Fig. 2: The crosstalk between CAFs, cancer cells and immune cells.
From: Cancer-associated fibroblasts in pancreatic ductal adenocarcinoma
CAFs secrete ECM components and contribute to the fibrotic tumour microenvironment. Cancer cell-derived cytokines such as SHH, TGF-β, IL-1, PDGF, and HIF-1 are important in CAF activation, and activated CAFs promote cancer cell proliferation by secreting pro-tumourigenic factors. Furthermore, exosomes released by PDAC cells can aid in the recruitment and activation of CAFs. Pancreatic CAFs contribute to the formation of the inhibitory immune microenvironment by secreting factors such as IL-6, CXCL2, CXCL12, and CXCL8. CAFs are not only responsible for the recruitment and regulation of immunosuppressive cells, but also prevent CD8+ T cells from performing anti-tumour functions by upregulating immune checkpoint markers.
