METTL3 乙酰化介导的 N6-甲基腺苷减少促进 MTF1 表达和肝癌细胞生长。
Reduced N6-Methyladenosine Mediated by METTL3 Acetylation Promotes MTF1 Expression and Hepatocellular Carcinoma Cell Growth.
机构信息
Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, P. R. China.
Department of the 3rd Ward of Special Treatment, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, 200438, P. R. China.
出版信息
Chem Biodivers. 2022 Nov;19(11):e202200333. doi: 10.1002/cbdv.202200333. Epub 2022 Oct 17.
N6-Methyladenosine (m6A), one of the post-transcriptional modifications of RNA, is important in hepatocellular carcinoma (HCC). However, the mechanism of its regulation remains elusive. We here show that exposure of HCC cells to sulfatide significantly reduced the total mRNA m6A modification. Interestingly, METTL3 protein was robustly acetylated and the binding of METTL3 to MTF1 mRNA, METTL14 or WTAP was weakened in cells treated with sulfatide. Further investigation of the METTL3 complex revealed recruitment of the deacetylase scaffold SIN3B, but a diminished level of histone deacetylase HDAC2, which might enhance the acetylation of METTL3. The m6A abundance in MTF1 mRNA was markedly decreased in cells after sulfatide treatment. The expression of MTF1, a zinc-dependent transcription factor, was significantly strengthened with reduced m6A modification. Sulfatide prolonged the half-life of MTF1 mRNA, while the mutation (A to C) on 7 methylation sites in the 3'UTR of MTF1 mRNA enhanced MTF1 mRNA stability. 3-deaza-adenosine, an m6A methylation inhibitor, significantly reduced the m6A modification of MTF1 mRNA but extended its half-life time. Importantly, overexpression of MTF1 prompted HCC cell proliferation and was associated with poor prognosis. In conclusion, the METTL3-METTL14-WTAP complex was regulated by acetylation induced by sulfatide to control MTF1 m6A methylation and its mRNA transcription, which was important for the tumor growth and migration of HCC.
N6-甲基腺苷(m6A)是 RNA 转录后修饰的一种,在肝细胞癌(HCC)中很重要。然而,其调控机制仍不清楚。我们这里表明,HCC 细胞暴露于神经节苷脂显著降低了总 mRNA m6A 修饰。有趣的是,METTL3 蛋白被强烈乙酰化,并且神经节苷脂处理的细胞中 METTL3 与 MTF1 mRNA、METTL14 或 WTAP 的结合减弱。对 METTL3 复合物的进一步研究揭示了去乙酰化酶支架 SIN3B 的募集,但组蛋白去乙酰化酶 HDAC2 的水平降低,这可能增强了 METTL3 的乙酰化。神经节苷脂处理后,MTF1 mRNA 的 m6A 丰度明显降低。锌依赖性转录因子 MTF1 的表达随着 m6A 修饰的减少而显著增强。神经节苷脂延长了 MTF1 mRNA 的半衰期,而 MTF1 mRNA 3'UTR 上 7 个甲基化位点的突变(A 突变为 C)增强了 MTF1 mRNA 的稳定性。m6A 甲基化抑制剂 3-脱氮腺苷显著降低了 MTF1 mRNA 的 m6A 修饰,但延长了其半衰期。重要的是,MTF1 的过表达促使 HCC 细胞增殖,并与预后不良相关。总之,METTL3-METTL14-WTAP 复合物受神经节苷脂诱导的乙酰化调节,以控制 MTF1 m6A 甲基化及其 mRNA 转录,这对 HCC 的肿瘤生长和迁移很重要。