Modeling diverse genetic subtypes of lung adenocarcinoma with a next-generation alveolar type 2 organoid platform [2D and 3D]

Lung cancer is the leading cause of cancer-related death worldwide. Lung adenocarcinoma (LUAD), the most common histological subtype, accounts for 40% of all cases. While existing genetically engineered mouse models (GEMMs) recapitulate the histological progression and transcriptional evolution of human LUAD, they are time-consuming and technically demanding. In contrast, cell line transplant models are fast and flexible, but these models fail to capture the full spectrum of disease progression. Organoid technologies provide a means to create next-generation cancer models that integrate the most advantageous features of autochthonous and transplant-based systems. However, robust and faithful LUAD organoid platforms are currently lacking. Here, we describe optimized conditions to continuously expand murine alveolar type 2 cells (AT2), a prominent cell-of-origin for LUAD, in organoid culture. These organoids display canonical features of AT2 cells, including marker gene expression, the presence of lamellar bodies, and an ability to differentiate into the AT1 lineage. We used this system to develop flexible and versatile immunocompetent organoid-based models of KRAS, BRAF, and ALK-mutant LUAD. Notably, organoid-based tumors display extensive burden and complete penetrance, and are histopathologically indistinguishable from their autochthonous counterparts. Altogether, this organoid platform is a powerful, versatile new model system to study LUAD. Comparative gene expression profiling analysis of RNA-seq data for eGFP+/- cells.

肺癌是全球范围内与癌症相关死亡的首要病因。肺腺癌（Lung adenocarcinoma, LUAD）是最常见的组织学亚型，占所有肺癌病例的40%。尽管现有的基因工程小鼠模型（genetically engineered mouse models, GEMMs）能够重现人类肺腺癌的组织学进展与转录组演化过程，但该类模型耗时较长且技术要求较高。相比之下，细胞系移植模型虽具备快速、灵活的优势，却无法完整捕获疾病进展的全谱系特征。类器官技术为构建下一代癌症模型提供了途径，这类模型可整合自发瘤模型与移植模型的最优特性。然而，目前仍缺乏稳定且能忠实模拟肺腺癌的类器官平台。在此研究中，我们描述了可在类器官培养体系中持续扩增小鼠肺泡Ⅱ型细胞（murine alveolar type 2 cells, AT2）的优化培养条件——该细胞是肺腺癌的主要起源细胞之一。此类类器官具备肺泡Ⅱ型细胞的典型特征，包括标记基因表达、板层小体的存在，以及向肺泡Ⅰ型细胞谱系分化的能力。我们利用该体系构建了具备免疫活性的、灵活通用的类器官模型，可用于研究携带KRAS、BRAF及ALK突变的肺腺癌。值得注意的是，类器官来源的肿瘤具有广泛的负荷量与完全的外显率，且在组织病理学上与自发瘤模型的肿瘤无明显差异。综上，该类器官平台是一款功能强大、用途广泛的新型肺腺癌研究模型体系。本研究针对eGFP±细胞的RNA测序（RNA-seq）数据进行了比较基因表达谱分析。