Autocrine/Paracrine

Growth factors control various processes, including embryonic development, stem cell maintenance, and tissue homeostasis. These signaling molecules bind and activate specific receptors, which trigger a cascade of biochemical events that ultimately determine the biological response in the target cells. Aberrant activation of several growth factor pathways is involved in the onset and progression of most types of cancer. To do so, tumor cells utilize different signaling modes, including autocrine, paracrine, and juxtacrine, that affect cell proliferation, differentiation, and motility, not only within the tumor, but also in the surrounding microenvironment.