Fig. 2.

Paracrine signalling via cytokines produced by malignant cells leads to PCSs activation. While activated, PSCs secrete factors, which increase ability of malignant cells to proliferate and migrate, increase metastatic potential and resistance to chemotherapeutics. Both malignant cells and activated PSCs produce factors which further activate PSCs. PDGF: platelet derived growth factor, VEGF – vascular endotelial growth factor, TGF – tumor growth factor; miRNA – microRNA; ECM - extracellular matrix; CTGF – connective tissue growth factor; EMT – epitelial-mesenchymal transformation; CSF1 – colony-stimulating factor 1; FGF – fibroblast growth factor. Modified from: Carter et al. (2021)