背景:L型钙通道是唯一对钙通道阻滞剂敏感的蛋白质通道,并在各种癌症类型中表达。癌症基因组图谱数据库显示,食管鳞状细胞癌肿瘤组织中多个L型钙通道亚基的mRNA水平明显高于正常食管上皮组织。因此,我们假设氨氯地平,长效二氢吡啶L型钙通道阻滞剂,可能抑制食管癌的发生和发展。
目的:探讨氨氯地平通过内质网应激对EC的抑制作用。
方法:检测50对EC组织和相应的癌旁组织中Cav1.3蛋白的表达水平。随后,使用3-(4,5-二甲基-2-噻唑基)-2,5-二苯基-2-H-四唑溴化物和Transwell测定法检测氨氯地平对EC细胞增殖和迁移的抑制作用。使用鼠异种移植模型进行体内实验。为了阐明潜在的机制,进行了体外细胞研究以证实ER应激在用氨氯地平处理的EC细胞的增殖抑制和迁移中起作用。
结果:Cav1.3在食管癌中的表达水平比癌旁组织高1.6倍。氨氯地平治疗以剂量和时间依赖性方式降低了食管癌细胞的活力。体内动物实验也清楚地表明,氨氯地平抑制小鼠EC肿瘤的生长。此外,氨氯地平通过抑制上皮间质转化(EMT)减少肿瘤细胞的迁移。机制研究表明,氨氯地平诱导内质网应激介导的细胞凋亡并抑制EMT。此外,氨氯地平诱导的自噬的特征是自噬溶酶体的增加和轻链3B蛋白的积累。氨氯地平与ER应激抑制剂4-苯基丁酸的组合进一步证实了ER应激反应在氨氯地平诱导的细胞凋亡中的作用,EMT,和自噬。此外,阻断自噬可增加细胞凋亡和迁移的比例。
结论:总的来说,我们首次证明氨氯地平促进细胞凋亡,诱导自噬,并通过内质网应激抑制迁移,从而在EC中发挥抗肿瘤作用。
BACKGROUND: L-type calcium channels are the only protein channels sensitive to calcium channel blockers, and are expressed in various cancer types. The Cancer Genome Atlas database shows that the mRNA levels of multiple L-type calcium channel subunits in esophageal squamous cell carcinoma tumor tissue are significantly higher than those in normal esophageal epithelial tissue. Therefore, we hypothesized that amlodipine, a long-acting dihydropyridine L-type calcium channel blocker, may inhibit the occurrence and development of esophageal cancer (EC).
OBJECTIVE: To investigate the inhibitory effects of amlodipine on EC through endoplasmic reticulum (ER) stress.
METHODS: Cav1.3 protein expression levels in 50 pairs of EC tissues and corresponding paracancerous tissues were examined. Subsequently, the inhibitory effects of amlodipine on proliferation and migration of EC cells in vitro were detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and Transwell assays. In vivo experiments were performed using murine xenograft model. To elucidate the underlying mechanisms, in vitro cell studies were performed to confirm that ER stress plays a role in inhibition proliferation and migration of EC cells treated with amlodipine.
RESULTS: The expression level of Cav1.3 in esophageal carcinoma was 1.6 times higher than that in paracancerous tissues. Amlodipine treatment decreased the viability of esophageal carcinoma cells in a dose- and time-dependent manner. In vivo animal experiments also clearly indicated that amlodipine inhibited the growth of EC tumors in mice. Additionally, amlodipine reduces the migration of tumor cells by inhibiting epithelial-mesenchymal transition (EMT). Mechanistic studies have demonstrated that amlodipine induces ER stress-mediated apoptosis and suppresses EMT. Moreover, amlodipine-induced autophagy was characterized by an increase in autophagy lysosomes and the accumulation of light chain 3B protein. The combination of amlodipine with the ER stress inhibitor 4-phenylbutyric acid further confirmed the role of the ER stress response in amlodipine-induced apoptosis, EMT, and autophagy. Furthermore, blocking autophagy increases the ratio of apoptosis and migration.
CONCLUSIONS: Collectively, we demonstrate for the first time that amlodipine promotes apoptosis, induces autophagy, and inhibits migration through ER stress, thereby exerting anti-tumor effects in EC.