Fig. 5: Chemotherapy-induced COX-2 expression modulates the inflammatory response to dying tumor cells.

a 4T1 tumor cells were pre-treated with cisplatin (50 µM) or doxorubicin (10 µM) for 4 h or 5-FU (100 µM) for 24 h. Cells were injected intraperitoneally (i.p.) and the next day the peritoneal lavage was collected for analysis. b Frequency (left panel) and total number (right panel) of live CD45⁺ immune cells present in mice injected with PBS (-), untreated, cisplatin or 5-FU treated 4T1 cells. LPM = large peritoneal macrophages, SPM = small peritoneal macrophages. n = 4 (cisplatin) or 5 (PBS, untreated, 5-FU) mice per group. c, d Total number of neutrophils and monocytes recruited by i.p. injection of untreated or CTX-treated 4T1 cells. n = 4 (cisplatin) or 5 (untreated, 5-FU, doxorubicin) mice per group. e Total number of neutrophils and monocytes recruited by i.p. injection of untreated or CTX-treated 4T1 COX-2^WT, COX-2^KO, or COX-2^REST cells. n = 4 (untreated COX-2^WT) or 5 (all other groups) mice per group. f, g Concentrations of soluble factors measured within the peritoneal lavage in mice injected with untreated, cisplatin treated cells (f) or 5-FU treated cells (g). WT + CXB group received cells pre-treated with 5-FU in the presence of the COX-2 inhibitor celecoxib (CXB, 5 µM). n = 5 mice per group. h Heatmaps showing detectable soluble factors within the peritoneal lavage. Rows represent z-score normalized ng/ml values, each column represents one mouse, n = 5 mice per group. Data in b–g are represented as mean ± SEM of individual mice, ns = not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 as determined by one-way ANOVA with Tukey’s multiple comparisons test or Kruskal–Wallis test with Dunn’s multiple comparisons test for non-parametric data. Source data and exact p values are provided as a Source Data file.