bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mouse Model of MYC-Deregulating Chromosomal Translocations Associated with Human Burkitt Lymphoma and Multiple Myeloma.
Authors: Janz Siegfried , John Shaughnessy D. 
Published: October 2019

Abstract
Purpose: Burkitt lymphoma (BL) is tightly associated with chromosomal t(8;14)(q24;q32) translocations that result in the deregulated expression of the MYC (c-myc) oncogene due to its juxtaposition to enhancers of the immunoglobulin-heavy chain locus IGH. The t(8;14)(q24;q32) MYC-IGH translocation is widely believed to be the initiating event in the pathogenesis of BL. Multiple myeloma (MM) is a malignant neoplasm of plasma cells that is often associated with complex cytogenetic alterations that juxtapose MYC, analogous to the t(8;14)(q24;q32) translocation, to IGH enhancers. However, MYC-IGH rearrangements of this sort occur during the progression of MM, not as tumor-initiating events as in BL. Accurate mouse models of MYC deregulation associated with human BL and MM are needed to study the events involved in tumor initiation and progression and design new approaches for treatment and prevention. To that end, we have generated a new mouse model of human t(8;14)(q24;q32) translocation.
Experimental procedure: We inserted a His6-tagged mouse Myc cDNA, MycHis, into two different locations of the mouse immunoglobulin heavy-chain locus, Igh, just 5′ of Eμ or Cμ. In the latter case, Eμ was deleted during gene targeting. The newly developed gene-insertion strains were designated iMycEμ and iMycCμ. The iMycEμ mice provide a specific model of the t(8;14)(q24;q32) observed in endemic BL (eBL). The iMycCμ mice mimic the t(8;14)(q24;q32) found in sporadic BL (sBL) and immunodeficiency-associated BL (iBL) (Fig. 1).
Figure 1 Figure 1.
Result: Both “iMyc” gene-insertion strains are prone to the spontaneous development of mature B cell and plasma cell tumors. However, in the Eμ-containing iMycEμ mice, tumors arose earlier and tumor incidence was higher compared to the Eμ-deleted iMycCμ (Fig. 2 left).
Figure 2 Figure 2.
This correlated well with the control of MycHis expression by Eμ, as MycHis mRNA levels were higher in B cells from iMycEμ than iMycCμ mice. Interestingly, the iMycCμ transgene was as effective in inducing inflammation-dependent peritoneal plasmacytomas as the iMycCμ transgene (Fig. 2 right). This indicated that host factors, such as chronic inflammation, can greatly enhance the transformation-inducing potency of a deregulated Myc gene that is only weakly oncogenic in spontaneous tumor development.
Conclusion: The “iMyc” mice provide a model of Myc deregulation that is conducive to plasma cell tumors in mice. The mice may thus afford a good opportunity to identify the genes that collaborate with Myc in neoplastic plasma cell development. Combined with the transgenic expression of MM genes, such as DKK1, the “iMyc” mice may also be useful as a platform for modelling human plasma cell neoplasms in mice.
Pharmacological Blockade of NF-kB with AS602868, a Potent Small Molecule Inhibitor of IKK2 Leads to Apoptosis of Sensitive and Resistant Chronic Myeloid Leukemia Cells.
Authors: Imbert Veronique , Gonthier Nadege , Frelin Catherine , Sirvent Nicolas , Hummelsberger Michael , von Bueltzingsloewen Anne Sirvent , Cassuto Jill-Patrice , Mahon Francois-Xavier , Rousselot Philippe , Dreano Michel , Peyron Jean-Francois 
Published: October 2019

Abstract
The Bcr-Abl inhibitor imatinib mesylate is now the first choice treatment for all newly diagnosed CML patients. Nevertheless not all patients reach a complete cytogenetic response (CCR) and many develop resistance for the drug upon disease progression. Additional cellular targets should be thus identified to develop alternative therapeutic strategies. The transcription factor NF-kB appears as a promising target for the treatment of cancer since it is a pro-survival factor, found abnormaly active in numerous hematologic malignancies and solid tumors. NF-kB activation relies on ubiquitin-mediated degradation of its inhibitor IkB after phosphorylation by 2 specific kinases, IKK1 and IKK2. We disrupted NF-kB signaling pathway by the use of AS602868, a small molecule inhibitor of IKK2 on two CML cell lines, LAMA84 and BaF3/Bcr-Abl and on primary CML cells. First we showed that NF-kB is constitutively activated in both CML cell lines and that this constitutive activation is under the control of the Bcr-Abl kinase. We next demonstrated that IKK2 targeting by AS602868 led to apoptosis of CML cells. AS602868 induced a dose dependent growth inhibition (IC50 3–4μM) of CML cell lines. This inhibition was associated with activation of cellular caspases 3, 8 and 9 and induction of DNA fragmentation. Interestingly AS602868 could induce death of imatinib resistant cellular clones derived from LAMA84 and BaF3-Bcr-Abl cells (IC50 1–2μM). Finally AS602868 selectively inhibited the proliferation and the hematopoietic colony formation of primary CML cells derived from imatinib sensitive or resistant patients. Although the exact mechanism of NF-kB activation by Bcr-Abl remains to be elucidated, our data strongly suggest that targeting NF-kB with the IKK2 inhibitor AS602868 may represent a new promising therapeutic tool for the treatment of CML.
ZAP-70 Expression Is More Predictive Than VH Gene Mutational Status of BCR-Mediated Tyrosine Phosphorylation, NF-κB Activation and CLL Cell Survival.
Authors: Pepper Chris , Alghazal Suhair , Brennan Paul , Rowntree Clare , Pratt Guy , Fegan Chris 
Published: October 2019

Abstract
We analysed tyrosine phosphorylation, NF-κB activation and survival in a cohort of 64 chronic lymphocytic leukemia patients. By graphing VH gene mutational status, CD38 expression and ZAP-70 expression as continuous variables, we investigated correlations between these prognostic markers and cell signaling. There was a strong correlation between CD38 expression and basal levels of tyrosine phosphorylation (r2 = 0.68). VH gene mutational status and ZAP-70 expression correlated with the induction of tyrosine phosphorylation by anti-IgM (r2 = 0.31 and 0.46 respectively). These findings suggest that tyrosine phosphorylation integrates these three prognostic phenotypes. In the context of NF-κB signaling, the percentage change in tyrosine phosphorylation (post anti-IgM) and ZAP-70 expression correlated with NF-κB activation (r2 = 0.2 and 0.19 respectively) and the ability to activate NF-κB was strongly correlated with cell survival (r2 = 0.67). The therapeutic rationale for the inhibition of NF-κB was strengthened by our observations that the NF-κB inhibitor, BAY 11–7082, caused a concentration-dependent increase in apoptosis in CLL samples. Taken together, our data suggest that CD38 is a surrogate marker of basal cellular activation in CLL that is independent of the B-cell receptor. Furthermore, ZAP-70 expression is the most important predictor of tyrosine phosphorylation, downstream NF-κB activation and CLL cell survival following B-cell receptor cross-linking. These findings provide a mechanism-based rationale for the poor prognosis of CD38+ and ZAP-70+ CLL patients.
How Frequently Is Venous Thromboembolism in Heparin-Treated Patients Associated with Heparin-Induced Thrombocytopenia?.
Authors: Hursting Marcie J. , McCollum David , Levine Robert L. 
Published: October 2019

Abstract
Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are routinely used for prophylaxis or treatment of venous thromboembolism (VTE) yet paradoxically can promote VTE in a patient with heparin-induced thrombocytopenia (HIT), an immune-mediated prothrombotic reaction to heparins. The purpose of this meta-analysis was to estimate how frequently new or recurrent VTE in heparin-treated patients is HIT-associated. Studies using UFH or LMWH for prophylaxis or treatment of thrombosis in which an outcome variable was new or recurrent VTE and in which information was available for the determination of HIT were abstracted to determine the proportion of patients with VTE that was associated with HIT. From a comprehensive literature search, we identified 10 studies (6 randomized trials, 3 prospective cohort studies, 1 retrospective cohort study) of intravenous (iv) or subcutaneous (sc) UFH or LMWH therapy that reported objectively confirmed VTE (at least 1 event per study) both overall and in patients with comorbid HIT, which was prospectively defined in each study (typically a platelet count <100–150 x109/L or a 30–50% decrease in count, with serologic confirmation). In each study, which may have included 2 treatment groups, medical or surgical patients received UFH iv (5 studies), UFH sc (3 studies), or LMWH sc (5 studies) therapy typically for 7–10 days and were followed in hospital or for 10 to 90 days for new or recurrent VTE. Across the studies in a total of 6219 heparin-treated patients, 386 patients had new or recurrent VTE, and 34 had HIT-associated VTE. The frequency of HIT-associated VTE among heparin-treated patients with VTE was not different between iv and sc UFH therapy (13.2% versus 12.4%, P>0.99) but was significantly different between UFH and LMWH therapy (12.8% versus 0.7%, P<0.001) (Table 1). These data indicate that new or recurrent VTE is HIT-associated infrequently (<1%) in LMWH-treated patients yet often (approximately 1 in 8 cases) in UFH-treated patients. Because continued or repeated exposure to heparins can be catastrophic in HIT, physicians should have a high degree of suspicion for HIT in patients developing VTE during or soon after UFH therapy and should use alternative anticoagulation until HIT has been excluded.
Table 1. VTE and HIT-associated VTE in heparin-treated patients Heparin type (#studies) Heparin-treated patients Patients with VTE, n (%) Patients with HIT-associated VTE, n (%) HIT-associated VTE/any VTE, % (95% CI) *P>0.99 vs sc UFH; **P<0.001 vs LMWH UFH, iv (5 studies) 2687 129 (4.8) 17 (0.6) 13.2 (8.3 - 20.3)* UFH, sc (3 studies) 1105 113 (10.2) 14 (1.3) 12.4 (6.9 - 19.9) UFH, iv or sc 3792 242 (6.4) 31 (0.8) 12.8 (8.9 - 17.7)** LMWH, sc (5 studies) 2427 144 (5.9) 1 (0.04) 0.7 (0.02 - 3.8)
DAP10 Costimulates Chimeric Receptor-Mediated T Cell Responses to Tumor Antigen.
Authors: Altvater Bianca , Pscherer Sibylle , Juergens Heribert , Rossig Claudia 
Published: October 2019

Abstract
Chimeric receptors (chRecs) combining extracellular recognition domains with the T cell receptor ζ an redirect the cellular immune response of primary T-cells to tumor cells. T cell activation by chRec induces efficient cytokine release and cytotoxicity, however, it fails to mediate proliferative responses, limiting the usefulness of chRec-gene-modified T cells for adoptive immunotherapy of cancer. Inclusion of a CD28 costimulatory signaling component in the chRec endodomain enhances antigen-specific proliferation. Whereas the signal mediated by ligation of CD28 is of crucial importance for the activation of resting CD4+ T cells, further molecules with costimulatory functions have contributory roles. NKG2D is a stimulatory receptor that was first identified in NK cells, but is also expressed in cytotoxic T cells and positively modulates CD8+ T cell immune responses. We hypothesized that inclusion of the NKG2D-associated signaling domain DAP10 would enhance the capacity of chRecs to induce tumor-specific activation and proliferation of in vitro expanded effector T cells. Based on a GD2-specific scFv, we generated chRecs containing either the DAP10 signaling chain alone (14.G2a-DAP10) or combined with TCRζ 14.G2a-DAP10ζ), and expressed them in nonspecifically activated human peripheral blood T cells of three individual donors by retroviral gene transfer. As controls, T cells were transduced with 14.G2a-ζ and -CD28ζ chRec. High chRec surface expression was obtained with all four constructs (55±11%, ζ; 85±3, CD28ζ; 68±5%, DAP10; 78±1%; DAP10ζ). Immunophenotypes were dominated by a CD3+CD8+ population in all cell cultures. Whereas DAP10 alone failed to mediate specific tumor cell lysis, 51Cr release assays revealed efficient and comparable lysis of GD2+ tumor targets by T cells transduced with all ζ-containing constructs, with 49±8% (ζ), 52±7% (CD28ζ), and 52±18% (DAP10ζ) cytolysis at an effector-to-target ratio of 40:1. Intracellular cytokine secretion by chRec+ T cells was induced in response to tumor targets by 14.G2a-ζ (up to 37% IFN-γ secreting cells), CD28ζ, and DAPζ (both up to 22%), but not by DAP10 alone (0,2%). Weekly stimulation with tumor cells for 6 weeks induced only limited expansion of T cells transduced with 14.G2a-ζ (7–45fold) or with 14.G2a-DAP10 (14–26-fold). Adding CD28 or DAP10 domains significantly enhanced expansion by a comparable degree (270–483-fold and 126–436-fold, respectively). Thus, while neither CD28 nor DAP10 enhances antigen-specific cytokine secretion and cytolysis, DAP10 signaling can completely replace CD28 signaling in costimulating antigen-specific proliferation of peripheral blood T cells. DAP10-containing chRec may be a powerful new tool for adoptive immunotherapy of cancer.
Induction of CML28-Specific Cytotoxic T Cells by Dendritic Cells Cotransfected with CML28 Nucleic Acid Vaccination and SOCS1-Specific siRNA Expression Vector In Vitro.
Authors: Zhang Donghua , Zhou Hongsheng , Zhang Lu , Wang Yaya , Dai Min , Zhang Li 
Published: October 2019

Abstract
CML28 is a new tumor-associated antigen overexpressed in tumor cells, which is an attractive target for antigen-specific immunotherapy. In this study, we evaluated the possibility to induce CML28-specific cytotoxic T cells by cotransfection of CML28 nucleic acid vaccination and SOCS1-specific siRNA expression vector with dendritic cells in vitro. The full length CML28 cDNA was amplified from K562 by RT-PCR and cloned into a bicistronic vector pIRES2-EGFP to construct the CML28 nucleic acid vaccination. Dendritic cells (DCs) were generated from peripheral blood mononuclear cells (PBMNCs) of HLA-A2+ healthy donor. Construct the recombinant plasmid psiRNA-hH1neo-SOCS1 encoding hairpin small interfering RNA (siRNA) targeting to suppressors of cytokine signaling 1 (SOCS1) sequences using a vector-base RNA interference technology. Cotransfect CML28 nucleic acid vaccination and recombinant siRNA vector psiRNA-hH1neo-SOCS1 into DCs by electroporation. Real-time RT-PCR was performed to validate the SCOS1 gene silencing efficacy. The expression products of CML28 nucleic acid vaccination, His-CML28 fusion protein and GFP protein, were measured by Western Blotting and fluorescence microscope respectively. Labeling autologous nonadherent fraction of PBMNCs as responder cells by 5, 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) firstly, and then coculture with cotransfected DCs for mixed lymphocyte reaction (MLR). Autogous T cell proliferative response of MLR was measured by FACS by detecting CFSE. Cotransfected DCs and the PBMNCs of a HLA-A2+ primary leukemia patient were used as target cells, untransfected DCs, K562 and HL60 were used as control. The standard 51Cr-release assay was performed to measure cytotoxicity of stimulated lyphocytes. CML28 nucleic acid vaccination could encode His-CML28 and GFP protein in DCs successfully. SOCS1-specific siRNA expression vector psiRNA-hH1neo-SOCS1 significantly suppress the expression of SOCS1 in DCs. Down regulation of SOCS1 resulted in higher expression level of CD80, CD86 and CD83 in cotranfected DCs and more rounds of cell division of responder cells in CFSE-MLR, which indicates SOCS1 gene silencing greatly contribute to maturation of DCs and enhance the the proliferative response of responder cells. CTLs induced by cotransfected DCs exhibit stronger CML28-specific cytotoxicity against HLA- matched target cells comparing to CTLs induced by CML28 nucleic acid vaccination transfected DCs only. SOCS1 gene silencing in DCs could greatly enhance the anti-tumor efficacy of CML28 nucleic acid vaccination. DCs cotransfected with CML28 nucleic acid vaccination and SOCS1-specific siRNA expression vector could effectively induce autologous CML28-specific cytotoxic T cells that lyse CML28 positive tumor cells in an antigen-specific and major histocompatibility complex (MHC) class I-restricted manner.
p21-Activated Kinase 1 Regulates Hyperproliferation of Nf1 Haploinsufficient Mast Cells In Vitro and In Vivo Via Activation of the MAPK Pathway.
Authors: McDaniel Andrew S. 
Published: October 2019

Abstract
p21-activated kinases (Paks) are downstream mediators of Rho GTPase proteins and have been implicated in yeast and immortalized cells as positive regulators of MAPK pathway members in modulating cell growth and cytoskeletal functions. However, their role in primary mammalian cells has not been described.
NF1 encodes neurofibromin, which negatively regulates p21Ras activity by stimulating its intrinsic GTPase activity, and accelerating hydrolysis of Ras from the GTP to the GDP confirmation. Disruption of the NF1 locus results in neurofibromatosis type I (NF1), an inherited disorder characterized by the development of neurofibromas that contain large numbers of degranulating mast cells that have been implicated in tumor progression. Utilizing a genetic intercross of Pak 1−/− mice with mice haploinsufficient at the Nf1 locus, we studied the role of Pak1 in the context of normal and hyperactivated Ras-MAPK signaling in primary inflammatory mast cells. Pak1 was found to directly contribute to Ras-dependent signaling by modulating both Raf-1, Mek-1 and ERK1/2 activation. Loss of Pak1 fully corrects the hyperphosphorylation of ERK1/2 found in Nf1+/− mast cells to that of wild type controls. Deletion of Pak1 in Nf1+/− mast cells is associated with a correction of Kit ligand mediated proliferation to wild type levels in vitro. Further, after subcutaneous administration of Kit ligand via micro osmotic pumps, which is an established model that stimulates local proliferation of mast cells in vivo (Ingram, JEM 2001), we confirmed that genetic disruption of Pak1 corrects the proliferation of Nf1+/− mast cells in vivo to that of wild type controls. These data provide direct genetic evidence that Pak1 modulates the Ras-Raf-Mek-Erk pathway and identifies a specific molecular target within the inflammatory tumor microenvironment for the treatment or prevention of neurofibromas.
Mutant CXCR4 Identified in Neutropenic Patients with Myelokathexis Impairs Survival of Human Myeloid Cells.
Authors: Makaryan Vahagn , Dale David C. , Aprikyan Andrew A. 
Published: October 2019

Abstract
Myelokathexis (WHIM syndrome) is a very rare hematopoietic congenital disorder that is characterized by extremely low level of circulating neutrophils in peripheral blood. It is inherited as an autosomal dominant disease and is diagnosed in early childhood. These patients may have hypogammaglobulinemia and suffer from recurrent infections associated with warts. The hallmark of myelokathexis is a hyperplastic bone marrow and hypersegmented neutrophils with nuclear lobs connected with thin filaments. Myelokathexis is due to a characteristic retention of mature neutrophils in bone marrow, which are not being released to peripheral circulation. We and others reported abnormal cell survival characteristics and impaired bcl-x expression in bone marrow myeloid cells of myelokathexis patients that was partially restored by G-CSF treatment. Recently, it has also been reported that heterozygous truncation mutations in the carboxyterminal domain of the CXCR4 gene, a sole receptor for SDF-1 chemokine, were observed in most, but not all of the families with WHIM syndrome. Subsequently, an impaired receptor internalization and increased chemotaxis towards SDF-1 have been observed in cells expressing truncated CXCR4. Nevertheless, the mechanism of mutant CXCR4 induced myelokathexis remains largely unknown.
We performed mutational analysis of the CXCR4 gene in 3 unrelated families with myelokathexis and identified a previously reported R334ter truncation mutation in exon 2 in two of the families. In addition, two silent polymorphisms have been identified in exon 2 of the CXCR4 gene in one of these patients. The third family with afflicted mother and son had a new mutation in the CXCR4 carboxyterminal domain, which resulted in deletion of the last 16 amino acids and subsequent frame shift. None of these mutations were observed in healthy volunteers examined. Since the morphological examination by electron microscopy and flow cytometry analysis of bone marrow cells from some of these patients revealed characteristic apoptotic features, we examined the effect of mutant CXCR4 gene expression on survival of human promyelocytic HL-60 cells. Preliminary data demonstrated that human promyelocytic cells transfected with truncated CXCR4 exhibited impaired cell survival characteristics compared with control HL-60 cells transfected with intact CXCR4. The truncated, but not wild type CXCR4 also increased apoptosis in HL-60 cells induced to differentiate along the granulocytic pathway as determined by flow cytometry of annexin V labeled cells. Thus, these data link together the abnormal survival of proliferating and differentiating myeloid cells in WHIM syndrome with mutant CXCR4 expression. Current studies are focused on elucidation of specific signaling pathways mediating mutant CXCR4-triggered myelokathexis.
In Vitro and In Vivo Immunomodulatory Effects of Mesenchymal Stem Cells from Adipose Tissue.
Authors: Yañez Rosa M. , Lamana Maria L. , Garcia-Castro Javier , Ramirez Manuel , Bueren Juan A. 
Published: October 2019

Abstract
Previous studies have shown the immunomodulatory properties of bone marrow mesenchymal stem cells (BM-MSCs), opening the possibility of using these cells for the treatment of graft-versus-host disease (GVHD) in patients transplanted with allogeneic hematopoietic grafts. Additionally, Phase I studies in patients with Crohn’s disease suggested the efficacy of adipose tissue-derived mesenchymal stem cells (Ad-MSCs) for the healing of Crohn’s fistulas. In the present study we have investigated in vitro and in vivo, the immunomodulatory effects of Ad-MSCs, compared to BM-MSCs. We observed that both BM-MSCs and Ad-MSCs were negative for CD34, CD45, CD14, CD31 and MHC class I expression, while positive for CD29, CD44, CD90 and CD105. When studying the immunomodulatory effects of these cells in vitro, we found that - as happened with BM-MSCs - Ad-MSCs did not induce proliferation of allogeneic lymphocytes and were not lysed by cytotoxic T cells or alloreactive natural killer cells, indicating that Ad-MSCs are non-immunogenic. Additionally, the presence of Ad-MSCs inhibited in a dose-dependent fashion, both the mixed lymphocyte reaction (MLR) and the T cell proliferation induced by mitogens. To determine whether cell-to-cell contact between Ad-MSCs and PBMNCs was required for immunosuppression, transwell experiments were conducted. Phytohaemagglutinin (PHA)-stimulated lymphocytes were cultured in the upper chamber of a transwell, while irradiated Ad-MSCs remained in the lower chamber. As observed with BM-MSCs, Ad-MSCs were also capable of suppressing the lymphocytes proliferation in this transwell assay. When conditioned medium from Ad-MSCs was added to the MLR, the immuno-suppressive effect persisted, although at a lower level than that observed in a cell-to-cell contact system. Next we studied whether our in vitro findings were of significance in an in vivo mouse model of haploidentical transplantation. In these experiments irradiated F1(C57Bl/Balbc) recipient mice received 1x107 bone marrow cells from C57Bl mice, together with 2x107 splenocytes from the donor, to induce GVHD. One cohort of recipient mice received additional i.v. infusions of 5x105 mouse Ad-MSCs, administered at periodic intervals for up to 28 days post-transplant. When compared to the control group, the severity of the GVHD was significantly reduced in mice receiving Ad-MSCs. Our results suggest that Ad-MSCs obtained from adipose tissue may constitute a new and readily available source of immunomodulatory cells for the prophylaxis and/or treatment of GVHD in patients transplanted with allogeneic grafts.