julilili42/papers huggingface dataset:
Autocrine Function of Cysteinyl-Leukotrienes and Their Receptor CysLT1 in Chronic Lymphocytic Leukemia (B-CLL).
2009-11-20

Abstract Abstract 2325 Poster Board II-302 Leukocytes, including B cells, represent the physiological source of lipid mediators of the cysteinyl-leukotriene family. In malignant B cells, particularly in B-CLL, even higher levels of enzymes involved in leukotriene biosynthesis have been detected. The major receptor for cysteinyl-leukotrienes, CysLT1, mediates pleiotropic effects on cell migration, proliferation and survival. In the present study, we found that CysLT1 was consistently overepressed in B-CLL with mRNA levels 2-4-fold greater than in normal B cells, as detected by real-time PCR. The CysLT1 receptor was highly active in CLL cell lines (MEC-1, EHEB) and primary B-CLL cells, as demonstrated by ligand-induced intracellular calcium fluxes and actin polymerization (measured by flow cytometry), chemotaxis (Boyden chamber assay), and MAP-kinase/Erk1/2 phosphorylation (analyzed with Western blot). The effects were completely blocked by the CysLT1 antagonist MK-571. Upregulation of both the CysLT1 receptor and enzymes of leukotriene biosynthesis, in conjunction with the CysLT1-mediated activation of the MAP-kinase/Erk signaling pathway, suggest an autocrine loop contributing to cell survival. Indeed, incubation of CLL cells in serum-free medium with the CysLT1 antagonist reduced their viability in a dose-dependent manner by up to 70% (24 h) and 80% (48 h) compared to cells which were cultured without the antagonist. Our results provide evidence that cysteinyl-leukotrienes and their receptor regulate survival of CLL cells in an autocrine fashion, and imply a therapeutic potential of CysLT1 receptor antagonists, currently used in asthma therapy, also in the treatment of B-CLL. Disclosures: No relevant conflicts of interest to declare.
Glucocorticoid-Induced TNFR-Related Protein (GITR) Ligand Mediates Tumor Immunoediting in Chronic Lymphocytic Leukemia and Impairs Direct and Rituximab-Induced NK Cell Anti-Leukemia Reactivity.
2009-11-20

Abstract Abstract 4403 Members of the TNF/TNF receptor (TNFR) family of proteins govern differentiation, proliferation, activation, and death of both tumor and immune effector cells and thus play an important role in tumor immunoediting, the reciprocal interaction of tumor cells and anti-tumor immunity. Activation of the TNFR family member GITR has recently been shown to stimulate T cell-mediated anti-tumor immunity in mice. However, available data suggest that GITR mediates different effects in mice and men, and may impair anti-tumor immunity of human NK cells. Here we studied the expression and function of GITR ligand (GITRL) in patients with chronic lymphocytic leukemia (CLL) and the consequences of GITR-GITRL interaction for NK cell reactivity against CLL cells. Substantial GITRL expression was detected on primary B-CLL cells in 38 of 48 (79%) investigated patients. Upon interaction with its cognate receptor, GITRL induced the release of immunoregulatory cytokines like TNF by the leukemia cells, which demonstrated that CLL-expressed GITRL is functional and capable to transduce bidirectional signals. Moreover, disruption of GITR-GITRL interaction in cultures of allogenic NK cells with patient CLL cells by addition of blocking antibody caused a significant increase in NK cell granule mobilization, cytotoxicity and IFN-γ production. The inhibitory effect of tumor-expressed GITRL on the reactivity of human NK cells was also confirmed in cocultures of C1R lymphoma cells transfected to express GITRL with mock transfectants serving as control. In addition, blocking GITR-GITRL interaction also considerably augmented both antibody-dependent cellular cytotoxicity (ADCC) and antibody-induced IFN-γ production of NK cells in cultures with allogenic CLL cells upon Rituximab exposure. Of note, GITR blockade also significantly enhanced anti-leukemia reactivity of autologous NK cells among PBMC of B-CLL patients, and this reinforcement of NK cell effector functions was observed both regarding the direct and, more pronounced, Rituximab-induced anti-leukemia reactivity (both n=10, p&lt;0.01, Student's T test). Thus, expression of functional GITRL by CLL cells potently influences tumor immunoediting and impairs anti-tumor immunity by diminishing both direct and Rituximab-dependent anti-leukemia reactivity of NK cells. Modulation of the GITR-GITRL system might therefore serve to enhance the efficacy of therapeutic approaches in CLL which, like Rituximab-induced ADCC or stem cell transplantation, rely on a sufficient NK cell anti-tumor response. Disclosures: No relevant conflicts of interest to declare.
PTEN Regulates SYK-Directed AKT Activation in MCL.
2009-11-20

Abstract Abstract 2941 Poster Board II-917 Mantle cell lymphoma (MCL) can be divided into two clinicopathologic subtypes, a common or “typical” form, and an aggressive “blastoid” variant. A subset of MCL, including all of the aggressive blastoid variants, shows constitutive activation of the PI3K/AKT pathway. Since the BCR-associated SYK tyrosine kinase can activate the PI3K/AKT pathway during normal BCR signaling, we wished to assess its role in MCL. Five MCL cell lines (Granta 519, Rec-1, Jeko, Z138C and JVM-2) and 32 primary cases were studied for SYK activation and phosphorylation of several SYK targets, including blnk and PLC-gamma. The functional role of SYK was assessed by pharmacologic inhibition with R406, Piceatannol and SYK II inhibitor (2-(2-Aminoethylamino)-4-(3-trifluoromethyl-anilino)-pyrimidine-5-carboxamide, Dihydrochloride, Dihydrate). To rule out off target effects functional data was validated by siRNA experiments. Subsequently we analysed the effects of PTEN and constitutively active (S380A) PTEN in 2 cell lines (Granta 519 and Z138C). All cell lines were found to have constitutively activated SYK accompanied by phosphorylation of its downstream targets blnk and PLC-gamma. Inhibition of SYK with pharmacologic inhibitors or by specific siRNA resulted in AKT inactivation, suggesting a causal relationship between SYK activation and AKT activation in the cell lines. However, all primary MCL cases demonstrated constitutive activation of SYK, regardless of the activation state of AKT. Interestingly, p-AKT expression correlated with PTEN inactivation, as assessed by p-PTEN expression, in both primary cases and MCL cell lines. Increasing PTEN phosphatase activity, by introducing a constitutively active PTEN, abrogated AKT phosphorylation, without affecting SYK activity. These data suggest that SYK activity in MCL is necessary, but not sufficient to activate the PI3K/AKT pathway, and that an additional critical step is the inactivation of PTEN. This study reveals new complexity in the dysregulation of survival pathways in MCL that may be relevant to pathogenesis. Disclosures: No relevant conflicts of interest to declare.
Identification of Genes Which Play a Crucial Role in C/EBPβ Downstream Signalling in ALK+ ALCL Cell Lines.
2009-11-20

Abstract Abstract 1943 Poster Board I-966 Introduction: ALK+ anaplastic large cell lymphomas (ALCL) overexpress C/EBPβ, as a consequence of NPM-ALK kinase activity. We recently reported C/EBPβ as a transcription regulator of NPM-ALK induced cellular proliferation. To identify the downstream targets of C/EBPβ that might be responsible for cell proliferation and survival, we performed gene expression profiling and pathway analyses after C/EBPβ gene silencing Materials and Methods: C/EBPβ knockdown was done by lentiviral shRNA-transduction into two ALK+ ALCL cell lines with strong C/EBPβ expression – SUDHL1 and KiJK. At day three after infection, RNA was extracted and used for Gene Chip expression analysis (U133 Plus 2.0 arrays/ Affymetrix). Genes regulated in both cell lines were applied to Genomatix Bibliosphere Pathway analysis. Candidate genes were either strongly influenced by C/EBPβ knockdown, or had promoter binding sites for C/EBPβ, or showed remarkable pathway connections. The influence of C/EBPβ on these genes was validated by qRT-PCR and in part by Western blot. Results: Gene expression profiling analysis resulted in 167 genes being regulated in both cell lines, of which 26 genes were chosen for further analysis. Validation by qRT-PCR confirmed 23/26 genes. Pathway analysis revealed c-Jun, which is a member of the dimeric transcription factor AP-1, as a regulator of C/EBPβ expression. Silencing C/EBPβ led to a clear up-regulation of c-Jun mRNA. Western blot analysis demonstrated that C/EBPβ influenced not only the expression of c-Jun but also its phosphorylation on Ser63 and Ser73. In contrast to what has been reported, we found very low levels of c-Jun expression in ALK+ALCL cells lines and its expression correlated inversely with C/EBPβ mRNA levels. Although it has been shown that c-Jun regulates C/EBPβ expression directly, in ALK+ALCL the expression of C/EBPβ is clearly independent of c-Jun. Our data suggest that c-Jun up-regulation after C/EBPβ knockdown is a compensatory mechanism to maintain C/EBPβ expression. Additionally, of the 26 selected genes, Bibliosphere Analysis identified 12 genes, which might be transcriptionally regulated by C/EBPβ and are primary targets in C/EBPβ downstream signalling. Two of these genes are of particular interest. The anti-apoptotic protein BCL2A1 contains a promoter-binding site for C/EBPβ and has been shown previously to be both strongly regulated in ALK+ALCL and absolutely necessary for its transformation. The second is a DEAD box nucleolar RNA helicase protein involved in ribosomal RNA production and proliferation which we found to be strongly expressed in ALK+ALCL cell lines and primary cases. Conclusions: C/EBPβ silencing in ALK+ALCL cell lines showed 1) an inverse correlation between c-Jun and C/EBPβ mRNA expression levels, 2) the expression of C/EBPβ in ALK+ALCL is independent of c-Jun, 3) genes transcriptionally regulated by C/EBPβ seem to be essential for proliferation and survival in ALK+ALCL. Disclosures: No relevant conflicts of interest to declare.
KIT Inhibition Affects Heat Shock Protein (HSP) Activity: A Potential Rescue Mechanism towards KIT Tyrosine Kinase Inhibition and a Rationale for Dual KIT/HSP Inhibition.
2009-11-20

Abstract Abstract 2753 Poster Board II-729 Activating mutations of the KIT class III receptor tyrosine kinases are associated with core binding factor leukemias (CBF AML), systemic mastocytosis (SM), gastrointestinal stromal tumors (GIST), melanomas, seminoma/dysgerminoma and sinonasal natural killer/T-cell non-Hodgkin lymphoma. Despite the encouraging therapeutic potential of KIT-tyrosine kinase inhibitors (TKI), resistance leading to disease progression occurs in many patients, specifically after TKI monotherapy. We hypothesized that resistance to therapy is promoted by activation of alternative signaling pathways which override TKI inhibition. To explore the downstream signaling pathways of class III receptor tyrosine kinases, we performed unbiased phoshoproteomic analyses of mutant FLT3 or KIT leukemia and mastocytosis cell lines before and after TKI treatment. Tantalizingly, immunoaffinity purification of phosphopeptides followed by tandem mass spectrometry following KIT-inhibition with Imatinib at IC90 (100nM) revealed a significant upregulation of phosphorylation levels of peptides identified as members of the heat shock protein (HSP) family. Of interest, mRNA GeneChip® Array analysis of hematopoietic Ba/F3 cells transfected with either a mutant KIT isoform (D816V) or a mutant FLT3 isoform (ITD) and treated with TKI revealed significant downregulation of HSP family members in the FLT3 model – but stable mRNA levels in the KIT model. Taken together, our phosphoproteome and mRNA data suggest a protective function of HSP in mutant-KIT tumors treated with TKI. Next we studied the antiproliferative and proapoptotic effects of the HSP90 inhibitor IPI-504, a 17-AGG-derivative, in mutant-KIT cell models. IPI-504 potently inhibited proliferation and induced apoptosis with an IC50 of 0.5 up to 5μM depending on the KIT isoform. Importantly, combination of IPI-504 with TKIs resulted in potentiation of the antiproliferative and proapoptotic effects achieved by either drug alone. Antitumor efficacy in combination therapy was observed even at HSP90 inhibitor concentrations that did not display antitumor activity if administered alone. In conclusion, our model suggests that inhibition of KIT affects heat shock protein activity serving to stabilize the functionality of targeted autoactivated receptor tyrosine kinases, which provides a potential mechanism for resistance to TKI therapy. Importantly, we provide a rationale to combine TKI with (low-dose) HSP-inhibitors such as IPI-504 to optimize TKI therapy. Disclosures: Normant: Infinity: Employment.
Faculty Opinions recommendation of Infliximab and anterior optic neuropathy: case report and review of the literature.
2009-11-20

BACKGROUND: Anti-tumor necrosis factor alpha (TNF alpha) agents have been increasingly used to treat patients with Crohn's disease, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, and persistent uveitis. We describe a 68-year-old man with Crohn's esophagitis who developed a possible bilateral toxic anterior optic neuropathy during infliximab infusion.METHODS: This is an observational case report, with review of the PubMed literature from 1977 to present.RESULTS: This 68-year-old man with a 2-year history of Crohn's esophagitis developed acute bilateral visual loss during his third infliximab infusion. His clinical features and laboratory tests were characteristic for a bilateral anterior optic neuropathy. Only three cases of possible infliximab-associated anterior optic neuropathy have been reported in the literature to date.CONCLUSION: It is important to consider the possibility of anterior optic neuropathy, in addition to retrobulbar optic neuritis, in patients who experience sudden-onset visual loss while being treated with infliximab. PMID: 19916016
Differential Target Gene Activation by the Staphylococcus aureus Two-Component System saeRS
2009-11-21

ABSTRACT The saePQRS system of Staphylococcus aureus controls the expression of major virulence factors and encodes a histidine kinase (SaeS), a response regulator (SaeR), a membrane protein (SaeQ), and a lipoprotein (SaeP). The widely used strain Newman is characterized by a single amino acid change in the sensory domain of SaeS (Pro18 in strain Newman [SaeS P ], compared with Leu18 in other strains [SaeS L ]). SaeS P determines activation of the class I sae target genes ( coa , fnbA , eap , sib , efb , fib , sae ), which are highly expressed in strain Newman. In contrast, class II target genes ( hla , hlb , cap ) are not sensitive to the SaeS polymorphism. The SaeS L allele ( saeS L ) is dominant over the SaeS P allele, as shown by single-copy integration of saePQRS L in strain Newman, which results in severe repression of class I target genes. The differential effect on target gene expression is explained by different requirements for SaeR phosphorylation. From an analysis of saeS deletion strains and strains with mutated SaeR phosphorylation sites, we concluded that a high level of SaeR phosphorylation is required for activation of class I target genes. However, a low level of SaeR phosphorylation, which can occur independent of SaeS, is sufficient to activate class II target genes. Using inducible saeRS constructs, we showed that the expression of both types of target genes is independent of the saeRS dosage and that the typical growth phase-dependent gene expression pattern is not driven by SaeRS.
Liposome Formulations of Hydrophobic Drugs
2009-11-21

Here, we report methods of preparation for liposome formulations containing lipophilic drugs. In contrast to the encapsulation of water-soluble compounds into the entrapped aqueous volume of a liposome, drugs with lipophilic properties are incorporated into the phospholipid bilayer membrane. Water-soluble molecules, for example, cytotoxic or antiviral nucleosides can be transformed into lipophilic compounds by attachment of long alkyl chains, allowing their stable incorporation into liposome membranes and taking advantage of the high loading capacity lipid bilayers provide for lipophilic molecules. We created a new class of cytotoxic drugs by chemical transformation of the hydrophilic drugs cytosine-arabinoside (ara-C), 5-fluoro-deoxyuridine (5-FdU) and ethinylcytidine (ETC) into lipophilic compounds and their formulation in liposomes. The concept of chemical modification of water-soluble molecules by attachment of long alkyl chains and their stable incorporation into liposome bilayer membranes represent a very promising method for the development of new drugs not only for the treatment of tumors or infections, but also for many other diseases.
Phenotypical and functional characterization of T helper 17 cells in multiple sclerosis
2009-11-23

Multiple sclerosis is a T cell-mediated demyelinating disease of the central nervous system. Interleukin-17-producing T helper cells, named Th17 cells, represent a novel CD4+ T cell effector subset involved in the response against extracellular pathogens. In addition, Th17 cells are pathogenic in several animal models of autoimmune disease, including the animal model for multiple sclerosis, but their function in multiple sclerosis remains to be elucidated. In this study, we analysed the frequency and the phenotype of Th17 cells in the cerebrospinal fluid and peripheral blood of multiple sclerosis patients. We show that the frequency of Th17 cells is significantly higher in the cerebrospinal fluid of patients with relapsing-remitting multiple sclerosis during relapse, in comparison to relapsing-remitting patients in remission or to patients with other non-inflammatory neurological diseases. Similarly, in patients with clinically isolated syndrome during their first neurological episode, Th17 cells are more abundant than in clinically isolated syndrome patients with no acute symptoms. Patients with inflammatory neurological diseases other than multiple sclerosis also showed increased frequency of Th17 cells compared to patients with no inflammatory diseases. To assess a potential pathological impact of Th17 cells in disease, we generated T cell clones from the cerebrospinal fluid and peripheral blood of patients with multiple sclerosis. We found that Th17 clones expressed higher basal levels of the activation markers CD5, CD69, CD2 and human leukocyte antigen-DR as well as of the CD28-related family of co-stimulatory molecules, when compared to Th1 clones, and confirmed these findings with ex vivo human T cells. Molecules involved in T cell adhesion to endothelium, such as CD49d, CD6 and the melanoma cell adhesion molecule, were also more abundant on the Th17 than on the Th1 cells. Furthermore, functional assays showed that Th17 clones were more prone than Th1 clones to melanoma cell adhesion molecule-mediated adhesion to endothelial cells, and that Th17 cells had a higher proliferative capacity and were less susceptible to suppression than Th1 cells. Altogether our data suggest that Th17 cells display a high pathogenic potential and may constitute a relevant pathogenic subset in multiple sclerosis.
Association of trait emotional intelligence and individual fMRI‐activation patterns during the perception of social signals from voice and face
2009-11-23

Abstract Multimodal integration of nonverbal social signals is essential for successful social interaction. Previous studies have implicated the posterior superior temporal sulcus (pSTS) in the perception of social signals such as nonverbal emotional signals as well as in social cognitive functions like mentalizing/theory of mind. In the present study, we evaluated the relationships between trait emotional intelligence (EI) and fMRI activation patterns in individual subjects during the multimodal perception of nonverbal emotional signals from voice and face. Trait EI was linked to hemodynamic responses in the right pSTS, an area which also exhibits a distinct sensitivity to human voices and faces. Within all other regions known to subserve the perceptual audiovisual integration of human social signals (i.e., amygdala, fusiform gyrus, thalamus), no such linked responses were observed. This functional difference in the network for the audiovisual perception of human social signals indicates a specific contribution of the pSTS as a possible interface between the perception of social information and social cognition. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
A paediatric bone index derived by automated radiogrammetry
2009-11-23

As part of the BoneXpert method for automated bone age determination, our method facilitates retrospective research studies involving validation of the proposed index against fracture incidence and adult bone mineral density.
BK Channels Control Cerebellar Purkinje and Golgi Cell Rhythmicity In Vivo
2009-11-23

Calcium signaling plays a central role in normal CNS functioning and dysfunction. As cerebellar Purkinje cells express the major regulatory elements of calcium control and represent the sole integrative output of the cerebellar cortex, changes in neural activity- and calcium-mediated membrane properties of these cells are expected to provide important insights into both intrinsic and network physiology of the cerebellum. We studied the electrophysiological behavior of Purkinje cells in genetically engineered alert mice that do not express BK calcium-activated potassium channels and in wild-type mice with pharmacological BK inactivation. We confirmed BK expression in Purkinje cells and also demonstrated it in Golgi cells. We demonstrated that either genetic or pharmacological BK inactivation leads to ataxia and to the emergence of a beta oscillatory field potential in the cerebellar cortex. This oscillation is correlated with enhanced rhythmicity and synchronicity of both Purkinje and Golgi cells. We hypothesize that the temporal coding modification of the spike firing of both Purkinje and Golgi cells leads to the pharmacologically or genetically induced ataxia.
Activation of mTOR in renal cell carcinoma is due to increased phosphorylation rather than protein overexpression
2009-11-23

The altered expression and activation of the mammalian target of rapamycin (mTOR) promotes the invasiveness and metastatic potential in a variety of malignancies. The aim of the present pilot study was to determine mTOR expression in clear cell renal cell carcinoma (RCC) and to evaluate mTOR activation and phosphorylation at Ser2448. Tissue microarray immunohistochemistry and Western blot analysis of tumor and benign tissue from 10 patients subjected to tumor nephrectomy were investigated. Staining of mTOR and phosphorylated-mTOR (p-mTOR) was documented and determined as percentage of the maximum. Western blots were evaluated densitometrically. Ratios of tumor versus benign tissue were calculated and compared by the Wilcoxon/Kruskal-Wallis test. Immunohistochemical expressions of mTOR and p-mTOR were 49 and 40% in benign renal parenchyma, whereas it was 20 and 42% in tumor tissue. Ratios of tumor versus benign tissue revealed a reduction to 0.44 for mTOR and corresponding elevation to 1.29 for p-mTOR (p<0.05). The rate of p-mTOR to mTOR was 1.19 in benign, whereas it was 5.30 in tumor tissue. Western blot densitometry detected lower expressions of mTOR in tumor compared to benign tissues. Ratio of p-mTOR to mTOR were significantly different in benign versus tumor tissue (0.86 vs. 1.37; p<0.04). The observation that RCC specimens exhibit higher levels of p-mTOR in RCC compared to benign renal parenchyma indicate the role of mTOR phosphorylation in RCC tumor development and progression. This study found a concomitant reduction of the RCC mTOR protein expression, which suggests that elevated levels of activated p-mTOR result predominantly from an increased mTOR phosphorylation rather than from protein overexpression. These pilot study results may contribute to the clarification of mTOR-pathway regulation processes in RCC on the way to the protein profiling-predicted targeted therapy.