Cancer Stem Cells and Macrophages: Implications in Tumor Biology and Therapeutic Strategies

Figure 4

TAM-secreted factors regulate CSC phenotypes. TAMs have been shown to secrete LL-37, ISG15, IL-17, EGF, IL-6, MFGE-8, and IL-8 (among others), which in turn activate MAPK, STAT3/NFκB, and other yet-to-be-defined signaling pathways, leading to the activation of CSC properties, such as self-renewal, chemoresistance, migration, and invasion.