5-甲基胞嘧啶转移酶NSUN2驱动非小细胞肺癌中NRF2介导的铁死亡抗性。
5-Methylcytosine transferase NSUN2 drives NRF2-mediated ferroptosis resistance in non-small cell lung cancer.
作者信息
Chen Youming, Jiang Zuli, Zhang Chenxing, Zhang Lindong, Chen Huanxiang, Xiao Nan, Bai Lu, Liu Hongyang, Wan Junhu
机构信息
Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
出版信息
J Biol Chem. 2024 Apr;300(4):106793. doi: 10.1016/j.jbc.2024.106793. Epub 2024 Feb 24.
RNA 5-methylcytosine (m5C) is an abundant chemical modification in mammalian RNAs and plays crucial roles in regulating vital physiological and pathological processes, especially in cancer. However, the dysregulation of m5C and its underlying mechanisms in non-small cell lung cancer (NSCLC) remain unclear. Here we identified that NSUN2, a key RNA m5C methyltransferase, is highly expressed in NSCLC tumor tissue. We found elevated NSUN2 expression levels strongly correlate with tumor grade and size, predicting poor outcomes for NSCLC patients. Furthermore, RNA-seq and subsequent confirmation studies revealed the antioxidant-promoting transcription factor NRF2 is a target of NSUN2, and depleting NSUN2 decreases the expression of NRF2 and increases the sensitivity of NSCLC cells to ferroptosis activators both in vitro and in vivo. Intriguingly, the methylated-RIP-qPCR assay results indicated that NRF2 mRNA has a higher m5C level when NSUN2 is overexpressed in NSCLC cells but shows no significant changes in the NSUN2 methyltransferase-deficient group. Mechanistically, we confirmed that NSUN2 upregulates the expression of NRF2 by enhancing the stability of NRF2 mRNA through the m5C modification within its 5'UTR region recognized by the specific m5C reader protein YBX1, rather than influencing its translation. In subsequent rescue experiments, we show knocking down NRF2 diminished the proliferation, migration, and ferroptosis tolerance mediated by NSUN2 overexpression. In conclusion, our study unveils a novel regulatory mechanism in which NSUN2 sustains NRF2 expression through an m5C-YBX1-axis, suggesting that targeting NSUN2 and its regulated ferroptosis pathway might offer promising therapeutic strategies for NSCLC patients.
RNA 5-甲基胞嘧啶(m5C)是哺乳动物RNA中一种丰富的化学修饰,在调节重要的生理和病理过程中发挥着关键作用,尤其是在癌症中。然而,m5C在非小细胞肺癌(NSCLC)中的失调及其潜在机制仍不清楚。在这里,我们发现关键的RNA m5C甲基转移酶NSUN2在NSCLC肿瘤组织中高表达。我们发现NSUN2表达水平的升高与肿瘤分级和大小密切相关,预示着NSCLC患者的预后不良。此外,RNA测序及后续的验证研究表明,抗氧化促进转录因子NRF2是NSUN2的一个靶点,敲低NSUN2可降低NRF2的表达,并在体外和体内增加NSCLC细胞对铁死亡激活剂的敏感性。有趣的是,甲基化RNA免疫沉淀定量PCR分析结果表明,当NSUN2在NSCLC细胞中过表达时,NRF2 mRNA的m5C水平较高,但在NSUN2甲基转移酶缺陷组中无显著变化。机制上,我们证实NSUN2通过特异性m5C阅读蛋白YBX1识别其5'UTR区域内的m5C修饰来增强NRF2 mRNA的稳定性,从而上调NRF2的表达,而不是影响其翻译。在随后的拯救实验中,我们发现敲低NRF2可减弱NSUN2过表达介导的增殖、迁移和铁死亡耐受性。总之,我们的研究揭示了一种新的调控机制,即NSUN2通过m5C-YBX1轴维持NRF2的表达,提示靶向NSUN2及其调控的铁死亡途径可能为NSCLC患者提供有前景的治疗策略。