Steven Peter Treon

Increased angiogenesis has recently been recognized in active multiple myeloma (MM). Since vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are two key mediators of angiogenesis, we characterized the production of VEGF, b-FGF and interleukin-6 (IL-6) (a MM growth and survival factor) in MM cell lines and Epstein–Barr virus (EBV) transformed B cell lines from MM patients, patient MM cells, as well as bone marrow stromal cells (BMSCs) from normal healthy ...

Activating mutations in MYD88 are present in ∼95% of patients with Waldenström macroglobulinemia (WM), as well as other B-cell malignancies including activated B-cell (ABC) diffuse large B-cell lymphoma (DLBCL). In WM, mutated MYD88 triggers activation of Bruton tyrosine kinase (BTK). Ibrutinib, a pleiotropic kinase inhibitor that targets BTK, is highly active in patients with mutated MYD88. We observed that mutated MYD88 WM and ABC DLBCL cell lines, as well as primary WM cells show ...

Interleukin-6 (IL-6) is a growth factor for multiple myeloma (MM) cells and can inhibit MM cell apoptosis. Our recent studies show that IL-6 facilitates MM cell growth via phosphorylation of retinoblastoma protein (pRB); however, the effects of IL-6 on those cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors (CDIs) that are known to regulate phosphorylation of pRB have not been defined in MM cells. In the present report, we cultured MM cell lines and patient cells with IL-6 ...

BACKGROUND: Waldenström's macroglobulinemia is an incurable, IgM-secreting lymphoplasmacytic lymphoma (LPL). The underlying mutation in this disorder has not been delineated.

METHODS: We performed whole-genome sequencing of bone marrow LPL cells in 30 patients with Waldenström's macroglobulinemia, with paired normal-tissue and tumor-tissue sequencing in 10 patients. Sanger sequencing was used to validate the findings in samples from an expanded cohort of patients with LPL, those with ...

Interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) promote the proliferation of multiple myeloma (MM) cells and protect them against dexamethasone (Dex)-induced apoptosis. We have previously shown that Apo2 ligand/TNF-Related apoptosis inducing ligand (Apo2L/TRAIL) induces apoptosis of MM cells, including cells either sensitive or resistant to Dex and cytotoxic drugs, and overcomes the growth and survival effect of IL-6; conversely, NF-κB transcriptional activity attenuates ...

Multiple myeloma (MM) remains incurable and novel treatments are urgently needed. Preclinical in vitro and in vivo evaluations were performed to assess the potential therapeutic applications of human recombinant tumor necrosis factor (TNF)-related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo2L) in MM. TRAIL/Apo2L potently induced apoptosis of MM cells from patients and the majority of MM cell lines, including cells sensitive or resistant to dexamethasone (Dex), doxorubicin (Dox), ...

Myeloid differentiation factor 88 (MYD88) L265P somatic mutation is highly prevalent in Waldenström macroglobulinemia (WM) and supports malignant growth through nuclear factor κB (NF-κB). The signaling cascade(s) by which MYD88 L265P promotes NF-κB activation in WM remain unclear. By lentiviral knockdown or use of a MYD88 inhibitor, decreased phosphorylation of the NF-κB gatekeeper IκBα and survival occurred in MYD88 L265P-expressing WM cells. Conversely, WM cells engineered to ...

The anti-CD20 chimeric monoclonal antibody rituximab (Rituxan) is used to treat patients with various B-cell tumors, including patients with plasma cell dyscrasias who have CD20+ disease. Many patients with CD20+ disease have either primary unresponsive disease or progress after initially responding to rituximab; therefore, understanding how tumor cells are, or become, resistant to rituximab is of clinical relevance. In this report, we determined whether tumor cells express antigens that ...

Multiple myeloma (MM) is characterized by clonal expansion of malignant plasma cells in the bone marrow and their egress into peripheral blood with progression to plasma cell leukemia. Our previous study defined a functional role of CD40 activation in MM cell homing and migration. In this study, we examine signaling events mediating CD40-induced MM cell migration. We show that cross-linking CD40, using either soluble CD40L (sCD40L) or anti-CD40 monoclonal antibody (mAb), induces ...

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL, Apo2 ligand) effectively kills multiple myeloma (MM) cells in vitro irrespective of refractoriness to dexamethasone and chemotherapy. Because clinical trials with this anticancer agent are expected shortly, we investigated the signaling pathway of TRAIL-induced apoptosis in MM. We detected rapid cleavage of caspases-8, -9, -3, and -6, as well as the caspase substrates poly(ADP-ribose) polymerase (PARP) and DNA fragmentation ...

The antiangiogenic activity of thalidomide (Thal), coupled with an increase in bone marrow angiogenesis in multiple myeloma (MM), provided the rationale for the use of Thal in MM. Previously, the direct anti-MM activity of Thal and its analogues (immunomodulatory drugs, IMiDs) on MM cells was demonstrated, suggesting multiple mechanisms of action. In this study, the potential immunomodulatory effects of Thal/IMiDs in MM were examined. It was demonstrated that Thal/IMiDs do not induce ...

PURPOSE: CD52 is a GPI-linked glycoprotein expressed by B cells, T cells, monocytes, and macrophages. The humanized monoclonal antibody alemtuzumab (CAMPATH-1H) is specific for CD52 and is Food and Drug Administration - approved for the treatment of relapsed or refractory chronic lymphocytic leukemia (CLL). The utility of CAMPATH in the treatment of other hematologic neoplasms has been explored; however, a comprehensive survey of CD52 expression among a broad spectrum of WHO-defined ...

Our previous studies have shown that activation of a related adhesion focal tyrosine kinase (RAFTK) (also known as Pyk2) is required for dexamethasone (Dex)-induced apoptosis in multiple myeloma (MM) cells and that human interleukin-6 (IL-6), a known growth and survival factor for MM cells, blocks both RAFTK activation and apoptosis induced by Dex. However, the mechanism whereby IL-6 inhibits Dex-induced apoptosis is undefined. In this study, we demonstrate that protein-tyrosine ...

Whole genome sequencing has revealed activating somatic mutations in MYD88 (L265P) and CXCR4 in Waldenström macroglobulinemia (WM). CXCR4 somatic mutations in WM are the first ever reported in human cancer and are similar to nonsense (NS) and frameshift (FS) germline mutations found in warts, hypogammaglobulinemia, infections and myelokathexis (WHIM) syndrome. We genotyped lymphoplasmacytic cells from 175 WM patients and observed significantly higher bone marrow (BM) disease involvement, ...