胰腺导管腺癌（PDAC）是一种具有较高肿瘤内异质性的致命恶性肿瘤。目前对PDAC缺乏有效的治疗方法。Entosis是一种由细胞内细胞结构（CIC）介导的非凋亡调节细胞死亡形式，在多种癌症中已有报道。然而，Entosis在PDAC进展中的作用尚不清楚。我们利用免疫组织化学和免疫荧光染色评估CIC。通过悬浮培养诱导CIC的形成。通过荧光活化细胞分选和单细胞RNA测序（scRNA-seq），我们收集了形成Entosis的细胞并分析其差异基因表达。采用细胞功能实验和小鼠模型研究恶性表型。通过回顾性分析建立了Entosis与PDAC之间的临床相关性。Entosis与PDAC患者不良预后相关，并且在肝转移中更为常见而不是初发肿瘤中。scRNA-seq结果显示与亲本细胞相比，形成Entosis的细胞中有几个癌基因上调。这些高度Entosis的细胞在体外和体内表现出更高的致癌特性。NET1（神经上皮细胞转化基因1）是一个与Entosis相关的基因，在PDAC进展中起关键作用，并与不良结局相关。Entosis与PDAC进展相关，尤其是在肝转移中。NET1是一个新验证的与Entosis相关的基因，也是不良预后的分子标志物。PDAC细胞通过Entosis产生上调NET1的高侵袭亚群，可能推动PDAC进展。© 2023年AGA学会。由Elsevier Inc.发表，版权所有。

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy with high intratumoral heterogeneity. There is a lack of effective therapeutics for PDAC. Entosis, a form of nonapoptotic regulated cell death mediated by cell-in-cell structures (CICs), has been reported in multiple cancers. However, the role of entosis in PDAC progression remains unclear.We evaluated CICs using immunohistochemistry and immunofluorescence staining. The formation of CICs was induced by suspension culture. Through fluorescence-activated cell sorting and single-cell RNA sequencing (scRNA-seq), we collected entosis-forming cells and analyzed their differential gene expression. Cell functional assays and mouse models were used to investigate malignant phenotypes. Clinical correlations between entosis and PDAC were established by retrospective analysis.Entosis was associated with an unfavorable PDAC patient prognosis and was more prevalent in liver metastases than in primary tumors. The scRNA-seq results revealed that several oncogenes were upregulated in entosis-forming cells compared with parental cells. These highly entotic cells demonstrated higher oncogenic characteristics in vitro and in vivo. NET1, neuroepithelial cell transforming gene 1, is an entosis-related gene that plays a pivotal role in PDAC progression and is correlated with poor outcomes.Entosis is correlated with PDAC progression, especially in liver metastasis. NET1 is a newly validated entosis-related gene and a molecular marker of poor outcomes. PDAC cells generate a highly aggressive subpopulation marked by upregulated NET1 via entosis, which may drive PDAC progression.Copyright © 2023 AGA Institute. Published by Elsevier Inc. All rights reserved.