Biology subjects

Horbinski, C. M.

Publications and source records attributed to Horbinski, C. M..

6 recordsLinked to original sources

bioRxiv2026

Murine modeling of IDH-mutant 1p/19q-codeleted oligodendroglioma reveals genotype specific phenotypes

Oligodendroglioma is a primary central nervous system tumor classified by the presence of isocitrate dehydrogenase (IDH) mutations and codeletion of 1p/19q. Here we describe the generation of an IDH-mutant 1p/19q-codeleted oligodendroglioma mouse model using in utero electroporation. We identified IDH1R132H, PIK3CAE545K, CicKO, Fubp1KO and Cdkn2aKO as the optimal combination (termed OligoCdkn2a) to drive fully penetrant tumors that histologically resemble human grade II/III IDH-mutant, 1p/19q-codeleted oligodendroglioma. Replacing Cdkn2a with Trp53 loss in this mouse model shifted tumor histology towards high grade astrocytoma. OligoCdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. OligoCdkn2a tumors represent the first mouse model system to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas, offering a platform to further dissect tumor biology and test new therapeutic strategies.

cancer biology↗

bioRxiv2025

High Dimensional Proteomic Multiplex Imaging of the Central Nervous System Using the COMET(TM) System

Sequential multiplex methodologies such as Akoya CODEX, Miltenyi MACSima, Rarecyte Orion, and others require modification of the antibodies by conjugation to an oligo or a specific fluorophore which means the use of off-the-shelf reagents is not possible. Modifications of these antibodies are typically performed via reduction chemistry and thus require verification and validation post-modification. Fixed panels are therefore developed due to various limitations including spectral overlap that creates spectral unmixing issues, steric hindrance, harsh antibody removal, and tissue degradation throughout the labeling. As such, a complex interrogation evaluating multiple study hypotheses and/or endpoints requires the development of sequential panels, reconstruction, and realignment of the tissue that necessitate a z-stack strategy. Standardized antibody panels are typically fixed and require substantial validation efforts to modify a single target and thus do not evolve with the pace of research interests. To increase the throughput of profiling cells within the human central nervous system (CNS), we developed and validated a CNS-specific library with an associated analysis platform using the newly developed Lunaphore COMETTM platform. The COMETTM is an automated staining/imaging instrument integrating a reagent deck for staining buffers and off-the-shelf label-free primary antibodies and fluorophore-labeled secondary antibodies, which feed into a circular plate holding up to 4 slides that are automatically imaged in microscope-operated control software. For this study, standard formalin fixed paraffin embedded histology slides are used. However, the COMET is capable of imaging fresh-frozen samples using specialized settings. Our methodologies address an unmet need in the neuroscience field while leveraging prior developmental efforts in the domain of immunology spatial profiling. Cataloging and validating a large series of antibodies on the COMET along with developing CNS autofluorescence management strategies while optimizing standard operating procedures have allowed for the visualization at the subcellular level. Forty analytes can be used to analyze one specimen which has clinical utility in cases in which the CNS can only be sampled by biopsy. CNS biopsies, depending on the anatomical location, can have limited available volume to a degree that requires prioritization and restriction to select analysis. In-depth bioinformatic imaging analysis can be done using standard bioinformatic tools and software such as Visiopharm(R). These results establish a general framework for imaging and quantifying cell populations and networks within the CNS while providing the scientific community with standard operating procedures.

bioinformatics↗

bioRxiv2023

NOTCH3 drives meningioma tumorigenesis and resistance to radiotherapy

Meningiomas are the most common primary intracranial tumors1-3. Treatments for patients with meningiomas are limited to surgery and radiotherapy, and systemic therapies remain ineffective or experimental4,5. Resistance to radiotherapy is common in high-grade meningiomas6, and the cell types and signaling mechanisms driving meningioma tumorigenesis or resistance to radiotherapy are incompletely understood. Here we report NOTCH3 drives meningioma tumorigenesis and resistance to radiotherapy and find NOTCH3+ meningioma mural cells are conserved across meningiomas from humans, dogs, and mice. NOTCH3+ cells are restricted to the perivascular niche during meningeal development and homeostasis and in low-grade meningiomas but are expressed throughout high-grade meningiomas that are resistant to radiotherapy. Integrating single-cell transcriptomics with lineage tracing and imaging approaches across mouse genetic and xenograft models, we show NOTCH3 drives tumor initiating capacity, cell proliferation, angiogenesis, and resistance to radiotherapy to increase meningioma growth and reduce survival. An antibody stabilizing the extracellular negative regulatory region of NOTCH37,8 blocks meningioma tumorigenesis and sensitizes meningiomas to radiotherapy, reducing tumor growth and improving survival in preclinical models. In summary, our results identify a conserved cell type and signaling mechanism that underlie meningioma tumorigenesis and resistance to radiotherapy, revealing a new therapeutic vulnerability to treat meningiomas that are resistant to standard interventions.

cancer biology↗

bioRxiv2021

A New Mouse Model of Diffuse Midline Glioma to Test Targeted Immunotherapies

BACKGROUNDDiffuse midline gliomas remain incurable, with consistently poor outcomes in children despite radiotherapy. Immunotherapeutic approaches hold promise, with the integration of the hosts immune system fundamental to their design. Here, we describe a new, genetically engineered immunocompetent model that incorporates interleukin 13 receptor alpha 2 (IL13R2), a tumor-associated antigen, which is suitable for further evaluation of the antitumor activity of IL13R2-targeted immunotherapeutics in preclinical studies. METHODSThe RCAS-Tv-a delivery system was used to induce gliomagenesis through overexpression of PDGFB and p53 deletion with and without human IL13R2 in Nestin-Tva; p53fl/fl mice. Hindbrain or cerebral cortex nestin progenitors of neonatal pups were infected with Cre recombinase and PDGFB+IL13R2 or Cre recombinase and PDGFB to model diffuse midline glioma and supratentorial high-grade glioma, respectively. Immunoblotting and flow cytometry was used to confirm target expression. Kaplan-Meier survival curves were established to compare tumor latency in both models. Tumor tissue was analyzed through immunohistochemistry and H&E staining. Cell lines generated from tumor-bearing mice were used for in vitro studies and orthotopic injections. RESULTSThe protein expression of PDGFB and IL13R2 was confirmed by flow cytometry and western blot. In both groups, de novo tumors developed without significant difference in median survival between PDGFB and p53 loss (n=25, 40 days) and PDGFB, IL13R2, and p53 loss (n=33, 38 days, p=0.62). Tumors demonstrated characteristics of high-grade glioma such as infiltration, palisading necrosis, microvascular proliferation, high Ki-67 index, heterogeneous IL13R2 expression, and CD11b+ macrophages, along with a low proportion of CD3+ T cells. Orthotopic tumors developed from cell lines retained histopathological characteristics of de novo tumors. Mice orthotopically implanted with cells in the hindbrain or right cortex showed a median survival of 42 days and 41 (p=0.56) days, respectively. CONCLUSIONGeneration of de novo tumors using the RCAS-Tv-a delivery system was successful, with tumors possessing histopathologic features common to pediatric diffuse gliomas. The development of these models opens the opportunity for preclinical assessment of IL13R2-directed immunotherapies with the potential for clinical translation.

cancer biology↗

bioRxiv2020

Myeloid-derived suppressor cell subsets drive glioblastoma growth in a sex-specific manner

Myeloid-derived suppressor cells (MDSCs) that block anti-tumor immunity are elevated in glioblastoma (GBM) patients. However, the distinct contribution of monocytic (mMDSC) versus granulocytic (gMDSC) subsets has yet to be determined. We observed that mMDSCs were enriched in the male tumor microenvironment, while gMDSCs were elevated in the circulation of female GBM models. Depletion of peripheral gMDSCs extended the survival only in female mice. Using gene expression signatures coupled with network medicine analysis, we demonstrated in pre-clinical models that mMDSCs could be targeted with anti-proliferative agents in males, whereas gMDSC function in females could be inhibited by IL-1{beta} blockade. Analysis of patient data confirmed that proliferating mMDSCs were the predominant population in male tumors, and that a high gMDSC/IL-1{beta} gene signature correlated with poor prognosis of female patients. These findings demonstrate that MDSC subsets differentially drive immune suppression in a sex-specific manner and can be leveraged for therapeutic intervention in GBM. Statement of SignificanceSexual dimorphism at the level of MDSC subset prevalence, localization and gene expression profile comprises a therapeutic opportunity. Our results indicate that chemotherapy can be used to target mMDSC in males, while IL-1 pathway inhibitors can provide benefit to females through blockade of gMDSC function.

immunology↗

bioRxiv2018

Interleukin-8/CXCR2 signaling regulates therapy-induced plasticity and enhances tumorigenicity in glioblastoma

Glioblastoma (GBM) remains one of the least treatable types of cancer. Recent work highlights two key factors contributing to this resistant phenotype--cellular plasticity, the ability of GBM cells to adopt many phenotypes, and the microenvironment. Here, we provide evidence that Interleukin-8 (IL-8) plays a vital role in promoting cellular plasticity and cancer initiating cells (CICs) niche during anti-glioma chemotherapy. IL-8 expression is significantly elevated during chemotherapy, and immunohistochemical analysis of matched primary and recurrent patient GBM tissues revealed about 60% of recurrent tissues IL-8 expression is upregulated. In silico analysis of the TCGA data indicated that IL-8 signaling could promote epigenetic plasticity by altering the polycomb repressor complex activity. We are proposing that such regulation my promote epigenetic plasticity, which allows the GBM cells to adapt therapy and may promote therapeutic resistance. Our data show that IL-8 is a crucial microenvironmental factor involved in developing therapeutic adaptation and can be targeted in combination with conventional chemo-and radiotherapy to prevent disease recurrence.\n\nABSTRACTEmerging evidence reveals enrichment of glioma initiating cells (GICs) following therapeutic intervention. This enrichment occurs partly by dedifferentiation of non-GICs to GICs within the tumor, which may contribute to therapeutic resistance and the generation of lethal recurrent tumors. To elucidate the molecular mechanisms governing therapy-induced cellular plasticity, we performed genome-wide chromatin immunoprecipitation sequencing (ChIP-Seq) and gene expression analysis (gene microarray analysis) during treatment with standard of care temozolomide (TMZ) chemotherapy. Analysis revealed significant enhancement of open chromatin marks in known astrocytic enhancers for Interleukin-8 (IL-8) loci as well as elevated expression during anti-glioma chemotherapy. The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project data demonstrated that IL-8 transcript expression is negatively correlated with GBM patient survival (p=0.001) and positively correlated with that of genes associated with the CIC phenotype such as KLF4, c-Myc and HIF2 (p<0.001). Immunohistochemical analysis of patient samples demonstrated elevated IL-8 expression in about 60% of recurrent GBM tumors relative to matched primary tumors and this expression also positively correlates with time to recurrence. Exposure to IL-8 significantly enhanced the self-renewing capacity of patient-derived xenograft (PDX) GBM (average 3-fold, p<0.0005). Furthermore, IL-8 knockdown significantly delayed PDX GBM tumor growth in vivo (p<0.0005). Finally, guided by in silico analysis of TCGA data, we examined the effect of therapy-induced IL-8 expression on the epigenomic landscape of GBM cells and observed increased trimethylation of H3K9 and H3K27. Our results show that IL-8 alters cellular plasticity and mediates alterations in histone status. These finding suggest that IL-8 signaling participates in regulating GBM adaptation to therapeutic stress and therefore represents a promising target for combination with conventional chemotherapy in order to limit GBM recurrence.

cancer biology↗