Zhang Yong, Tian Rongrong, Feng Xudong, Xiao Bin, Yue Qi, Wei Jinling, Wang Li
The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, China.
The First People's Hospital of Yunnan Province, Kunming, 650032, Yunnan, China; The Affiliated Hospital of Kunming University of Science and Technology, Kunming, 650032, Yunnan, China.
Biochem Biophys Res Commun. 2025 May 1;761:151714. doi: 10.1016/j.bbrc.2025.151714. Epub 2025 Mar 28.
Radiation-induced bystander effects (RIBE) increase the complexity of radiation therapy (RT). m6A modification is implicated in ionizing radiation damage. This study aims to investigate the RIBE and the mechanism after promoting m6A modification.
Lung adenocarcinoma cells were treated to simulate a hypoxic and 0.5 Gy RT environment. The expression levels of METTL3, METTL14, and YTDHF2 were quantified by RT-qPCR. Paracellular clonogenicity and the expression of 53BP1 and γ-H2AX were assessed by immunofluorescence. The proliferative rate was evaluated by CCK-8. Probes were employed to measure ROS levels. Micronucleus formation was evaluated microscopically. m6A-mRNA/lncRNA microarrays, MERIP-PCR, RT-qPCR, and ELISA were utilized to assess m6A modification levels and the expression of inflammatory factors.
m6A modification levels were significantly diminished under hypoxic, low-dose irradiation conditions. The overexpression of METTL3 in irradiated cancer cells resulted in increased clonogenicity and proliferation of paracellular cells, suppressed the rate of micronucleus formation, and reduced DNA damage by modulating the inflammatory response. m6A-mRNA/lncRNA microarray analyses revealed a higher correlation of inflammatory molecules NF-κB and TRAF6. Further analysis demonstrated that the m6A modification levels of inflammation-related factors such as IL-6, TLR4, NF-κB2, and TRAF6 were significantly up-regulated, while their mRNA expression levels were notably decreased. Additionally, the expression of IL-10 and TGF-β was significantly reduced, with no significant changes observed in IL-1 expression.
The overexpression of METTL3 facilitated m6A modification and mitigated the inflammatory response, thereby promoting paracellular cloning and proliferation, inhibiting micronucleus formation, alleviating DNA damage, and achieving the objective of suppression of RIBE.
辐射诱导的旁观者效应（RIBE）增加了放射治疗（RT）的复杂性。m6A修饰与电离辐射损伤有关。本研究旨在探讨促进m6A修饰后的RIBE及其机制。
处理肺腺癌细胞以模拟缺氧和0.5 Gy放射治疗环境。通过RT-qPCR定量METTL3、METTL14和YTDHF2的表达水平。通过免疫荧光评估细胞间克隆形成能力以及53BP1和γ-H2AX的表达。通过CCK-8评估增殖率。使用探针测量活性氧水平。通过显微镜评估微核形成。利用m6A-mRNA/lncRNA微阵列、甲基化RNA免疫沉淀PCR（MERIP-PCR）、RT-qPCR和酶联免疫吸附测定（ELISA）评估m6A修饰水平和炎症因子的表达。
在缺氧、低剂量照射条件下，m6A修饰水平显著降低。照射癌细胞中METTL3的过表达导致细胞间克隆形成能力增加和细胞增殖，抑制微核形成率，并通过调节炎症反应减少DNA损伤。m6A-mRNA/lncRNA微阵列分析显示炎症分子NF-κB和TRAF6的相关性更高。进一步分析表明，IL-6、TLR4、NF-κB2和TRAF6等炎症相关因子的m6A修饰水平显著上调，而它们的mRNA表达水平显著降低。此外，IL-10和TGF-β的表达显著降低，IL-1表达无显著变化。
METTL3的过表达促进了m6A修饰并减轻了炎症反应，从而促进细胞间克隆和增殖，抑制微核形成，减轻DNA损伤，实现抑制RIBE的目的。
