T-bet regulates metastasis rate in a murine model of primary prostate cancer.

The local progression of primary tumors is extrinsically controlled by type 1 immune responses, particularly via the cytokine IFN-gamma, whose secretion is highly dependent on helper T cells. The T-box transcription factor T-bet (Tbx21) plays a critical role in the development of type 1 helper T cells and is essential for the production of IFN-gamma. Here, the T-bet pathway in the autochthonous transgenic adenocarcinoma mouse prostate model is demonstrated to have only a modest effect on the characteristics of primary prostate cancers but rather exerts a significant suppressor function in the development of metastatic disease.