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The caspase recruitment domain family member (CARD)11-Bcl10-Malt1 signalosome controls TGF-β–activated kinase 1 (TAK1) activation and regulates BCR-induced NF-κB activation. In this study, we discovered that CARD19 interacted with TAK1 and inhibited TAB2-mediated TAK1 ubiquitination and activation. Although CARD19 deficiency in mice did not affect B cell development, it enhanced clonal deletion, receptor editing, and anergy of self-reactive B cells, and it reduced autoantibody production. Mechanistically, CARD19 deficiency increased BCR/TAK1-mediated NF-κB activation, leading to increased expression of transcription factors Egr2/3, as well as the E3 ubiquitin ligases c-Cbl/Cbl-b, which are known inducers of B cell tolerance in self-reactive B cells. RNA sequencing analysis revealed that although CARD19 deficiency did not affect the overall Ag-induced gene expression in naive B cells, it suppressed BCR signaling and increased hyporesponsiveness of self-reactive B cells. As a result, CARD19 deficiency prevented Bm12-induced experimental systemic lupus erythematosus. In summary, CARD19 negatively regulates BCR/TAK1-induced NF-κB activation and its deficiency increases Egr2/3 and c-Cbl/Cbl-b expression in self-reactive B cells, thereby enhancing B cell tolerance.

PDF file - 251K, Chemical structures of ganetespib and crizotinib.

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PDF file - 486K, The addition of ganetespib to crizotinib does not result in added toxicity in H3122 xenografts.

PDF file - 2538K, Crizotinib-resistant H3122 CR1 cells express an EMT phenotype.

The CARD11-Bcl10-Malt1 (CBM) signalosome controls TAK1 activation to regulate B-cell receptor (BCR)-induced NF-κB activation and B cell biology. The biological function of caspase recruitment domain family member 19 (CARD19), originally identified as a BCL10-interacting CARD protein (BinCARD), is not known. Here we found CARD19 strongly interacted with TAK1 but not BCL10 or other CBM components and prevented TAK1's association with TAB2, thereby inhibiting TAB2-mediated TAK1 ubiquitination and activation and subsequent NF-κB activation. CARD19 was ubiquitously expressed in hematopoietic lineages but its deficiency in mice had no effect on hematopoiesis, including B cell development and humoral immune response. CARD19 deficiency enhanced clonal deletion, receptor editing and anergy of self-reactive B cells, thus reducing autoantibody production in vivo. Mechanistically, CARD19 deficiency led to an increase of BCR/TAK1-mediated NF-κB activation. Activation of NF-κB, such as c-Rel, was responsible for the up-regulation of BCR-induced expression of the transcription factor early growth response genes 2 and 3 (Egr2, Egr3) and the E3 ubiquitin ligases, c-Cbl and Cbl-b, the important inducers of B-cell tolerance in B cells. Further, high-throughput RNA sequencing analysis revealed that CARD19 deficiency did not affect the overall antigen-induced gene expression in naïve B cells but suppressed BCR signaling to increase hyporesponsiveness of self-reactive B cells. Consequently, CARD19 deficiency prevented Bm12-induced experimental systemic lupus erythematosus (SLE) and autoimmunity in a B cell-intrinsic manner. Taken together, CARD19 negatively regulates BCR-induced NF-κB activation via blocking TAK1/TAB2 interaction and its deficiency leads to NF-κB-induced expression of Egr2/3 and c-Cbl/Cbl-b in self-reactive B cells, which enhances B-cell tolerance and thus prevents autoimmunity. Disclosures No relevant conflicts of interest to declare.

A20, a tumor suppressor in several types of lymphomas, has been suggested to be an nuclear factor kappa B (NF-κB) target gene; conversely, the deubiquitylation activity of A20 is required for inhibition of Bcl10-mediated activation of NF-κB. BCL10, which is activated in a recurrent chromosomal translocation that causes human mucosa-associated lymphoid tissue lymphomas, is known to be essential for NF-κB activation in B cells. We report here that Bcl10 upregulates endogenous A20 gene expression in B lymphocytes upon B-cell receptor engagement of anti-IgM. Transient transfection assays in HEK 293 cells indicate that Bcl10 can activate the A20 promoter, which contains NF-κB-binding sites. We also construct a theoretical structure of mouse Bcl10 and analyze the structure by molecular modeling and molecular dynamics simulation. Lastly, we found that marginal zone B cells from BCL10-transgenic mice proliferate more readily than wild-type B cells, whereas, surprisingly, the transgenic follicular B cells from these mice proliferate comparably to wild-type cells. Collectively, our results indicate that Bcl10 is an essential regulator of A20 gene expression and B-cell proliferation mediated by B-cell receptor signaling.

The common food additive carrageenan is a known activator of inflammation in mammalian tissues and stimulates both the canonical and noncanonical pathways of NF-κB activation. Exposure to low concentrations of carrageenan (10 μg/mL in the water supply) has produced glucose intolerance, insulin resistance, and impaired insulin signaling in C57BL/6 mice. B-cell leukemia/lymphoma 10 (Bcl10) is a mediator of inflammatory signals from Toll-like receptor (TLR) 4 in myeloid and epithelial cells. Since the TLR4 signaling pathway is activated in diabetes and by carrageenan, we addressed systemic and intestinal inflammatory responses following carrageenan exposure in Bcl10 wild type, heterozygous, and null mice. Fecal calprotectin and circulating keratinocyte chemokine (KC), nuclear RelA and RelB, phospho(Thr559)-NF-κB-inducing kinase (NIK), and phospho(Ser36)-IκBαin the colonic epithelial cells were significantly less (P<0.001) in the carrageenan-treated Bcl10 null mice than in controls. IL-10-deficient mice exposed to carrageenan in a germ-free environment showed an increase in activation of the canonical pathway of NF-κB (RelA) activation, but without increase in RelB or phospho-Bcl10, and exogenous IL-10 inhibited only the canonical pathway of NF-κB activation in cultured colonic cells. These findings demonstrate a Bcl10 requirement for maximum development of carrageenan-induced inflammation and lack of complete suppression by IL-10 of carrageenan-induced inflammation.

BCL10, required for nuclear factor κB (NF-κB) activation during antigen-driven lymphocyte responses, is aberrantly expressed in mucosa-associated lymphoid tissue-type marginal zone (MZ) lymphomas because of chromosomal translocations. Eμ-driven human BCL10 transgenic (Tg) mice, which we created and characterize here, had expanded populations of MZ B cells and reduced follicular and B1a cells. Splenic B cells from Tg mice exhibited constitutive activation of both canonical and noncanonical NF-κB signaling pathways is associated with increased expression of NF-κB target genes. These genes included Tnfsf13b, which encodes the B-cell activating factor (BAFF). In addition, levels of BAFF were significantly increased in sera from Tg mice. MZ B cells of Tg mice exhibited reduced turnover in vivo and enhanced survival in vitro, indicative of lymphoaccumulation rather than lymphoproliferation as the cause of MZ expansion. In vivo antibody responses to both T-independent, and especially T-dependent, antigens were significantly reduced in Tg mice. Mortality was accelerated in Tg animals, and some mice older than 8 months had histologic and molecular findings indicative of clonal splenic MZ lymphoma. These results suggest that, in addition to constitutive activation of BCL10 in MZ B cells, other genetic factors or environmental influences are required for short latency oncogenic transformation.

Neuroblastoma, an embryonal tumour of the peripheral sympathetic nervous system, accounts for approximately 15% of all deaths due to childhood cancer. High-risk neuroblastomas are rapidly progressive; even with intensive myeloablative chemotherapy, relapse is common and almost uniformly fatal. Here we report the detection of previously unknown mutations in the ALK gene, which encodes a receptor tyrosine kinase, in 8% of primary neuroblastomas. Five non-synonymous sequence variations were identified in the kinase domain of ALK, of which three were somatic and two were germ line. The most frequent mutation, F1174L, was also identified in three different neuroblastoma cell lines. ALK complementary DNAs encoding the F1174L and R1275Q variants, but not the wild-type ALK cDNA, transformed interleukin-3-dependent murine haematopoietic Ba/F3 cells to cytokine-independent growth. Ba/F3 cells expressing these mutations were sensitive to the small-molecule inhibitor of ALK, TAE684 (ref. 4). Furthermore, two human neuroblastoma cell lines harbouring the F1174L mutation were also sensitive to the inhibitor. Cytotoxicity was associated with increased amounts of apoptosis as measured by TdT-mediated dUTP nick end labelling (TUNEL). Short hairpin RNA (shRNA)-mediated knockdown of ALK expression in neuroblastoma cell lines with the F1174L mutation also resulted in apoptosis and impaired cell proliferation. Thus, activating alleles of the ALK receptor tyrosine kinase are present in primary neuroblastoma tumours and in established neuroblastoma cell lines, and confer sensitivity to ALK inhibition with small molecules, providing a molecular rationale for targeted therapy of this disease.

Previous studies have demonstrated that Bcl10 (B-cell leukemia/lymphoma 10) is essential for T cell receptor-mediated NF-κB activation and subsequent proliferation and interleukin 2 (IL2) production. However, here we demonstrate that, contrary to expectations, Bcl10 is differentially required for T cell activation, including for both proliferation and cytokine production. When CD4+ and CD8+ T cells were divided based on expression levels of CD44, which distinguishes naive cells (CD44lo) versus those that are antigen-experienced (CD44hi), IL2 production by and proliferation of CD4+CD44lo naive cells and both subpopulations of CD8+ T cells were clearly Bcl10-dependent, whereas these same functional properties of CD4+CD44hi T cells occurred largely independent of Bcl10. As with the other subpopulations of T cells, CD4+CD44hi T cells did not activate the NF-κB pathway in the absence of Bcl10; nevertheless, these CD4+CD44hi antigen-experienced T cells efficiently secreted IL2 after T cell receptor stimulation. Strikingly, therefore, T cell receptor-mediated IL2 production in these cells is NF-κB-independent. Our studies suggest that antigen-experienced CD4+ T cells differ from their naive counterparts and from CD8+ T cells in their ability to achieve activation independent of the Bcl10/NF-κB pathway.

Activating NK cell receptors transduce signals through ITAM-containing adaptors, including FcRγ and DAP12. Although the caspase recruitment domain (CARD)9-Bcl10 complex is essential for FcRγ/DAP12-mediated NF-κB activation in myeloid cells, its involvement in NK cell receptor signaling is unknown. Herein we show that the deficiency of CARMA1 or Bcl10, but not CARD9, resulted in severe impairment of cytokine/chemokine production mediated by activating NK cell receptors due to a selective defect in NF-κB activation, whereas cytotoxicity mediated by the same receptors did not require CARMA1-Bcl10-mediated signaling. IκB kinase (IKK) activation by direct protein kinase C (PKC) stimulation with PMA plus ionomycin (P/I) was abrogated in CARMA1-deficient NK cells, similar to T and B lymphocytes, whereas CARD9-deficient dendritic cells (DCs) exhibited normal P/I-induced IKK activation. Surprisingly, CARMA1 deficiency also abrogated P/I-induced IKK activation in DCs, indicating that CARMA1 is essential for PKC-mediated NF-κB activation in all cell types, although the PKC-CARMA1 axis is not used downstream of myeloid ITAM receptors. Consistently, PKC inhibition abrogated ITAM receptor-mediated activation only in NK cells but not in DCs, suggesting PKC-CARMA1-independent, CARD9-dependent ITAM receptor signaling in myeloid cells. Conversely, the overexpression of CARD9 in CARMA1-deficient cells failed to restore the PKC-mediated NF-κB activation. Thus, NF-κB activation signaling through ITAM receptors is regulated by a cell type-specific mechanism depending on the usage of adaptors CARMA1 and CARD9, which determines the PKC dependence of the signaling.

The adaptor protein B cell lymphoma 10 (Bcl10) plays an essential role in the functions of the AgRs in T and B cells. In this study, we report that Bcl10 also plays an important role in mast cells. Bcl10 is expressed in mast cells. Although Bcl10-deficient mast cells undergo normal development, we demonstrate that Bcl10 is essential for specific functions of FcεR. Although Bcl10-deficient mast cells have normal de novo synthesis and release of the lipid mediator arachidonic acid, the mutant cells possess impaired FcεR-mediated degranulation, indicated by decreased serotonin release, and impaired cytokine production, measured by release of IL-6. In addition, Bcl10-deficient mice display impaired IgE-mediated passive cutaneous anaphylaxis. Moreover, although Bcl10-deficient mast cells have normal FcεR-mediated Ca2+ flux, activation of PI3K, and activation of the three types of MAPKs (ERKs, JNK, and p38), the mutant cells have markedly diminished FcεR-mediated activation of NF-κB and decreased activation of AP-1. Thus, Bcl10 is essential for FcεR-induced activation of AP-1, NF-κB, degranulation, and cytokine production in mast cells.

To detect the frequency of ROS1 gene rearrangement in non-small cell lung cancer ( NSCLC) patients by FISH, and to analyze the relationship between ROS1 gene rearrangement and clinical features (including age, sex, stage, histology, smoking history) with NSCLC.The ROS1 gene rearrangement in histological sections of 1 652 NSCLC tissues was detected by FISH. The extracted RNA was amplified and the sequences were analyzed by Sanger sequencing for ROS1-positive samples.ROS1 rearrangement was identified in 53 specimens (3.2%) from the 1 652 NSCLC tissues. Among these positive cases, 15 were CD74-ROS1, 13 were SLC34A2-ROS1, 13 were SDC4-ROS1 and 12 were TPM3-ROS1. The frequency of ROS1 rearrangement was significantly higher in never-smoking patients (49 cases) than in smokers (4 cases) (P0.05). Patients with ROS1-positive NSCLC tended to be younger and there was no significant difference in sex (P0.05). All of the ROS1-positive samples were adenocarcinomas, with a tendency toward higher clinical stage (P0.05).ROS1 rearrangement has diversity, and may be defined as a new molecular subtype of NSCLC. ROS1 rearrangement tends to occur in younger, and never-smoker lung adenocarcinoma patients.

PLCgamma2 plays a critical role in B cell receptor (BCR) signaling and its targeted deletion results in defective B cell development and function. Here, we show that PLCgamma2 deficiency specifically blocks B cell maturation at the transitional type 2 (T2) to follicular (FO) B cell transition and the PLCgamma2 pathway regulates survival of B cells. BCR-induced apoptosis is dramatically enhanced in all subsets of splenic PLCgamma2-deficient B cells, especially in T2 and FO B cell subpopulations. We also find that all splenic PLCgamma2-deficient B cell subpopulations express abnormally low levels of Bcl-2 protein. In addition, PLCgamma2 deficiency disrupts BCR-mediated induction of A1 expression. Enforced expression of Bcl-2 prevents BCR-induced apoptosis in all splenic PLCgamma2-deficient B cell subpopulations and partially restores the numbers of PLCgamma2-deficient FO B cells. In contrast to Bcl-2, enforced expression of A1 preferentially prevents BCR-induced apoptosis in PLCgamma2-deficient FO B cells and partially restores the numbers of these B cells. Therefore, the PLCgamma2 pathway provides a survival signal via regulation of Bcl-2 in all splenic B cell subpopulations and via additional induction of A1 in mature FO B cells.

Bcl10 is an intracellular protein essential for nuclear factor (NF)-kappaB activation after lymphocyte antigen receptor stimulation. Using knockout mice, we show that absence of Bcl10 impeded conversion from transitional type 2 to mature follicular B cells and caused substantial decreases in marginal zone and B1 B cells. Bcl10-deficient B cells showed no excessive apoptosis. However, both Bcl10-deficient follicular and marginal zone B cells failed to proliferate normally, although Bcl10-deficient marginal zone B cells uniquely failed to activate NF-kappaB efficiently after stimulation with lipopolysaccharide. Bcl10-deficient marginal zone B cells did not capture antigens, and Bcl10-deficient (Bcl10-/-) mice failed to initiate humoral responses, leading to an inability to clear blood-borne bacteria. Thus, Bcl10 is essential for the development of all mature B cell subsets.

Objective Approximately 60% of all anaplastic large-cell lymphomas (ALCL) contain a specific t(2;5)(p23;q35) chromosomal translocation leading to overexpression of NPM-ALK. As the chimeric tyrosine kinase is involved in tumorigenesis and pathogenesis of ALCL, we were interested to inhibit NPM-ALK expression using an exogenous and an endogenous ribozyme approach. Methods We designed five anti- ALK hammerhead ribozymes that were targeted to cleave the ALK proportion of NPM-ALK. The ribozyme with the highest cleavage activity was used as a modified RNA/DNA chimera (RZ1*) for transient transfection and as a self-splicing ribozyme vector (pRZ1) for endogenous expression. Ribozyme performance was tested in 293 cells (cotransfected with NPM-ALK) and in the ALCL cell line Karpas 299 by transient and stable transfection and Western blotting. The half-life time of NPM-ALK was determined by pulse-chase experiments. Results In vitro cleavage assays demonstrated different catalytic efficiencies depending on the targeted site of the substrate. Constant transfection of Karpas 299 cells with RZ1* for 96 hours did not lead to a significant reduction of NPM-ALK protein, presumably due to the long half-life of NPM-ALK (48 hours). In contrast, NPM-ALK protein expression was almost completely suppressed in transiently transfected 293 cells. Stable transfection of Karpas 299 cells with pRZ1 also resulted in significant reduction of NPM-ALK expression. Conclusion These results suggest that ribozymes targeted against NPM-ALK are able to inhibit expression of this oncogenic kinase efficiently and will be a useful tool to analyze its role in the pathophysiology of ALCL.

To establish a repeat-free ROS1 gene fluorescence in situ hybridization (FISH) probe, and to compare its efficacy with those of commercial FISH probes in non-small cell lung cancer.The probe was constructed by combining human Cot-1 DNA genome into double-stranded sequence, and then digested by duples specific nuclease to establish a repeat-free sequence. The final repeat-free ROS1 FISH probe was labeled by red and green fluoresceins.Compared with the commercialized probe, repeat-free FISH probe exhibited excellent efficiency and low signal to noise ratio (SNR) in samples. There was statistical significance in the difference between the hybridization rate of these two probes (P0.05) , but there was no difference between the accuracy rate (P0.05).The repeat-free ROS1 FISH probe significantly improves the probe hybridization efficiency and SNR in non-small cell lung cancer (NSCLC), resulting in an increased accuracy of detection.

Mucosa-associated lymphoid tissue (MALT) lymphomas most frequently involve the gastrointestinal tract and are the most common subset of extranodal non-Hodgkin lymphoma (NHL). Here we describe overexpression of BCL10, a novel apoptotic signalling gene that encodes an amino-terminal caspase recruitment domain (CARD), in MALT lymphomas due to the recurrent t(1;14)(p22;q32). BCL10 cDNAs from t(1;14)-positive MALT tumours contained a variety of mutations, most resulting in truncations either in or carboxy terminal to the CARD. Wild-type BCL10 activated NF-kappaB but induced apoptosis of MCF7 and 293 cells. CARD-truncation mutants were unable to induce cell death or activate NF-kappaB, whereas mutants with C-terminal truncations retained NF-kappaB activation but did not induce apoptosis. Mutant BCL10 overexpression might have a twofold lymphomagenic effect: loss of BCL10 pro-apoptosis may confer a survival advantage to MALT B-cells, and constitutive NF-kappaB activation may provide both anti-apoptotic and proliferative signals mediated via its transcriptional targets.

Five clones isolated from a channel catfish cDNA library were each reactive with monoclonal antibodies (mAbs) C3-1 and 51A only. The size of the cDNA inserts from C3-1 and 51A positive clones was 2.5 Kb and identical based on sequence analysis. Monoclonal antibodies C3-1 and 51A specifically reacted with the expressed product of the 2.5 Kb cDNA clone. The complete DNA sequence indicated that the 2.5 Kb cDNA encoded an approximately 50 Kd protein molecule consisting of 445 amino acids. Sequence analysis showed that this putative protein was a potential leucine-zipper DNA binding protein. Comparison of the deduced amino acid sequence demonstrated homology (14.6 to 19.5%) throughout the sequence of the catfish protein with a group of cytoplasmic-leucine zipper containing proteins of humans; paraneoplastic cellebellar degeneration related (cdr) antigen 2 and 3 with 39.8 to 56.3% homology in the leucine-zipper motif (amino acids 52 through 175 in the catfish protein). This protein was detected in nuclear extracts, cytoplasmic membrane preparations and cytosolic extracts of neutrophils and lymphocytes when reacted with mAbs C3-1 and 51A in an ELISA. However, the intensity of the reactions was dependent upon the cell type and cellular component. The putative cdr protein was not detected with any appreciable intensity in preparations from other cell types. This finding strongly suggests that this protein is expressed in a leukocyte-specific manner and is unique among the cdr group in that it is being expressed in a site that is not immune privileged.

EML4–ALK gene rearrangements define a unique subset of patients with non–small cell lung carcinoma (NSCLC), and the clinical success of the anaplastic lymphoma kinase (ALK) inhibitor crizotinib in this population has become a paradigm for molecularly targeted therapy. Here, we show that the Hsp90 inhibitor ganetespib induced loss of EML4–ALK expression and depletion of multiple oncogenic signaling proteins in ALK-driven NSCLC cells, leading to greater in vitro potency, superior antitumor efficacy, and prolonged animal survival compared with results obtained with crizotinib. In addition, combinatorial benefit was seen when ganetespib was used with other targeted ALK agents both in vitro and in vivo. Importantly, ganetespib overcame multiple forms of crizotinib resistance, including secondary ALK mutations, consistent with activity seen in a patient with crizotinib-resistant NSCLC. Cancer cells driven by ALK amplification and oncogenic rearrangements of ROS1 and RET kinase genes were also sensitive to ganetespib exposure. Taken together, these results highlight the therapeutic potential of ganetespib for ALK-driven NSCLC. Significance: In addition to direct kinase inhibition, pharmacologic blockade of the molecular chaperone Hsp90 is emerging as a promising approach for treating tumors driven by oncogenic rearrangements of ALK. The bioactivity profile of ganetespib presented here underscores a new therapeutic opportunity to target ALK and overcome multiple mechanisms of resistance in patients with ALK-positive NSCLC. Cancer Discov; 3(4); 430–43. ©2013 AACR. This article is highlighted in the In This Issue feature, p. 363

Adhesion of leukocytes to endothelium and extracellular matrix proteins is an important step in the inflammatory process. Therefore, the adhesion of channel catfish neutrophils to a surface coated with extracellular matrix proteins, LPS, and non-immune catfish serum was evaluated. Stimulation of neutrophils with phorbol dibutyrate (PDBU) resulted in at least two-fold increases in cellular adhesion to all substrates tested except laminin. When EDTA was included during or after PDBU stimulation, neutrophil adhesion to fibrinogen and LPS coated surfaces was reduced to the level of unstimulated neutrophils or to 50-60% of that for stimulated neutrophils. Similarly, EDTA and Ca2+/Mg2+ deficient medium reduced homotypic aggregation of PDBU stimulated neutrophils to background levels. Adhesion of stimulated neutrophils to fibrinogen coated surfaces was inhibited 44, 33, and 50% when soluble fibrinogen, fibronectin, and serum, respectively, were used to block the adhesion assay. The tripeptide integrin adhesion recognition sequence, Arg-Gly-Asp (RGD), caused 83% reduction and the fibrinogen-binding inhibitor protein caused 10% reduction in binding of stimulated neutrophils to fibrinogen coated surfaces. Two hexapeptides tested did not reduce neutrophil adhesion to fibrinogen. The binding of channel catfish neutrophils to the matrices used in the present study is suggestive that integrin mediated adhesion occurs during biological and pathological processes of teleosts.

Anaplastic Lymphoma Kinase (Alk) is a receptor tyrosine kinase expressed throughout the adult mammalian hippocampus. Recent studies in Drosophila and prior studies in Caenorhabditis elegans have implicated Alk signaling in learning and neurogenesis. We have studied the roles of Alk and the closely related receptor Leukocyte Tyrosine Kinase (Ltk) in learning, behavior and neurogenesis. In the hippocampus, both receptors are expressed throughout the dentate gyrus, CA1 and CA3. To assess the functional roles of Alk and Ltk in the mammalian brain, we analyzed phenotypes in Alk mutant, Ltk mutant and Alk/Ltk double-mutant mice compared to wild-type littermates. Similar to Drosophila, we found enhanced performance in spatial memory in Alk mutant mice. Also similar to Drosophila, we observed reduced neurogenesis associated with loss of Alk function. We also report genetic interactions between Alk and Ltk with respect to neurogenesis and behavioral measures such as activity, anxiety levels, and retention of spatial memory.

Anaplastic lymphoma kinase (Alk) is a gene expressed in the nervous system that encodes a receptor tyrosine kinase commonly known for its oncogenic function in various human cancers. We have determined that Alk is associated with altered behavioral responses to ethanol in the fruit fly Drosophila melanogaster, in mice, and in humans. Mutant flies containing transposon insertions in dAlk demonstrate increased resistance to the sedating effect of ethanol. Database analyses revealed that Alk expression levels in the brains of recombinant inbred mice are negatively correlated with ethanol-induced ataxia and ethanol consumption. We therefore tested Alk gene knockout mice and found that they sedate longer in response to high doses of ethanol and consume more ethanol than wild-type mice. Finally, sequencing of human ALK led to the discovery of four polymorphisms associated with a low level of response to ethanol, an intermediate phenotype that is predictive of future alcohol use disorders (AUDs). These results suggest that Alk plays an evolutionary conserved role in ethanol-related behaviors. Moreover, ALK may be a novel candidate gene conferring risk for AUDs as well as a potential target for pharmacological intervention.

Previous studies have demonstrated that Bcl10 (B-cell leukemia/lymphoma 10) is essential for T cell receptor-mediated NF-κB activation and subsequent proliferation and interleukin 2 (IL2) production. However, here we demonstrate that, contrary to expectations, Bcl10 is differentially required for T cell activation, including for both proliferation and cytokine production. When CD4+ and CD8+ T cells were divided based on expression levels of CD44, which distinguishes naïve cells (CD44lo) versus those that are antigen-experienced (CD44hi), IL2 production by and proliferation of CD4+CD44lo naïve cells and both subpopulations of CD8+ T cells were clearly Bcl10-dependent, whereas these same functional properties of CD4+CD44hi T cells occurred largely independent of Bcl10. As with the other subpopulations of T cells, CD4+CD44hi T cells did not activate the NF-κB pathway in the absence of Bcl10; nevertheless, these CD4+CD44hi antigen-experienced T cells efficiently secreted IL2 after T cell receptor stimulation. Strikingly, therefore, T cell receptor-mediated IL2 production in these cells is NF-κB-independent. Our studies suggest that antigen-experienced CD4+ T cells differ from their naïve counterparts and from CD8+ T cells in their ability to achieve activation independent of the Bcl10/NF-κB pathway.

Immunoreceptor tyrosine-based activation motifs (ITAMs) are crucial in antigen receptor signaling in acquired immunity. Although receptors associated with the ITAM-bearing adaptors FcRgamma and DAP12 on myeloid cells have been suggested to activate innate immune responses, the mechanism coupling those receptors to 'downstream' signaling events is unclear. The CARMA1-Bcl-10-MALT1 complex is critical for the activation of transcription factor NF-kappaB in lymphocytes but has an unclear function in myeloid cells. Here we report that deletion of the gene encoding the Bcl-10 adaptor-binding partner CARD9 resulted in impaired myeloid cell activation of NF-kappaB signaling by several ITAM-associated receptors. Moreover, CARD9 was required for Toll-like receptor-induced activation of dendritic cells through the activation of mitogen-activated protein kinases. Although Bcl10-/- and Card9-/- mice had similar signaling impairment in myeloid cells, Card11-/- (CARMA1-deficient) myeloid cell responses were normal, and although Card11-/- lymphocytes were defective in antigen receptor-mediated activation, Card9-/- lymphocytes were not. Thus, the activation of lymphoid and myeloid cells through ITAM-associated receptors or Toll-like receptors is regulated by CARMA1-Bcl-10 and CARD9-Bcl-10, respectively.

G protein-coupled receptors (GPCRs) play pivotal roles in cell proliferation, differentiation, and survival. Although many studies indicate that the stimulation of GPCRs leads to NF-kappaB activation, the molecular mechanism by which GPCRs induced NF-kappaB activation remains largely unknown. Bcl10 is an essential adaptor molecule connecting antigen receptor signaling cascades to NF-kappaB activation in lymphocytes. However, the function of Bcl10 in nonlymphoid cells remains to be determined. In this study, we demonstrated that the deficiency of Bcl10 resulted in the defect in NF-kappaB activation induced by either expressing the constitutively active mutant of G protein or stimulation of cells with lysophosphatidic acid or endothelin-1, which activate their GPCR. In contrast, TNF-alpha-, LPS-, and integrin-induced NF-kappaB activation was not affected in Bcl10-deficient cells. Together, our results provide genetic evidence showing that Bcl10 is a key signaling component mediating NF-kappaB activation induced by GPCRs in nonlymphoid cells.

Accumulating evidence indicates that expression of anaplastic lymphoma kinase (ALK), typically due to t(2;5) translocation, defines a distinct type of T/null-cell lymphoma (TCL). The resulting nucleophosmin (NPM) /ALK chimeric kinase is constitutively active and oncogenic. Downstream effector molecules triggered by NPM/ALK remain, however, largely unidentified. Here we report that NPM/ALK induces continuous activation of STAT3. STAT3 displayed tyrosine phosphorylation and DNA binding in all (four of four) ALK+ TCL cell lines tested. The activation of STAT3 was selective because none of the other known STATs was consistently tyrosine phosphorylated in these cell lines. In addition, malignant cells in tissue sections from all (10 of 10) ALK+ TCL patients expressed tyrosine-phosphorylated STAT3. Transfection of BaF3 cells with NPM/ALK resulted in tyrosine phosphorylation of STAT3. Furthermore, STAT3 was constitutively associated with NPM/ALK in the ALK+ TCL cell lines. Additional studies into the mechanisms of STAT3 activation revealed that the ALK+ TCL cells expressed a positive regulator of STAT3 activation, protein phosphatase 2A (PP2A), which was constitutively associated with STAT3. Treatment with the PP2A inhibitor calyculin A abrogated tyrosine phosphorylation of STAT3. Finally, ALK+ T cells failed to express a negative regulator of activated STAT3, protein inhibitor of activated STAT3. These data indicate that NPM/ALK activates STAT3 and that PP2A and lack of protein inhibitor of activated STAT3 may be important in maintaining STAT3 in the activated state in the ALK+ TCL cells. These results also suggest that activated STAT3, which is known to display oncogenic properties, as well as its regulatory molecules may represent attractive targets for novel therapies in ALK+ TCL.

Lung cancer is the main cause of cancer mortality worldwide. Approximately ∼80% of lung cancer cases are non-small cell lung cancer (NSCLC) in type and >50% of NSCLC are adenocarcinoma in histopathology. A shifting paradigm in the field of pulmonary oncology is the identification of molecular markers that are therapeutic targets and/or provide prognostic information. The recent recognition of the role biomarkers such as EGFR, KRAS, and ALK play in NSCLC adenocarcinoma patients demonstrates this trend. Although these three highly characterized molecular markers make up one-quarter to two-thirds of NSCLC adenocarcinoma patients, the remaining population, termed “Triple-Negative Lung Cancer” (TNLC), has yet to be fully defined. The complete absence of therapeutic targets for triple-negative lung cancer patients undeniably supports the need to identify up-regulated and mutated genes that better define this poor prognostic cohort. Recent genome-wide expression profiles subdivided TNLC patients into a poor prognostic group based on the overexpression of the DEP domain containing 1 gene (DEPDC1) (Okayama et al., 2011). We hypothesized that overexpression of DEPDC1 correlates with a specific sub-population of adenocarcinoma patients. Our initial studies indicate that DEPDC1 is constitutively expressed in both normal lung as well as lung cancer specimens. DEPDC1 transcripts are present as two variants (V1 and V2), with constitutive expression of the V1 variant in normal lung. We hypothesized that expression of the V2 transcript could be unique to NSCLC adenocarcinomas. Screening of FFPE NSCLC adenocarcinoma specimens using a proprietary qPCR approach demonstrated the presence of the DEPDC1 V2 variant but at levels that were not sufficient to serve as a sole biomarker. We therefore investigated whether the ratio of DEPDC1 V2 expression relative to V1 could serve as a biomarker in TNLC. Our preliminary data suggest that the ratio of V2 to V1 expression of DEPDC1 does in fact segregate TNLC into specific sub-populations. These studies have exciting diagnostic as well as therapeutic implications as Phase I/II studies using novel peptide vaccines derived against DEPDC1 have proven tolerable and efficacious for patients with bladder cancer and could potentially be extended to target these newly identified TNLC sub-populations. Citation Format: Brock L. Schweitzer, Kasey D. Lawrence, John Handshoe, Rachel Skelton, Lindsay Chatfield, Liquan Xue, Stephan W. Morris, David R. Hout. The unknown piece of the pie: Molecular markers in triple-negative lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1930. doi:10.1158/1538-7445.AM2013-1930

3090 Background: Ganetespib is a potent inhibitor of heat shock protein 90 (Hsp90) currently being studied in a broad range of clinical trials. Phase II results with ganetespib demonstrated an encouraging objective response rate of 50% in non-small cell lung carcinoma (NSCLC) patients whose tumors contained ALK translocations and had progressed on previous treatments. To further understand the clinical potential of ganetespib in ALK-driven cancers, we evaluated its activity in (1) crizotinib-sensitive and -resistant cancer cells harboring ALK fusions; (2) cells expressing amplified ALK or ROS1 translocations (a kinase structurally similar to ALK); and (3) in combination with crizotinib. Methods: H3122 NSCLC cells, which express EML4-ALK, were treated with ganetespib, crizotinib or the combination, and cell viability and signaling cascades were assessed. Similar experiments were done in cells with amplified, constitutively active ALK (NB-39-nu) or ROS1 kinase fusions (HCC-78, U118MG). To generate a model of crizotinib resistance, NPM-ALK-expressing BaF3 cells were exposed to various crizotinib concentrations. Fifteen different ALK kinase domain substitutions were identified; clonal NPM-ALK/BaF3 cells were made for each resistance mutation and assayed for sensitivity to ganetespib. Results: Ganetespib was 50-fold more potent than crizotinib in killing H3122 cells, and when combined together at sub-lethal doses, displayed strong synergistic anticancer activity. Ganetespib showed similar potency in other cells driven by constitutively active ALK or ROS1 kinase fusions, due to abrogation of their oncogenic kinase activity. All 15 of the crizotinib-resistant NPM-ALK/BaF3 mutant clones were highly sensitive to ganetespib (IC50 values ranging from 14-23 nM), including the 7 mutations reported to date in patients with ALK-driven tumors. Conclusions: Ganetespib effectively inhibits the activity of ALK and ROS1, kinases associated with several tumor types, resulting in marked single agent anticancer activity in cells driven by them. Importantly, ganetespib retains its potency irrespective of the mutational status of ALK. The strong synergy observed between ganetespib and crizotinib warrants further study.

e21070 Background: Anaplastic lymphoma kinase (ALK) fusions cause a variety of malignancies (e.g. NSCLC and NHL). Patients with ALK fusion-driven cancers treated with the ALK inhibitor crizotinib, ...

More than 15 different ALK fusions (e.g., CLTC-ALK, multiple EML4-ALK variants, KIF5B-ALK, NPM-ALK, RanBP2-ALK, TFG-ALK, TPM4-ALK, others) cause malignancies including NSCLC, NHL, and inflammatory myofibroblastic tumors. Preliminary studies suggest several other cancer subsets may also express ALK fusions (e.g., breast, colorectal and esophageal cancers). Several ALK small-molecule inhibitors are in development, and patients treated with one clinical stage inhibitor have had marked antitumor responses. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) for ALK have been used to select patients likely to benefit from ALK inhibitor therapy; however, these methods are problematic. Both methods have suboptimal sensitivity for certain ALK fusions (e.g., EML4-ALK), and FISH is technically demanding and has a prolonged turn-around time (5-7 days). To address the unmet need for a highly sensitive, practical assay for clinical ALK detection, we developed Insight ALK Screen™, a real-time PCR test for ALK fusions and wild-type ALK upregulation. The test operates by qPCR of two regions corresponding to the ALK extracellular and intracellular kinase domains; for example, EML4-ALK or other ALK fusion events result in a ΔCt (change in threshold cycle) increase in transcripts encoding the ALK kinase domain over wild-type ALK expression levels.This assay design enables Insight ALK Screen to detect any ALK fusion regardless of the ALK fusion partner. We are validating Insight ALK Screen in comparison to ALK IHC and FISH using NSCLC FFPE specimens from the Clarient tumor bank. Eighty-two NSCLCs were screened using Insight ALK Screen, and 17 of the 82 (20.7%) showed either an ALK fusion or wild-type ALK upregulation. All 17 ALK-expressing NSCLCs were next tested using an EML4-ALK variant-specific RT-PCR assay; 6 (35.3%) of the 17 cases (7.3% of the original 82 cases) were shown to be EML4-ALK-positive. Ongoing studies are assessing the genetic mechanisms (e.g., other EML4-ALK variants not tested, other ALK fusions, ALK gene amplification, chromosome 2 polysomy, etc.) underlying the aberrant ALK expression in the other 11 of 17 NSCLCs; these data will be presented at the meeting together with complete IHC, FISH and clinical-molecular correlative information. Together with its ease-of-use, small tissue requirements, multiplex compatibility, quantitation of ALK expression levels, lack of bias for specific fusions, and quick turn-around (24-48 hrs), our preliminary results support Insight ALK Screen as the first-line ALK diagnostic method of choice. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2220. doi:10.1158/1538-7445.AM2011-2220

The BCL10 gene was isolated from the breakpoint region of the t(1;14)(p22;q32) chromosomal translocation, a recurrent chromosomal abnormality in mucosa-associated lymphoid tissue (MALT)-type lymphomas. The translocation results in constitutive over-expression and nuclear location of the BCL10 protein. To understand the physiological and pathogenic roles played by BCL10 in B-cell biology, a transgenic (TG) mouse model was developed with a human BCL10 gene driven by Em. The TG was expressed in thymic but not peripheral T cells and in the spleen; lymph nodes were negative. Although the lymphoid compartments of the TG mice were grossly normal, histologic studies showed the splenic marginal zone (MZ) to be significantly expanded and, in older mice, to compress the white pulp. In addition, about 10% of animals developed B-cell neoplasms by 18 months of age. By FACS analyses, the number of MZ B cells was increased nearly 2-fold, and both MZ and follicular (FOL) B cells exhibited a marked down-regulation of CD23 expression. In the peritoneum of TG mice, the B1a B-cell population was markedly reduced while the B1b subset was increased over 2-fold. Studies of purified MZ and FOL B cells from normal and TG mice showed that MZ B cells from TG mice had a survival advantage in culture. Studies of the canonical NF-κB signaling pathway that lies downstream from BCL10 showed that it was constitutively activated with high levels of nuclear p50 and p65 protein identified by Western blotting. Quantitative real-time RT-PCR analyses of purified splenic B cells from normal and TG mice for expression of 384 genes identified 44 with significant differences in expression. Almost half of these genes were known NF-κB targets and included genes known to influence B-cell survival (BAFF, IL-10) or associated with MZ lymphomas (S100A9). These results indicate that constitutive expression of BCL10 in B cells is not sufficient to induce transformation alone and that as-yet-unknown secondary mutations are required. Nonetheless, expression of BCL10 clearly resulted in constitutive activation of the canonical NF-κB signaling pathway and a prominent expansion of the MZ B-cell population, thereby setting the stage for later development of lymphomas.