Inhibition of GPR137 expression reduces the proliferation and colony formation of malignant glioma cells.

GPR137 are ubiquitously expressed in the central nervous system. However, the role o f GPR137 in human malignant glioma is still poorly known. In the present study, we firstly detected the expression of GPR137 in 29 human glioma tissue specimens by immunohistochemistry and in 5 malignant glioma cell lines by quantitative RT-PCR. The expression of GPR137 was much stronger in high-grade gliomas than in low-grade gliomas. Lentivirus-mediated small interfering RNAs (siRNAs) were employed to knock down GPR137 expression in glioma cells. Inhibition of GPR137 expression by RNAi significantly inhibited the proliferation and colony-forming capacity of U251, A172 and U373 cells. Moreover, flow cytometry analysis showed that knockdown of GPR137 led to the cell-cycle arrest at the S phase. Our results indicated that GPR137 is involved in the progression of human glioma, suggesting GPR137 as a potential oncogene of glioma cells.