Targetable signaling pathway mutations and progression of IDH-mutant glioma.
Year: 2014
Type: conference-abstract
Abstract: 2061 Background: Isocitrate dehydrogenase (IDH) gene mutations occur in low-grade and high-grade gliomas. We sought to identify the genetic basis of malignant phenotype heterogeneity in IDH-mutant gliomas. Methods: We prospectively implanted tumor specimens from 20 consecutive IDH1-mutant glioma resections into mouse brains and genotyped all resection specimens using a CLIA-certified molecular panel. Gliomas with cancer driver mutations were tested for sensitivity to targeted inhibitors in vitro. Associations between genomic alterations and outcomes were analyzed in patients. Results: By 10 months, 8 of 20 IDH1-mutant gliomas developed intracerebral xenografts. All xenografts maintained mutant IDH1 and high levels of 2-hydroxyglutarate on serial transplantation. All xenograft-producing gliomas harbored “lineage-defining” mutations in CIC (oligodendroglioma) or TP53 (astrocytoma), and 6 of 8 additionally had activating mutations in PIK3CA or amplification of PDGFRA, MET, or N-MYC. Only IDH1 and CIC/TP53 mutations were detected in non-xenograft-forming gliomas (P = 0.0007). Targeted inhibition of the additional alterations decreased proliferation in vitro. Moreover, we detected alterations in known cancer driver genes in 13.4% of IDH-mutant glioma patients, including PIK3CA, KRAS, AKT or PTEN mutation or PDGFRA, MET or N-MYC amplification. IDH/CIC mutant tumors were associated with PIK3CA/KRAS mutations while IDH/TP53 tumors correlated with PDGFRA/MET amplification. Presence of driver alterations at progression was associated with shorter subsequent progression-free survival (median 9.0 vs. 36.1 months, P=0.0011). Conclusions: A subset of IDH-mutant gliomas with mutations in driver oncogenes has a more malignant phenotype in patients. Identification of these alterations may provide an opportunity for use of targeted therapies in these patients.
Source: Journal of Clinical Oncology
Authors: Hiroaki Wakimoto, Shota Tanaka, William T. Curry, Franziska Loebel, Dan Zhao, Kensuke Tateishi, Juxiang Chen, Lindsay K. Klofas, Nina Lelic, James C. Kim, Dora Dias-Santagata, Leif W. Ellisen, Darrell R. Borger, Sarah-Maria Fendt, Matthew Vander Heiden, Tracy Batchelor, A. John Iafrate, Daniel P. Cahill, Andrew S. Chi
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2906978897