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Identification of a new selective chemical inhibitor of mutant isocitrate dehydrogenase-1.

Kim HJ, Choi BY, Keum YS - J Cancer Prev (2015)

Bottom Line: We have found that IDH1, but not IDH1-R132H, can catalyze the conversion of isocitrate into α-ketoglutarate (α-KG).We have observed an underlying biochemical mechanism explaining how a heterozygous IDH1 mutation contributes to the generation of R-2HG and increases cellular histone H3 trimethylation levels.We have also identified a novel selective IDH1-R132H chemical hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one, which could be used for a future lead development against IDH1-R132H.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Dongguk University, Goyang, Seowon University, Cheongju, Korea.

ABSTRACT

Background: Recent genome-wide sequencing studies have identified unexpected genetic alterations in cancer. In particular, missense mutations in isocitrate dehydrogenase-1 (IDH1) at arginine 132, mostly substituted into histidine (IDH1-R132H) were observed to frequently occur in glioma patients.

Methods: We have purified recombinant IDH1 and IDH1-R132H proteins and monitored their catalytic activities. In parallel experiments, we have attempted to find new selective IDH1-R132H chemical inhibitor(s) from a fragment-based chemical library.

Results: We have found that IDH1, but not IDH1-R132H, can catalyze the conversion of isocitrate into α-ketoglutarate (α-KG). In addition, we have observed that IDH1-R132H was more efficient than IDH1 in converting α-KG into (R)-2-hydroxyglutarate (R-2HG). Moreover, we have identified a new hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective IDH1-R132H inhibitor.

Conclusions: We have observed an underlying biochemical mechanism explaining how a heterozygous IDH1 mutation contributes to the generation of R-2HG and increases cellular histone H3 trimethylation levels. We have also identified a novel selective IDH1-R132H chemical hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one, which could be used for a future lead development against IDH1-R132H.

No MeSH data available.


Related in: MedlinePlus

Identification of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective chemical inhibitor of isocitrate dehydrogenase-1 (IDH1)-R132H. (A) Inhibitory effects of individual compounds derived from a fragment-based chemical library on the IDH1-R132H activity. A newly identified compound (No. 398) bearing the most significant inhibitory effect against IDH1-R132H was marked with a double asterisk. Statistical analysis was conducted by Student t-test and the asterisk indicates a statistical significance with P < 0.01. (B) Chemical structure of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one. (C) 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity. In this experiment, 2-(3-trifluoromethylphenyl) isothioazol-3(2H)-one was added at the concentration of 10 μM. Control indicates the experiment setup without an addition of purified recombinant IDH1.
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f2-jcp-20-78: Identification of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective chemical inhibitor of isocitrate dehydrogenase-1 (IDH1)-R132H. (A) Inhibitory effects of individual compounds derived from a fragment-based chemical library on the IDH1-R132H activity. A newly identified compound (No. 398) bearing the most significant inhibitory effect against IDH1-R132H was marked with a double asterisk. Statistical analysis was conducted by Student t-test and the asterisk indicates a statistical significance with P < 0.01. (B) Chemical structure of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one. (C) 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity. In this experiment, 2-(3-trifluoromethylphenyl) isothioazol-3(2H)-one was added at the concentration of 10 μM. Control indicates the experiment setup without an addition of purified recombinant IDH1.

Mentions: In order to find out new selective IDH1-R132H chemical inhibitors, we have screened 500 synthetic chemicals derived from a fragment-based chemical library at the concentration of 5 μM. While several synthetic chemicals exhibited mild inhibitory effects, we observed that a synthetic fragment chemical (No. 398) strongly inhibited the IDH1-R132H activity more than 80% (Fig. 2A). The chemical was identified to be 2-(3-trifluoromethyl-phenyl)isothioazol-3(2H)-one and its chemical structure is provided herein (Fig. 2B). In order to exclude the possibility whether this compound also interferes with the wild-type IDH1 activity, the recombinant IDH1 protein was mixed with 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one and the resulting enzymatic activity was assessed. As a result, we observed that 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity, demonstrating the selectivity of this compound against IDH1-R132H (Fig. 2C).


Identification of a new selective chemical inhibitor of mutant isocitrate dehydrogenase-1.

Kim HJ, Choi BY, Keum YS - J Cancer Prev (2015)

Identification of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective chemical inhibitor of isocitrate dehydrogenase-1 (IDH1)-R132H. (A) Inhibitory effects of individual compounds derived from a fragment-based chemical library on the IDH1-R132H activity. A newly identified compound (No. 398) bearing the most significant inhibitory effect against IDH1-R132H was marked with a double asterisk. Statistical analysis was conducted by Student t-test and the asterisk indicates a statistical significance with P < 0.01. (B) Chemical structure of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one. (C) 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity. In this experiment, 2-(3-trifluoromethylphenyl) isothioazol-3(2H)-one was added at the concentration of 10 μM. Control indicates the experiment setup without an addition of purified recombinant IDH1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384718&req=5

f2-jcp-20-78: Identification of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective chemical inhibitor of isocitrate dehydrogenase-1 (IDH1)-R132H. (A) Inhibitory effects of individual compounds derived from a fragment-based chemical library on the IDH1-R132H activity. A newly identified compound (No. 398) bearing the most significant inhibitory effect against IDH1-R132H was marked with a double asterisk. Statistical analysis was conducted by Student t-test and the asterisk indicates a statistical significance with P < 0.01. (B) Chemical structure of 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one. (C) 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity. In this experiment, 2-(3-trifluoromethylphenyl) isothioazol-3(2H)-one was added at the concentration of 10 μM. Control indicates the experiment setup without an addition of purified recombinant IDH1.
Mentions: In order to find out new selective IDH1-R132H chemical inhibitors, we have screened 500 synthetic chemicals derived from a fragment-based chemical library at the concentration of 5 μM. While several synthetic chemicals exhibited mild inhibitory effects, we observed that a synthetic fragment chemical (No. 398) strongly inhibited the IDH1-R132H activity more than 80% (Fig. 2A). The chemical was identified to be 2-(3-trifluoromethyl-phenyl)isothioazol-3(2H)-one and its chemical structure is provided herein (Fig. 2B). In order to exclude the possibility whether this compound also interferes with the wild-type IDH1 activity, the recombinant IDH1 protein was mixed with 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one and the resulting enzymatic activity was assessed. As a result, we observed that 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one does not interfere with the IDH1 activity, demonstrating the selectivity of this compound against IDH1-R132H (Fig. 2C).

Bottom Line: We have found that IDH1, but not IDH1-R132H, can catalyze the conversion of isocitrate into α-ketoglutarate (α-KG).We have observed an underlying biochemical mechanism explaining how a heterozygous IDH1 mutation contributes to the generation of R-2HG and increases cellular histone H3 trimethylation levels.We have also identified a novel selective IDH1-R132H chemical hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one, which could be used for a future lead development against IDH1-R132H.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Dongguk University, Goyang, Seowon University, Cheongju, Korea.

ABSTRACT

Background: Recent genome-wide sequencing studies have identified unexpected genetic alterations in cancer. In particular, missense mutations in isocitrate dehydrogenase-1 (IDH1) at arginine 132, mostly substituted into histidine (IDH1-R132H) were observed to frequently occur in glioma patients.

Methods: We have purified recombinant IDH1 and IDH1-R132H proteins and monitored their catalytic activities. In parallel experiments, we have attempted to find new selective IDH1-R132H chemical inhibitor(s) from a fragment-based chemical library.

Results: We have found that IDH1, but not IDH1-R132H, can catalyze the conversion of isocitrate into α-ketoglutarate (α-KG). In addition, we have observed that IDH1-R132H was more efficient than IDH1 in converting α-KG into (R)-2-hydroxyglutarate (R-2HG). Moreover, we have identified a new hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one as a new selective IDH1-R132H inhibitor.

Conclusions: We have observed an underlying biochemical mechanism explaining how a heterozygous IDH1 mutation contributes to the generation of R-2HG and increases cellular histone H3 trimethylation levels. We have also identified a novel selective IDH1-R132H chemical hit molecule, e.g., 2-(3-trifluoromethylphenyl)isothioazol-3(2H)-one, which could be used for a future lead development against IDH1-R132H.

No MeSH data available.


Related in: MedlinePlus