Gramd2+ alveolar type I cells can give rise to Kras-induced lung adenocarcinoma

ABSTRACT: Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer and arises in the distal lung. LUAD encompasses several pathologic subtypes, including solid, lepidic, papillary, micropapillary, acinar and mixed subtypes, each with differing clinical outcomes or biological behavior. Specifically, lepidic histology is associated with improved survival relative to other LUAD histologies. Yet, the molecular and cellular underpinnings of these subtypes are largely unknown. Understanding which cell populations in the distal lung contribute to LUAD could provide insights for the marked heterogeneity in LUAD pathologic features, clinical presentation and responses to therapy.Recent studies have seen tumor-derived epithelial cells with an AT1 transcriptomic cell signature, suggesting AT1 cells may contribute to a subset of LUAD cases. We tested the ability of AT1 cells to give rise to LUAD by inducing KrasG12D, a known oncogenic driver in human LUAD. Activation of KrasG12D in Gram-domain containing 2 (Gramd2)+ AT1 cells gave rise to multiple LUAD lesions, primarily of papillary histology. In contrast, activation of KrasG12D in Sftpc+ AT2 cells resulted in LUAD lesions of lepidic histology. Immunohistochemistry established Gramd2:KrasG12D lesions were of primary lung origin and not metastatic events. Spatial transcriptomic profiling revealed distinct pathway alterations occurring within Gramd2- and Sftpc-derived LUAD. Immunofluorescence confirmed differences observed in the Spatial transcriptomic analysis in expression patterns and distribution of cell-specific markers between cell of origin, while universal upregulation of the Krt8 intermediate cell state marker was observed. Our results are consistent with Gramd2+ AT1 cells serving as a putative cell of origin for LUAD and suggest that LUAD may be a collection of adenocarcinomas that share a common location within the distal lung, but which arise from different cells of origin.

ORGANISM(S): Mus musculus

PROVIDER: GSE215858 | GEO | 2022/10/19

REPOSITORIES: GEO