TGF-β Signaling and Oncogenesis

The objective of this literature-based investigation is to review the current model used to describe how TGF-β signaling is involved in the oncogenic process. The transforming growth factors-β are a group of signaling polypeptides that control cell growth, differentiation and apoptosis. TGF-βs and their receptors are expressed in virtually all tissues. TGF-β works as tumor suppressor in pre and early oncogenic stages. However, as tumor growth progresses, TGF-β switches to pro-oncogenic activities. TGF-β type proteins work via a signal transduction pathway that involves the activation of key proteins known as Smads. Smads are directly involved in transcription by entering the nucleus and binding to specific genes, including those involved in cell cycle regulation such as p21. As new information is discovered about this pathway and the players involved new insights are being gained about the oncogenic process, which may lead to new therapeutic approaches.