SCF/c-Kit signal induces the mast cell–mediated remodeling of tumor inflammatory microenvironment. (A) Expression of proinflammatory genes in mast cells. Mast cells were cultured in the presence or absence of SCF and anti–c-Kit antibody. The levels of IL-6, TNF-α, VEGF, Cox-2, iNOS, and CCL2 mRNAs were detected by real-time PCR. (B-E) Expression of proinflammatory genes in tumor and the activities of NF-κB and AP-1 in tumor cells. The mice bearing WT H22 tumor received the intravenous injection of mast cells and anti–c-Kit antibody as indicated. The mice bearing SCF-knockdown H22 tumor received the intratumor injection of mast cells. The levels of IL-6, TNF-α, VEGF, Cox-2, iNOS, CCL2, and IL-17 mRNAs in tumor tissues were detected by real-time PCR (B,C). IL-17 expression (IL-17⁺) cells in immune cells from tumor were analyzed by flow cytometry (D). Numbers on plots are percentages of total cells gated. Tumor cells were isolated from tumor tissue as described in “Assay of the activities of NF-κB and AP-1.” (E). *P < .05, compared with control tumor cells or WT tumor control. Error bars represent SD.