
==== Front
Neurooncol Adv
Neurooncol Adv
noa
Neuro-Oncology Advances
2632-2498
Oxford University Press US

10.1093/noajnl/vdae090.020
vdae090.020
Final Category: Basic Science Leptomeningeal Disease
AcademicSubjects/MED00300
AcademicSubjects/MED00310
BSLM-10 MOLECULAR AND HISTOLOGICAL CHARACTERIZATION OF NSCLC PROGRESSION TO LEPTOMENINGEAL METASTASIS WITH COMORBID INTRAPARENCHYMAL DISEASE
Kandigian Savannah E Yale School of Medicine, New Haven, CT, USA

Chande Sampada Yale School of Medicine, New Haven, CT, USA

Dolezal Darin Yale School of Medicine, New Haven, CT, USA

Tang Tang Yale School of Medicine, New Haven, CT, USA

Wang Dejiang Yale School of Medicine, New Haven, CT, USA

Arnal-Estapé Anna Yale School of Medicine, New Haven, CT, USA

Cheok Stephanie K Medical College of Wisconsin, Milwaukee, WI, USA

McGuone Declan Yale School of Medicine, New Haven, CT, USA

Liu Yang Yale School of Medicine, New Haven, CT, USA

Goldberg Sarah B Yale School of Medicine, New Haven, CT, USA

Blondin Nicholas A Yale School of Medicine, New Haven, CT, USA

Chiang Veronica L Yale School of Medicine, New Haven, CT, USA

Nguyen Don X Yale School of Medicine, New Haven, CT, USA

8 2024
02 8 2024
02 8 2024
6 Suppl 1 2024 SNO/ASCO CNS Metastases Conference i7i7
© The Author(s) 2024. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.
2024
https://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com

Abstract

Leptomeningeal disease (LMD) is a rare form of central nervous system (CNS) metastasis wherein tumor cells invade the cerebrospinal fluid (CSF) filled space that surrounds the brain and spinal cord. For patients with LMD, prognosis is extremely poor even with aggressive treatment. The mechanisms of progression to LMD and the adaptations tumor cells make to survive in this metabolically sparse microenvironment are poorly understood. As 60% of patients with LMD have concurrent or prior parenchymal metastases, our laboratory examined our established murine models of parenchymal metastases for signs of leptomeningeal infiltration. We identify two xenograft non-small cell lung cancer (NSCLC) models of intraparenchymal metastasis following intra-arterial injection that show progression to LMD in a subset of cases. In the H2030-BrM3 model, this occurs de novo, whereas the EGFR-mutant PC9-R2 model progresses to LMD only following onset of resistance to tyrosine kinase inhibitor treatment. Subsequent in vivo passaging of the H2030-BrM3 line through the cerebral lateral ventricles resulted in the H2030-LMD2 cell line, which has high affinity for leptomeningeal metastases and shows extensive perivascular invasion within the brain parenchyma. In vitro, the H2030-LMD2 line shows altered clustering behavior and increased survival when cultured in suspension. RNA-sequencing of this cell line across adherent and suspension culture conditions shows multiple biological processes upregulated in the LMD-tropic line, including chemotaxis, apical junction formation, and TGF-β signaling. Targetable pathways emerging from this analysis will be functionally investigated for their role in promoting progression to LMD, including through validation in the syngeneic KPN1-BrM line which has been selected for its CNS affinity and shows progression to LMD. Spatial sequencing and multiplexed immunofluorescence will furthermore investigate the tumor microenvironment in the perivascular niche and subarachnoid spaces. These findings will be clinically corroborated with molecular characterization of the CSF of patients with leptomeningeal metastases.
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