Zhou Cheng, Zhang Yong, Shi Shi-Ming, Yin Dan, Li Xue-Dong, Shi Ying-Hong, Zhou Jian, Wang Zheng, Chen Qing
Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Fudan University, Shanghai, 200032, China.
Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
Cell Biosci. 2025 May 2;15(1):58. doi: 10.1186/s13578-025-01395-w.
Dysregulation of N6-methyladenosine (m6A) modifications has been implicated in various cancers, including hepatocellular carcinoma (HCC). This study aimed to elucidate the role of m6A modifications in HCC prognosis and the molecular mechanisms involved, particularly focusing on the demethylase FTO.
We analyzed m6A expression in a cohort of 323 HCC patients using immunohistochemical (IHC) staining. The expression of m6A-related genes (FTO, ALKBH5, METTL3, METTL14) was evaluated by qRT-PCR in 120 paired HCC tissues. Further, we established HCC cell lines with altered FTO expression to assess its impact on cell proliferation, invasion, and metastasis through various in vitro assays and in vivo orthotopic HCC mouse models. Statistical analyses included Pearson chi-square test, Kaplan-Meier survival analysis, and both univariate and multivariate Cox regression analyses.
IHC staining revealed elevated m6A levels in HCC tissues compared to adjacent non-tumorous tissues, with 57.3% of HCC patients showing increased m6A expression. High m6A levels were correlated with poorer overall survival (OS) and recurrence-free survival (RFS) rates. FTO, a demethylase, was significantly downregulated in HCC tissues and cell lines, particularly in highly metastatic lines. Overexpression of FTO in HCC cells reduced proliferation, migration, and invasion, whereas FTO knockdown had the opposite effect. In vivo, FTO overexpression decreased tumor growth and metastasis. RNA-Seq analysis identified VEGFA as a key gene downregulated by FTO, implicating its role in angiogenesis and tumor progression.
Our findings suggest that elevated m6A levels are associated with poor prognosis in HCC patients. FTO downregulation contributes to aberrant m6A modifications, promoting HCC progression and metastasis. FTO acts as a tumor suppressor by negatively regulating VEGFA expression, highlighting its potential as a therapeutic target for HCC treatment. These results highlight the significance of m6A modifications in HCC and provide a foundation for future research on targeted therapies.
N6-甲基腺苷（m6A）修饰失调与包括肝细胞癌（HCC）在内的多种癌症有关。本研究旨在阐明m6A修饰在HCC预后中的作用及相关分子机制，尤其聚焦于去甲基化酶FTO。
我们采用免疫组织化学（IHC）染色分析了323例HCC患者队列中的m6A表达。通过qRT-PCR评估了120对HCC组织中m6A相关基因（FTO、ALKBH5、METTL3、METTL14）的表达。此外，我们建立了FTO表达改变的HCC细胞系，通过各种体外实验和体内原位HCC小鼠模型评估其对细胞增殖、侵袭和转移的影响。统计分析包括Pearson卡方检验、Kaplan-Meier生存分析以及单因素和多因素Cox回归分析。
IHC染色显示，与相邻非肿瘤组织相比，HCC组织中的m6A水平升高，57.3%的HCC患者m6A表达增加。高m6A水平与较差的总生存期（OS）和无复发生存期（RFS）率相关。去甲基化酶FTO在HCC组织和细胞系中显著下调，尤其是在高转移细胞系中。HCC细胞中FTO的过表达降低了细胞增殖、迁移和侵袭，而FTO敲低则产生相反的效果。在体内，FTO过表达减少了肿瘤生长和转移。RNA测序分析确定VEGFA是FTO下调的关键基因，提示其在血管生成和肿瘤进展中的作用。
我们的研究结果表明，m6A水平升高与HCC患者预后不良相关。FTO下调导致异常的m6A修饰，促进HCC进展和转移。FTO通过负调控VEGFA表达发挥肿瘤抑制作用，凸显了其作为HCC治疗靶点的潜力。这些结果突出了m6A修饰在HCC中的重要性，并为未来靶向治疗的研究奠定了基础。
