*105 B16F10-TdTomato cells. Quantitative data shown as mean±SEM (n=4 mice for SFM treated group, n=5 mice for TCM treated group). Two-way ANOVA and Tukey’s multiple comparisons test were performed. f. Representative flow cytometry analysis of tumor cells (TdTomato+) in the lung tissues of Mapk14fl/fl and Mapk14ΔFib mice pretreated with SFM, B16F10 TCM, or MH6499c4 TCM followed by intravenous injection of 5*105 B16F10-TdTomato cells. The experiments in a, b, c, f were repeated three times independently with similar results, and the results of one representative experiment are shown.