Department of Hematology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China.
Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China; National Clinical Research Center for Hematologic Diseases, the First Affiliated Hospital of Soochow University, Suzhou 251006, China.
J Adv Res. 2024 Sep;63:17-33. doi: 10.1016/j.jare.2023.10.010. Epub 2023 Oct 19.
Epigenetic alterations play crucial roles in diffuse large B-cell lymphoma (DLBCL). Disturbances in lipid metabolism contribute to tumor progression. However, studies in epigenetics, especially its critical regulator YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), on lipid metabolism regulation in DLBCL are unidentified.
Elucidate the prognostic value and biological functions of YTHDF2 in DLBCL and illuminate the underlying epigenetic regulation mechanism of lipid metabolism by YTHDF2 in DLBCL development.
The expression and clinical value of YTHDF2 in DLBCL were performed in public databases and clinical specimens. The biological functions of YTHDF2 in DLBCL were determined in vivo and in vitro through overexpression and CRISPR/Cas9-mediated knockout of YTHDF2. RNA sequencing, lipidomics, methylated RNA immunoprecipitation sequencing, RNA immunoprecipitation-qPCR, luciferase activity assay, and RNA stability experiments were used to explore the potential mechanism by which YTHDF2 contributed to DLBCL progression.
YTHDF2 was highly expressed in DLBCL, and related to poor prognosis. YTHDF2 overexpression exerted a tumor-promoting effect in DLBCL, and knockdown of YTHDF2 restricted DLBCL cell proliferation, arrested cell cycle in the G2/M phase, facilitated apoptosis, and enhanced drug sensitivity to ibrutinib and venetoclax. In addition, YTHDF2 knockout drastically suppressed tumor growth in xenograft DLBCL models. Furthermore, a regulatory role of YTHDF2 in ceramide metabolism was identified in DLBCL cells. Exogenous ceramide effectively inhibited the malignant phenotype of DLBCL cells in vitro. The binding of YTHDF2 to m6A sites on alkaline ceramidase 2 (ACER2) mRNA promoted its stability and expression. Enhanced ACER2 expression hydrolyzed ceramides, disrupting the balance between ceramide and sphingosine-1-phosphate (S1P), activating the ERK and PI3K/AKT pathways, and leading to DLBCL tumorigenesis.
This study demonstrated that YTHDF2 contributed to the progression of DLBCL by regulating ACER2-mediated ceramide metabolism in an m6A-dependent manner, providing novel insights into targeted therapies.
表观遗传改变在弥漫性大 B 细胞淋巴瘤（DLBCL）中起着关键作用。脂质代谢紊乱有助于肿瘤进展。然而，在 DLBCL 中，关于表观遗传学，特别是其关键调节因子 YTH N6-甲基腺苷 RNA 结合蛋白 2（YTHDF2）对脂质代谢调控的研究尚不清楚。
阐明 YTHDF2 在 DLBCL 中的预后价值和生物学功能，并阐明 YTHDF2 在 DLBCL 发展过程中对脂质代谢的潜在表观遗传调控机制。
在公共数据库和临床标本中检测 YTHDF2 在 DLBCL 中的表达和临床价值。通过过表达和 CRISPR/Cas9 介导的 YTHDF2 敲除，在体内和体外确定 YTHDF2 在 DLBCL 中的生物学功能。采用 RNA 测序、脂质组学、甲基化 RNA 免疫沉淀测序、RNA 免疫沉淀-qPCR、荧光素酶活性测定和 RNA 稳定性实验，探讨 YTHDF2 促进 DLBCL 进展的潜在机制。
YTHDF2 在 DLBCL 中高表达，并与不良预后相关。YTHDF2 的过表达在 DLBCL 中发挥促肿瘤作用，而 YTHDF2 的敲低则限制了 DLBCL 细胞的增殖，使细胞周期在 G2/M 期停滞，促进细胞凋亡，并增强对伊布替尼和 venetoclax 的药物敏感性。此外，YTHDF2 敲除明显抑制异种移植 DLBCL 模型中的肿瘤生长。此外，还鉴定了 YTHDF2 在神经酰胺代谢中的调节作用在 DLBCL 细胞中。外源性神经酰胺在体外有效抑制了 DLBCL 细胞的恶性表型。YTHDF2 与碱性神经酰胺酶 2（ACER2）mRNA 上的 m6A 结合位点的结合促进了其稳定性和表达。增强的 ACER2 表达水解神经酰胺，破坏神经酰胺和鞘氨醇-1-磷酸（S1P）之间的平衡，激活 ERK 和 PI3K/AKT 途径，导致 DLBCL 肿瘤发生。
本研究表明，YTHDF2 通过依赖于 m6A 的方式调节 ACER2 介导的神经酰胺代谢促进 DLBCL 的进展，为靶向治疗提供了新的见解。
