Loss of DAB2IP in RCC cells enhances their growth and resistance to mTOR-targeted therapies.
Oncogene
; 35(35): 4663-74, 2016 09 01.
Article
en En
| MEDLINE
| ID: mdl-26876207
ABSTRACT
Targeted therapies using small-molecule inhibitors (SMIs) are commonly used in metastatic renal cell cancer (mRCC) patients; patients often develop drug resistance and eventually succumb to disease. Currently, understanding of mechanisms leading to SMIs resistance and any identifiable predictive marker(s) are still lacking. We discovered that DAB2IP, a novel Ras-GTPase-activating protein, was frequently epigenetically silenced in RCC, and DAB2IP loss was correlated with the overall survival of RCC patients. Loss of DAB2IP in RCC cells enhances their sensitivities to growth factor stimulation and resistances to SMI (such as mammalian target of rapamycin (mTOR) inhibitors). Mechanistically, loss of DAB2IP results in the activation of extracellular signal-regulated kinase/RSK1 and phosphoinositide-3 kinase/mTOR pathway, which synergizes the induction of hypoxia-inducible factor (HIF)-2α expression. Consequently, elevated HIF-2α suppresses p21/WAF1 expression that is associated with resistance to mTOR inhibitors. Thus combinatorial targeting both pathways resulted in a synergistic tumor inhibition. DAB2IP appears to be a new prognostic/predictive marker for mRCC patients, and its function provides a new insight into the molecular mechanisms of drug resistance to mTOR inhibitors, which also can be used to develop new strategies to overcome drug-resistant mRCC.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Carcinoma de Células Renales
/
Resistencia a Antineoplásicos
/
Proteínas Activadoras de ras GTPasa
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Proliferación Celular
/
Serina-Treonina Quinasas TOR
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Aged
/
Animals
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Female
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Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Oncogene
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
2016
Tipo del documento:
Article
País de afiliación:
China