Purine metabolism regulates DNA repair and therapy resistance in glioblastoma

Authors

Document Type

Article

Abstract

Intratumoral genomic heterogeneity in glioblastoma (GBM) is a barrier to overcoming therapy resistance. Treatments that are effective independent of genotype are urgently needed. By correlating intracellular metabolite levels with radiation resistance across dozens of genomically-distinct models of GBM, we find that purine metabolites, especially guanylates, strongly correlate with radiation resistance. Inhibiting GTP synthesis radiosensitizes GBM cells and patient-derived neurospheres by impairing DNA repair. Likewise, administration of exogenous purine nucleosides protects sensitive GBM models from radiation by promoting DNA repair. Neither modulating pyrimidine metabolism nor purine salvage has similar effects. An FDA-approved inhibitor of GTP synthesis potentiates the effects of radiation in flank and orthotopic patient-derived xenograft models of GBM. High expression of the rate-limiting enzyme of de novo GTP synthesis is associated with shorter survival in GBM patients. These findings indicate that inhibiting purine synthesis may be a promising strategy to overcome therapy resistance in this genomically heterogeneous disease.

Medical Subject Headings

Animals; Brain Neoplasms (genetics, radiotherapy); Cell Line, Tumor; DNA Repair (genetics); Female; Glioblastoma (genetics, radiotherapy); Guanosine Monophosphate (metabolism); Humans; Male; Mice; Mice, Knockout; Mice, SCID; Purine Nucleosides (metabolism); Radiation Tolerance (genetics); Xenograft Model Antitumor Assays

Publication Date

7-30-2020

Publication Title

Nature communications

E-ISSN

2041-1723

Volume

11

Issue

1

First Page

3811

PubMed ID

32732914

Digital Object Identifier (DOI)

10.1038/s41467-020-17512-x

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