虽然 p53 突变发生在 Barrett 食管 (BE) 进展为食管腺癌 (EAC) 的早期，但它们在胃贲门干细胞中的作用仍不清楚。本研究探讨了 p53 突变对 BE 至 EAC 中贲门祖细胞的命运和功能的影响我们使用带有 Trp53 突变 (R172H) 的 BE 小鼠模型 (L2-IL1β) 来研究 p53 对 Cck2r 心脏祖细胞的影响。我们采用谱系追踪、病理分析、类器官培养、单细胞 RNA 测序 (scRNA-seq) 和计算分析来研究祖细胞行为、分化模式和肿瘤进展的变化。此外，我们对分选的化生和突变祖细胞进行了原位移植，以评估它们在体内的致瘤潜力。p53突变充当扩展祖细胞并抑制其向化生分化的开关，但仅限于慢性损伤。在 L2-IL1β 小鼠中，p53 突变增加了祖细胞的扩增和谱系追踪，从化生转变为不典型增生。 scRNA-seq 揭示发育不良细胞直接由突变祖细胞产生，而不是通过化生进展。在体外，p53突变增强了BE祖细胞的类器官形成效率、生长、DNA损伤抵抗力和向非整倍体的进展。分选的化生细胞生长不良，没有进展为不典型增生，而突变祖细胞在原位移植中引起不典型增生。计算分析表明，p53 突变通过 Notch 激活抑制干细胞分化。p53 突变通过增加未分化心脏祖细胞的扩张和适应性并防止其分化为化生，从而促进 BE 进展。© 作者（或其雇主）2024 . 禁止商业重复使用。请参阅权利和权限。英国医学杂志出版。

While p53 mutations occur early in Barrett's oesophagus (BE) progression to oesophageal adenocarcinoma (EAC), their role in gastric cardia stem cells remains unclear.This study investigates the impact of p53 mutation on the fate and function of cardia progenitor cells in BE to EAC progression, particularly under the duress of chronic injury.We used a BE mouse model (L2-IL1β) harbouring a Trp53 mutation (R172H) to study the effects of p53 on Cck2r+ cardia progenitor cells. We employed lineage tracing, pathological analysis, organoid cultures, single-cell RNA sequencing (scRNA-seq) and computational analyses to investigate changes in progenitor cell behaviour, differentiation patterns and tumour progression. Additionally, we performed orthotopic transplantation of sorted metaplastic and mutant progenitor cells to assess their tumourigenic potential in vivo.The p53 mutation acts as a switch to expand progenitor cells and inhibit their differentiation towards metaplasia, but only amidst chronic injury. In L2-IL1β mice, p53 mutation increased progenitors expansion and lineage-tracing with a shift from metaplasia to dysplasia. scRNA-seq revealed dysplastic cells arise directly from mutant progenitors rather than progressing through metaplasia. In vitro, p53 mutation enhanced BE progenitors' organoid-forming efficiency, growth, DNA damage resistance and progression to aneuploidy. Sorted metaplastic cells grew poorly with no progression to dysplasia, while mutant progenitors gave rise to dysplasia in orthotopic transplantation. Computational analyses indicated that p53 mutation inhibited stem cell differentiation through Notch activation.p53 mutation contributes to BE progression by increasing expansion and fitness of undifferentiated cardia progenitors and preventing their differentiation towards metaplasia.© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.