Cross-species genomics matches driver mutations and cell compartments to model ependymoma

Area of Science:

• Neuro-oncology
• Cancer Genomics
• Developmental Neuroscience

Background:

• Ependymomas exhibit histological similarity but molecular heterogeneity, complicating biological understanding.
• Identifying cancer's cellular origins and drivers is crucial for deciphering tumor subgroups.

Purpose of the Study:

• To decipher ependymoma heterogeneity by integrating genetic alterations with candidate cells of origin.
• To generate accurate ependymoma disease models using cross-species genomics.

Main Methods:

• Subgrouping human ependymomas based on genetic alterations.
• Matching human tumor transcriptomes to mouse neural stem cells (NSCs) from various developmental stages and CNS regions.
• Utilizing Ink4a/Arf locus status in NSCs for cellular compartment selection.
• Activating Ephb2 signaling in matched NSCs to generate a mouse model.

Main Results:

• Identified novel subgroup-specific genetic alterations in ependymoma.
• Matched human supratentorial ependymomas to embryonic cerebral Ink4a/Arf(-/-) NSCs based on transcriptomic profiles.
• Generated a highly penetrant mouse model of ependymoma by activating Ephb2 signaling in specific NSCs.
• Revealed deregulation of synaptogenesis genes in matched human and mouse tumors.

Conclusions:

• Cross-species genomics effectively matches driver mutations with cellular origins for accurate cancer modeling.
• Disruption of synaptogenesis is a critical event in a specific subgroup of supratentorial ependymomas.
• This study provides a powerful framework for modeling and interrogating cancer subgroups.