Involvement of P2X7 Receptor in Proliferation and Migration of Human Glioma Cells

Previous studies have demonstrated that activation of P2X(7) receptors (P2X(7) R) results in the proliferation and migration of some types of tumor. Here, we asked whether and how the activated P2X(7) R contribute to proliferation and migration of human glioma cells. Results showed that the number of P2X(7) R positive cells was increasing with grade of tumor. In U87 and U251 human glioma cell lines, both expressed P2X(7) R and the expression was enhanced by 3'-O-(4-benzoylbenzoyl) ATP (BzATP), the agonist of P2X(7) R, and siRNA. Our results also showed that 10 mu MBzATP was sufficient to induce the proliferation of glioma cell significantly, while the cell proliferation reached the peak with 100 mu MBzATP. Also, the migration of U87 and U251 cells was significantly increased upon BzATP treatment. However, the number of apoptotic cells ofU87 andU251 was not significantly changed by BzATP. In addition, the expression of ERK, p-ERK, and proliferating cell nuclear antigen (PCNA) protein was increased in BzATP-treated U87 and U251 glioma cells. PD98059, an inhibitor of the MEK/ERK pathway, blocked the increased proliferation and migration of glioma cells activated by BzATP. These results suggest that ERK pathway is involved in the proliferation and migration of glioma cells induced by P2X(7) R activation.