大多数子宫内膜癌（EC）患者的早期诊断具有良好的预后，而复发或转移的局部晚期患者预后较差。辅助治疗可以改善高危因素患者的预后。不幸的是，尚未达成具有重要预后价值的分子分类一致性，需要进一步细化。本研究旨在基于子宫内膜癌患者衍生的类器官（PDO）方法，鉴定在EC中具有预后价值的新靶点，并进一步研究其疗效和机制。使用癌症基因组图谱（TCGA）数据库确定SNORD14E表达；利用CCK8、Transwell、伤愈和移植模型实验研究SNORD14E的效应；采用流式细胞术测量细胞凋亡。设计靶向SNORD14E的反义寡核苷酸（ASO），建立EC患者的PDO模型。采用移植模型和PDO模型评估靶向SNORD14E的ASO的效果。通过RNA-seq、Nm-seq和RNA免疫沉淀（RIP）实验验证SNORD14E诱导的剪接和修饰。进行迷你基因记者基因检测验证可变外显子上的剪接和剪接因子。采用Actinomycin-d（Act-D）和低脱氧核糖核苷酸三磷酸浓度下的反转录随后聚合酶链式反应（RTL-P）确认2'-O甲基化修饰对FOXM1的影响。我们发现SNORD14E在EC组织中过表达，高表达的SNORD14E分布在TCGA生物分子分类亚组中没有差异。此外，SNORD14E能够降低EC患者的无病生存期（DFS）和无复发生存期（RFS）。SNORD14E在体外促进了EC细胞的增殖、迁移和侵袭，并抑制了细胞凋亡。靶向SNORD14E的ASO抑制了细胞的增殖、迁移和侵袭，同时促进了细胞凋亡。靶向SNORD14E的ASO抑制了移植模型中的肿瘤生长。TCGA-UCEC数据库显示根据EMSO-ESGO-ESTRO指南推荐进行辅助治疗的中-高风险和高风险患者中，SNORD14E高表达的比例超过50％。接下来，我们根据EMSO-ESGO-ESTRO指南，纳入了8例高风险和高风险EC患者，并成功构建了EC-PDO。靶向SNORD14E的ASO抑制了EC-PDO的生长。从机制上讲，SNORD14E可以识别FOXM1的mRNA，并招募SRSF1促进FOXM1可变外显子VIIa的剪切，导致FOXM1恶性亚型FOXM1b和FOXM1c的过度表达。此外，SNORD14E通过2'-O甲基化修饰FOXM1 mRNA，延长了FOXM1 mRNA的半衰期。由于异常的FOXM1表达引起的β-连环蛋白核红素的核聚集导致EC进展。靶向SNORD14E的ASO可以成为EC的有效治疗方法。© 2023. 意大利国家癌症研究所'Regina Elena'。

Most of the endometrial cancer (EC) patients are diagnosis in early stage with a good prognosis while the patients with locally advanced recurrent or metastatic result in a poor prognosis. Adjuvant therapy could benefit the prognosis of patients with high-risk factors. Unfortunately, the molecular classification of great prognostic value has not yet reached an agreement and need to be further refined. The present study aims to identify new targets that have prognostic value in EC based on the method of EC patient-derived organ-like organs (PDOs), and further investigate their efficacy and mechanism.The Cancer Genome Atlas (TCGA) database was used to determine SNORD14E expression. The effects of SNORD14E were investigated using CCK8, Transwell, wound-healing assays, and a xenograft model experiment; apoptosis was measured by flow cytometry. Antisense oligonucleotide (ASO) targeting SNORD14E was designed and patient-derived organoids (PDO) models in EC patients was established. A xenograft mouse and PDO model were employed to evaluate the effects of ASO targeting SNORD14E. RNA-seq, Nm-seq, and RNA immunoprecipitation (RIP) experiments were employed to confirm the alternative splicing (AS) and modification induced by SNORD14E. A minigene reporter gene assay was conducted to confirm AS and splicing factors on a variable exon. Actinomycin-d (Act-D) and Reverse Transcription at Low deoxy-ribonucleoside triphosphate concentrations followed by PCR (RTL-P) were utilized to confirm the effects of 2'-O methylation modification on FOXM1.We found that SNORD14E was overexpressed in EC tissues and patients with high expressed SNORD14E were distributed in the TCGA biomolecular classification subgroups without difference. Further, SNORD14E could reduce disease-free survival (DFS) and recurrence free survival (RFS) of EC patients. SNORD14E promoted proliferation, migration, and invasion and inhibited the apoptosis of EC cells in vitro. ASOs targeting SNORD14E inhibited cell proliferation, migration, invasion while promoted cell apoptosis. ASOs targeting SNORD14E inhibited tumor growth in the xenograft mouse model. TCGA-UCEC database showed that the proportion of patients with high expression of SNORD14E in middle-high risk and high-risk patients recommended by EMSO-ESGO-ESTRO guidelines for adjuvant therapy is more than 50%. Next, we enrolled 8 cases of high-risk and high-risk EC patients according to EMSO-ESGO-ESTRO guidelines and successfully constructed EC-PDOs. ASOs targeting SNORD14E inhibited the EC-PDO growth. Mechanistically, SNORD14E could recognize the mRNA of FOXM1 and recruit SRSF1 to promote the shearing of the variable exon VIIa of FOXM1, resulting in the overexpression of the FOXM1 malignant subtypes FOXM1b and FOXM1c. In addition, SNORD14E modified FOXM1 mRNA with 2`-O-methylation, which prolonged the half-life of FOXM1 mRNA. The nucleus accumulation of β-catenin caused by aberrant FOXM1 expression led to EC progression.ASO targeting SNORD14E can be an effective treatment for EC.© 2023. Italian National Cancer Institute ‘Regina Elena’.