Isocitrate dehydrogenases (IDHs) catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. IDH1 is a NADP(+)-dependent isocitrate dehydrogenase found in the cytoplasm and peroxisomes. IDH1 serves a significant role in cytoplasmic NADPH production. Somatic mutations in IDH1 have recently been identified in multiple human cancers. Mutation at the site of R132 of IDH1 confer on this enzymes a new activity: catalysis of alpha-ketoglutarate (2-OG) to the (R)-enantiomer of 2-hydroxyglutarate (R-2HG).
AG-120 is a selective inhibitor of R132 mutated IDH1. The inhibitory IC50s of AG-120 against IDH1-R132 mutants IDH1-R132H, IDH1-R132C, IDH1-R132G, IDH1-R132L and IDH1-R132S were 12, 13, 8, 13, and 12 nM, respectively. The inhibitory IC50s of AG-120 against IDH1-R132 mutated HT1080, COR-L105 and HCCC-9810 cells were 8, 15 and 12 nM, respectively[2]. In IDH1-R132 mutated samples derived from AML patients, AG-120 reduced the level of intracellular 2-HG by 96% at the lowest tested dose (0.5 μM) and by 98.6% and 99.7%, respectively, at 1 and 5 μM. 5 μM AG-120 also enhanced ability of primary patient myeloblasts to form differentiated colonies in methylcellulose assays[2].
In HT1080 xenografts established in nude mice, a single oral dose of AG-120 at 50 or 150 mg/kg reduced tumor 2-HG concentration with maximum inhibition of 92.0% and 95.2%, respectively, achieved at about 12h post dose[2].
搜索
