Sézary Syndrome is a rare leukemic form of cutaneous T-cell lymphoma defined as erythroderma, adenopathy, and circulating atypical T-lymphocytes. It is rarely curable with poor prognosis. Here we present a multi-platform genomic analysis of 37 Sézary Syndrome patients that implicates dysregulation of the cell cycle checkpoint and T-cell signaling. Frequent somatic alterations were identified in TP53, CARD11, CCR4, PLCG1, CDKN2A, ARID1A, RPS6KA1, and ZEB1. Activating CCR4 and CARD11 mutations were detected in nearly a third of patients. ZEB1, a transcription repressor essential for T-cell differentiation, was deleted in over half of patients. IL32 and IL2RG were over-expressed in nearly all cases. Analysis of T-cell receptor Vβ and Vα expression revealed ongoing rearrangement of the receptors after the expansion of a malignant clone in one third of subjects. Our results demonstrate profound disruption of key signaling pathways in Sézary Syndrome and suggest potential targets for novel therapies.

Multiple myeloma remains an incurable disease. One of the major problems is that myeloma cells develop drug resistance on interaction with bone marrow stromal cells. In this study, we examined the effects of macrophages (Mvarphis), a type of stromal cells, on myeloma cell survival and response to chemotherapy. We showed that Mvarphi, in particular tumor-associated Mvarphi, is a protector of myeloma cells. The protective effect was dependent on direct contact between Mvarphis and myeloma cells. Mvarphis protected both myeloma cell lines and primary myeloma cells from spontaneous and chemotherapy drug-induced apoptosis by attenuating the activation and cleavage of caspase-dependent apoptotic signaling. These findings are clinically relevant because we found that CD68+ Mvarphis heavily infiltrate the bone marrow of patients with myeloma but not the bone marrow of control patients. Thus, our results indicate that Mvarphis may contribute to myeloma cell survival and resistance to chemotherapeutic treatment in vivo.

Elevated levels of C-reactive protein (CRP) are present in many disease situations including malignancies and may contribute to the pathogenesis of cardiovascular disorders. This study was undertaken in a myeloma setting to determine whether CRP affects tumor cell growth and survival. We show that CRP enhanced myeloma cell proliferation under stressed conditions and protected myeloma cells from chemotherapy drug-induced apoptosis in vitro and in vivo. CRP binds activating Fcgamma receptors; activates PI3K/Akt, ERK, and NF-kappaB pathways; and inhibits caspase cascade activation induced by chemotherapy drugs. CRP also enhanced myeloma cell secretion of IL-6 and synergized with IL-6 to protect myeloma cells from chemotherapy drug-induced apoptosis. Thus, our results implicate CRP as a potential target for cancer treatment.

Previous studies demonstrated that circulating dendritic cells (DCs) in myeloma patients were functionally abnormal. However, the phenotype and function of patients' monocyte-derived DCs (MoDCs), which are commonly used for immunotherapy, were poorly defined. This study was undertaken to examine the quality of MoDCs from myeloma patients compared with cells from healthy donors. We found that patient-derived MoDCs are phenotypically and functionally defective. Compared with their normal counterparts, patient-derived, mature MoDCs expressed significantly lower levels of CD1a, CD40, CD80, and HLA-DR and were poor at activating alloreactive T cells, presenting recall antigen, and activating autologous antigen-and myeloma-specific T cells. These abnormalities may be attributed to elevated production of autocrine cytokines such as IL-6, activated p38 and STAT3, and inhibited MEK/ERK signaling pathways in the progenitor cells. Treatment with neutralizing IL-6-specific antibody and, more importantly, p38 inhibitor, or both, could correct these abnormalities. Treating patient-derived cells with these agents not only significantly increased cell yield but also produced MoDCs that were as functional as their normal counterparts. Thus, this study has delineated the mechanistic defects of MoDCs from myeloma patients and identi- IntroductionDendritic cells (DCs) are the sentinels of the immune system. [1][2][3] In their immature state, DCs are distributed primarily in tissues where they efficiently survey for incoming pathogens. Encounter with pathogens leads to DC activation and migration to secondary lymphoid organs, and during the migration they undergo maturation. Mature DCs not only acquire the ability to stimulate quiescent, naive CD4 ϩ and CD8 ϩ T cells and B cells and initiate primary immune responses but can also induce a strong secondary immune response with relatively small numbers of DCs and low levels of antigen. 2 Given their central role in controlling immunity, DCs are logical targets for many clinical situations that involve T cells, such as graft rejection, allergy, autoimmune diseases, resistance to infection and tumors, immunodeficiency, and vaccination.DC-based immunotherapy holds great promise for treating malignancies 4-6 including multiple myeloma (MM). [7][8][9][10] However, preliminary reports of DC-based immunotherapy in human MM have demonstrated minor clinical responses. [7][8][9][10] The lack of effectiveness of DC vaccines in tumor patients may be associated, at least in part, with defects in DCs. [11][12][13][14] Indeed, previous studies showed that the numbers of circulating DCs were significantly lower in patients with MM than in healthy individuals, 14 and the phenotype and function of these cells were also impaired. 13,14 The underlying mechanisms are largely unknown. Using the 5T2 myeloma mouse model, we have recently shown that myeloma cells or tumor-culture conditioning medium (TCCM) were able to inhibit differentiation and function of murine bone marrowderived DCs. 15 However, the phen...

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