Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou, China.
Mol Cancer. 2019 Aug 22;18(1):127. doi: 10.1186/s12943-019-1053-8.
N6-methyladenosine (m6A) methylation, a well-known modification with new epigenetic functions, has been reported to participate in the tumorigenesis of hepatocellular carcinoma (HCC), providing novel insights into the molecular pathogenesis of this disease. However, as the key component of m6A methylation, Wilms tumor 1-associated protein (WTAP) has not been well studied in HCC. Here we investigated the biological role and underlying mechanism of WTAP in liver cancer.
We determined the expression of WTAP and its correlation with clinicopathological features using tissue microarrays and the Cancer Genome Atlas (TCGA) dataset. And we clarified the effects of WTAP on HCC cells using cell proliferation assay, colony formation, Edu assay and subcutaneous xenograft experiments. We then applied RNA sequencing combined with gene expression omnibus (GEO) data to screen candidate targets of WTAP. Finally, we investigated the regulatory mechanism of WTAP in HCC by m6A dot blot assay, methylated RNA immunoprecipitation (MeRIP) assay, dual luciferase reporter assay, RNA immunoprecipitation (RIP) assay and Chromatin immunoprecipitation (ChIP) assay.
We demonstrated that WTAP was highly expressed in HCC which indicated the poor prognosis, and that WTAP expression served as an independent predictor of HCC survival. Functionally, WTAP promoted the proliferation capability and tumor growth of HCC cells in vitro and in vivo. Furthermore, ETS proto-oncogene 1 (ETS1) was identified as the downstream effector of WTAP. The m6A modification regulated by WTAP led to post-transcriptional suppression of ETS1, with the implication of Hu-Antigen R (HuR) as an RNA stabilizer. Then ETS1 was found to inhibit the progression of HCC and could rescue the phenotype induced by WTAP deficiency. Moreover, WTAP modulated the G2/M phase of HCC cells through a p21/p27-dependent pattern mediated by ETS1.
We have identified that WTAP is significantly up-regulated in HCC and promotes liver cancer development. WTAP-guided m6A modification contributes to the progression of HCC via the HuR-ETS1-p21/p27 axis. Our study is the first to report that WTAP-mediated m6A methylation has a crucial role in HCC oncogenesis, and highlights WTAP as a potential therapeutic target of HCC treatment.
N6-甲基腺苷（m6A）甲基化是一种具有新的表观遗传功能的已知修饰，已有报道称其参与肝癌的发生发展，为该疾病的分子发病机制提供了新的见解。然而，作为 m6A 甲基化的关键组成部分，Wilms 肿瘤 1 相关蛋白（WTAP）在肝癌中的研究尚未深入。本研究旨在探讨 WTAP 在肝癌中的生物学作用及其潜在机制。
我们使用组织微阵列和癌症基因组图谱（TCGA）数据集确定了 WTAP 的表达及其与临床病理特征的相关性。通过细胞增殖试验、集落形成试验、Edu 试验和皮下异种移植实验阐明了 WTAP 对肝癌细胞的影响。然后，我们应用 RNA 测序结合基因表达综合数据库（GEO）数据筛选 WTAP 的候选靶标。最后，我们通过 m6A 斑点印迹分析、甲基化 RNA 免疫沉淀（MeRIP）分析、双荧光素酶报告基因分析、RNA 免疫沉淀（RIP）分析和染色质免疫沉淀（ChIP）分析研究了 WTAP 在肝癌中的调控机制。
我们证实 WTAP 在肝癌中高表达，预示着预后不良，WTAP 表达可作为肝癌生存的独立预测因子。功能上，WTAP 促进了 HCC 细胞在体外和体内的增殖能力和肿瘤生长。此外，ETS 原癌基因 1（ETS1）被鉴定为 WTAP 的下游效应物。WTAP 调节的 m6A 修饰导致 ETS1 的转录后抑制，其中 Hu 抗原 R（HuR）作为 RNA 稳定剂。然后发现 ETS1 可抑制 HCC 的进展，并可挽救由 WTAP 缺乏引起的表型。此外，WTAP 通过 ETS1 介导的 p21/p27 依赖性模式调节 HCC 细胞的 G2/M 期。
我们发现 WTAP 在 HCC 中显著上调，并促进肝癌的发展。WTAP 指导的 m6A 修饰通过 HuR-ETS1-p21/p27 轴促进 HCC 的进展。本研究首次报道了 WTAP 介导的 m6A 甲基化在 HCC 致癌中具有重要作用，并强调 WTAP 是 HCC 治疗的潜在治疗靶点。
Zotero 插件
