大鼠神经胶质瘤和嗜铬细胞瘤中P2X受体的表达特征研究

目的：采用实时荧光定量PCR技术，研究P2X受体在大鼠神经胶质瘤和嗜铬细胞瘤及原代培养皮层神经元和星形胶质细胞上的表达差异。方法：取新生1~3天SD大鼠大脑皮层，分离纯化神经元和星形胶质细胞，并采用实时荧光定量PCR技术，比较P2X受体在大鼠胶质瘤C6细胞、大鼠肾上腺嗜铬细胞瘤PC-12细胞、星形胶质细胞和皮层神经元上的表达差异。结果：C6细胞P2X2、P2X3和P2X5表达水平显著高于星形胶质细胞，P2X4、P2X6和P2X7表达水平显著低于星形胶质细胞，PC-12细胞P2X1、P2X2、P2X3和P2X6表达水平显著高于皮层神经元，P2X5和P2X7表达水平则显著低于皮层神经元。此外，本实验还发现P2X2、P2X5和P2X6在C6和PC-12细胞上的表达水平存在显著差异。结论：大鼠胶质瘤和嗜铬细胞瘤细胞表达多种P2X受体，且与原代培养细胞存在表达差异，提示核苷酸介导的信号传递系统可能作为潜在的肿瘤治疗靶点。

Expression Patterns of P2X Receptors in Rat Glioma and Pheochromocytoma

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.