A biphasic hydrogel prevents glioblastoma recurrence by activating an EZH2-NeuroD1-SRCIN1 neuronal conversion axis

Glioblastoma (GBM) recurrence upon resection remains a pivotal challenge in brain cancer treatments. The proneural transcription factor NeuroD1 holds potential to reprogram residual GBM cells into neurons to prevent recurrence. However, it can also act as a tumor initiation and maintenance factor in GBM. Here, we define an EZH2-NeuroD1-SRCIN1 therapeutic axis. Within this axis, inhibition of the lysine methyltransferase EZH2 decreases histone H3 lysine 27 trimethylation (H3K27me3) that leads to chromatin opening, which in turn enhances the expression and activity of endogenous and exogenously delivered NeuroD1. This initiates a GBM-to-neuron conversion while suppressing GBM cell proliferation in vitro through the induction of the neurogenesis-associated protein SRCIN1. To maintain the long-term neuronal reprogramming efficiency, we developed a biphasic hydrogel (biHG) for the co-delivery of an EZH2 inhibitor and exogenous NeuroD1 into the resection cavity in both murine syngeneic and human xenograft orthotopic GBM resection models. This strategy not only significantly impedes tumor recurrence but also successfully reprograms residual GBM cells into neuron-like cells with partial functionality, exhibiting a predominantly VGLUT1-positive glutamatergic phenotype. Thus, targeting EZH2 to sensitize GBM cells for NeuroD1-SRCIN1-mediated neuronal conversion represents a promising therapeutic approach against post-surgical GBM recurrence.