Compared to medulloblastoma (MB), atypical teratoid rhabdoid tumor (AT/RT) is characterized by a lower incidence, younger age at onset, and a poorer prognosis. Preoperative clinical and neuroimaging differentiation between these tumors remains challenging. This study aimed to evaluate the diagnostic utility of conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in distinguishing AT/RT from MB in children. We retrospectively included 32 patients with AT/RT and 82 patients with MB confirmed by surgery and pathology in our hospital between 2010 and 2023. We analyzed the clinical data, preoperative MRI characteristics, and apparent diffusion coefficient (ADC) values of these patients to evaluate their diagnostic value. The overall survival time of AT/RT patients was significantly shorter than that of MB patients (P < 0.001), with a higher mortality rate (81.4% vs. 35.5%,P = 0.007). Significant differences were found between AT/RT and MB in T2WI signal, off-midline growth, supratentorial ventriculomegaly, cystic degeneration, hemorrhage, peritumoral edema, tumor boundary clarity, and metastasis/dissemination (P < 0.05). No significant differences were observed in gender, age, lesion size, T1WI signal, or enhancement pattern (P > 0.05). The mean ADC value differed significantly between the two groups (P < 0.001), with an optimal cut-off value of 0.622 × 10⁻3 mm2/s. MRI features, including more cystic degeneration, hemorrhage, supratentorial ventriculomegaly, and peritumoral edema, combined with a lower ADC value may provide reliable information to differentiate AT/RT from MB in children.

High-dose chemotherapy (HDCT) with autologous stem cell rescue (ASCR) has been employed to mitigate the long-term side effects of radiotherapy and improve survival outcomes in infants with embryonal central nervous system (CNS) tumors. This prospective study, supported by federal funding from the National Oncological Care Support Program, included children younger than 5years of age with newly diagnosed CNS embryonal tumors treated with surgery and HDCT/ASCR. Between 2016 and 2019, 36 patients were included: 22 with medulloblastoma (MB) and 14 with other CNS embryonal tumors. In the MB cohort, the mean age was 2.5years, 13 were male. Gross total resection (GTR) was achieved in 18 patients; 15 had non-metastatic disease (M0). Among non-MB patients, the mean age was 2.7years, 11 were female. Nine patients had GTR; 12 had M0. According to the MB molecular subgroup, the 2- and 5-year event-free survival (EFS) rates for the SHH subgroup were 76.9%, and overall survival (OS) was 92.3%. For the non-WNT/non-SHH subgroup, the 2- and 5-year EFS rates were 33.3% and 22.2%, and OS, 66.7% and 55.6%, respectively. Two SHH and five non-WNT/non-SHH patients were successfully salvaged with craniospinal irradiation after a mean of 12months (range, 7-36months). Among non-MB patients, the 2- and 5-year EFS and OS were 28.6/19.0% and 42.9/32.1%, respectively. All patients developed grade 3-4 mucositis/typhlitis and febrile neutropenia and 13.9% invasive fungal infections during HDCT. HDCT/ASCR is feasible in a middle-income country setting and provides favorable outcomes in SHH medulloblastoma. However, prognosis remains poor for non-SHH MB and other embryonal tumors, highlighting the need for novel molecularly guided therapies.

Multi-omics characterization of radiation-induced cerebellar remodeling and tumorigenic transcriptional programs.

RNF138 polyubiquitinates glioma-associated oncogene 1 on K815/K942 to suppress Sonic Hedgehog signaling in medulloblastoma.

Deregulation of the Sonic Hedgehog (SHH)/GLI signaling pathway has been strongly implicated in carcinogenesis, particularly in brain and skin tumors, through mutations affecting various pathway components. Given its central role in tumor development, the SHH/GLI axis has emerged as a key target for therapeutic intervention, underscoring the need to identify GLI-specific targets in cancer cells. Netrin-1, a multifunctional signaling molecule with pro-oncogenic properties, is overexpressed in diverse tumor types. While its tumor-promoting functions are well documented, the regulatory mechanisms governing its expression remain poorly understood. Here, we provide through gene expression profiling and in vitro and ex vivo analyses evidence demonstrating that Netrin-1 (NTN1) is a direct transcriptional target of canonical SHH signaling. We further show that in conditions of SHH pathway hyperactivation-such as in SHH-driven medulloblastoma (MB) NTN1 is significantly upregulated. This overexpression promotes the self-renewal of MB stem-like cells through the modulation of ERK signaling, thereby contributing to enhanced cancer stemness. Our findings identify NTN1 as a novel downstream effector of the SHH/GLI pathway and demonstrate that quantifying NTN1 levels can refine molecular classification of SHH-subtype medulloblastomas-distinguishing tumors with high SHH pathway activation and enhanced stem-like properties, with potential implications for prognosis and targeted therapy selection.

Tumor-associated macrophages (TAMs) are key contributors to the brain tumor microenvironment. However, their role in medulloblastoma (MB) progression and chemoresistance remains elusive. We utilized the CD11b-diphtheria toxin receptor (DTR)/Ptch1-deficient MB model to genetically delete TAMs. NeuroD2-SmoA1 MB mice were treated with CSF1R inhibitor PLX3397, PI3K inhibitor buparlisib, and a combination of PLX3397 with chemotherapy to examine the functional significance of TAMs in MB. Tumor tissues and cell co-culture system were analyzed using RNA sequencing (RNA-seq), Western blotting, flow cytometry, immunohistochemistry, quantitative polymerase chain reaction, and EdU assay to delineate mechanistic interactions. Myeloid-derived TAMs were abundant in MB tissues and primarily exhibited M2-like polarization. We demonstrated that TAM depletion, achieved either genetically via diphtheria toxin or pharmacologically via PLX3397-mediated preferential targeting of M2-like TAMs, markedly downregulates Zic1 expression and impedes MB growth. Mechanistically, M2-like TAMs secreted high levels of IGF1 to activate the PI3K/mTOR/Zic1 axis in MB cells, whereas the PI3K inhibitor buparlisib effectively reduced the population of Zic1-expressing cells and restricted MB growth. Notably, the PI3K/mTOR/Zic1 axis was demonstrated to confer chemoresistance. While chemotherapy exacerbates M2-like TAM accumulation within MB, combining PLX3397 with chemotherapy abrogates this infiltration and attenuates IGF1/PI3K/Zic1 signaling axis. This combination strategy synergistically inhibits tumor growth and extends survival in mice. Our findings demonstrate that inhibiting the TAM-induced IGF1/PI3K/Zic1 signaling axis results in MB regression and chemosensitization. These results underscore the therapeutic potential of combining a clinical CSF1R inhibitor with standard chemotherapy as an effective treatment strategy for SHH-MB.

Medulloblastoma (MB) is the most common malignant pediatric brain tumor with poor prognosis, high recurrence, and severe treatment-related toxicities. One-third of MB are driven by aberrant activation of the Sonic hedgehog (SHH) signaling pathway. In current study, through analysis of clinical patient cohorts and animal model database, and utilizing genetically engineered primary and xenograft mouse MB models, we investigated the role of Sirtuin1 (Sirt1), a class III histone deacetylase (HDAC), in SHH signaling and MB. We found that Sirt1 was highly expressed in both human and mouse SHH-type MB, and its expression positively correlated with SHH pathway activity and tumor proliferation. Knockdown of Sirt1 in primary MB cells significantly suppressed SHH signaling and MB proliferation in vitro, further impaired neoplastic progression and extended survival in orthotopic transplantation MB model. Mechanistically, we discovered that Sirt1 modulates SHH signaling at downstream by interacting with and deacetylating full-length Gli3 (Gli3FL), thereby inhibiting its proteolytic processing into the repressor form (Gli3R), which attenuates the negative feedback regulation of SHH signaling, sustaining pathway activation and promoting tumor progression. Importantly, pharmacological inhibition of Sirt1 demonstrated promising therapeutic efficacy in both subcutaneous transplantation and primary MB models. Our findings identify Sirt1 as a potential therapeutic target for SHH-driven MB and other cancers.

Differentiating pediatric medulloblastoma (MB) from ependymoma (EA) in the fourth ventricle remains challenging due to overlapping clinical and imaging features. This study aimed to identify distinctive semantic features and develop a feature-based model for differentiating MB from EA using conventional MRI. This multi-center retrospective MRI study enrolled 295 pediatric patients, including 184 MB and 111 EA cases, allocated to the training, internal validation set, and external testing set. Subsequently, 13 semantic features were extracted. After feature selection, quantitative parametric models and mixed parametric models were constructed and evaluated. Finally, three junior and three senior radiologists completed independent and model-assisted assessments. MB showed significantly greater left-right/upper-lower (0.98 vs. 0.76) and anterior-posterior/upper-lower (0.88 vs. 0.66) diameter ratios compared to EA (both p < 0.001). The pathognomonic "sea anemone sign" (100% specific for MB) occurred in 38.60% of MB cases. The support vector machine (SVM) model achieved optimal performance, with areas under the receiver operating characteristic curves (AUCs) of 0.946/0.921/0.915 and accuracies of 0.906/0.907/0.832 across training/internal validation/external testing sets. With SVM model assistance, diagnostic performance improved for both senior and junior radiologists across all datasets. In the external testing set, the AUCs increased to 0.849-0.893 for junior radiologists and 0.893-0.913 for senior radiologists, with the accuracies of 0.832-0.858 and 0.850-0.867, respectively. The sea anemone sign is highly specific for MB. The SVM model using conventional MRI semantic features achieved robust discrimination between MB and EA, significantly augmenting the diagnostic accuracy of radiologist assessment.

Pediatric posterior fossa tumors represent a major subset of childhood central nervous system neoplasms; however, overlapping MRI features often hinder accurate non-invasive characterization. This study aimed to evaluate machine learning (ML) and deep learning (DL) models for classifying these tumors using MRI-derived radiomic features. This retrospective study analyzed MRI data from 63 pediatric patients with confirmed posterior fossa tumors, including 21 medulloblastoma (MB), 20 pilocytic astrocytoma (PA), 11 ependymoma (EP), and 11 diffuse midline glioma (DMG) cases. T2-weighted imaging, diffusion-weighted imaging, and apparent diffusion coefficient sequences showing the best single-model performance were used to construct gradient boosting machine (GBM), decision tree (DT), and random forest (RF) models and their ensemble combinations. Model performance was evaluated using standard classification metrics. A ResNet101V2-based DL model was developed using multiple MRI sequences. ML models were validated using fivefold cross-validation, whereas the DL model was trained using a 67/33 train-test split with data augmentation. The RF + GBM ensemble achieved the highest ML performance, with an overall accuracy of 78%, and showed the strongest classification for MB and PA, whereas EP and DMG remained difficult to distinguish. The DL model demonstrated high performance on T1-weighted imaging and contrast-enhanced T1-weighted imaging, achieving accuracies of 98% and 96%, respectively, but showed lower performance on diffusion-based sequences. ML and DL approaches improve MRI-based classification of pediatric posterior fossa tumors; however, accurate differentiation of EP and DMG remains challenging. These findings support the potential of AI-driven methods as clinically relevant, non-invasive decision-support tools in pediatric neuro-oncology.

In spatial proteomics, multiplexed immunofluorescence (mIF) enables high-plex visualization of protein expression in preserved tissue, offering insights into tumor heterogeneity and the microenvironment. While MACSima and PhenoCycler-Fusion employ distinct strategies, direct comparisons under biologically controlled invivo conditions remain limited. We applied both platforms to sagittal formalin-fixed, paraffin-embedded (FFPE) sections from an orthotopic xenograft mouse model of human medulloblastoma (MB), featuring leptomeningeal seeding (LMS). These longitudinal sections spanning brain and spinal cord allowed simultaneous assessment of areas with distinct cellular architecture. Fifteen-marker mIF was performed. MACSima utilized MICS technology with MACS iQ View for automated workflows; PhenoCycler-Fusion used a DNA-barcoded antibody system and QuPath for open-ended image processing. Segmentation was evaluated using identical MACSima data. Both platforms enabled high-plex imaging mIF while preserving tissue morphology. DAPI, Ki-67, and Actin were consistently detected across both systems. Ki-67 expression localized to densely packed tumor regions and was also observed in lower-density areas. Analyzing MACSima data, MACS iQ View detected fewer cells but a higher Ki-67 positive rate in dense regions; conversely, QuPath detected more cells but with a lower positivity rate. In low-density areas, both tools yielded similar results. These differences reflect distinct segmentation algorithms and thresholding strategies. This study confirms both platforms support mIF-based spatial proteomic analysis in complex, heterogeneous tissues. However, analysis tools influence quantification. Therefore, standardization of algorithmic settings and additional validation are crucial for precise data interpretation. This research provides practical insights for platform selection in basic, translational, and clinical applications by directly evaluating staining, image acquisition, and analysis pipelines.

The scaffold protein FRS2 is central to FGFR signaling, linking receptor activation to MAPK/ERK and PI3K/AKT pathways. Elevated FRS2 expression correlates with aggressive tumor phenotypes and poor prognosis across multiple cancers, including the pediatric cerebellar tumor medulloblastoma (MB).Here, we characterized FRS2's subcellular localization and interactome in MB cells, employing live-cell imaging, phosphoproteomics, immunoprecipitation, and APEX2-based proximity labeling. We found that increased FRS2 expression is associated with increased motile and invasive behavior in MB tumor cells. We furthermore identified novel candidate FRS2-associated proteins involved in actin cytoskeleton remodeling, cell junction assembly, and translation initiation, which indicate a growth factor-dependent reorganization of the FRS2 signalosome. Our data furthermore indicate a regulatory role of FRS2 in directing subcellular distribution of the cell junction and cell motility regulator TJP1.Our findings highlight the relevance of FRS2 as a mediator of cell motility and invasiveness and provide candidate proteins associated with FRS2 that are involved in cellular processes governing migration and invasion. This study thus provides a framework for exploring the FRS2 interactome as a possible target to attenuate FGFR-driven oncogenic processes with next-generation therapeutic strategies.

Medulloblastoma (MB) is one of the most prevalent solid brain tumors in the pediatric population. Although hundreds of Differentially Expressed Genes (DEGs) have been identified as diagnostic molecules and therapeutic targets for Medulloblastoma (MB), the function of metabolism-associated genes in the pathophysiological mechanisms of MB remains unclear. The Gene Expression Omnibus (GEO) provided five datasets that contain mRNA expression profiles and clinical information. In detail, 599 MB samples extracted from GSE85217 were set as the training set (n = 400) and test set (n = 199). For validation, 74 samples from GSE37418, 8 scRNA-seq samples, and 37 RNA-seq samples were used. Nonnegative matrix factorization clustering was conducted, leading to the identification of four MB subclasses (C1, C2, C3, and C4) in both the training and test sets. C1 and C3 are metabolically active, and C2 involves metabolic hypoactivity; C4 did not exhibit obvious metabolic characteristics. Next, GSE50161, GSE74195, and GSE86574 were used to identify DEGs, and a 17-gene metabolism-associated signature for prognosis prediction was established. The authors performed transcriptome and single-cell sequencing on medulloblastoma bulk specimens to further validate metabolic subclasses and the prognosis prediction model at the transcriptome and cellular level. The present study classifies Medulloblastoma (MB) based on metabolic signatures, supplementing existing subtype characterization from a metabolic perspective. The authors provide preliminary insights into MB's metabolic hallmarks and a potential reference for developing multimolecule-based personalized therapies and prognostic tools ‒ with the caveat that the 17-gene signature requires additional multi-center validation to confirm clinical utility.

Medulloblastoma (MB), the most common malignant pediatric brain tumor, is treated with intensive multimodal regimens that cause substantial long-term toxicity and fail to prevent recurrence in up to 30% of patients. We investigated triiodothyronine (T3), an FDA-approved thyroid hormone, as a differentiation-based therapeutic strategy for MB. Using a Sonic Hedgehog (SHH)-driven mouse model, two patient-derived xenografts (SHH and group 3), and drug-resistant TP53-mutant MB cells, we found that T3 and cytotoxic chemotherapy suppress tumor growth through complementary biological mechanisms: T3 promotes terminal differentiation of tumor cells, whereas cyclophosphamide (CTX) and irinotecan (CPT-11) induce caspase-3-dependent apoptosis. In vitro, T3 enhanced the tumor inhibitory effects of CTX and CPT-11, suppressed proliferation in chemotherapy-resistant cells, and promoted differentiation across MB subgroups. In vivo, sequential administration of T3 following chemotherapy suppressed post-treatment tumor regrowth and prolonged survival without increasing systemic toxicity. T3-induced transient tachycardia was effectively controlled with propranolol without compromising antitumor activity. Together, these findings support the potential of T3 as a clinically accessible differentiation-based therapy that enhances chemotherapy responses and suppresses post-treatment tumor regrowth in medulloblastoma.

In pediatric brain tumors medulloblastoma (MB) and diffuse midline glioma (DMG), tumor-associated myeloid cells (TAMs) support malignant progression by secreting paracrine growth factors and suppressing local immune function. We studied the potential for reversing this cancer-supportive phenotype by stimulating TAM pathogen receptors using ResiPOx, a brain-permeant, polyoxazoline nanoparticle formulation of the TLR7/8 agonist resiquimod. ResiPOx showed blood-brain barrier penetration and anti-tumor efficacy, extending progression-free survival (PFS) in mice with MB and DMG. Integrated cellular and molecular analysis including scRNA-seq showed that ResiPOx expanded TAM populations and reprogrammed TAMs toward anti-tumoral states, blocking paracrine IGF1 signaling and inducing local cytokine signaling and phagocytosis of tumor cells. In rhesus macaques, systemic ResiPOx was well tolerated and induced brain transcriptional patterns that resembled ResiPOx responses in DMG and MB mouse models, indicating effects in non-human primates that highlight translational potential. Our data show that ResiPOx reshapes the brain tumor microenvironment to inhibit tumor growth. As a systemically administered, brain penetrant immunomodulator, ResiPOx is able to reach multifocal and unresectable brain tumors, including MB and DMG.

Medulloblastoma (MB) is the most frequent brain malignancy in children, frequently driven by deregulated Sonic Hedgehog (SHH) signaling. We previously identified the antidiabetic drug phenformin (Phen) as a potent Gli1 inhibitor that suppresses SHH-subtype MB growth. Despite its efficacy, systemic administration of Phen is limited by its potential to induce lactic acidosis, primarily through the suppression of hepatic gluconeogenesis. Here, we provide proof-of-concept that phospholipid (liposomes) and non-phospholipid (niosomes) vesicles (<200 nm) can be used to deliver phenformin selectively. Our results show that these vesicle-based delivery systems efficiently entrap Phen (around 50%) and release it into SHH MB cells, reducing proliferation and activating energy stress responses at higher doses. Furthermore, treated cells exhibit marked downregulation of SHH target genes Gli1 and Ptch1. In vivo, phenformin-loaded nanocarriers selectively increased drug accumulation in cerebellar tumors while minimizing systemic and hepatic exposure. Notably, niosomes demonstrated superior brain tumor targeting compared to free drug or liposome administration, as reflected by higher intratumoral concentrations of Phen compared to free drug or liposome administration. Consistent with this targeted delivery, we observed a substantial decline in intratumoral Gli1 and Ptch1 expression, confirming effective SHH pathway modulation. Together, these findings propose a promising nanotechnology-based method to improve phenformin therapeutic index in SHH MB by enhancing tumor specificity and reducing systemic toxicity.

Medulloblastoma (MB) is a heterogeneous pediatric brain tumor characterized by distinct molecular subtypes. Although genomics and transcriptomics have improved subtype classification and informed targeted therapies, the clinical utility of integrated molecular profiling in real-world settings remains incompletely defined. We conducted a retrospective analysis of 131 patients with MB from a Chinese cohort. All cases underwent both targeted genomic sequencing and NanoString-based transcriptomic profiling. We evaluated the impact of integrated molecular profiling on diagnostic refinement, identification of germline predisposition, and detection of actionable alterations. Incorporation of genomic data led to optimized or revised molecular classification in 67.2% of patients. Germline variants in Fanconi anemia pathway genes (FANCL, FANCC, NBN) were significantly enriched among patients with Group 3 and Group 4 MB, suggesting a potentially inherited susceptibility component. Furthermore, 52.7% of patients harbored potentially actionable somatic mutations, supporting the feasibility of precision-targeted therapeutic approaches. Notably, we identified one case of WNT-subtype MB harboring a homozygous deletion of CDKN2A, which was associated with unusually poor clinical outcome. Integrated genomic and transcriptomic profiling substantially improves molecular subtyping of MB and reveals inherited risk factors relevant to specific subgroups. Our findings support the implementation of combined molecular diagnostics in routine clinical management of MB and underscore their potential in guiding individualized treatment strategies.

Group 4 medulloblastoma (MB) is rare in young children. Data on craniospinal irradiation (CSI)-sparing approaches are limited. This multicenter study reported outcomes for patients younger than 7years old with Group 4 MB treated with high-dose chemotherapy (HDC) without adjuvant CSI. Thirty-eight patients were included (26 M/12 F). Median age at diagnosis was 46.4months (25.9-78), with 24% ≤36months. Twenty-four patients (63.2%) had localized disease. Fourteen (36.8%) presented with metastatic disease, and 26 (68.4%) underwent gross total resection (GTR). The most used HDC regimens were carboplatin/thiotepa (76.3%) and carboplatin/thiotepa/etoposide (21.1%). Twenty (52.6%) relapses occurred at a median 21.9months (5-99.8) from diagnosis. Patients with upfront GTR and/or who received three cycles of HDC had better PFS (p = 0.02 and p = 0.002, respectively). Local relapse accounted for 45%. Eighteen patients received salvage therapy with curative intent, all with radiotherapy (16 = CSI, 2 = focal). The CSI dose ranged from 18 to 36Gy, and 43.7% received ≤23.4Gy. Patients who underwent salvage surgery and/or chemotherapy were more likely to receive CSI ≤23.4Gy (p = 0.008 and p = 0.03). The 5-year post-relapse survival and overall survival (OS) were, respectively, 60.3% (95% confidence interval [CI]: 26.9-82) and 72.7% (95% CI: 51.9-85.7). The 5-year CSI-free OS was 69.7% (95% CI: 39.1-87.1). High dose chemotherapy for Group 4 MB was associated with a relapse rate of 52.6%, which favorably compares to data reported with conventional chemotherapy. Salvage radiotherapy retrieved more than two-thirds of the patients. Half of the survivors never received radiotherapy. Such an approach may represent an alternative to upfront CSI for young children with Group 4 MB.

Medulloblastoma (MB) and pilocytic astrocytoma (PA) are common in pediatric brain tumors and difficult to distinguish. To establish and evaluate a radiomics model based on multimodal MRI to distinguish medulloblastoma from pilocytic astrocytoma. Retrospective collection of magnetic resonance images from 113 patients with MB and 74 patients with PA. Radiomics analysis was performed on Dynamic Contrast-Enhanced T1 weighted imaging (DCE-T1WI), T2 weighted imaging (T2WI), and Apparent diffusion coefficient (ADC) images, respectively. A multimodal MRI combined radiomics model incorporating DCE-T1WI, T2WI, and ADC sequence features was developed by extraction of valuable features, and the radiomics nomogram was generated to evaluate its diagnostic capability. The DeLong test was used to compare the diagnostic performance of DCE-T1WI, T2WI, ADC single sequence model, and multimodal MRI radiomics model. The combined model showed the highest performance among all models, with an area under the curve (AUC) of 0.999 on the primary cohort and maintained an AUC of 0.994 during the validation cohort. For the single-sequence model, the ADC sequence model performs better in the primary cohort, with an AUC of 0.996; the T2WI sequence model slightly outperforms in validation cohort, with an AUC of 0.985. The DCE-T1WI sequence model performed slightly worse than ADC and T2WI in the validation cohort, with an AUC of 0.951. Overall, the combined model performed best in the differential diagnosis of MB and PA. Multimodal MRI-based radiomics analysis is effective in differentiating MB from PA and radiomics imaging may have important clinical significance in the preoperative detection of posterior fossa brain tumors in children.

Back-splicing is a noncanonical splicing event driving circular RNA (circRNA) biogenesis. While its molecular mechanisms are partly known, global regulation in tumors remains unclear. Here, we uncover an hnRNP C-dependent mechanism that represses a broad repertoire of circRNAs in group 3 medulloblastoma (MB). HnRNP C binds Alu elements, preventing pre-mRNA circularization. Expression of hnRNP C modulates the balance between linear and circular splicing, ensuring efficient expression of genes that sustain the oncogenic phenotype of group 3 MB cells. In the absence of hnRNP C, introns flanking the circularizing exons generate cytoplasmic double-stranded RNAs via inverted Alu base pairing, triggering an interferon-induced antiviral response. These findings unveil hnRNP C as a guardian of transcriptome integrity by repressing circRNA biogenesis. Last, targeting hnRNP C in group 3 MB may trigger an inflammatory immune response, thereby boosting cancer surveillance.

Medulloblastoma (MB) is the most common malignant tumor of the cerebellum in children. The Sonic Hedgehog (SHH) subgroup of MB (SHH-MB) is driven by aberrant activation of the SHH pathway; however, mutations in genes related to this pathway are relatively rare, posing challenges for therapeutic development. Glypican-6 (GPC6), a heparan sulfate proteoglycan, is highly expressed in SHH-MB. In this study, we demonstrate the synchronous expression of GPC6 with GLI family zinc finger 1 (GLI1) in both the developing cerebellum and medulloblastoma. GPC6 promotes cell proliferation, migration, and invasion in SHH-MB cell lines (DAOY and ONS-76). Consistently, GPC6 enhances the SHH pathway activity by upregulating GLI1 expression, supports ciliogenesis essential for signal transduction, and facilitates SHH ligand expression via extracellular vesicles. These findings suggest that GPC6 acts as a key regulator of SHH signaling and represents a potential therapeutic target in SHH-MB.