Open AccessBIMG-20. METABOLIC BIOMARKERS IN MICRODIALYSATE OF IDH-1 MUTANT TUMORS
Author(s) -
Karishma Rajani,
Lucas P. Carlstrom,
Joshua J. Jacobs,
Mark A. Schroeder,
Ian Olson,
Matthew Hainy,
JuHee Oh,
William F. Elmquist,
Jann N. Sarkaria,
Terry C. Burns
Publication year - 2021
Publication title -
neuro-oncology advances
Language(s) - English
Resource type - Journals
ISSN - 2632-2498
DOI - 10.1093/noajnl/vdab024.019
Subject(s) - microdialysis , isocitrate dehydrogenase , metabolomics , temozolomide , cancer research , biomarker , idh1 , glioma , medicine , pharmacology , mutant , biology , bioinformatics , central nervous system , biochemistry , enzyme , gene
Glioblastoma (GBM) is a common deadly malignant brain cancer of the central nervous system, with a median survival of 12–15 months. Scientific advancements are lacking in developing effective therapies for both primary GBM, as well as secondary GBMs, that typically originate as malignant transformation of lower-grade isocitrate dehydrogenase (IDH) 1-mutant tumors. The unique metabolomic profile of IDH1-mutant tumors presents opportunities to develop biomarker signatures of therapeutic efficacy. Microdialysis is an extracellular fluid sampling collection technique utilizing a perfused semipermeable catheter to permit diffusion of molecules between brain interstitium and the perfusate. We hypothesized that microdialysis may identify a metabolomics-based biomarker response to therapy in IDH1-mutant tumors. To test this hypothesis, orthotopic xenografts were generated from patient-derived xenografts (PDX) harboring mutant IDH-1 (R132H). Perfusates were collected from intra-cranial tumors in athymic nude mice sampled at baseline and 72h post treatment with temozolomide (TMZ), an oral alkylating agent used to treat IDH1-mutant gliomas, compared with vehicle treatment. Perfusates were analyzed via untargeted metabolomic profiling using liquid chromatography-mass spectrometry. Tumor specific metabolites such as (D)-2 hydroxyglutarate, were detected in microdialysate from IDH-1 mutant tumor bearing mice compared to non-tumor bearing mice. We also found high levels of metabolites such as 5-methylthioadenosine, and dimethylarginine and wide range of amino acids in microdialysate from IDH-1 mutant tumor bearing mice. TMZ treatment induced changes to metabolites in creatine and histidine metabolism. Our results indicate that microdialysis is a feasible technology to identify metabolomics-based biomarkers in IDH1-mutant gliomas and their response to therapy. We suggest that in vivo intratumoral microdialysis over several days could yield metabolic pharmacodynamic biomarkers of value to therapeutic translation for IDH-mutant gliomas.