A small-molecule inhibitor suppresses the tumor-associated mitochondrial NAD(P)+-dependent malic enzyme (ME2) and induces cellular senescence.
Oncotarget
; 6(24): 20084-98, 2015 Aug 21.
Article
em En
| MEDLINE
| ID: mdl-26008970
ABSTRACT
Here, we found a natural compound, embonic acid (EA), that can specifically inhibit the enzymatic activity of mitochondrial NAD(P)+-dependent malic enzyme (m-NAD(P)-ME, ME2) either in vitro or in vivo. The in vitro IC50 value of EA for m-NAD(P)-ME was 1.4 ± 0.4 µM. Mutagenesis and binding studies revealed that the putative binding site of EA on m-NAD(P)-ME is located at the fumarate binding site or at the dimer interface near the site. Inhibition studies reveal that EA displayed a non-competitive inhibition pattern, which demonstrated that the binding site of EA was distinct from the active site of the enzyme. Therefore, EA is thought to be an allosteric inhibitor of m-NAD(P)-ME. Both EA treatment and knockdown of m-NAD(P)-ME by shRNA inhibited the growth of H1299 cancer cells. The protein expression and mRNA synthesis of m-NAD(P)-ME in H1299 cells were not influenced by EA, suggesting that the EA-inhibited H1299 cell growth occurs through the suppression of in vivo m-NAD(P)-ME activity EA treatment further induced the cellular senescence of H1299 cells. However, down-regulation of the enzyme-induced cellular senescence was not through p53. Therefore, the EA-evoked senescence of H1299 cells may occur directly through the inhibition of ME2 or a p53-independent pathway.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Inibidores Enzimáticos
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Malato Desidrogenase
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Naftóis
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Oncotarget
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Taiwan