Second Ward, Department of Neurosurgery, Huaihe Hospital of Henan University, Kaifeng, China.
J Cell Biochem. 2019 Apr;120(4):6322-6329. doi: 10.1002/jcb.27919. Epub 2018 Oct 25.
Purinergic receptor P2X 4 (P2X4R), a member of purinergic channels family and a subtype of ionotropic adenosine triphosphate receptors, plays a critical role in tumorigenesis. Evidence suggested that P2X4R is expressed in rat C6 glioma model, however, its role and the underlying mechanism of action are still unclear in human glioblastoma multiforme (GBM). In the current study, our aim is to examine the function and the molecular basis of P2X4R in GBM. We first observed that GBM cells, U251, T98, U87, U373, and A172 were all high expressed P2X4R, when compared with the normal human astrocytes (NHA) cells. To gain the function of P2X4R, P2X4R silence cells were constructed by transfection with P2X4R small interfering RNA (siRNA). We found that P2X4R deletion impeded T98 and U87 cell viability and proliferation, and further studies indicated that cell apoptosis and caspase-3 activity was increased in T98 and U87 cell transfected with P2X4R siRNA. Subsequently, we confirmed that P2X4R silence suppressed brain-derived neurotrophic factor (BDNF), Trk receptor tyrosine kinases (TrkB), and activating transcription factor 4 (ATF4) expression in T98 and U87 cells. And P2X4R siRNA-induced ATF4-expression inhibition dependent on BDNF/TrkB signaling pathway. The impact of P2X4R silence on T98 and U87 cell growth and apoptosis was reversed by ATF4 overexpression. In summary, this study provides the first evidence that P2X4R plays important roles in GBM cell growth and apoptosis.
嘌呤能受体 P2X4（P2X4R）是嘌呤能通道家族的成员，也是离子型三磷酸腺苷受体的一种亚型，在肿瘤发生中起着关键作用。有证据表明，P2X4R 在大鼠 C6 神经胶质瘤模型中表达，但在人类多形性胶质母细胞瘤（GBM）中，其作用及其潜在的作用机制尚不清楚。在本研究中，我们旨在研究 P2X4R 在 GBM 中的功能和分子基础。我们首先观察到，与正常人类星形胶质细胞（NHA）细胞相比，GBM 细胞 U251、T98、U87、U373 和 A172 均高表达 P2X4R。为了获得 P2X4R 的功能，我们通过转染 P2X4R 小干扰 RNA（siRNA）构建了 P2X4R 沉默细胞。我们发现 P2X4R 缺失阻碍了 T98 和 U87 细胞的活力和增殖，进一步的研究表明，在转染了 P2X4R siRNA 的 T98 和 U87 细胞中，细胞凋亡和 caspase-3 活性增加。随后，我们证实 P2X4R 沉默抑制了 T98 和 U87 细胞中脑源性神经营养因子（BDNF）、Trk 受体酪氨酸激酶（TrkB）和激活转录因子 4（ATF4）的表达。并且 P2X4R siRNA 诱导的 ATF4 表达抑制依赖于 BDNF/TrkB 信号通路。ATF4 过表达逆转了 P2X4R 沉默对 T98 和 U87 细胞生长和凋亡的影响。总之，本研究首次提供了证据表明 P2X4R 在 GBM 细胞生长和凋亡中起重要作用。
