Department of Oncology, Molecular Oncology Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, 350000, China; Department of Oncology, National Regional Medical Center, Binhai Campus of The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350212, China.
Department of Oncology, Molecular Oncology Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, 350000, China; Department of Oncology, National Regional Medical Center, Binhai Campus of The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350212, China; Fujian Key Laboratory of Precision Medicine for Cancer, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, 350000, China.
Cancer Lett. 2024 May 1;589:216811. doi: 10.1016/j.canlet.2024.216811. Epub 2024 Mar 13.
Super-enhancers (SEs) exerted a crucial role in regulating the transcription of oncogenes across various malignancies while the roles of SEs driven genes and the core regulatory elements remain elusive in LUAD. In this study, cancer-specific-SE-genes of lung adenocarcinoma (LUAD) were profiled through H3K27ac ChIP-seq data of cancer cell lines and normal lung tissues, which enriched in in biological processes and pathways integral to the pathophysiology of LUAD. Based on this study, LUAD cells were susceptible to SEs inhibitors, with a reduction of cell proliferation as well as an elevation of apoptosis upon JQ1 or THZ1 intervention. Moreover, the integration of SEs landscapes, CRISPRi, ChIP-PCR, Hi-C data analysis and dual-luciferase reporter assays revealed that myeloma overexpressed gene (MYEOV) was aberrantly overexpressed in LUAD via transcriptional activation by the core SE elements. Functionally, the knockdown of MYEOV undermined cell proliferation in vitro and tumor growth in vivo. In addition, the knockdown of MYEOV generated a prominent ferroptotic phenotype, characterized by elevation of intracellular ferrous iron, reactive oxygen species and lipid peroxidation, together with alteration in marker proteins (SLC7A11, GPX4, FTH1, and ACSL4). Instead, the overexpression of MYEOV accelerated cell proliferation and abrogated ferroptosis. Clinically, the overexpression of MYEOV was observed in LUAD tissues indicating a poor prognosis in patients with LUAD. Mechanistically, SMPD1-induced autophagic degradation of GPX4 assumed a crucial role in the process of ferroptosis triggered by MYEOV knockdown. Serving as an oncogene repressing ferroptosis, promoting proliferation as well as shortening survival in LUAD, SEs-mediated activation of MYEOV might distinguish as a promising therapeutic target.
超级增强子 (SEs) 在调节各种恶性肿瘤中的癌基因转录中发挥着关键作用,而 SEs 驱动的基因和核心调控元件在 LUAD 中的作用仍不清楚。在这项研究中,通过癌症细胞系和正常肺组织的 H3K27ac ChIP-seq 数据,对肺腺癌 (LUAD) 的癌症特异性 SE 基因进行了分析,这些基因富集在与 LUAD 病理生理学密切相关的生物学过程和途径中。基于这项研究,LUAD 细胞对 SE 抑制剂敏感,JQ1 或 THZ1 干预后,细胞增殖减少,细胞凋亡增加。此外,SE 景观、CRISPRi、ChIP-PCR、Hi-C 数据分析和双荧光素酶报告基因检测的整合表明,骨髓瘤过表达基因 (MYEOV) 通过核心 SE 元件的转录激活在 LUAD 中异常过表达。功能上,MYEOV 的敲低削弱了体外细胞增殖和体内肿瘤生长。此外,MYEOV 的敲低导致了明显的铁死亡表型,其特征是细胞内亚铁离子、活性氧和脂质过氧化的升高,以及标记蛋白 (SLC7A11、GPX4、FTH1 和 ACSL4) 的改变。相反,MYEOV 的过表达加速了细胞增殖并消除了铁死亡。临床上,在 LUAD 组织中观察到 MYEOV 的过表达,表明 LUAD 患者预后不良。从机制上讲,SMPD1 诱导的 GPX4 自噬降解在 MYEOV 敲低触发的铁死亡过程中起着关键作用。作为一种抑制铁死亡、促进 LUAD 增殖和缩短生存期的致癌基因,SEs 介导的 MYEOV 激活可能成为有前途的治疗靶点。