Metabotropic glutamate receptor-1 as a novel target for the antiangiogenic treatment of breast cancer.

Speyer CL1, Hachem AH2, Assi AA2, Johnson JS3, DeVries JA4, Gorski DH5.
Source: PLoS ONE
Publication Date: (2014)
Issue: 9(3):: e88830.
Research Area:
Basic Research
Cells used in publication:
Endothelial, MV lung, human (HMVEC-L)
Species: human
Tissue Origin: lung
Endothelial, MV dermal (HMVEC-d), human
Species: human
Tissue Origin: dermal
Metabotropic glutamate receptors (mGluRs) are normally expressed in the central nervous system, where they mediate neuronal excitability and neurotransmitter release. Certain cancers, including melanoma and gliomas, express various mGluR subtypes that have been implicated as playing a role in disease progression. Recently, we detected metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in breast cancer and found that it plays a role in the regulation of cell proliferation and tumor growth. In addition to cancer cells, brain endothelial cells express mGluR1. In light of these studies, and because angiogenesis is both a prognostic indicator in cancer correlating with a poorer prognosis and a potential therapeutic target, we explored a potential role for mGluR1 in mediating endothelial cell (EC) proliferation and tumor-induced angiogenesis. GRM1 and mGluR1 were detected in various types of human ECs and, using mGluR1-specific inhibitors or shRNA silencing, we demonstrated that EC growth and Matrigel tube formation are dependent on mGluR1 signaling. In addition, loss of mGluR1 activity leads to reduced angiogenesis in a murine Matrigel sponge implant model as well as a murine tumor model. These results suggest a role for mGluR1 in breast cancer as a pro-angiogenic factor as well as a mediator of tumor progression. They also suggest mGluR1 as a potential new molecular target for the anti-angiogenic therapy of breast cancer.