Figure 2.

Dual role of TGFβ in the tumor microenvironment of colorectal cancer. TGFβ mediates tumor-promoting effects, e.g., by contributing to a pro-inflammatory environment and suppressing the anti-tumor immune response. Tumor-promoting inflammation is mediated by CAFs or infiltrating TAMs and TANs, which release pro-inflammatory cytokines such as IL-17, IL-22, or IL-11, as well as MMPs and VEGF. TGFβ directly induces Tregs and MDSC to suppress the cytotoxic anti-tumor immune response of Th1 CD4⁺ T cells and CD8⁺ T cells. At the same time, TGFβ inhibits ll proliferation and induces the apoptosis of cancer cells. TGFβ = transforming growth factor β; IL-17 = interleukin-17; IL-22 = interleukin-22; IL-11 = interleukin-11; MDSC = myeloid-derived suppressor cells; TAM = tumor-associated macrophage; TAN = tumor-associated neutrophil; CAF = cancer-associated fibroblast; MMP = matrix metalloproteinase; VEGF = vascular endothelial growth factor.