bluuebunny/crossref_metadata_2025_split huggingface dataset:
γ-Aminobutyric Acid (GABA) Stimulates Pancreatic Cancer Growth through Overexpressing GABAA Receptor π Subunit
Authors: Takehara Akio , Hosokawa Masayo , Eguchi Hidetoshi , Ohigashi Hiroaki , Ishikawa Osamu , Nakamura Yusuke , Nakagawa Hidewaki 
Published: October 2007

Abstract
γ-Aminobutyric acid (GABA) functions primarily as an inhibitory neurotransmitter in the mature central nervous system, and GABA/GABA receptors are also present in nonneural tissues, including cancer, but their precise function in nonneuronal or cancerous cells has thus far been poorly defined. Through the genome-wide cDNA microarray analysis of pancreatic ductal adenocarcinoma (PDAC) cells as well as subsequent reverse transcription-PCR and Northern blot analyses, we identified the overexpression of GABA receptor π subunit (GABRP) in PDAC cells. We also found the expression of this peripheral type GABAA receptor subunit in few adult human organs. Knockdown of endogenous GABRP expression in PDAC cells by small interfering RNA attenuated PDAC cell growth, suggesting its essential role in PDAC cell viability. Notably, the addition of GABA into the cell culture medium promoted the proliferation of GABRP-expressing PDAC cells, but not GABRP-negative cells, and GABAA receptor antagonists inhibited this growth-promoting effect by GABA. The HEK293 cells constitutively expressing exogenous GABRP revealed the growth-promoting effect of GABA treatment. Furthermore, GABA treatment in GABRP-positive cells increased intracellular Ca2+ levels and activated the mitogen-activated protein kinase/extracellular signal–regulated kinase (MAPK/Erk) cascade. Clinical PDAC tissues contained a higher level of GABA than normal pancreas tissues due to the up-regulation of glutamate decarboxylase 1 expression, suggesting their autocrine/paracrine growth-promoting effect in PDACs. These findings imply that GABA and GABRP could play important roles in PDAC development and progression, and that this pathway can be a promising molecular target for the development of new therapeutic strategies for PDAC. [Cancer Res 2007;67(20):9704–12] [Cancer Res 2007;67(20):9704–12]
Deficiency of NRH:Quinone Oxidoreductase 2 Differentially Regulates TNF Signaling in Keratinocytes: Up-regulation of Apoptosis Correlates with Down-regulation of Cell Survival Kinases
Authors: Ahn Kwang Seok , Gong Xing , Sethi Gautam , Chaturvedi Madan M. , Jaiswal Anil K. , Aggarwal Bharat B. 
Published: October 2007

Abstract
NRH:quinone oxidoreductase 2 (NQO2) is a cytosolic flavoprotein that catalyzes the two-electron reduction of quinones and quinoid compounds to hydroquinones. Although the role of a homologue, NAD(P)H:quinone oxidoreductase 1 (NQO1), is well defined in oxidative stress, neoplasia, and carcinogenesis, little is known about the mechanism of actions of NQO2 in these cellular responses. Whether NQO2 has any role in tumor necrosis factor (TNF) signaling was investigated using keratinocytes derived from wild-type and NQO2 knockout (NQO2−/−) mice. Although exposure of wild-type cells to TNF led to activation of nuclear factor-κB (NF-κB) and IκBα kinase, IκBα degradation, p65 phosphorylation, and p65 nuclear translocation, this cytokine had no effect on NQO2−/− cells. Deletion of NQO2 also abolished TNF-induced c-Jun NH2-terminal kinase, Akt, p38, and p44/p42 mitogen-activated protein kinase activation. The induction of various antiapoptotic gene products (MMP-9, cyclin D1, COX-2, IAP1, IAP2, Bcl-2, cFLIP, and XIAP) by TNF was also abolished in NQO2−/− cells. This correlated with potentiation of TNF-induced apoptosis as indicated by cell viability, Annexin V staining, and caspase activation. In agreement with this, we also found that TNF activated NQO2, and NQO2-specific small interfering RNA abrogated the TNF-induced NQO2 activity and NF-κB activation. Overall, our results indicate that deletion of NQO2 plays a differential role in TNF signaling pathway: by suppressing cell survival signals and potentiating TNF-induced apoptosis. [Cancer Res 2007;67(20):10004–11]
Reduced Inflammation in the Tumor Microenvironment Delays the Accumulation of Myeloid-Derived Suppressor Cells and Limits Tumor Progression
Authors: Bunt Stephanie K. , Yang Linglin , Sinha Pratima , Clements Virginia K. , Leips Jeff , Ostrand-Rosenberg Suzanne 
Published: October 2007

AbstractChronic inflammation is frequently associated with malignant growth and is thought to promote and enhance tumor progression, although the mechanisms which regulate this relationship remain elusive. We reported previously that interleukin (IL)-1β promoted tumor progression by enhancing the accumulation of myeloid-derived suppressor cells (MDSC), and hypothesized that inflammation leads to cancer through the production of MDSC which inhibit tumor immunity. If inflammation-induced MDSC promote tumor progression by blocking antitumor immunity, then a reduction in inflammation should reduce MDSC levels and delay tumor progression, whereas an increase in inflammation should increase MDSC levels and hasten tumor progression. We have tested this hypothesis using the 4T1 mammary carcinoma and IL-1 receptor (IL-1R)–deficient mice which have a reduced potential for inflammation, and IL-1R antagonist–deficient mice, which have an increased potential for inflammation. Consistent with our hypothesis, IL-1R–deficient mice have a delayed accumulation of MDSC and reduced primary and metastatic tumor progression. Accumulation of MDSC and tumor progression are partially restored by IL-6, indicating that IL-6 is a downstream mediator of the IL-1β–induced expansion of MDSC. In contrast, excessive inflammation in IL-1R antagonist–deficient mice promotes the accumulation of MDSC and produces MDSC with enhanced suppressive activity. These results show that immune suppression by MDSC and tumor growth are regulated by the inflammatory milieu and support the hypothesis that the induction of suppressor cells which down-regulate tumor immunity is one of the mechanisms linking inflammation and cancer. [Cancer Res 2007;67(20):10019–26]
Silent Polymorphisms Speak: How They Affect Pharmacogenomics and the Treatment of Cancer
Authors: Sauna Zuben E. , Kimchi-Sarfaty Chava , Ambudkar Suresh V. , Gottesman Michael M. 
Published: October 2007

Abstract
Polymorphisms in the human genome contribute to wide variations in how individuals respond to medications, either by changing the pharmacokinetics of drugs or by altering the cellular response to therapeutic agents. The goal of the emerging discipline of pharmacogenomics is to personalize therapy based on an individual's genotype. Due to the relatively large frequency of single-nucleotide polymorphisms (SNP) in the human genome, synonymous SNPs are often disregarded in many pharmacogenomic studies based on the assumption that these are silent. We have shown recently that synonymous SNPs in ABCB1 (P-glycoprotein), which is implicated both in determining drug pharmacokinetics and multidrug resistance in human cancer cells, can affect protein conformation and function. We discuss the importance of polymorphisms in drug metabolizing enzymes and transporters in anticancer therapy and suggest that synonymous polymorphisms may play a more significant role than is currently assumed. [Cancer Res 2007;67(20):9609–12]
MicroRNA Let-7a Down-regulates MYC and Reverts MYC-Induced Growth in Burkitt Lymphoma Cells
Authors: Sampson Valerie B. , Rong Nancy H. , Han Jian , Yang Qunying , Aris Virginie , Soteropoulos Patricia , Petrelli Nicholas J. , Dunn Stephen P. , Krueger Leslie J. 
Published: October 2007

Abstract
Regulation of the MYC oncogene remains unclear. Using 10058-F4, a compound that inhibits MYC-MAX transcription factor, MYC protein and gene expression were down-regulated in Namalwa cells, a Burkitt lymphoma. Compound 10058-F4 decreased MYC mRNA (45%), MYC protein (50%), and cell growth (32%). MYC-MAX transcription factor was disrupted 24 h after treatment, resulting in transcriptional inhibition of target genes. Because microRNAs (miRNA) disrupt mRNA translation, let-7a, let-7b, and mir-98 were selected using bioinformatics for targeting MYC. Inhibition of MYC-MAX transcription factor with 10058-F4 increased levels of members of the let-7 family. In inhibited cells at 24 h, let-7a, let-7b, and mir-98 were induced 4.9-, 1.3-, and 2.4-fold, respectively, whereas mir-17-5p decreased 0.23-fold. These results were duplicated using microRNA multianalyte suspension array technology. Regulation of MYC mRNA by let-7a was confirmed by transfections with pre-let-7a. Overexpression of let-7a (190%) decreased Myc mRNA (70%) and protein (75%). Down-regulation of Myc protein and mRNA using siRNA MYC also elevated let-7a miRNA and decreased Myc gene expression. Inverse coordinate regulation of let-7a and mir-17-5p versus Myc mRNA by 10058-F4, pre-let-7a, or siRNA MYC suggested that both miRNAs are Myc-regulated. This supports previous results in lung and colon cancer where decreased levels of the let-7 family resulted in increased tumorigenicity. Here, pre-let-7a transfections led to down-regulation of expression of MYC and its target genes and antiproliferation in lymphoma cells. These findings with let-7a add to the complexity of MYC regulation and suggest that dysregulation of these miRNAs participates in the genesis and maintenance of the lymphoma phenotype in Burkitt lymphoma cells and other MYC-dysregulated cancers. [Cancer Res 2007;67(20):9762–70]
Mouse Model of Colonic Adenoma-Carcinoma Progression Based on Somatic Apc Inactivation
Authors: Hinoi Takao , Akyol Aytekin , Theisen Brian K. , Ferguson David O. , Greenson Joel K. , Williams Bart O. , Cho Kathleen R. , Fearon Eric R. 
Published: October 2007

Abstract
Mutations in the adenomatous polyposis coli (APC) gene are pivotal in colorectal tumorigenesis. Existing mouse intestinal tumor models display mainly small intestinal lesions and carcinomas are rare. We defined human CDX2 sequences conferring colon epithelium-preferential transgene expression in the adult mouse. Mice carrying a CDX2P-NLS Cre recombinase transgene and a loxP-targeted Apc allele developed mainly colorectal tumors, with carcinomas seen in 6 of 36 (17%) of mice followed for 300 days. Like human colorectal lesions, the mouse tumors showed biallelic Apc inactivation, β-catenin dysregulation, global DNA hypomethylation, and aneuploidy. The predominantly distal colon and rectal distribution of tumors seen in mice where one Apc allele was inactivated in epithelial cells from distal ileum to rectum suggests that regional differences in the intestinal tract in the frequency and nature of secondary genetic and epigenetic events associated with adenoma outgrowth have a contributing role in determining where adenomas develop. The presence of large numbers of small intestine tumors seemed to inhibit colorectal tumor development in the mouse, and gender-specific effects on tumor multiplicity in the distal mouse colon and rectum mimic the situation in humans where males have a larger number of advanced adenomas and carcinomas in the distal colon and rectum than females. The mouse model of colon-preferential gene targeting described here should facilitate efforts to define novel factors and mechanisms contributing to human colon tumor pathogenesis, as well as work on tumor-promoting environmental factors and agents and strategies for cancer prevention and treatment. [Cancer Res2007;67(20):9721–30]
The dual role of the contact system in bacterial infectious disease
Authors: Frick Inga-Maria , Björck Lars , Herwald Heiko 
Published: October 2007

SummaryHemostasis is a sensitive and tightly regulated process, involving the vascular endothelium and blood cells as well as factors of the coagulation and fibrinolytic cascades. Over the last four decades evidence has accumulated that during infection, inflammatory mediators from the microbe and/or host are capable to modulate the equilibrium between the procoagulant and anticoagulant status of the host. Dependent on the mode of activation, these changes can cause either local or systemic inflammatory reactions that may be beneficial or deleterious to the human host. The present review aims to present the state of the art with respect to the role of the contact system (also known as the intrinsic pathway of coagulation or the kallikrein/kinin system) in innate immunity and systemic inflammatory reactions.
Molecular characterization of four ADAMTS13 mutations responsible for congenital thrombotic thrombocytopenic purpura (Upshaw-Schulman syndrome)
Authors: Hommais Antoine , Rayes Julie , Houllier Anne , Obert Bernadette , Legendre Paulette , Veyradier Agnes , Ribba Anne-Sophie , Girma Jean-Pierre 
Published: October 2007

SummaryADAMTS13 mutations S203P, R268P, R507Q and A596V were previously identified in French patients with hereditary thrombotic thrombocytopenic purpura (TTP) (Upshaw-Schulman syndrome). Mutated recombinant (r) ADAMTS13 were transiently expressed in COS-7 cells and characterized in comparison with wild-type (WT) rADAMTS13.ADAMTS13 antigen was qualitatively and quantitatively estimated by electrophoretic analysis and ELISA. Enzymatic activity was qualitatively and quantitatively estimated using GST-VWF73,FRETS-VWF73 fragments and full-length rVWF-WT as substrates. The four mutants and rADAMTS13-WT were present within the cells. Secretion level of rADAMTS13-WT reached 1,200 ng/ml. The four mutations strongly altered the secretion and biological activity of rADAMTS13. The percentage secretion was 21, 38 and 17% for rADAMTS13-S203P, -R268P and -A596V compared with rADAMTS13- WT. rADAMTS13-R507Q concentration was under the detection limit of the assay. In the four cases, no enzymatic activity was detected. After concentration, we confirmed that mutations S203P and R268P totally abolished the proteolytic activity of ADAMTS13. Due to the very low protease concentration, activity of rADAMTS13-R507Q was below the threshold of the assays. rADAMTS13-A596V had no proteolytic activity towards the full-length rVWF-WT whereas it exhibited a decreased specific activity of about 30% of that of rADAMTS13- WT towards FRETS-VWF73 fragment. Binding study of mutated rADAMTS13-S203P, -R268P and -A596V showed that the three mutations strongly decreased the interaction of ADAMTS13 with VWF. In conclusion, the four mutations, which led to a secretion defect, a loss of enzymatic activity and a decreased binding to the substrate, are responsible for the hereditary TTP in patients.
Local paclitaxel delivery after coronary stenting in an experimental animal model
Authors: Dommke Christoph , Süselbeck Tim , Streitner Ines , Haghi Dariush , Metz Jürgen , Borggrefe Martin , Herdeg Christian , Haase Karl 
Published: October 2007

SummaryThe goal of this study was to test the safety and efficacy of local paclitaxel delivery via a newly designed application catheter in an experimental animal study. Drug-eluting stents reduce restenosis in comparison to bare-metal stents. The drug-eluting polymer, however, may exert potential thrombogenic and inflammatory effects. A catheter-based local paclitaxel delivery offers further advantages, particularly a homogenous drug transfer into the vessel wall and a pharmacotherapy of the stent edges. In 30 pigs, both bare-metal stent (3.0 × 13mm) implantation and balloon angioplasty were performed. Ten pigs received subsequent local delivery of paclitaxel-solution via a newly designed catheter (Genie™, ACROSTAK corp., Switzerland), 10 animals served as a sham group and received vehicle (0.9% NaCl solution) and 10 animals were used as a control group. All animals were treated with aspirin and clopidogrel to prevent stent thrombosis. After final angiography the vessels were excised 42 days after intervention and prepared for histological and histomorphometric analysis. All coronary arteries showed complete endothelialization 42 days following treatment. Paclitaxel treatment led to a marked reduction of neointimal proliferation either post stent implantation (neointimal area: 1.04 ± 0.10 mm2 vs. 2.37 ± 0.23 mm2, p<0.001) or post balloon dilatation (neontimal area: 0.35 ± 0.14 mm2, vs. 0.68 ± 0.24 mm2, p<0.01).There were no significant angiographic or histomorphometric differences between the control and the sham group. In both paclitaxel groups neither angiographic edge phenomena nor a significant histomorphometric inflammatory response were found in the treated vessel segments. In conclusion, the local application of paclitaxel via the Genie™ catheter is safe and effective to significantly reduce the proliferative response post-stent implantation or balloon dilatation in an experimental animal model.
Effects of toll-like receptor-4 gene polymorphisms on soluble P-selectin and von Willebrand factor levels in hypercholesterolemic patients
Authors: Nisio Marcello Di , Febbo Concetta Di , Moretta Valeria , Guglielmi Maria Domenica , Stuppia Liborio , Cuccurullo Franco , Porreca Ettore 
Published: October 2007

SummaryToll-like receptor-4 (TLR-4) gene polymorphisms have been associated with a lower risk of atherosclerosis. High levels of soluble P-selectin (sP-selectin) and von Willebrand factor predict an increased risk for cardiovascular events and correlate to atherosclerotic risk factors. The relationship between these markers and TLR-4 gene polymorphisms was evaluated in a cohort of consecutive hypercholesterolemic outpatients. TLR-4 gene polymorphisms were detected in 48 out of 330 (14%) patients with hypercholesterolemia. Lipid and inflammatory markers, sP-selectin and von Willebrand were evaluated in carriers and in 96 (ratio 2:1 to cases) age- and sex-matched TLR-4 wild-type patients randomly selected from the same population. A cohort of normocholesterolemic outpatients (n=262) served as the control group.sP-selectin was sensibly lower in carriers of TLR-4 variants as compared to wild-types and controls (89 ng/ ml vs. 162 ng/ml and 163 ng/dl, respectively, p=0.0001). Similarly, carriers showed lower von Willebrand factor values (683 mU/ ml) than wild-types (910 mU/ml; p=0.001). In multivariate analysis, TLR-4 gene polymorphisms were positively associated with sP-selectin, whereas the relationship with von Willebrand factor was no longer significant. HMG-CoA reductase inhibitors reduced sP-selectin and von Willebrand factor levels independently of TLR-4 gene variants. Plasma concentrations of these markers, however, remained lower in carriers of TLR-4 gene polymorphisms even after cholesterol lowering. In conclusion, carriership of Asp299 andThr399IleTLR-4 gene polymorphisms is associated with lower levels of sP-selectin and von Willebrand factor among hypercholesterolemic patients. While the underlying mechanisms remain to be investigated, such an association may indicate a protective effect of TLR-4 variants for atherosclerosis.
Fibrinolysis and host response in bacterial infections
Authors: Bergmann Simone , Hammerschmidt Sven 
Published: October 2007

SummaryThe plasminogen activation system is part of the fibrinolysis which is tightly regulated and protected against dysfunction by various activators and inhibitors. However, microorganisms including bacteria, fungi and also parasites have been proven to interact in a specific manner with components of the fibrinolytic pathways. Pathogenic bacteria are capable to subvert the function of proteases, activators or inhibitors for their own benefits including dissemination within the host and evasion of host inflammatory immune response. Here, we provide a state of the art overview of the divers strategies employed by bacteria to interact with components of the fibrinolytic system and to exploit the system for invasion. Moreover, the role of factors of the fibrinolytic cascade in inflammatory host response due to different bacterial infections will be presented.
Exclusion of the α2 subunit of platelet-activating factor acetylhydrolase 1b (PAFAH1B2) as a prothrombotic gene in a protein C-deficient kindred and population-based case-control sample
Authors: Scott Bruce , Rosendaal Frits , Callas Peter , Vossen Carla , Long George , Bovill Edwin , Hasstedt Sandra 
Published: October 2007

SummaryProtein C deficiency increases the risk of venous thromboembolic disease among members of KindredVermont II, but fails to fully account for the inheritance pattern. A genome scan of the pedigree supported the presence of a prothrombotic gene on chromosome 11q23 (107–119Mb, nominal P<0.0001), with weaker support on chromosomes 10p12 (11–25Mb, P<0.0003) and 18p11.2-q11 (12–24Mb, P<0.0007).The 11q23 region contains the α2 subunit (gene name PAFAH1B2) of platelet-activating factor acetylhydrolase 1b, a candidate prothrombotic gene. Re-sequencing of the PAFAH1B2 regulatory region in 137 pedigree members, including 25 thrombosis cases, revealed 12 variants; eight were present in only 0–2 affected individuals; the other four assorted into three haplotypes and included three variants predicted to destroy transcription factor-binding sites. More extensive re-sequencing of the PAFAH1B2 gene in 11 affected and five unaffected pedigree members revealed an additional 13 variants that assorted into the same three haplotypes. We rejected as thrombosis risk factors each of the three presumed destructive variants as well as each of the three haplotypes. We also rejected (odds ratio=1.31 CI: 0.91–1.88) one of the three variants in 469 cases and 472 controls from the Leiden Thrombophilia Study (LETS). Therefore, PAFAH1B2 is not the gene responsible for the linkage evidence on chromosome 11q23.
Coagulation factor V and thrombophilia: Background and mechanisms
Authors: Segers Kenneth , Dahlbäck Björn , Nicolaes Gerry 
Published: October 2007

SummaryHuman coagulation factor V (FV) is an essential coagulation protein with functions in both the pro- and anticoagulant pathways. Failure to express and control FV functions can either lead to bleeding, or to thromboembolic disease. Both events may develop into a life-threatening condition. Since the first description of APC resistance, and in particular the description of the so-called factor VLeiden mutation, in which a prominent activated protein C cleavage site in FV has been abolished through a mutation in the FV gene, FV has been in the center of attention of thrombosis research. In this review we describe how the functions of FV are expressed and regulated and provide an extensive description of the role that FV plays in the etiology of thromboembolic disease.
Invasion mechanisms of Gram-positive pathogenic cocci
Authors: Nitsche-Schmitz Patric , Rohde Manfred , Chhatwal Gursharan 
Published: October 2007

SummaryGram-positive cocci are important human pathogens. Streptococci and staphylococci in particular are a major threat to human health,since they cause a variety of serious invasive infections. Their invasion into normally sterile sites of the host depends on elaborated bacterial mechanisms that involve adhesion to the host tissue, its degradation, internalisation by host cells, and passage through epithelia and endothelia. Interactions of bacterial surface proteins with proteins of the host’s extracellular matrix as well as with cell surface receptors are crucial factors in these processes, and some of the key mechanisms are similar in many pathogenic Gram-positive cocci.Therapies that interfere with these mechanisms may become efficient alternatives to today’s antibiotic treatments.