mA 去甲基化 FOSL1 mRNA 可保护肝癌细胞免受葡萄糖剥夺引起的坏死。

mA demethylation of FOSL1 mRNA protects hepatoma cells against necrosis under glucose deprivation.

机构信息

Department of Infectious Diseases, Institute for Viral Hepatitis, the Key Laboratory of Molecular Biology for Infectious Diseases, Chinese Ministry of Education, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.

出版信息

Cell Death Differ. 2024 Aug;31(8):1029-1043. doi: 10.1038/s41418-024-01308-3. Epub 2024 May 18.

Abstract

Stress-adaptive mechanisms enabling cancer cells to survive under glucose deprivation remain elusive. N-methyladenosine (mA) modification plays important roles in determining cancer cell fate and cellular stress response to nutrient deficiency. However, whether mA modification functions in the regulation of cancer cell survival under glucose deprivation is unknown. Here, we found that glucose deprivation reduced mA modification levels. Increasing mA modification resulted in increased hepatoma cell necrosis under glucose deprivation, whereas decreasing mA modification had an opposite effect. Integrated mA-seq and RNA-seq revealed potential targets of mA modification under glucose deprivation, including the transcription factor FOSL1; further, glucose deprivation upregulated FOSL1 by inhibiting FOSL1 mRNA decay in an mA-YTHDF2-dependent manner through reducing mA modification in its exon1 and 5'-UTR regions. Functionally, FOSL1 protected hepatoma cells against glucose deprivation-induced necrosis in vitro and in vivo. Mechanistically, FOSL1 transcriptionally repressed ATF3 by binding to its promoter. Meanwhile, ATF3 and MAFF interacted via their leucine zipper domains to form a heterodimer, which competed with NRF2 for binding to antioxidant response elements in the promoters of NRF2 target genes, thereby inhibiting their transcription. Consequently, FOSL1 reduced the formation of the ATF3-MAFF heterodimer, thereby enhancing NRF2 transcriptional activity and the antioxidant capacity of glucose-deprived-hepatoma cells. Thus, FOSL1 alleviated the necrosis-inducing effect of glucose deprivation-induced reactive oxygen species accumulation. Collectively, our study uncovers the protective role of mA-FOSL1-ATF3 axis in hepatoma cell necrosis under glucose deprivation, and may provide new targets for cancer therapy.

摘要

使癌细胞能够在葡萄糖缺乏的情况下存活的应激适应机制仍然难以捉摸。N6-甲基腺苷(m6A)修饰在决定癌细胞命运和细胞对营养缺乏的应激反应中起着重要作用。然而,m6A 修饰是否在调节葡萄糖剥夺下的癌细胞存活中发挥作用尚不清楚。在这里,我们发现葡萄糖剥夺降低了 m6A 修饰水平。增加 m6A 修饰会导致葡萄糖剥夺下肝癌细胞坏死增加,而降低 m6A 修饰则产生相反的效果。综合 m6A-seq 和 RNA-seq 揭示了 m6A 修饰在葡萄糖剥夺下的潜在靶点,包括转录因子 FOSL1;此外,葡萄糖剥夺通过抑制 FOSL1mRNA 降解,在 m6A-YTHDF2 依赖性方式上调 FOSL1,从而减少其外显子 1 和 5'-UTR 区域的 m6A 修饰。功能上,FOSL1 保护肝癌细胞免受葡萄糖剥夺诱导的体外和体内坏死。在机制上,FOSL1 通过结合其启动子转录抑制 ATF3。同时,ATF3 和 MAFF 通过其亮氨酸拉链结构域相互作用形成异二聚体,与 NRF2 竞争结合 NRF2 靶基因启动子中的抗氧化反应元件,从而抑制其转录。因此,FOSL1 减少了 ATF3-MAFF 异二聚体的形成,从而增强了葡萄糖剥夺肝癌细胞中 NRF2 的转录活性和抗氧化能力。因此,FOSL1 减轻了葡萄糖剥夺诱导活性氧积累引起的坏死诱导作用。总之,我们的研究揭示了 m6A-FOSL1-ATF3 轴在葡萄糖剥夺下肝癌细胞坏死中的保护作用,可为癌症治疗提供新的靶点。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索