RNA 假尿苷化是一种重要的转录后修饰，可影响基因表达并影响各种生物功能。尽管 mRNA 假尿苷化具有重要意义，但人们对其在癌症中的作用仍知之甚少。本研究探讨了假尿苷合酶 7 (PUS7) 介导的α-酮戊二酸依赖性双加氧酶 alkB 同源物 3 (ALKBH3) mRNA 假尿苷化对胃癌的影响。采用免疫组织化学和蛋白质印迹法评估人胃癌组织中 PUS7 蛋白水平。使用 3D 集落​​形成测定和皮下异种移植模型检查 PUS7 与胃癌进展之间的关系。进行实时定量 PCR (RT-qPCR)、蛋白质印迹和多核糖体分析分析来研究 PUS7 如何调节 ALKBH3。使用位点特异性假尿苷 (Ψ) 检测分析来识别 ALKBH3 mRNA 上的 Ψ 位点。我们的研究结果表明，与邻近的非肿瘤组织相比，胃癌组织中的 PUS7 显着减少。功能分析表明，PUS7 通过其催化活性抑制胃癌细胞增殖和肿瘤生长。此外，PUS7 通过用假尿苷修饰 U696 位点来增强 ALKBH3 mRNA 的翻译效率，从而减弱肿瘤生长。重要的是，ALKBH3在胃癌中发挥肿瘤抑制因子的作用，其表达与肿瘤组织中PUS7的水平密切相关。ALKBH3 mRNA的PUS7依赖性假尿苷化增强其翻译，从而抑制胃癌进展。这些发现强调了mRNA假尿苷化在癌症生物学中的潜在意义，并提出了胃癌的治疗靶点。PUS7通过其对ALKBH3 mRNA的假尿苷化活性增强ALKBH3的翻译效率，从而抑制胃肿瘤的发生。 PUS7 和 ALKBH3 的表达水平在胃肿瘤中显着相关，可能是胃癌患者潜在的预后预测因子和治疗靶标。© 2024 作者。约翰·威利出版的《临床与转化医学》

RNA pseudouridylation is a critical post-transcriptional modification that influences gene expression and impacts various biological functions. Despite its significance, the role of mRNA pseudouridylation in cancer remains poorly understood. This study investigates the impact of pseudouridine synthase 7 (PUS7)-mediated pseudouridylation of Alpha-ketoglutarate-dependent Dioxygenase alkB Homolog 3 (ALKBH3) mRNA in gastric cancer.Immunohistochemistry and Western blotting were used to assess PUS7 protein levels in human gastric cancer tissues. The relationship between PUS7 and gastric cancer progression was examined using 3D colony formation assays and subcutaneous xenograft models. Real-time quantitative PCR (RT-qPCR), Western blotting, and polysome profiling assays were conducted to investigate how PUS7 regulates ALKBH3. A locus-specific pseudouridine (Ψ) detection assay was used to identify Ψ sites on ALKBH3 mRNA.Our findings indicate a significant reduction of PUS7 in gastric cancer tissues compared to adjacent non-tumour tissues. Functional analyses reveal that PUS7 inhibits gastric cancer cell proliferation and tumour growth via its catalytic activity. Additionally, PUS7 enhances the translation efficiency of ALKBH3 mRNA by modifying the U696 site with pseudouridine, thereby attenuating tumour growth. Importantly, ALKBH3 functions as a tumour suppressor in gastric cancer, with its expression closely correlated with PUS7 levels in tumour tissues.PUS7-dependent pseudouridylation of ALKBH3 mRNA enhances its translation, thereby suppressing gastric cancer progression. These findings highlight the potential significance of mRNA pseudouridylation in cancer biology and suggest a therapeutic target for gastric cancer.PUS7 enhances the translation efficiency of ALKBH3 through its pseudouridylation activity on ALKBH3 mRNA, thereby inhibiting gastric tumourigenesis. The expression levels of PUS7 and ALKBH3 are significantly correlated in gastric tumours, which may be potential prognostic predictors and therapeutic targets for patients with gastric cancer.© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.