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Biology subjects

Erickson, A. W.

Publications and source records attributed to Erickson, A. W..

4 recordsLinked to original sources

Medulloblastoma Forms Symbiotic Metabolic Partnerships with Macrophages to Establish Leptomeningeal Metastases

Leptomeningeal metastases are the primary source of morbidity and mortality for pediatric medulloblastoma patients. Due to limited surgical sampling of metastases in patients, little is understood of the mechanisms of metastasis. Here, we identify biologically distinct quiescent small metastases (designated as micrometastases) and mitotically active larger metastases (macrometastases). Macrometastases are more metabolically active than micrometastases and contain higher levels of lipids, particularly cholesterol. Macrometastases secrete CXCL12, which attracts lipid-laden macrophages into the tumor. Lipid-laden macrophages upregulate the cholesterol transporter ABCG1, promoting the efflux of free cholesterol, which is then taken up by tumor cells via the HDL receptor SCARB1. CXCL12-driven macrophage recruitment and exogenous cholesterol are sufficient and necessary to drive progression of medulloblastoma leptomeningeal metastases in vivo. High fat diets drive metastatic progression in vivo. Dietary or pharmacological interventions targeting the CXCL12-SCARB1-cholesterol axis represent therapeutic strategies to either prevent or treat medulloblastoma leptomeningeal metastases.

cancer biology↗

Ependymomas are cancers of the pre-neural crest/roof plate lineage

Distinct molecular variants of the brain cancer ependymoma are distributed along the rostral-caudal extent of the central nervous system (CNS). Historically proposed to arise from ventricular ependyma, recent studies have suggested conflicting cellular origins, including the neural radial glia and the roof plate lineages. Using single-cell transcriptomics, immunohistochemistry, and lineage tracing, we demonstrate that ependymomas across all CNS compartments transcriptionally mirror MSX1+ve pre-neural crest/roof plate (Pre-NC/RP) lineage derivatives. Ependymoma subgroups recapitulate the spatial and molecular diversity of regional Pre-NC/RP populations, while retaining conserved MSX1 expression. Expression of the oncogenic fusion ZFTA-RELA within the murine Pre-NC/RP lineage generated tumors that faithfully resembled human ependymoma. These findings identify a common embryonic cellular origin for ependymomas and reconcile previously conflicting models of tumorigenesis.

developmental biology↗

Inferred Developmental Origins of Brain Tumors from Single Cell RNA-Sequencing Data

The reactivation of neurodevelopmental programs in cancer highlights parallel biological processes that occur in both normal development and brain tumors. Achieving a deeper understanding of how dysregulated developmental factors play a role in the progression of brain tumors is therefore crucial for identifying potential targets for therapeutic interventions. Single-cell RNA sequencing (scRNA-Seq) provides an opportunity to understand how developmental programs are dysregulated and reinitiated in brain tumors at single-cell resolution. Here, we introduce COORS (Cell Of ORigin like CellS), as a computational tool trained on developmental human brain single-cell datasets that enables annotation of "developmental-like" cell states in brain tumor cells. Applying COORS to various brain cancer datasets, including medulloblastoma (MB), glioma, and diffuse midline glioma (DMG), we identified developmental-like cells that represent putative cells of origin in these tumors. Our work adds to our cumulative understanding of brain tumor heterogeneity and helps pave the way for tailored treatment strategies.

bioinformatics↗

In vivo functional genomics identifies essentiality of potassium homeostasis in medulloblastoma

The identification of cancer maintenance genes--driver genes essential to tumor survival--is fundamental for developing effective cancer therapy. Transposon-based insertional mutagenesis screens can identify cancer driver genes broadly but not discriminate maintenance from progression or initiation drivers, which contribute to cancer phenotypes and tumorigenesis, respectively. We engineered a nested, double-jumping transposon system to first dysregulate gene expression during tumorigenesis and then restore gene expression following tumor induction, allowing for genome-wide screening of maintenance essentiality in vivo. In a mouse model of medulloblastoma, the most common pediatric malignancy, insertion and remobilization of this nested transposon uncovers potassium channel genes as recurrent maintenance drivers. In human medulloblastoma, KCNB2 is the most overexpressed potassium channel across Group 3, Group 4, and SHH subgroups, and Kcnb2 knockout in mice diminishes the replicative potential of medulloblastoma-propagating cells to mitigate tumor growth. Kcnb2 governs potassium homeostasis to regulate plasma membrane tension-gated EGFR signaling, which drives proliferative expansion of medulloblastoma-propagating cells. Thus, our novel transposon system reveals potassium homeostasis as essential to tumor maintenance through biomechanical modulation of membrane signaling.

cancer biology↗