The orphan G protein-coupled receptor GPR55 promotes cancer cell proliferation via ERK, Oncogene 30

GPR55 is an orphan G protein-coupled receptor that may be engaged by some lipid ligands such as lysophosphatidylinositol and cannabinoid-type compounds. Very little is known about its expression pattern and physio-pathological relevance, and its pharmacology and signaling are still rather controversial. Here we analyzed the expression and function of GPR55 in cancer cells. Our data show that human tumors from different origins express GPR55 in an aggressive manner. Moreover, GPR55 promotes cancer cell proliferation, both in cell cultures and in xenografted mice, through the overactivation of the extracellular signal-related kinase cascade. These findings reveal the importance of GPR55 in human cancer, and suggest that it could constitute a new biomarker and therapeutic target in oncology