The microRNA networks of TGFβ signaling in cancer.

In metazoans, the transforming growth factor β (TGFβ) signaling regulates a host of activities ranging from embryonic development to tissue homeostasis. The normal as well as tumor cells respond to this cytokine signaling pathway in a highly context-dependent manner. It acts as a potent tumor suppressor initially by inducing cell cycle arrest and apoptosis. But advanced tumors often misuse TGFβ signaling for tumor progression by selectively disabling the tumor suppressor arm and using other properties of TGFβ signaling such as induction of angiogenesis, epithelial to mesenchymal transition, and metastases. This dual role of TGFβ in cancer remained a mystery until recently. But recent advances in the field of microRNA provided a deeper understanding about this dual nature of TGFβ signaling in cancers. In the present review, we present an account of the role of microRNAs in deregulating TGFβ signaling and modulating cancer cell behavior during tumor initiation and cancer progression. This review also includes a discussion on the recent advances in the deregulation of TGFβ signaling in carcinogenesis.