Enhancer reprogramming in PRC2-deficient malignant peripheral nerve sheath tumors induces a targetable...

Area of Science:

• Oncology
• Epigenetics
• Developmental Biology

Background:

• Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas.
• Genetic alterations in Polycomb Repressor Complex 2 (PRC2) components (SUZ12, EED) are common in MPNSTs.

Purpose of the Study:

• To investigate the functional consequences of PRC2 loss in MPNSTs.
• To identify therapeutic targets associated with PRC2-mutant MPNSTs.

Main Methods:

• Comparative analysis of PRC2-mutant and PRC2-wild-type MPNSTs.
• Chromatin state profiling and epigenomic analysis.
• Cross-species comparative analysis using MPNST models.
• Functional validation using epigenetic editing and bromodomain inhibitors.

Main Results:

• PRC2 loss induces a dedifferentiated early neural crest phenotype specific to MPNSTs.
• Epigenomic reprogramming involves gains of active enhancers on neural crest regulators in PRC2-mutant MPNSTs.
• Enhancer activity, particularly on DLX5, is functionally critical for the neural crest phenotype.
• Bromodomain inhibitors targeting enhancer activity suppressed tumor growth in PRC2-mutant models.

Conclusions:

• PRC2-mutant MPNSTs accumulate a dedifferentiated neural crest-like state.
• Targeting enhancer activity represents a potential therapeutic strategy for PRC2-mutant MPNSTs.