Fig. 1.

Regulation of inflammatory responses in the tumor microenvironment of colon cancer by PGE₂-EP2 signaling. PGE₂-EP2 signaling shapes tumor environment in multiple steps, i.e., (1) the synergistic induction of cytokines and growth factors from tumor-associated fibroblasts (TAFs) and neutrophils with TNF-α, (2) the formation of a positive feedback loop involving COX-2-PGE₂-EP2 signaling to exacerbate inflammation once triggered, (3) the induction of CXCL1 to recruit neutrophils and alternate active cell populations in situ, and (4) the formation of a self-amplification loop among neutrophils