E6AP ubiquitin ligase regulates PML-induced senescence in Myc-driven lymphomagenesis.
Blood
; 120(4): 822-32, 2012 Jul 26.
Article
em En
| MEDLINE
| ID: mdl-22689861
ABSTRACT
Neoplastic transformation requires the elimination of key tumor suppressors, which may result from E3 ligase-mediated proteasomal degradation. We previously demonstrated a key role for the E3 ubiquitin ligase E6AP in the regulation of promyelocytic leukemia protein (PML) stability and formation of PML nuclear bodies. Here, we report the involvement of the E6AP-PML axis in B-cell lymphoma development. A partial loss of E6AP attenuated Myc-induced B-cell lymphomagenesis. This tumor suppressive action was achieved by the induction of cellular senescence. B-cell lymphomas deficient for E6AP expressed elevated levels of PML and PML-nuclear bodies with a concomitant increase in markers of cellular senescence, including p21, H3K9me3, and p16. Consistently, PML deficiency accelerated the rate of Myc-induced B-cell lymphomagenesis. Importantly, E6AP expression was elevated in â¼ 60% of human Burkitt lymphomas, and down-regulation of E6AP in B-lymphoma cells restored PML expression with a concurrent induction of cellular senescence in these cells. Our findings demonstrate that E6AP-mediated down-regulation of PML-induced senescence is essential for B-cell lymphoma progression. This provides a molecular explanation for the down-regulation of PML observed in non-Hodgkin lymphomas, thereby suggesting a novel therapeutic approach for restoration of tumor suppression in B-cell lymphoma.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Proteínas Nucleares
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Proteínas Proto-Oncogênicas c-myc
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Linfoma Difuso de Grandes Células B
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Linfoma de Burkitt
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Senescência Celular
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Proteínas Supressoras de Tumor
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Ubiquitina-Proteína Ligases
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Blood
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Austrália