Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China.
Shandong University School of Medicine, Jinan, Shandong, China.
Mol Neurobiol. 2015 Dec;52(3):1521-1526. doi: 10.1007/s12035-014-8955-7. Epub 2014 Nov 4.
The chemokine receptor CXCR4 and its ligand stromal cell-derived factor 1 (SDF-1) plays an important role in tumor progression and are associated with angiogenesis. Meanwhile, the implications of C23 in multiple signaling pathways have been also investigated. However, the effects of C23 on CXCR4 pathway in glioblastoma are not fully characterized. In the present study, C23 and CXCR4 of U87 cell line were inhibited by anti-C23 and anti-CXCR4 antibodies, respectively; and then C23 and CXCR4 siRNAs were used to knock down endogenous C23 and CXCR4, respectively. In addition, MTT assay was also introduced. Our data showed that either anti-C23 or anti-CXCR4 antibodies efficaciously repressed the phosphorylation levels of ERK (p < 0.000) and AKT (p < 0.000) compared with SDF-1 alone and control. As expected, either C23 or CXCR4 siRNAs indeed resulted in C23 and CXCR4 knockdown and further suppressed the expression of p-ERK and p-AKT. Most importantly, immunoprecipitation revealed C23 interacted with CXCR4 once U87 was exposed to SDF-1 treatment. In addition, MTT assay identified that C23 or CXCR4 siRNAs could obviously decreased cell proliferation capacity (p = 0.002). In conclusion, our results suggest that C23 plays a crucial role in activation of SDF-1-induced ERK and PI3K/AKT pathways via interacting with CXCR4. Furthermore, C23 could be recommended as an important element in glioblastoma development and a new target for glioblastoma treatment.
趋化因子受体 CXCR4 及其配体基质细胞衍生因子 1（SDF-1）在肿瘤进展中发挥重要作用，并与血管生成有关。同时，C23 在多种信号通路中的作用也得到了研究。然而，C23 对胶质母细胞瘤中 CXCR4 途径的影响尚未完全阐明。在本研究中，分别用抗 C23 和抗 CXCR4 抗体抑制 U87 细胞系中的 C23 和 CXCR4；然后使用 C23 和 CXCR4 siRNAs 分别敲低内源性 C23 和 CXCR4。此外，还引入了 MTT 测定法。我们的数据表明，与 SDF-1 单独处理和对照相比，抗 C23 或抗 CXCR4 抗体均能有效地抑制 ERK（p < 0.000）和 AKT（p < 0.000）的磷酸化水平。正如预期的那样，C23 或 CXCR4 siRNAs 确实导致 C23 和 CXCR4 敲低，并进一步抑制了 p-ERK 和 p-AKT 的表达。最重要的是，免疫沉淀显示，一旦 U87 暴露于 SDF-1 处理，C23 就会与 CXCR4 相互作用。此外，MTT 测定法表明，C23 或 CXCR4 siRNAs 可明显降低细胞增殖能力（p = 0.002）。总之，我们的结果表明，C23 通过与 CXCR4 相互作用在激活 SDF-1 诱导的 ERK 和 PI3K/AKT 途径中发挥关键作用。此外，C23 可作为胶质母细胞瘤发展的重要因素，并作为胶质母细胞瘤治疗的新靶点。
