Wang Sen, Xuan Zhe, Chen Zetian, Xu Penghui, Fang Lang, Li Zheng, Zhang Yigang, Liu Hongda, Wang Linjun, Zhang Diancai, Xu Hao, Yang Li, Xu Zekuan
Gastric Cancer Center, Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Institute of Gastric Cancer, Nanjing Medical University, Nanjing, China.
Int J Biol Sci. 2025 Jan 1;21(1):346-362. doi: 10.7150/ijbs.97464. eCollection 2025.
Chemoresistance severely deteriorates the prognosis of advanced gastric cancer (GC) patients. Several studies demonstrated that (HP)-positive GC patients showed better outcomes after receiving chemotherapy than HP-negative ones. This study aims to confirm the role of HP in GC chemotherapy and to study the underlying mechanisms. The HP infection co-culture with GC cell lines were performed. The mA-seq and NGS were used for bioinformatic analysis. Western Blot, qRT-PCR and IHC were adopted for expressions of METTL3, BRD2 and YTHDF2. The ATPGlow, flow cytometry and IF were used to detect the cell viability, DNA damage, apoptosis and pyroptosis. Luciferase reporter assay and CHIP were applied to explore the mechanisms. The HP infection sensitized GC cells to 5-FU and induced expressions of METTL3 and YTHDF2. The HP infection promoted transcription of METTL3 through NF-κB pathway, therefore promoting the mA modification level. METTL3 induced the mA modification of BRD2 while YTHDF2 promoted the decay of mRNA of BRD2, both of which could promote the apoptosis and pyroptosis induced by 5-FU. In addition, BRD2 regulated the transcription of FLIP by importing FOXO4 into nucleus, thereby inhibiting the activation of Caspase-8, which was considered as the molecular switch of both apoptosis and pyroptosis. HP-induced mA methylation could sensitize gastric cancers to 5-FU with activation of caspase-8 and induced apoptosis and pyroptosis. The Methylated BRD2 activated by NF-κB pathway regulates Caspase-8 by binding to FLIP-promoter FOXO4. This study provides new sights to the HP-positive gastric cancer chemotherapy.
化疗耐药严重恶化了晚期胃癌（GC）患者的预后。多项研究表明，幽门螺杆菌（HP）阳性的GC患者在接受化疗后的预后优于HP阴性患者。本研究旨在证实HP在GC化疗中的作用并探究其潜在机制。进行了HP感染与GC细胞系的共培养。采用mA-seq和NGS进行生物信息学分析。采用蛋白质免疫印迹法、实时定量聚合酶链反应和免疫组化法检测METTL3、BRD2和YTHDF2的表达。采用ATP发光法、流式细胞术和免疫荧光法检测细胞活力、DNA损伤、凋亡和焦亡。应用荧光素酶报告基因检测和染色质免疫沉淀法探究其机制。HP感染使GC细胞对5-氟尿嘧啶敏感并诱导METTL3和YTHDF2的表达。HP感染通过NF-κB途径促进METTL3的转录，从而提高mA修饰水平。METTL3诱导BRD2的mA修饰，而YTHDF2促进BRD2 mRNA的降解，二者均能促进5-氟尿嘧啶诱导的凋亡和焦亡。此外，BRD2通过将FOXO4导入细胞核来调节FLIP的转录，从而抑制Caspase-8的激活，Caspase-8被认为是凋亡和焦亡的分子开关。HP诱导的mA甲基化可通过激活Caspase-8使胃癌对5-氟尿嘧啶敏感，并诱导凋亡和焦亡。由NF-κB途径激活的甲基化BRD2通过与FLIP启动子FOXO4结合来调节Caspase-8。本研究为HP阳性胃癌化疗提供了新的视角。
