Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Road, 430022 Wuhan, Hubei Province, People's Republic of China.
Med Oncol. 2011 Mar;28(1):105-11. doi: 10.1007/s12032-009-9397-3. Epub 2009 Dec 30.
Cisplatin (DDP)-based adjuvant chemotherapy is widely used for the treatment of esophageal cancer. However, DDP resistance has become more common and thus new approaches are required to be explored. Cisplatin was used to induce autophagy in the human esophageal cancer cell line, EC9706 cells, and the effect of autophagy on the survival of EC9706 cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by CCK8 assay. Apoptosis and cell cycle were detected by flow cytometry. Monodansylcadaverine (MDC) was used to detect autophagy. Western blotting assay was used to investigate the molecular changes that occurred in the course of treatment. DDP inhibited cell proliferation, induced cell death and cell cycle arrest at S phage. Moreover, autophagy was activated through class III PI3K pathway. The expression of autophagy-related Beclin1 and LC3-I was up-regulated and part of LC3-I was converted into LC3-II. However, after the combination treatment of 3-MA and DDP, the cell inhibitory rate increased; the apoptosis rate and the numbers of cells in S phase also increased. Furthermore, the accumulation of autophagic vacuoles was decreased; the expression of Beclin1 and LC3 was significantly down-regulated and the release of cytochrome c was decreased. DDP-induced apoptosis in EC9706 cells can be enhanced by the inhibitor of autophagy, 3-MA. Autophagy might play a role as a self-protective mechanism in DDP-treated esophageal cancer cells, and its inhibition could be a novel strategy for the adjuvant chemotherapy of esophageal cancer.
顺铂（DDP）为基础的辅助化疗广泛用于食管癌的治疗。然而，DDP 耐药性变得更为常见，因此需要探索新的方法。本研究采用顺铂诱导人食管癌细胞系 EC9706 细胞自噬，并用自噬抑制剂 3-MA 研究自噬对 EC9706 细胞存活的影响。通过 CCK8 法检测细胞活力。用流式细胞术检测细胞凋亡和细胞周期。用单丹磺酰戊二胺（MDC）检测自噬。通过 Western blot 检测治疗过程中发生的分子变化。DDP 抑制细胞增殖，诱导 S 期细胞死亡和细胞周期停滞。此外，通过 III 型 PI3K 途径激活自噬。自噬相关蛋白 Beclin1 和 LC3-I 的表达上调，部分 LC3-I 转化为 LC3-II。然而，3-MA 和 DDP 联合处理后，细胞抑制率增加；细胞凋亡率和 S 期细胞数增加。自噬小体的积累减少；Beclin1 和 LC3 的表达显著下调，细胞色素 c 的释放减少。自噬抑制剂 3-MA 可增强 DDP 诱导的 EC9706 细胞凋亡。自噬可能在 DDP 处理的食管癌细胞中作为一种自我保护机制发挥作用，其抑制可能是食管癌辅助化疗的一种新策略。
