G-quadruplex stabilizer CX-5461 effectively combines with ionizing radiation to selectively target ATRX-deficient malignant glioma [CUT&Tag]
Mutational inactivation of ?-thalassaemia/mental retardation X-linked (ATRX) represents a defining molecular feature in large subsets of adult and pediatric malignant glioma. ATRX deficiency gives rise to abnormal G-quadruplex (G4) DNA secondary structures at GC-rich regions of the genome, altering chromatin accessibility and enhancing DNA damage. Building on earlier work, we sought to assess the extent to which pharmacological G4 stabilization selectively enhances DNA damage and cell death in preclinical models of ATRX-deficient glioma. To investigate the effect of G4 stabilization on histone variant H3.3 deposition on the genome, we treated patient-derived glioma stem cells (GSCs) with G4 stabilizer CX-5461 and performed cleavage under targets and tagmentation (CUT&Tag) for H3.3. Our analyses show that G4 stabilizer CX-541 disrupts H3.3 deposition in ATRX-deficient GSCs and likely enhances replication stress and DNA damage. Overall design: Comparative global genomic profiling analyses of CUT&Tag sequencing data for patient-derived glioma stem cells (GSCs) treated for 48 hours with either Vehicle (DMSO) or G4 stabilizer CX-5461 (1 µM). GSC lines were treated in triplicates for each condition (VEH or CX) and are as follows: TS 543-sh590 (ATRX-/-), TS 543 (ATRX wt).