Veterans Administration Boston Healthcare

West Roxbury, MA, United States

Veterans Administration Boston Healthcare

West Roxbury, MA, United States
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Driscoll J.J.,Veterans Administration Boston Healthcare | Driscoll J.J.,Dana-Farber Cancer Institute | Driscoll J.J.,Harvard University | Driscoll J.J.,U.S. National Cancer Institute | And 22 more authors.
Blood | Year: 2010

Multiple myeloma (MM) is a plasma cell neoplasm that proceeds through a premalignant state of monoclonal gammopathy of unknown significance; however, the molecular events responsible for myelomagenesis remain uncharacterized. To identify cellular pathways deregulated in MM, we addressed that sumoylation is homologous to ubiquitination and results in the attachment of the ubiquitin-like protein Sumo onto target proteins. Sumoylation was markedly enhanced in MM patient lysates compared with normal plasma cells and expression profiling indicated a relative induction of sumoylation pathway genes. The Sumoconjugating enzyme Ube2I, the Sumoligase PIAS1, and the Sumo-inducer ARF were elevated in MM patient samples and cell lines. Survival correlated with expression because 80% of patients with low UBE2I and PIAS1 were living 6 years after transplantation, whereas only 45% of patients with high expression survived 6 years. UBE2I encodes the sole Sumo-conjugating enzyme in mammalian cells and cells transfected with a dominant-negative sumoylation-deficient UBE2I mutant exhibited decreased survival after radiation exposure, impaired adhesion to bone marrow stroma cell and decreased bone marrow stroma cell-induced proliferation. UBE2I confers cells with multiple advantages to promote tumorigenesis and predicts decreased survival when combined with PIAS1. The sumoylation pathway is a novel therapeutic target with implications for existing proteasomal-based treatment strategies.


Hideshima T.,Dana-Farber Cancer Institute | Mitsiades C.,Dana-Farber Cancer Institute | Ikeda H.,Dana-Farber Cancer Institute | Chauhan D.,Dana-Farber Cancer Institute | And 8 more authors.
Blood | Year: 2010

Constitutive B-cell lymphoma 6 (Bcl-6) expression was undetectable in multiple myeloma (MM) cell lines, except U266 cells. However, it was up-regulated by coculture with bone marrow (BM) stromal cell-culture supernatant (SCCS). Bcl-6 expression in patient MM cells in the BM was positive. Anti-interleukin-6 (IL-6)-neutralizing antibody significantly blocked SCCS-induced Bcl-6 in MM cells. Indeed, IL-6 strongly triggered Bcl-6 expression in MM cells, whereas Janus kinase inhibitor and STAT3 siRNA down-regulated Bcl-6. Tumor necrosis factor-α (TNF-α) also triggered Bcl-6, but independently of STAT3, whereas IκB kinaseβ inhibitor down-regulated TNF-α-induced Bcl-6, indicating that the canonical nuclear factor-κB pathway mediates TNF-α-induced Bcl-6 expression. Importantly, down-regulation of Bcl-6 by shRNA significantly inhibited MM cell growth in the presence of SCCS. Our results therefore suggest that Bcl-6 expression in MM cells is modulated, at least in part, via Janus kinase/STAT3 and canonical nuclear factor-κB pathways and that targeting Bcl-6, either directly or via these cascades, inhibits MM cell growth in the BM milieu.


PubMed | Veterans Administration Boston Healthcare
Type: Journal Article | Journal: Blood | Year: 2010

Multiple myeloma (MM) is a plasma cell neoplasm that proceeds through a premalignant state of monoclonal gammopathy of unknown significance; however, the molecular events responsible for myelomagenesis remain uncharacterized. To identify cellular pathways deregulated in MM, we addressed that sumoylation is homologous to ubiquitination and results in the attachment of the ubiquitin-like protein Sumo onto target proteins. Sumoylation was markedly enhanced in MM patient lysates compared with normal plasma cells and expression profiling indicated a relative induction of sumoylation pathway genes. The Sumo-conjugating enzyme Ube2I, the Sumo-ligase PIAS1, and the Sumo-inducer ARF were elevated in MM patient samples and cell lines. Survival correlated with expression because 80% of patients with low UBE2I and PIAS1 were living 6 years after transplantation, whereas only 45% of patients with high expression survived 6 years. UBE2I encodes the sole Sumo-conjugating enzyme in mammalian cells and cells transfected with a dominant-negative sumoylation-deficient UBE2I mutant exhibited decreased survival after radiation exposure, impaired adhesion to bone marrow stroma cell and decreased bone marrow stroma cell-induced proliferation. UBE2I confers cells with multiple advantages to promote tumorigenesis and predicts decreased survival when combined with PIAS1. The sumoylation pathway is a novel therapeutic target with implications for existing proteasomal-based treatment strategies.

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