Ai Chengjin, Zhou Yu, Pu Kunming, Yang Yi, Zhou Yingying
Department of Laboratory Medicine, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 610072, P.R. China.
Department of Ultrasound, The Second People's Hospital of Chengdu, Chengdu, Sichuan 610072, P.R. China.
Oncol Lett. 2022 May 27;24(1):230. doi: 10.3892/ol.2022.13351. eCollection 2022 Jul.
Neurite outgrowth inhibitor A (Nogo-A), a member of the reticulon 4 family, is an axon regeneration inhibitor that is negatively associated with the malignancy of oligodendroglial tumors. It has been suggested that the Nogo-A/Nogo Receptor (NgR) pathway plays a promoting effect in regulating cancer stem-like cells (CSCs) derived from glioblastoma, indicating that Nogo-A could exert different roles in CSCs than those in parental cancer cells. In the present study, CSCs were generated from the human Uppsala 87 malignant glioma (U87MG) cell line. These U87MG-CSCs were characterized by the upregulation of CD44 and CD133, which are two markers of stemness. The expression levels of Nogo-A and the differentiation of U87MG-CSCs were investigated. In addition, the proliferation, invasion and colony formation U87MG-CSCs were examined. Using culture in serum-containing medium, U87MG-CSCs were differentiated into neuron-like cells specifically expressing MAP2, β-III-tubulin and nestin. Nogo-A was upregulated in U87MG-CSCs compared with parental cells. Knockdown of Nogo-A and inhibition of the Nogo-A/NgR signaling pathway in U87MG-CSCs markedly decreased cell viability, cell cycle entry, invasion and tumor formation, indicating that Nogo-A could regulate U87MG-CSC function. Moreover, Nogo-A was involved in intracellular ATP synthesis and scavenging of accumulated reactive oxygen species. Nogo-A/NgR pathway exerted protective effects against hypoxia-induced non-apoptotic and apoptotic cell death. These results suggest that Nogo-A plays an important role in regulating U87MG-CSCs via the Nogo-A/NgR signaling pathway. Nogo-A may also different roles in U87MG-CSCs compared with their parental cells.
神经突生长抑制因子A（Nogo-A）是网织蛋白4家族的成员，是一种轴突再生抑制剂，与少突胶质细胞瘤的恶性程度呈负相关。有人提出，Nogo-A/ Nogo受体（NgR）通路在调节源自胶质母细胞瘤的癌症干细胞（CSCs）中起促进作用，这表明Nogo-A在CSCs中可能发挥与亲代癌细胞不同的作用。在本研究中，从人乌普萨拉87恶性胶质瘤（U87MG）细胞系中生成了CSCs。这些U87MG-CSCs的特征是干性的两个标志物CD44和CD133上调。研究了Nogo-A的表达水平以及U87MG-CSCs的分化情况。此外，还检测了U87MG-CSCs的增殖、侵袭和集落形成情况。通过在含血清培养基中培养，U87MG-CSCs分化为特异性表达微管相关蛋白2（MAP2）、β-III微管蛋白和巢蛋白的神经元样细胞。与亲代细胞相比，U87MG-CSCs中Nogo-A上调。敲低U87MG-CSCs中的Nogo-A并抑制Nogo-A/NgR信号通路可显著降低细胞活力、细胞周期进入、侵袭和肿瘤形成，表明Nogo-A可调节U87MG-CSC功能。此外，Nogo-A参与细胞内ATP合成和清除积累的活性氧。Nogo-A/NgR通路对缺氧诱导的非凋亡和凋亡细胞死亡具有保护作用。这些结果表明，Nogo-A通过Nogo-A/NgR信号通路在调节U87MG-CSCs中起重要作用。与亲代细胞相比，Nogo-A在U87MG-CSCs中可能也发挥不同作用。
