Knockdown of Cathepsin L promotes radiosensitivity of glioma stem cells both in vivo and in vitro
Knockdown of Cathepsin L promotes radiosensitivity of glioma stem cells both in vivo and in vitro
复制标题
组织蛋白酶 L 的敲低可促进神经胶质瘤干细胞体内和体外的放射敏感性
DOI：
10.1016/j.canlet.2015.12.012
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发表时间：
2016-01-01
期刊：
影响因子：
9.7
通讯作者：
Liang, Zhongqin
中科院分区：
文献类型：
--
作者：
Wang, Wenjuan;Long, Linmei;Liang, Zhongqin
胶质瘤干细胞（GSCs）的存在与胶质瘤治疗耐药性有关。本研究评估了组织蛋白酶L的敲低是否会影响GSC生长、肿瘤放射敏感性和临床结果。采用免疫组化方法检测90例不同WHO分级胶质瘤和6例正常脑组织中Cathepsin L和干细胞标志物（CD 133和Nestin）的蛋白水平。用组织蛋白酶L短发夹状RNA表达载体稳定转染两株组织蛋白酶L过表达的胶质瘤干细胞系。评价了组织蛋白酶L抑制对放射敏感性、自我更新、干性、DNA损伤和凋亡的影响。此外，使用颅内动物模型和裸鼠皮下肿瘤异种移植物来评估体内肿瘤对组织蛋白酶L抑制的反应。结果表明，Cathepsin L和CD 133的表达与胶质瘤的恶性程度有关，而Nestin的表达与胶质瘤的恶性程度无关。组织蛋白酶L和CD 133共表达高的GSC具有非常强的放射抗性。组织蛋白酶L抑制与放射治疗显着减少GSC的生长，促进凋亡，并提高放射敏感性。组织蛋白酶L的敲低导致CD 133表达的显著降低，以及DNA修复检查点蛋白（ATM和DNA-PKcs）的磷酸化降低。此外，组织蛋白酶L抑制和放射治疗的组合在体内有效地阻断肿瘤生长并减少血管形成。总之，这些发现表明组织蛋白酶Las是GBM患者临床治疗的有希望的治疗靶点。(C)2015爱思唯尔爱尔兰有限公司版权所有。
The presence of glioma stem cells (GSCs) in tumor is relevant for glioma treatment resistance. This study assessed whether knockdown of Cathepsin L can influence GSC growth, tumor radiosensitivity, and clinical outcome. Protein levels of Cathepsin L and stem cell markers (CD133 and Nestin) were analyzed in samples from 90 gliomas of different WHO grades and 6 normal brain tissues by immunohistochemistry. Two glioma stem cell lines with overexpressed Cathepsin L were stably transfected with Cathepsin L short hairpin RNA expression vectors. The effects of Cathepsin L inhibition on radiosensitivity, self renewal, stemness, DNA damage, and apoptosis were evaluated. In addition, an intracranial animal model and subcutaneous tumor xenografts in nude mice were used to assess tumor response to Cathepsin L inhibition in vivo. Our results proved that expressions of Cathepsin L and CD133, but not of Nestin, correlated with malignant grades of glioma tissues. GSCs with high Cathepsin L and CD133 co-expression were extraordinarily radioresistant. Cathepsin L inhibition with radiotherapy significantly reduced GSC growth, promoted apoptosis, and improved radiosensitivity. Knockdown of Cathepsin L resulted in a dramatic reduction of CD133 expression, as well as the decreased phosphorylation of DNA repair checkpoint proteins (ATM and DNA-PKcs). Furthermore, combination of Cathepsin L inhibition and radiotherapy potently blocked tumor growth and decreased blood vessel formation in vivo. Taken together, these findings suggest Cathepsin Las a promising therapeutic target for clinical therapy in GBM patients. (C) 2015 Elsevier Ireland Ltd. All rights reserved.