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Updated: Jan 13, 2026
Intracranial Cannula Implantation for Serial Locoregional Chimeric Antigen Receptor CAR T Cell Infusions in Mice
Published on: February 24, 2023
GPC2-CAR T cells have potent preclinical activity against orthotopic medulloblastoma xenografts
Reona Okada1, Mia Fanuzzi1, Constanza Rodriguez1
1Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
Abstract:
Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients with group 3 and 4 MB have poor clinical outcomes, underscoring the urgent need for new therapies. Glypican-2 (GPC2) is a recently discovered oncofetal antigen. Given its expression in brain tumors, we evaluated the preclinical activity of our GPC2-chimeric antigen receptor (CAR) against MB and compared it to two existing CARs targeting GD2 and B7-H3. Gene expression analysis of publicly available datasets was performed and validated with immunohistochemistry staining of patient samples. The MB cell line D283 and a newly generated cell line patient-derived xenograft, MAF1433, were used. Cytokine bead assays and single-cell RNA sequencing (scRNA-seq) were used for mechanistic studies. MB patient samples express up to moderate levels of GPC2. GPC2-CARs lead to significant in vivo tumor regression in orthotopic tumor models via intravenous or intraventricular administration route and had equivalent activity to the B7-H3-CAR against D283 and enhanced activity than GD2-CAR in both models in vivo. T cell kinetic studies revealed that GPC2-CAR T cells home to the area of the primary tumor, expand, and upregulate genes critical for cytotoxicity and T cell homing. These results provide a preclinical rationale for including children with GPC2+ MB in our upcoming clinical GPC2-CAR T cell trial.
Insights
Chimeric antigen receptor (CAR) T cell therapy targeting Glypican-2 (GPC2) shows promise for treating pediatric medulloblastoma (MB). GPC2-CAR T cells effectively reduced tumors in preclinical models, offering a new therapeutic avenue.
Area of Science:
- Oncology
- Immunotherapy
- Pediatric Neuro-oncology
Background:
- Medulloblastoma (MB), particularly group 3 and 4, has poor outcomes, necessitating novel treatments.
- Glypican-2 (GPC2) is an oncofetal antigen expressed in brain tumors, presenting a potential therapeutic target.
- Existing therapies for aggressive MB are limited, highlighting the need for innovative approaches.
Purpose of the Study:
- To evaluate the preclinical efficacy of GPC2-chimeric antigen receptor (CAR) T cells against medulloblastoma (MB).
- To compare the activity of GPC2-CAR T cells with existing GD2-CAR and B7-H3-CAR therapies in MB models.
- To investigate the mechanism of action of GPC2-CAR T cells in MB.
Main Methods:
- Gene expression analysis of public datasets and immunohistochemistry on patient samples to assess GPC2 expression.
- Preclinical testing of GPC2-CAR T cells in MB cell lines (D283) and patient-derived xenografts (MAF1433).
- Utilized cytokine bead assays and single-cell RNA sequencing (scRNA-seq) for mechanistic insights.
Main Results:
- Medulloblastoma patient samples showed moderate GPC2 expression.
- GPC2-CAR T cells demonstrated significant in vivo tumor regression in orthotopic models via IV or intraventricular administration.
- GPC2-CAR T cells exhibited comparable activity to B7-H3-CAR and superior activity to GD2-CAR in preclinical MB models.
Conclusions:
- GPC2-CAR T cells show potent preclinical anti-MB activity, comparable or superior to existing CARs.
- Mechanistic studies confirmed GPC2-CAR T cell homing, expansion, and cytotoxic gene upregulation within the tumor microenvironment.
- These findings support the clinical investigation of GPC2-CAR T cells for GPC2-positive medulloblastoma patients.
