The protein-kinase-R- (PKR-) like endoplasmic reticulum kinase (PERK) signaling pathway is a well-known promoter of cell apoptosis. In this study, we aimed to determine whether salubrinal (Sal), a selective activator of eukaryotic translation initiation factor 2 (eIF2α), can induce apoptosis of human adrenocortical carcinoma (ACC) cell via activating the PERK/eIF2α/ATF4 signaling pathway, and the potential mechanisms of this action were explored. The ACC cell lines, including SW-13 and NCI–H295 R, were used. 3-(4,5)-Dimethylthiazol(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, cell scratch experiments, flow cytometry, and JC-1 staining assays were performed to detect the cell viability, cell migration, and cell apoptosis. The expression of PERK/eIF2α/ATF4 signaling-pathway-related proteins and apoptosis-related proteins was detected by western blot (WB). Intracellular Ca²⁺ ion concentration was determined by a confocal laser scanning microscope. The results showed that Sal inhibited the migration and proliferation of ACC cells. Sal remarkably increased the influx of Ca²⁺ ion and the apoptosis rate of ACC cells in vitro. Furthermore, the expression levels of PERK/eIF2α/ATF4 signaling-related proteins and apoptosis-related proteins were upregulated in the treatment of Sal. The research demonstrated that Sal reduces the cell viability, increases the intracellular calcium concentration, and promotes the apoptosis of ACC cells in vitro through increasing the phosphorylation level of eIF2α and activating the PERK/eIF2α/ATF4 signaling. PERK/eIF2α/ATF4 is expected to act as a potential therapeutic target for the treatment of adrenocortical carcinoma.

中文翻译：

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Salubrinal 通过 PERK/eIF2α/ATF4 信号通路调节肾上腺皮质癌细胞的凋亡

蛋白激酶R- (PKR-) 样内质网激酶 (PERK) 信号通路是众所周知的细胞凋亡启动子。在本研究中，我们旨在确定真核翻译起始因子 2 (eIF2 α )的选择性激活剂 Salubrinal (Sal) 是否可以通过激活 PERK/eIF2 α /ATF4 信号通路诱导人肾上腺皮质癌 (ACC) 细胞凋亡，并探讨了这一行动的潜在机制。使用了 ACC 细胞系，包括 SW-13 和 NCI-H295 R。3-(4,5)-Dimethylthiazol(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) 实验、细胞划痕实验、流式细胞术和 JC-1 染色实验检测细胞活力、细胞迁移和细胞凋亡。PERK/eIF2的表达通过蛋白质印迹（WB）检测α /ATF4信号通路相关蛋白和细胞凋亡相关蛋白。通过共聚焦激光扫描显微镜测定细胞内Ca ²⁺离子浓度。结果表明，Sal抑制ACC细胞的迁移和增殖。Sal在体外显着增加Ca ²⁺离子的流入和ACC细胞的凋亡率。此外，PERK /的eIF2的表达水平α / ATF4信令相关蛋白和细胞凋亡相关蛋白萨尔的治疗被上调。表明，萨尔降低细胞活力，研究增加细胞内钙浓度，促进ACC细胞凋亡在体外通过增加 eIF2 α的磷酸化水平和激活 PERK/eIF2 α /ATF4 信号。PERK /的eIF2 α / ATF4有望作为用于肾上腺皮质癌的治疗中的潜在治疗靶标。