Abstract: Objective: The expression of ionotropic ATP-gated channel, P2X receptors, was examined in rat glioma C6 cells, rat pheochromocytoma PC-12 cells, primary cultured rat cortex astrocytes and neurons by real-time polymerase chain reaction (real-time PCR). Methods: The neonatal rat cerebral cortex neurons and astrocytes were isolated and identified by immunohistochemical staining with anti-NSE and anti-GFAP, respectively. By using real-time PCR, the expression of P2X receptors in C6 cells, PC-12 cells, rat cortex astrocytes and neurons were measured. Results: The mRNA expression levels of P2X2, P2X3 and P2X5 in C6 cells were significantly higher than those in primary cultured astrocyte, whereas the mRNA levels of P2X4, P2X6 and P2X7 were lower. The mRNA expression levels of P2X1, P2X2, P2X3 and P2X6 in PC-12 cells were significantly higher than those in primary cultured cortical neurons, whereas the mRNA levels of P2X5 and P2X7 were significantly lower. Moreover, the mRNA levels of P2X2, P2X5 and P2X6 were significantly different between C6 and PC-12 cells. Conclusions: P2X receptors were expressed functionally in C6 and PC-12 cells, and had expression differences from primary cultured cells. These results suggested that nucleotide-mediated signal transduction systems may exist in nervous tumor cells and have potential as a novel antitumor drug target.

Key words: P2X receptors, rat cortex neuron, rat cortex astrocyte, glioma, pheochromocytoma