Targeting the cholinergic-astrocyte axis: A novel strategy for brain metastasis prevention in lung adenocarcinoma.

Brain metastasis (BM) represents a highly detrimental complication of lung adenocarcinoma (LUAD), persisting even following curative resection of primary tumors, with limited effective preventive measures. This study explores the role of cholinergic metabolism, a pathway crucial for both LUAD progression and brain function, in the pathogenesis of BM. Through comprehensive analysis of RNA-sequencing data from 875 LUAD cases and validation using tissue microarrays from 280 patients, we identified cholinergic metabolic activation as a defining characteristic of tumors prone to BM, which is significantly associated with poor survival outcomes. Mechanistic investigations revealed that acetylcholinesterase (AChE) facilitates BM via dual pro-metastatic mechanisms: immunosuppression and disruption of the blood-brain barrier (BBB). Specifically, AChE-induced overactivation of cholinergic receptors triggers excessive Ca2+ influx, leading to ATP release and astrocyte apoptosis, thereby promoting tumor extravasation across the BBB. Furthermore, choline acetyltransferase enhances tumor aggressiveness by stimulating proliferation and migration. Single-cell RNA sequencing of 26 BM sites and 8 normal brain samples, corroborated by in vitro experiments, elucidated tumor-mediated alterations in the BBB and immune cells. Notably, pharmacological intervention with the AChE inhibitor donepezil exhibited substantial efficacy in preventing BM. Collectively, these findings uncover a targetable cholinergic metabolism-astrocyte axis governing BM organotropism, providing a transformative strategy to intercept metastatic progression in LUAD.