Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200071, P.R. China.
Shanghai Institute of Thoracic Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, P.R. China.
Oncol Rep. 2021 Jun;45(6). doi: 10.3892/or.2021.8039. Epub 2021 Apr 13.
Ferroptosis is a new form of regulated cell death and closely related to cancer. However, the mechanism underlying the regulation of ferroptosis in lung adenocarcinoma (LUAD) remains unclear. IB, IHC and ELISA were performed to analyze protein expression. RT‑qPCR was used to analyze mRNA expression. Cell viability, 3D cell growth, MDA, the generation of lipid ROS and the Fe2+ concentration were measured to evaluate the responses to the induction of ferroptosis. Measurement of luciferase activity and ChIP were used to analyze the promoter activity regulated by the transcriptional regulator. Co‑IP assays were performed to identify protein‑protein interactions. In the present study, it was revealed that cAMP response element‑binding protein (CREB) was highly expressed in LUAD, and knockdown of CREB inhibited cell viability and growth by promoting apoptosis‑ and ferroptosis‑like cell death, concurrently. It was observed that CREB suppressed lipid peroxidation by binding the promoter region of glutathione peroxidase 4 (GPX4), and this binding could be enhanced by E1A binding protein P300 (EP300). The bZIP domain in CREB and the CBP/p300‑HAT domain in EP300 were essential for CREB‑EP300 binding in LUAD cells. Finally, it was revealed that CREB, GPX4, EP300 and 4‑HNE were closely related to tumor size and stage, and tumors with a higher degree of malignancy were more likely to have a low degree of lipid peroxidation. Therefore, targeting this CREB/EP300/GPX4 axis may provide new strategies for treating LUAD.
铁死亡是一种新的细胞死亡形式，与癌症密切相关。然而，肺腺癌（LUAD）中铁死亡调控的机制尚不清楚。通过免疫印迹、免疫组织化学和酶联免疫吸附试验分析蛋白表达。通过实时荧光定量聚合酶链反应分析 mRNA 表达。通过细胞活力、3D 细胞生长、MDA、脂质 ROS 的产生和 Fe2+浓度来评估对铁死亡诱导的反应。通过测量荧光素酶活性和染色质免疫沉淀来分析转录调节因子调控的启动子活性。通过共免疫沉淀实验来鉴定蛋白-蛋白相互作用。在本研究中，揭示了 cAMP 反应元件结合蛋白（CREB）在 LUAD 中高表达，敲低 CREB 通过促进凋亡样和铁死亡样细胞死亡，同时抑制细胞活力和生长。观察到 CREB 通过结合谷胱甘肽过氧化物酶 4（GPX4）的启动子区域抑制脂质过氧化，这种结合可以被 E1A 结合蛋白 P300（EP300）增强。CREB 中的 bZIP 结构域和 EP300 中的 CBP/p300-HAT 结构域是 CREB-EP300 在 LUAD 细胞中结合所必需的。最后，揭示了 CREB、GPX4、EP300 和 4-HNE 与肿瘤大小和分期密切相关，恶性程度较高的肿瘤更有可能脂质过氧化程度较低。因此，靶向该 CREB/EP300/GPX4 轴可能为治疗 LUAD 提供新的策略。
