GPR50 in TGFβ signaling and breast cancer

G protein-coupled receptors (GPCRs) are involved in many physiological and pathophysiological processes including cancer development. However, many functions of these receptors remain unknown, especially for the orphan GPCRs that do not have an identified ligand. We demonstrate here, for the first time, the anti-tumor properties of an orphan GPCR, GRP50. In mammary tumors, the formation of heterodimers between GRP50 and the type I TGFβ receptor (TβRI) activates the antiproliferative effect of the TGFβ receptor which results in a lower tumor growth. Moreover, in women with breast cancer, low expression of GPR50 has been associated with poor survival prognosis regardless of the subtype of breast cancer. These new results make GRP50 a promising diagnostic tool and therapeutic target for breast cancer [1]