Lv Shunzeng, Dai Congxin, Liu Yuting, Sun Bowen, Shi Ranran, Han Mingzhi, Bian Ruixiang, Wang Renzhi
J Mol Neurosci. 2015 Feb;55(2):519-24. doi: 10.1007/s12031-014-0375-7.
The epidermal growth factor (EGF) pathway has been reported as canonical causes in cancer development. Meanwhile, the involvement of C23 in multiple signaling pathways has been also investigated (Lv et al., 2014). However, the effect of C23 on EGF pathway in glioblastoma is not fully characterized. In the present study, C23 and the epidermal growth factor receptor (EGFR) of U251 cell line were inhibited by C23 and EGFR antibodies, respectively; and then C23 and EGFR siRNAs were used to knock down endogenous C23 and EGFR, respectively. In addition, soft-agar and MTT assay were also introduced. Compared with control, either C23 or EGFR antibodies efficiently repressed the phosphorylation levels of ERK1/2 (p<0.000) and AKT (p<0.000). Similarly, either C23 or EGFR siRNAs indeed resulted in C23 and EGFR knockdown, and further suppressed the expression of p-ERK1/2 and p-AKT. Most importantly, immunoprecipitation revealed C23 interacted with EGFR once U251 was exposed to EGF treatment. In addition, the MTT and soft-agar assay also identified that C23 or EGFR siRNAs could obviously affected cell growth (p=0.004) and invasiveness, as cell viability and colony formation decreased markedly. Our results suggest that C23 plays a crucial role in activation of EGF-induced ERK and PI3K-AKT pathways via interacting with EGFR; furthermore, C23 could be indicative of an important factor in glioblastoma development and a useful target for glioblastoma treatment.
表皮生长因子（EGF）信号通路已被报道为癌症发生发展的典型原因。同时，C23在多种信号通路中的作用也已得到研究（Lv等人，2014年）。然而，C23对胶质母细胞瘤中EGF信号通路的影响尚未完全明确。在本研究中，分别用C23抗体和表皮生长因子受体（EGFR）抗体抑制U251细胞系中的C23和EGFR；然后分别用C23和EGFR的小干扰RNA（siRNA）敲低内源性C23和EGFR。此外，还采用了软琼脂和MTT实验。与对照组相比，C23抗体或EGFR抗体均能有效抑制ERK1/2（p<0.000）和AKT（p<0.000）的磷酸化水平。同样，C23 siRNA或EGFR siRNA确实导致了C23和EGFR的敲低，并进一步抑制了p-ERK1/2和p-AKT的表达。最重要的是，免疫沉淀显示，U251细胞在接受EGF处理后，C23与EGFR相互作用。此外，MTT和软琼脂实验还表明，C23 siRNA或EGFR siRNA可显著影响细胞生长（p=0.004）和侵袭能力，细胞活力和集落形成明显降低。我们的结果表明，C23通过与EGFR相互作用，在EGF诱导的ERK和PI3K-AKT信号通路激活中起关键作用；此外，C23可能是胶质母细胞瘤发生发展中的一个重要因素，也是胶质母细胞瘤治疗的一个有效靶点。
