Toll-like receptors (TLRs) sense microbial products and initiate adaptive immune responses by activating dendritic cells (DCs). As pathogens may contain several TLR agonists, we sought to determine whether different TLRs cooperate in DC activation. In human and mouse DCs, TLR3 and TLR4 potently acted in synergy with TLR7, TLR8 and TLR9 in the induction of a selected set of genes. Synergic TLR stimulation increased production of interleukins 12 and 23 and increased the Delta-4/Jagged-1 ratio, leading to DCs with enhanced and sustained T helper type 1-polarizing capacity. Global gene transcriptional analysis showed that TLR synergy 'boosted' only approximately 1% of the transcripts induced by single TLR agonists. These results identify a 'combinatorial code' by which DCs discriminate pathogens and suggest new strategies for promoting T helper type 1 responses.

Notch2 mutations represent the most frequent lesion in splenic marginal zone lymphoma.

Purpose: In cancer cells, the epigenome is often deregulated, and inhibition of the bromodomain and extra-terminal (BET) family of bromodomain-containing proteins is a novel epigenetic therapeutic approach. Preliminary results of an ongoing phase I trial have reported promising activity and tolerability with the new BET bromodomain inhibitor OTX015.Experimental Design: We assessed the preclinical activity of OTX015 as single agent and in combination in mature B-cell lymphoma models and performed in vitro and in vivo experiments to identify the mechanism of action and the genetic features associated with sensitivity to the compound.Results: OTX015 showed antiproliferative activity in a large panel of cell lines derived from mature B-cell lymphoid tumors with median IC 50 of 240 nmol/L, without significant differences among the different histotypes. In vitro and in vivo experiments showed that OTX015 targeted NFKB/TLR/JAK/STAT signaling pathways, MYC-and E2F1-regulated genes, cell-cycle regulation, and chromatin structure. OTX015 presented in vitro synergism with several anticancer agents, especially with mTOR and BTK inhibitors. Gene expression signatures associated with different degrees of sensitivity to OTX015 were identified. Although OTX015 was mostly cytostatic, the compound induced apoptosis in a genetically defined subgroup of cells, derived from activated B-cell-like diffuse large B-cell lymphoma, bearing wtTP53, mutations in MYD88, and CD79B or CARD11.Conclusions: Together with the data coming from the ongoing phase I study, the in vitro and in vivo data presented here provide the basis for further clinical investigation of OTX015 as single agent and in combination therapies.

Patients with prostate cancer frequently show resistance to androgen-deprivation therapy, a condition known as castration-resistant prostate cancer (CRPC). Acquiring a better understanding of the mechanisms that control the development of CRPC remains an unmet clinical need. The well-established dependency of cancer cells on the tumour microenvironment indicates that the microenvironment might control the emergence of CRPC. Here we identify IL-23 produced by myeloid-derived suppressor cells (MDSCs) as a driver of CRPC in mice and patients with CRPC. Mechanistically, IL-23 secreted by MDSCs can activate the androgen receptor pathway in prostate tumour cells, promoting cell survival and proliferation in androgen-deprived conditions. Intra-tumour MDSC infiltration and IL-23 concentration are increased in blood and tumour samples from patients with CRPC. Antibody-mediated inactivation of IL-23 restored sensitivity to androgen-deprivation therapy in mice. Taken together, these results reveal that MDSCs promote CRPC by acting in a non-cell autonomous manner. Treatments that block IL-23 can oppose MDSC-mediated resistance to castration in prostate cancer and synergize with standard therapies.

Summary A systematic characterization of the genetic alterations driving ALCLs has not been performed. By integrating massive sequencing strategies, we provide a comprehensive characterization of driver genetic alterations (somatic point mutations, copy number alterations, and gene fusions) in ALK− ALCLs. We identified activating mutations of JAK1 and/or STAT3 genes in ∼20% of 155 ALK− ALCLs and demonstrated that 38% of systemic ALK− ALCLs displayed double lesions. Recurrent chimeras combining a transcription factor (NFkB2 or NCOR2) with a tyrosine kinase (ROS1 or TYK2) were also discovered in WT JAK1/STAT3 ALK− ALCL. All these aberrations lead to the constitutive activation of the JAK/STAT3 pathway, which was proved oncogenic. Consistently, JAK/STAT3 pathway inhibition impaired cell growth in vitro and in vivo.

Key Points• Richter syndrome has genomic complexity intermediate between chronic lymphocytic leukemia and diffuse large B-cell lymphoma.• Inactivation of TP53 and of CDKN2A is a main mechanism in the transformation to Richter syndrome.Richter syndrome (RS) occurs in up to 15% of patients with chronic lymphocytic leukemia (CLL). Although RS, usually represented by the histologic transformation to a diffuse large B-cell lymphoma (DLBCL), is associated with a very poor outcome, especially when clonally related to the preexisting CLL, the mechanisms leading to RS have not been clarified. To better understand the pathogenesis of RS, we analyzed a series of cases including 59 RS, 28 CLL phase of RS, 315 CLL, and 127 de novo DLBCL. RS demonstrated a genomic complexity intermediate between CLL and DLBCL. Cell-cycle deregulation via inactivation of TP53 and of CDKN2A was a main mechanism in the histologic transformation from CLL phase, being present in approximately one half of the cases, and affected the outcome of the RS patients. A second major subgroup was characterized by the presence of trisomy 12 and comprised one third of the cases. Although RS shared some of the lesions seen in de novo DLBCL, its genomic profile was clearly separate. The CLL phase preceding RS had not a generalized increase in genomic complexity compared with untransformed CLL, but it presented clear differences in the frequency of specific genetic lesions. (Blood. 2013;122(15):2673-2682

IntroductionMarginal zone lymphoma (MZL), a B-cell non-Hodgkin lymphoma (B-NHL) derived from marginal zone B cells, is currently classified as extranodal MZL (EMZL), nodal MZL (NMZL), and splenic MZL (SMZL). 1 Four recurrent and mutually exclusive chromosomal translocations: t(11;18)(q21; q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1; q32), have been described in EMZLs, but not in NMZLs or SMZLs, with frequencies ranging from 0% to 40% depending on the anatomic site and geographic regions. [2][3][4] At least 3 of these translocations, t(11;18) API2/MALT1, t(1;14) IgH/ BCL10, and t(14;18) IgH/MALT, result in constitutive activation of nuclear factor-B (NF-B), a transcription factor complex regulating multiple cellular processes, including cell growth and survival. 5 In addition, trisomy 3 or 18 has been reported in 30% to 60% of all MZLs and 7q22-32 deletions or translocations of the immunoglobulin heavy chain gene with various partners are found in 7% to 40% of SMZLs. 6,7 The functional consequences of these aberrations are, however, unknown. Currently, approximately 25% of MZLs lack any recognizable recurrent genetic alteration, and evidence of lesions affecting tumor suppressor genes in MZL is limited. 8,9 Recently, deletions of the 6q23.3-q24.1 region containing the tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20), a negative regulator of NF-B, were described in ocular adnexal MZLs. 10 Here, we report that A20 is targeted and inactivated by both somatic mutations and/or deletions in a significant fraction of MZL subtypes, indicating a role of NF-B deregulation in the pathogenesis of these B-NHLs. Methods Case selectionFrozen samples of newly diagnosed MZL (lesional content Ͼ 70%) and matched normal control tissue were obtained from the tumor banks of the Departments of Pathology, Columbia University and the Division of Hematology, Amedeo Avogadro University of Eastern Piedmont. Hematoxylin and eosin-stained sections were used for morphologic analysis. Immunohistochemical (IHC) staining and 4-color flow cytometry were performed for phenotypic characterization using antibodies described in Document S1 (available on the Blood website; see the Supplemental Materials link at the top of the online article). MZLs were classified according to the current WHO classification 1 as EMZL (n ϭ 11: 4 lung, 4 parotid gland, 1 skin, 1 jejunum, 1 orbit), NMZL (n ϭ 9), and SMZL (n ϭ 12; Table S1). The institutional review boards of Columbia University Medical Center and University of Eastern Piedmont approved this study. For personal use only. on May 11, 2018. by guest www.bloodjournal.org From formed as previously described. 11,12 FISH probes included IgH and MALT1 dual-color break-apart probes and centromeric probes for chromosomes 3 and 18 for all cases, and IAP2/MALT1 dual-color dual-fusion probes as indicated (Vysis, Downers Grove, IL). FISH analysis of the A20 locus was performed using BAC clones RP11-703G8 and RP11-102P5 spanning the gene (BACPAC Resources, http://bacpac.chori.org). A locus-spe...

Marginal zone B-cell lymphomas (MZLs) have been divided into 3 distinct subtypes (extranodal MZLs of mucosa-associated lymphoid tissue [MALT] type, nodalMZLs, and splenic MZLs). Nevertheless, the relationship between the subtypes is still unclear. We performed a comprehensive analysis of genomic DNA copy number changes in a very large series of MZL cases with the aim of addressing this question. Samples from 218 MZL patients (25 nodal, 57 MALT, 134 splenic, and 2 not better specified MZLs) were analyzed with the Affymetrix Human Mapping 250K SNP arrays, and the data combined with matched gene expression in 33 of 218 cases. MALT lymphoma presented significantly more frequently gains at 3p, 6p, 18p, and del(6q23) (TNFAIP3/A20), whereas splenic MZLs was associated with del(7q31), del(8p). Nodal MZLs did not show statistically significant differences compared with MALT lymphoma while lacking the splenic MZLs-related 7q losses. Gains of 3q and 18q were common to all 3 subtypes. del(8p) was often present together with del(17p) (TP53). Although del(17p) did not determine a worse outcome and del(8p) was only of borderline significance, the presence of both deletions had a highly significant negative impact on the outcome of splenic MZLs. (Blood. 2011;117(5):1595-1604)