Wang Jianying, Lv Chenjun, Lu Lu
Department of Pathology Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.
Department of Oncology, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, No. 34, Section 34, Qinhuai District, Nanjing, 210002, Jiangsu, China.
Dig Dis Sci. 2025 Aug 5. doi: 10.1007/s10620-025-09262-x.
Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide due to late-stage diagnosis and therapeutic resistance. Oxidative stress and autophagy play paradoxical roles in GC progression, yet their regulatory mechanisms remain incompletely understood. This study investigates the molecular interplay between chemokine CCL2, oxidative stress, autophagy, and m6A RNA demethylase fat mass and Obesity-associated protein (FTO) in GC pathogenesis.
Oxidative stress-related genes were identified through bioinformatics analysis using the GeneCards and GEO databases. Key hub genes were determined via protein-protein interaction network analysis. The expression of CCL2 and FTO in GC tissues and cell lines was examined by quantitative real-time PCR (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay (ELISA). Functional assays, including colony formation, apoptosis analysis, reactive oxygen species (ROS) measurement, and autophagy detection, were performed in GC cell lines. The m6A regulatory effects of FTO on CCL2 were evaluated using RNA immunoprecipitation (RIP), methylated RNA immunoprecipitation (MeRIP), and RNA stability assays. Furthermore, a GC xenograft model was used to validate in vivo tumorigenic effects.
Bioinformatics analyses identified significant dysregulation of oxidative stress-associated genes, notably highlighting CCL2 as a central hub gene strongly linked to poor prognosis. Experimental validation demonstrated elevated expression of CCL2 in GC tissues, patient serum, and cell lines, correlating with reduced overall survival. Functional assays revealed that CCL2 promotes GC cell proliferation and survival by suppressing autophagy and attenuating oxidative stress-induced apoptosis. Mechanistically, we identified that FTO-mediated m6A demethylation enhances CCL2 mRNA stability and expression, thus facilitating GC progression. Notably, FTO knockdown resulted in increased oxidative stress, enhanced autophagy, and reduced tumorigenicity, which were reversed by CCL2 overexpression. Moreover, YTHDF2, an m6A reader protein, was identified as a negative regulator of CCL2, promoting its degradation and counteracting FTO-mediated stabilization. Additionally, xenograft experiments confirmed the tumor-promoting effect of the FTO-CCL2 axis in vivo.
This study uncovers a novel regulatory mechanism by which FTO-mediated m6A demethylation stabilizes CCL2, leading to oxidative stress reduction, autophagy inhibition, and enhanced GC progression. Targeting the FTO-CCL2 axis may represent a promising therapeutic strategy for GC treatment.
由于晚期诊断和治疗耐药性，胃癌（GC）仍然是全球癌症相关死亡的主要原因。氧化应激和自噬在胃癌进展中发挥着矛盾的作用，但其调控机制仍未完全明确。本研究探讨趋化因子CCL2、氧化应激、自噬和m6A RNA去甲基化酶脂肪量与肥胖相关蛋白（FTO）在胃癌发病机制中的分子相互作用。
通过使用GeneCards和GEO数据库进行生物信息学分析来鉴定氧化应激相关基因。通过蛋白质-蛋白质相互作用网络分析确定关键枢纽基因。采用定量实时PCR（qRT-PCR）、蛋白质印迹法和酶联免疫吸附测定（ELISA）检测CCL2和FTO在胃癌组织和细胞系中的表达。在胃癌细胞系中进行功能实验，包括集落形成、凋亡分析、活性氧（ROS）测定和自噬检测。使用RNA免疫沉淀（RIP）、甲基化RNA免疫沉淀（MeRIP）和RNA稳定性实验评估FTO对CCL2的m6A调控作用。此外，使用胃癌异种移植模型验证体内致瘤作用。
生物信息学分析确定氧化应激相关基因存在显著失调，特别突出CCL2作为与不良预后密切相关的核心枢纽基因。实验验证表明CCL2在胃癌组织、患者血清和细胞系中表达升高，与总生存期缩短相关。功能实验表明CCL2通过抑制自噬和减轻氧化应激诱导的凋亡来促进胃癌细胞增殖和存活。机制上，我们发现FTO介导的m6A去甲基化增强CCL2 mRNA稳定性和表达，从而促进胃癌进展。值得注意的是，FTO敲低导致氧化应激增加、自噬增强和致瘤性降低，而CCL2过表达可逆转这些变化。此外，m6A阅读蛋白YTHDF2被确定为CCL2的负调节因子，促进其降解并抵消FTO介导的稳定性。此外，异种移植实验证实了FTO-CCL2轴在体内的促肿瘤作用。
本研究揭示了一种新的调控机制，即FTO介导的m6A去甲基化使CCL2稳定，导致氧化应激降低、自噬抑制和胃癌进展增强。靶向FTO-CCL2轴可能是一种有前景的胃癌治疗策略。
