Interactions of the Hdm2/p53 and proteasome pathways may enhance the antitumor activity of bortezomib.
Clin Cancer Res
; 15(23): 7153-60, 2009 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-19934289
ABSTRACT
PURPOSE:
p53 is inactivated in many human malignancies through missense mutations or overexpression of the human homologue of Mdm2 (Hdm2), an E3 ubiquitin ligase that ubiquitinates p53, thereby promoting its proteasomal degradation. The cis-imidazoline nutlin-3 can disrupt the p53-Hdm2 interaction and activate p53, inducing apoptosis in vitro in many malignancies, including multiple myeloma (MM). EXPERIMENTALDESIGN:
We hypothesized that suppression of Hdm2-mediated p53 ubiquitination may augment sequelae of p53 accumulation caused by proteasomal inhibition. We compared the response of MM cells versus several epithelial cancer models to the proteasome inhibitor bortezomib in combination with nutlin-3.RESULTS:
The combination of sublethal concentrations of bortezomib plus nutlin-3 induced additive cytotoxicity against bortezomib-sensitive MM cell lines. Importantly, however, in breast, prostate, colon, and thyroid (papillary, follicular, anaplastic, and medullary) carcinoma cell lines, this combination triggered synergistic cytotoxicity, and increased expression of p53, p21, Hdm2, Bax, Noxa, PUMA, and cleavage of caspase-3 and poly ADP ribose polymerase. Coculture with bone marrow stromal cells attenuated MM cell sensitivity to nutlin-3 monotherapy and was associated with evidence of suppression of p53 activity in MM cells, whereas combined bortezomib-nutlin-3 treatment maintained cytotoxicity even in the presence of bone marrow stromal cells.CONCLUSIONS:
This differential response of MM versus epithelial carcinomas to combination of nutlin-3 with bortezomib sheds new light on the role of p53 in bortezomib-induced apoptosis. Concurrent Hdm2 inhibition with bortezomib may extend the spectrum of bortezomib applications to malignancies with currently limited sensitivity to single-agent bortezomib or, in the future, to MM patients with decreased clinical responsiveness to bortezomib-based therapy.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Pirazinas
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Ácidos Borónicos
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Carcinoma
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Proteína p53 Supresora de Tumor
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Neoplasias Glandulares y Epiteliales
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Complejo de la Endopetidasa Proteasomal
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Proteínas Proto-Oncogénicas c-mdm2
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Mieloma Múltiple
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Antineoplásicos
Límite:
Humans
Idioma:
En
Revista:
Clin Cancer Res
Asunto de la revista:
NEOPLASIAS
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos