E6AP ubiquitin ligase regulates PML-induced senescence in Myc-driven lymphomagenesis
Details
Publication Year 2012-07-26, Volume 120, Issue #4, Page 822-832
Journal Title
BLOOD
Publication Type
Journal Article
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 similar to 60% of human Burkitt lymphomas, and down-regulation of E6AP in B-lymphoma cells restored PMLexpression 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. (Blood. 2012;120(4):822-832)
Publisher
AMER SOC HEMATOLOGY
Keywords
ACUTE PROMYELOCYTIC LEUKEMIA; B-CELL LYMPHOMAGENESIS; TUMOR-SUPPRESSOR; TRANSGENIC MICE; CERVICAL-CANCER; P53; DEGRADATION; MDM2; GENE; HETEROCHROMATIN
WEHI Research Division(s)
Molecular Genetics Of Cancer; Stem Cells And Cancer; Chemical Biology
Rights Notice
Copyright © 2012 by The American Society of Hematology


Creation Date: 2012-07-26 12:00:00
Last Modified: 0001-01-01 12:00:00
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