Guan Yongchang, Cheng Wen, Zou Cunyi, Wang Tingzhong, Cao Zhi
Department of Neurosurgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
Department of Neurosurgery, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
Clin Exp Pharmacol Physiol. 2017 Feb;44(2):244-256. doi: 10.1111/1440-1681.12697.
As the most prevalent and lethal type of brain tumours, gliomas, especially malignant ones, are relatively resistant to conventional therapies. Gremlin 1 (GREM1) is a secreted glycoprotein that is implicated in the maintenance of cancer stem cells in tumour hierarchy. In the current study, the role of GREM1 in the carcinogenesis of glioma was studied using a knockdown approach. We first examined the expression level of GREM1 in the clinical samples, and then evaluated the effect of GREM1 knockdown on the viability and colony formation capacity of U87-MG cells. Moreover, the migration ability, invasiveness, cell cycle, and apoptosis of GREM1-silenced cells were assessed. Furthermore, the involvement of functional GREM1 in the epithelial-mesenchymal transition (EMT) process of glioma was investigated by detecting the expression levels of glioma-associated oncogene homologue 3 (GLI3) and EMT-related molecules. Our results demonstrated that knockdown of GREM1 reduced cell viability, suppressed migration and invasion, and inhibited GLI3 expression and the EMT process in U87-MG cells. Meanwhile, GREM1 silencing promoted apoptosis in U87-MG cells through the accumulation of Bax, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase (PARP) as well as the downregulation of Bcl-2. In addition, GREM1 knockdown abolished transforming growth factor (TGF)-β1-mediated activation of the Smad pathway, which may underlie the mechanism of GREM1-regulated EMT. In conclusion, GREM1 plays an important role in the development of glioma, and it may serve as a potential target in glioma therapy.
作为最常见且致命的脑肿瘤类型，神经胶质瘤，尤其是恶性神经胶质瘤，对传统疗法相对耐药。Gremlin 1（GREM1）是一种分泌型糖蛋白，与肿瘤层级中癌症干细胞的维持有关。在本研究中，采用敲低方法研究了GREM1在神经胶质瘤发生中的作用。我们首先检测了临床样本中GREM1的表达水平，然后评估了GREM1敲低对U87-MG细胞活力和集落形成能力的影响。此外，还评估了GREM1沉默细胞的迁移能力、侵袭性、细胞周期和凋亡情况。进一步地，通过检测胶质瘤相关癌基因同源物3（GLI3）和上皮-间质转化（EMT）相关分子的表达水平，研究了功能性GREM1在神经胶质瘤EMT过程中的作用。我们的结果表明，敲低GREM1可降低U87-MG细胞的活力，抑制迁移和侵袭，并抑制GLI3表达和EMT过程。同时，GREM1沉默通过Bax、裂解的半胱天冬酶-3和裂解的聚（ADP-核糖）聚合酶（PARP）的积累以及Bcl-2的下调促进了U87-MG细胞的凋亡。此外，GREM1敲低消除了转化生长因子（TGF）-β1介导的Smad通路激活，这可能是GREM1调节EMT的机制基础。总之，GREM1在神经胶质瘤的发展中起重要作用，它可能成为神经胶质瘤治疗的潜在靶点。
