Columbia Softball Skull Base Award: A VEGF+ subpopulation of Schwann cells drives vestibular schwannoma tumorigenesis

Friday, May 3, 2024

1:15 PM – 1:19 PM CT

Location: S401ab

Presenting Author(s)

Maxwell T. Laws, MD (he/him/his)

Neurosurgery Resident
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health
Bethesda, MD, US

Co-Author(s)

ZA

Zied Abdullaev, PhD

Post-Doctoral Fellow
Laboratory of Pathology, National Cancer Institute, United States
Kenneth D. Aldape, MD

Senior Scientist
Laboratory of Pathology, National Cancer Institute
Bethesda, MD, United States
CA

Clint Allen, MD

Senior Investigator
Translational Tumor Immunology Program, National Institute on Deafness and Other Communication Disorders, United States
Martin Arhin, n/a

Medical Student
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke
Charlotte, North Carolina, United States
David T. Asuzu, MD, PhD, MPH

Neurosurgery Resident
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke
Bethesda, MD, US
SB

Shyama Bhatt, n/a

Post-baccalaureate Fellow
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
Emma C. Celano, MD

Neurosurgery Resident
Department of Neurological Surgery, MedStar Georgetown University Hospital
Washington, District of Columbia, United States
PC

Paul Clavijo, PhD

Clinical Research Scientist
Translational Tumor Immunology Program, National Institute on Deafness and Other Communication Disorders, United States
AE

Abdel Elkaloun, PhD

Associate Investigator
Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, United States
JG

Jasleen Gandhi, MS

Bioinformatics Data Scientist
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
KJ

Kory Johnson, PhD

Staff Scientist
DIR Bioinformatics Section, National Institute of Neurological Disorders and Stroke, United States
LL

Liyam Laraba, PhD

Research Fellow
Peninsula Medical School, United States
DM

Debjani Mandal, PhD

Staff Scientist
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
DM

Dragan Maric, PhD

Staff Scientist
Flow and Imaging Cytometry Core Facility, National Institute for Neurological Disorders and Stroke, United States
DM

Dustin Mullaney, n/a

Post-baccalaureate Fellow
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
DP

David Parkinson, PhD

Professor
Peninsula Medical School, United States
IR

Ihika Rampalli, n/a

Medical Student
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
AR

Abhik Ray-Chaudhury, MD

Neuropathologist
Laboratory of Pathology, National Cancer Institute, United States
JS

Jack Shern, MD

Lasker Clinical Research Scholar
Pediatric Oncology Branch, Tumor Evolution and Genomics Section, Center for Cancer Research, National Cancer Institute, United States
BS

Bayu Sisay, PhD

Biologist
Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, United States
SS

Stefan Stroica, n/a

Medical Student
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, United States
XZ

Xiyuan Zhang, PhD

Research Fellow
Pediatric Oncology Branch, Tumor Evolution and Genomics Section, Center for Cancer Research, National Cancer Institute, United States

Disclosure(s):

Maxwell T. Laws, MD: No financial relationships to disclose

David T. Asuzu, MD, PhD, MPH: No financial relationships to disclose

Introduction: Vestibular schwannomas (VS) arise from Schwann cells of the eighth cranial nerve, and are associated with severe morbidity. The molecular etiology of these lesions continue to be poorly understood. Our objective was to perform transcriptomic profiling of VS at single cell resolution to investigate novel tumorigenic mechanisms.

Methods: VS specimens were obtained from patients at the time of surgical resection (NF2-associated, n=9; sporadic, n=6). We performed single-cell or single-nucleus RNA sequencing (scRNAseq, n=4; snRNAseq, n=15), as well as assays for transposase-accessible chromatin (snATAC-seq, n=9) and bulk DNA methylation assays (n=15). Specific transcription factor binding was assayed using bulk chromatin immunoprecipitation and sequencing (ChIPseq). We validated our key findings at the mRNA and protein levels using RNAscope (n=9) and multiplex immunocytochemistry (mIHC, n=8). Mechanistic studies were conducted using NF2-null Cre+ mice versus their Cre- control littermates.

Results: We mapped the VS transcriptome at single cell resolution and identified markers for Schwann cells, macrophages, T cells and endothelial cells. We then created epigenome-wide maps using snATAC-seq and DNA methylation, and found several genes with coordinated chromatin availability. DNA hypomethylation and upregulation of pathways for vasculature development and cell migration was seen in VS Schwann cells. We unexpectedly identified a subset of VS Schwann cells with high expression of VEFGA, which was verified with RNAscope and mIHC. These cells were enriched for signaling via YAP1/TAZ-TEAD1, laminin, NRXN and NEGR pathways. Schwann cells showed increased TEAD1 expression as well as chromatin accessibility for TEAD family transcription factor motifs at several loci. We performed ChIPseq and confirmed increased TEAD1 binding at the promoters of (714) genes including EGFR, with strong enrichment for fibrinolytic pathways. NF2-null Cre+ mice showed increased VEGFA expression, and this was partly reversible by pharmacological TEAD inhibition in-vivo.

Conclusion : We performed detailed epigenetic and transcriptomic profiling of sporadic and NF2-associated VS and uncovered mechanistic TEAD1-mediated overexpression of VEGFA in VS. This pathway is reversible using pharmacological treatment. TEAD inhibition may constitute a novel therapeutic target for VS.