A druggable addiction to de novo pyrimidine biosynthesis in diffuse midline glioma

Abstract

Diffuse midline glioma (DMG) is a uniformly fatal pediatric cancer driven by oncohistones that do not readily lend themselves to drug development. To identify therapeutic targets for DMG, we conducted a genome-wide CRIPSR screen for DMG metabolic vulnerabilities, which revealed a DMG selective dependency on the de novo pathway for pyrimidine biosynthesis. The dependency is specific to pyrimidines as there is no selectivity for suppression of de novo purine biosynthesis. A clinical stage inhibitor of DHODH (a rate limiting enzyme in the de novo pathway) generates DNA damage and induces apoptosis through suppression of replication forks--an on target effect, as shown by uridine rescue. MALDI mass spectroscopy imaging demonstrates that BAY2402234 accumulates in brain at therapeutically relevant concentrations, suppresses de novo pyrimidine biosynthesis in vivo, and prolongs survival of mice bearing intracranial DMG xenografts. Our results highlight BAY2402234, a brain-penetrant DHODH inhibitor, as a promising therapy against DMGs.