缺氧诱导的自噬介导肺癌细胞对顺铂的耐药性。
Hypoxia-induced autophagy mediates cisplatin resistance in lung cancer cells.
作者信息
Wu Hui-Mei, Jiang Zi-Feng, Ding Pei-Shan, Shao Li-Jie, Liu Rong-Yu
机构信息
Department of Pulmonary, Anhui Geriatric Institute, the First Affiliated Hospital of Anhui Medical University, Jixi Road 218, Hefei 230022, China.
出版信息
Sci Rep. 2015 Jul 23;5:12291. doi: 10.1038/srep12291.
Hypoxia which commonly exists in solid tumors, leads to cancer cells chemoresistance via provoking adaptive responses including autophagy. Therefore, we sought to evaluate the role of autophagy and hypoxia as well as the underlying mechanism in the cisplatin resistance of lung cancer cells. Our study demonstrated that hypoxia significantly protected A549 and SPC-A1 cells from cisplatin-induced cell death in a Hif-1α- and Hif-2α-dependent manner. Moreover, compared with normoxia, cisplatin-induced apoptosis under hypoxia was markedly reduced. However, when autophagy was inhibited by 3-MA or siRNA targeted ATG5, this reduction was effectively attenuated, which means autophagy mediates cisplatin resisitance under hypoxia. In parallel, we showed that hypoxia robustly augmented cisplatin-induced autophagy activation, accompanying by suppressing cisplatin-induced BNIP3 death pathways, which was due to the more efficient autophagic process under hypoxia. Consequently, we proposed that autophagy was a protective mechanism after cisplatin incubation under both normoxia and hypoxia. However, under normoxia, autophagy activation 'was unable to counteract the stress induced by cisplatin, therefore resulting in cell death, whereas under hypoxia, autophagy induction was augmented that solved the cisplatin-induced stress, allowing the cells to survival. In conclusion, augmented induction of autophagy by hypoxia decreased lung cancer cells susceptibility to cisplatin-induced apoptosis.
实体瘤中普遍存在的缺氧,通过引发包括自噬在内的适应性反应导致癌细胞产生化学抗性。因此,我们试图评估自噬和缺氧的作用以及肺癌细胞顺铂耐药性的潜在机制。我们的研究表明,缺氧以依赖Hif-1α和Hif-2α的方式显著保护A549和SPC-A1细胞免受顺铂诱导的细胞死亡。此外,与常氧相比,缺氧条件下顺铂诱导的凋亡明显减少。然而,当自噬被3-MA或靶向ATG5的siRNA抑制时,这种减少有效地减弱了,这意味着自噬在缺氧条件下介导顺铂耐药性。同时,我们表明缺氧强烈增强顺铂诱导的自噬激活,同时抑制顺铂诱导的BNIP3死亡途径,这是由于缺氧条件下更有效的自噬过程。因此,我们提出自噬是顺铂孵育后在常氧和缺氧条件下的一种保护机制。然而,在常氧条件下,自噬激活无法抵消顺铂诱导的应激,因此导致细胞死亡,而在缺氧条件下,自噬诱导增强,解决了顺铂诱导的应激,使细胞得以存活。总之,缺氧增强自噬诱导降低了肺癌细胞对顺铂诱导凋亡的敏感性。