多种遗传和表观遗传调控机制在肿瘤发生和发展中起着重要作用。了解不同表观遗传修饰之间的相互作用及其对癌症转录调控的贡献对精准医学至关重要。本研究旨在研究N6-甲基腺苷（m6A）修饰与组蛋白修饰在肺腺癌（LUAD）中的相互作用。通过公共数据库中的染色质特性数据（ATAC-seq，DNase-seq），甲基化RNA免疫沉淀测序（MeRIP-seq）和基因表达数据（RNA-seq），我们发现了一个m6A相关的差异表达基因神经生长因子诱导（VGF），其在LUAD组织和正常肺组织之间表达差异显著。VGF在LUAD组织和细胞中高表达，并与LUAD的预后恶化相关，VGF沉默通过抑制PI3K/AKT/mTOR信号通路来抑制LUAD细胞的恶性表型。通过加权相关网络分析（WGCNA）和整合TCGA-LUAD RNA-seq和m6A甲基转移酶METTL3敲低RNA-seq数据，我们观察到METTL3和VGF之间存在显著的正相关。通过MeRIP-qPCR和双荧光素酶报告实验，我们证明METTL3敲低降低了LUAD细胞中VGF编码区的m6A修饰水平，颜色法m6A定量分析也显示METTL3敲低显著降低了LUAD细胞中的全局m6A修饰水平。有趣的是，我们发现METTL3敲低还通过增加VGF启动子上的H3K36me3修饰降低了VGF的表达。进一步研究揭示METTL3敲低通过在LUAD细胞中甲基化SETD2 mRNA 3'UTR上的m6A位点，上调了组蛋白甲基转移酶SETD2的表达，SETD2是主要的H3K36me3甲基转移酶。总之，我们的结果表明METTL3通过转录（通过组蛋白修饰）和转录后（通过m6A修饰）的方式时空调控LUAD细胞中的VGF表达。这些多种表观遗传机制的协同效应为肿瘤的诊断和精确治疗提供了新机会。© 2023. 版权归BioMed Central Ltd.所有，隶属于Springer Nature.

Multiple genetic and epigenetic regulatory mechanisms play a vital role in tumorigenesis and development. Understanding the interplay between different epigenetic modifications and its contribution to transcriptional regulation in cancer is essential for precision medicine. Here, we aimed to investigate the interplay between N6-methyladenosine (m6A) modifications and histone modifications in lung adenocarcinoma (LUAD).Based on the data from public databases, including chromatin property data (ATAC-seq, DNase-seq), methylated RNA immunoprecipitation sequencing (MeRIP-seq), and gene expression data (RNA-seq), a m6A-related differentially expressed gene nerve growth factor inducible (VGF) was identified between LUAD tissues and normal lung tissues. VGF was significantly highly expressed in LUAD tissues and cells, and was associated with a worse prognosis for LUAD, silencing of VGF inhibited the malignant phenotype of LUAD cells by inactivating the PI3K/AKT/mTOR pathway. Through the weighted correlation network analysis (WGCNA) and integration of TCGA-LUAD RNA-seq and m6A methyltransferase METTL3-knockdown RNA-seq data, a significant positive correlation between METTL3 and VGF was observed. By using the MeRIP-qPCR and dual-luciferase reporter assays, we demonstrated that METTL3 knockdown decreased m6A modification level of VGF coding sequences in LUAD cells, the colorimetric m6A quantification assay also showed that METTL3 knockdown significantly decreased global m6A modification level in LUAD cells. Interestingly, we found that METTL3 knockdown also reduced VGF expression by increasing H3K36me3 modification at the VGF promoter. Further research revealed that METTL3 knockdown upregulated the expression of histone methylase SETD2, the major H3K36me3 methyltransferase, by methylating the m6A site in the 3'UTR of SETD2 mRNA in LUAD cells.Overall, our results reveal that the expression of VGF in LUAD cells is regulated spatio-temporally by METTL3 through both transcriptional (via histone modifications) and post-transcriptional (via m6A modifications) mechanisms. The synergistic effect of these multiple epigenetic mechanisms provides new opportunities for the diagnosis and precision treatment of tumors.© 2023. BioMed Central Ltd., part of Springer Nature.