Three-dimensional regulatory hubs support oncogenic programs in glioblastoma

Area of Science:

• Genomics
• Cancer Biology
• Epigenetics

Background:

• Enhancer-promoter communication within the 3D nucleus is crucial for gene regulation.
• Dysregulation of this communication is implicated in cancer development.
• Glioblastoma stem cells (GSCs) present a unique model for studying cancer regulatory networks.

Purpose of the Study:

• To profile 3D enhancer-promoter networks in patient-derived GSCs versus neuronal stem cells (NSCs).
• To identify key regulatory hubs and vulnerabilities in glioblastoma.
• To investigate the role of these hubs in oncogenic programs.

Main Methods:

• 3D genome conformation capture techniques to map enhancer-promoter interactions.
• Single-cell RNA sequencing to analyze gene expression patterns.
• Epigenetic manipulation (silencing) of specific regulatory hubs.
• Bioinformatic analysis of integrated cancer datasets.

Main Results:

• Hyperconnected 3D regulatory hubs were identified in GSCs, associated with coordinated gene expression and oncogenic programs.
• Epigenetic silencing of a specific hub led to gene downregulation, altered transcriptional states, and reduced GSC clonogenicity.
• Both universal and cancer-specific hubs were found across different cancer types, linked to distinct oncogenic pathways.
• Genetic alterations explained only a minor portion of hyperconnected hub activity.

Conclusions:

• 3D regulatory hubs play a central role in controlling glioblastoma oncogenic programs.
• These hubs represent potential therapeutic vulnerabilities in brain tumors.
• The study provides a framework for identifying critical regulatory elements in cancer.