Fig 2: Effects of S100A8 and S100A9 knockdown on MC38 and LLC tumorigenicity. (a) Subcutaneous tumor growth in C57BL/6 mice following injection of control, S100A8 KD or S100A9 KD MC38 and LLC cells was monitored using calipers at the indicated times. (b) Volumes of subcutaneous tumors from control, S100A8 KD or S100A9 KD MC38 and LLC injected cells were assessed after 2.5 weeks. n=6 per group.

Fig 3: Effects of LPS on lung injury and S100A9 expression in mice. Mice were treated with LPS (5 mg/kg) and the lung tissues and BALF were collected at 4, 12 and 24 h following LPS treatment. a LPS induced lung injury starting at 4 h. b The protein expression levels of S100A9 in the lung tissues of mice are shown. The semi-quantified results of S100A9 expression are also shown. c The concentration of S100A9 in BALF is presented. d The concentration of S100A9 in lung homogenates is presented. Data are expressed as the mean ± SEM (n = 6 for each group). Statistical analysis was performed using two-way ANOVA followed by Tukey's multiple comparison test. **P < 0.01 vs. the corresponding control. LPS lipopolysaccharide, S100A9 S100 calcium binding protein A9, BALF bronchoalveolar lavage fluids

Fig 4: S100A9 blockade suppressed the activation of NLRP3 in the lungs. a–c Representative images and analysis of the protein expression of NLRP3 and caspase-1 in the lung tissues of LPS-treated mice. Data are expressed as the mean ± SEM (n = 6 for each group). Statistical analysis was carried out using one-way ANOVA followed by Tukey's multiple comparison test. **P < 0.01 vs. the control group; ##P < 0.01 vs. the LPS group. S100A9 S100 calcium binding protein A9, NLRP3 NOD-like receptor family pyrin domain containing 3, LPS lipopolysaccharide

Fig 5: Effects of ERK signaling in MC38 and LLC tumor cells. (a) MC38 and LLC cells were cultured in monocyte/macrophage- and granulocyte-conditioned media, and activation of the ERK signaling pathway (boxed area) was assessed using the PathScan Intracellular Signaling Array Kit by measuring densitometry values. Three independent experiments were performed, and representative image is shown. (b) Proliferation, (c) migration and (d) invasion of MC38 and LLC cells in response to monocytes/macrophages or granulocytes were tested in the presence of the ERK inhibitor U0126 (10 µm; +ERKi) using the WST or Cytoselect assays. Three independent experiments were performed, *P<0.05, **P<0.01. (e) Expression of S100a8 and S100a9 mRNA in MC38 and LLC cells cultured in monocyte/macrophage-conditioned medium was assessed by quantitative PCR after treatment with 10 µm ERK inhibitor U0126 for the indicated times. Three independent experiments were performed, *P<0.05, **P<0.01 compared with time 0 h.