IDH1 R132H decreases proliferation of glioma cell lines in vitro and in vivo

LBC Bralten, NK Kloosterhof, R Balvers… - Annals of …, 2011 - Wiley Online Library
LBC Bralten, NK Kloosterhof, R Balvers, A Sacchetti, L Lapre, M Lamfers, S Leenstra
Annals of neurology, 2011Wiley Online Library
Objective: A high percentage of grade II and III gliomas have mutations in the gene encoding
isocitrate dehydrogenase (IDH1). This mutation is always a heterozygous point mutation that
affects the amino acid arginine at position 132 and results in loss of its native enzymatic
activity and gain of alternative enzymatic activity (producing D‐2‐hydroxyglutarate). The
objective of this study was to investigate the cellular effects of R132H mutations in IDH1.
Methods: Functional consequences of IDH1R132H mutations were examined among others …
Objective
A high percentage of grade II and III gliomas have mutations in the gene encoding isocitrate dehydrogenase (IDH1). This mutation is always a heterozygous point mutation that affects the amino acid arginine at position 132 and results in loss of its native enzymatic activity and gain of alternative enzymatic activity (producing D‐2‐hydroxyglutarate). The objective of this study was to investigate the cellular effects of R132H mutations in IDH1.
Methods
Functional consequences of IDH1R132H mutations were examined among others using fluorescence‐activated cell sorting, kinome and expression arrays, biochemical assays, and intracranial injections on 3 different (glioma) cell lines with stable overexpression of IDH1R132H.
Results
IDH1R132H overexpression in established glioma cell lines in vitro resulted in a marked decrease in proliferation, decreased Akt phosphorylation, altered morphology, and a more contact‐dependent cell migration. The reduced proliferation is related to accumulation of D‐2‐hydroxyglutarate that is produced by IDH1R132H. Mice injected with IDH1R132H U87 cells have prolonged survival compared to mice injected with IDH1wt or green fluorescent protein–expressing U87 cells.
Interpretation
Our results demonstrate that IDH1R132H dominantly reduces aggressiveness of established glioma cell lines in vitro and in vivo. In addition, the IDH1R132H‐IDH1wt heterodimer has higher enzymatic activity than the IDH1R132H‐IDH1R132H homodimer. Our observations in model systems of glioma might lead to a better understanding of the biology of IDH1 mutant gliomas, which are typically low grade and often slow growing. Ann Neurol 2011;69:455–463
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