KDM1A/HDAC2-driven epigenetic dysregulation maintains a drug-resistant, relapse-initiating glioblastoma cell niche at the peri-tumoral margin.

Glioblastoma (GBM) is among the most aggressive primary brain tumors, marked by rapid proliferation, therapeutic resistance, and profound intratumoral heterogeneity. Epigenetic regulators such as lysine-specific demethylase 1A (KDM1A) and histone deacetylase 2 (HDAC2) are aberrantly expressed in resistant GBM subpopulations and strongly correlate with poor clinical outcomes. Here, we assessed the therapeutic potential of MPT0G521, a dual KDM1A/class I HDAC inhibitor, in disrupting epigenetic regulation and cell cycle progression. Bioinformatic analyses of resistance-associated gene profiles (temozolomide and 2 Gy radiation) and single-cell transcriptomic datasets from distinct tumor regions revealed enrichment of KDM1A and HDAC2 in high-cycling GBM clusters, particularly at invasive margins prone to recurrence. Functional assays demonstrated that MPT0G521 potently inhibited proliferation of both parental and temozolomide-resistant GBM cells, inducing G2/M arrest and apoptosis. Transcriptomic profiling further identified significant downregulation of centrosome integrity genes (FSD1, KIFC1), spindle regulators (TUBB, STMN1, KIF2C, KIF15), kinetochore components (AURKB, CDCA8, SPAG5), and G2/M checkpoint mediators (CENPF, MYBL2, CCNF, MYT1, CDC25A), resulting in disrupted mitotic progression. Mechanistically, MPT0G521 increased histone H3 methylation and acetylation, validating its dual inhibitory activity against KDM1A and class I HDACs. Collectively, these findings indicate that MPT0G521 disrupts the G2/M activation and mitotic machinery, thereby suppressing proliferative and resistant GBM subpopulations. This dual epigenetic strategy holds strong promise for overcoming GBM heterogeneity and reducing recurrence.