Elaiophylin作为一种新型自噬抑制剂在卵巢癌细胞中的抗肿瘤活性研究

发布时间：2018-08-17 09:46

【摘要】：细胞自噬是真核生物中一种进化保守的、溶酶体依赖的降解细胞内受损细胞器和长寿蛋白的分解代谢过程,是维持细胞内环境稳态和应对环境应激刺激的重要途径。细胞自噬通路的异常与机体多种疾病的发生发展密切相关,如：肿瘤、感染性疾病、神经退行性疾病、心血管疾病等。目前,在抗肿瘤药物研发领域,靶向自噬通路被认为是一项非常有潜力的新策略。本研究中,利用稳定表达GFP-LC3B的SKOV3细胞株,我们对华北制药集团有限公司(NCPC)微生物来源的纯化合物库进行了系统筛选,发现并鉴定Elaiophylin是一种新的自噬抑制剂。Elaiophylin虽然促进细胞内自噬体的累积,但是最终通过减弱溶酶体组织蛋白酶的活性而阻断自噬流,导致细胞内SQSTM1/p62蛋白水平的增高。此外,elaiophylin诱导溶酶体失稳,具体表现为细胞LysoTracker Red溶酶体染色减弱,以及组织蛋白酶B/组织蛋白酶D从溶酶体释放至细胞浆。Elaiophylin最终会降低细胞存活率,尤其是当它与顺铂联用或者当细胞处于低氧环境中时。而且,在卵巢癌原位移植的小鼠模型中,给予低剂量(2mg/kg)的elaiophylin单药治疗即可获得显著地抗肿瘤活性,并且没有毒副作用；但是,高剂量(8mg/kg)的elaiophylin会导致小肠潘氏细胞功能障碍,而这一点与ATG16L1敲除小鼠的小肠表型非常相似。总的来说,这些结果对该药物的潜在临床应用提供了一个安全的治疗窗。我们的研究结论首次表明elaiophylin是一种新的自噬抑制剂,单药或者与其他药物联用均可在卵巢癌细胞中发挥显著的抗肿瘤活性,为该药物应用于卵巢癌的治疗提供了潜在的可能性。
[Abstract]:Autophagy is an evolutionarily conserved, lysosomal dependent catabolism process of damaged organelles and long-lived proteins in eukaryotes, which is an important way to maintain homeostasis and respond to environmental stress. The abnormal autophagy pathway is closely related to the occurrence and development of many diseases, such as tumor, infectious diseases, neurodegenerative diseases, cardiovascular diseases and so on. At present, targeted autophagy pathway is regarded as a potential new strategy in the field of antitumor drug development. In this study, using SKOV3 cell lines expressing GFP-LC3B stably, we systematically screened the pure compound library from (NCPC) microorganism of Huabei Pharmaceutical Group Co., Ltd. It was found and identified that Elaiophylin is a new autophagy inhibitor. Elaiophylin promoted the accumulation of autophagy, but finally blocked the autophagy flow by decreasing the activity of lysosomal cathepsin, which resulted in the increase of intracellular SQSTM1/p62 protein level. In addition, elaiophylin induced the instability of lysosome, which was manifested by the decrease of LysoTracker Red lysosome staining, and the release of cathepsin B / cathepsin D from lysosome to cytoplasm. Elaiophylin eventually reduced the cell survival rate. Especially when it is used in combination with cisplatin or when cells are exposed to hypoxia. Moreover, in a mouse model of orthotopic transplantation of ovarian cancer, low-dose (2mg/kg) elaiophylin monotherapy resulted in significant anti-tumor activity and no side effects; however, high-dose (8mg/kg) elaiophylin resulted in small intestinal Panzon cell dysfunction. This is very similar to the small intestine phenotype of ATG16L1 knockout mice. Overall, these results provide a safe therapeutic window for potential clinical applications of the drug. Our results suggest for the first time that elaiophylin is a new autophagy inhibitor, which can play a significant antitumor activity in ovarian cancer cells either alone or in combination with other drugs, providing a potential for the use of the drug in the treatment of ovarian cancer.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R737.31

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