Medulloblastoma is the most common malignant brain tumor in children. Group 3 medulloblastoma (G3 MB) represents the most aggressive molecular subtype and is associated with poor prognosis, particularly in cases characterized by high expression or amplification of the MYC oncogene. Current treatment strategies are not tailored to this subgroup and are associated with significant long-term toxicities, highlighting the need for more specific therapeutic approaches.

This study aims to characterize biological processes and molecular pathways driven by high MYC expression in high-risk G3 medulloblastoma in order to identify potential therapeutic vulnerabilities. The study will investigate MYC-associated regulation of gene expression and RNA splicing in tumor cells and will define molecular dependencies that may be targeted using candidate or repurposed anticancer agents.

To achieve this, publicly available genomic datasets will be analyzed, findings will be validated in patient tumor specimens, and patient-derived three-dimensional (3D) tumor models will be established from surgical samples. These models will be used for ex vivo assessment of selected therapeutic strategies in a system that preserves key features of the original tumor.

This translational approach integrates computational analyses, molecular validation, and functional testing in patient-derived models to improve understanding of MYC-associated tumor biology in Group 3 medulloblastoma.

Group 3 medulloblastoma (G3 MB) is the most aggressive molecular subgroup of medulloblastoma and is associated with poor prognosis, particularly in tumors characterized by MYC amplification or high MYC expression. Despite multimodal treatment including surgery, chemotherapy, and craniospinal irradiation, overall survival remains limited and survivors frequently experience significant long-term treatment-related toxicities. Given the largely undruggable nature of MYC, identifying MYC-dependent biological processes that can be therapeutically targeted represents an unmet clinical need.

This study investigates molecular mechanisms underlying MYC-driven tumor aggressiveness and aims to identify actionable vulnerabilities in high-risk G3 medulloblastoma. The project integrates retrospective molecular analyses, prospective collection of tumor specimens, transcriptomic data mining, and functional validation using patient-derived models.

Publicly available RNA sequencing datasets will be analyzed to compare tumors with high versus low MYC expression. Differential gene expression and alternative splicing analyses will be integrated with existing experimental datasets from MYC-depleted medulloblastoma models to identify MYC-regulated pathways and molecular processes.

Candidate genes and molecular signatures identified through bioinformatic analyses will be validated in retrospective tumor specimens using quantitative gene expression assays and evaluation of MYC-associated transcriptional and splicing programs.

In parallel, tumor samples collected from prospectively enrolled patients undergoing standard-of-care surgical resection will be used to establish patient-derived three-dimensional (3D) cultures. These models will be characterized histologically and molecularly to assess concordance with the corresponding primary tumors. Only models that retain key histological and genomic features will be used for downstream functional studies.

Patient-derived 3D cultures will be used as ex vivo platforms to evaluate therapeutic strategies targeting MYC-dependent pathways identified in molecular analyses. Selected compounds will be tested individually or in combination using assays measuring cell viability, proliferation, and survival.

This study does not involve investigational medicinal products or medical devices. All clinical procedures, including surgery and tissue collection, are performed according to standard clinical practice, without additional interventions for research purposes.

This translational project integrates computational analyses, molecular validation, and functional testing in patient-derived models to improve understanding of MYC-driven tumor biology in Group 3 medulloblastoma. The molecular insights generated may also be relevant to other pediatric and adult malignancies characterized by MYC dysregulation.

Inclusion Criteria:

• Patients with histologically confirmed Group 3 medulloblastoma (G3 MB)
• Age between 0 and 20 years
• Undergoing surgical treatment at the UOC Child Neurosurgery Unit, Fondazione Policlinico Universitario "A. Gemelli", IRCCS, Rome
• Availability of tumor tissue obtained during standard-of-care surgical resection for molecular analyses and/or establishment of patient-derived organoids
• Written informed consent provided by the patient and/or parent/legal guardian (prospective cohort)
• Inclusion of retrospective cases in accordance with applicable Italian privacy regulations (Art. 110-bis)

Exclusion Criteria:

• None