Osteopontin at the Crossroads of Inflammation and Tumor Progression

Figure 4

OPN functions in the tumor microenvironment. In the tumor microenvironment, OPN has different functions ranging from the recruitment of leucocytes, endothelial cells, and mesenchymal stem cells (MSCs) from the periphery or bone marrow, to the reprogramming of local fibroblast to cancer-associated fibroblasts and transformation of M1 antitumorigenic macrophages to tumor-associated macrophages. These changes in the stroma favor tumor progression through angiogenesis, degradation of the extracellular matrix, epithelial to mesenchymal transition (EMT), and migration of metastatic cells.