Transforming Growth Factor-β and Cancer.

Normal tissue homeostasis is maintained by strict regulation of interactions between cells and their microenvironment. How a cell responds to stimulatory and inhibitory signals it receives from the microenvironment will directly impact whether or not that particular cell will proceed through the cell cycle and proliferate or stop cell cycle progression and undergo assessment. When cells no longer respond to their microenvironmental cues and proliferate autonomously, tumors arise. The major known negative regulators of cell proliferation are the transforming growth factor βs (TGF-βs). The TGF-β signaling pathways are tumor suppressive, yet once tumors have developed, TGF-β signaling can enhance tumor progression. [ABSTRACT FROM AUTHOR]