bluuebunny/crossref_metadata_2025 huggingface dataset:
Activity-Dependent Layer-Specific Changes in the Extracellular Chloride Concentration and Chloride Driving Force in the Rat Hippocampus
Authors: Kroeger D. , Tamburri A. , Amzica F. , Sík A.
Published: February 2010

The transmembrane distribution of chloride anions (Cl−) determines the direction of the Cl− flux through GABAA receptors; this establishes whether GABAA receptor-mediated responses are hyperpolarizing or depolarizing in neurons. Thus an activity-dependent reduction in the efficacy of inhibitory responses can be the result of an activity-induced reduction of the Cl− driving force. Using Cl−-sensitive electrodes, we measured the extracellular Cl− concentration ([Cl−]o) in each layer of the hippocampus under control conditions and after stimulation. In the control condition, [Cl−]o was lower within the CA1 region (112.9 ± 1.3 mM; mean ± SD) than the CA3/dentate gyrus areas (117.7 ± 1.2 mM). Stimulation of CA3 pyramidal cells led to an increase in the [Cl−]o. The maximum values were observed in the stratum lacunosum-moleculare (253.4 ± 51.1 mM) and in the hilus (261 ± 43.7 mM), whereas in the granular cell layer, it reached only 159.5 ± 41 mM. The stimulation-induced [Cl−]o increase was followed by a period of decreasing [Cl−]o that fell below the control values. The maximum undershoot (21.6 ± 0.7 mM) was observed in the s. radiatum. Systemic application of the gap junction blocker carbenoxolone significantly decreased the stimulation-induced Cl− extrusion in the dentate gyrus but only slightly modified it in the CA1 area. Carbenoxolone also drastically reduced the Cl− clearance. The time constant of the Cl− clearance was similar between layers (83.4 ± 15.9 ms) but increased after carbenoxolone application (207.1 ± 44.4 ms). Stimulation-induced changes in the [Cl−]o significantly decreased the Cl− driving force and resulted in large fluctuations between layers (Δ = 9.4 mV). The lowest value was observed in the stratum radiatum of the CA1 and the hilar region (7.7 mV), whereas the highest value was calculated for the granule cell layer (16.3 mV). We suggest that a decrease of the extracellular space is mainly responsible for the rapid [Cl−]o increase while the gap junction coupled astrocytic network plays a key role in the activity-dependent redistribution and clearance of Cl− across layers of the hippocampus.
Extended Durability of a Cloth-Covered Star-Edwards Caged Ball Prosthesis in Aortic Position
Authors: Ata Yusuf , Turk Tamer , Eris Cüneyt , Yalcin Mihriban , Ata Filiz , Ozyazicioğlu A.
Published: February 2010

The Starr-Edwards caged ball valve is one of the oldest cardiac valve prosthesis and was widely used all around the world in the past decades. Despite the long-term results that have been reported there are only a few cases reported that exceed 30 years of durability. Here in, we report a 53-year-old patient with a well-functioning 35-year-old aortic Starr-Edwards caged ball prosthesis.
Hydrothermal Preparation of Gd3+‐Doped Titanate Nanotubes: Magnetic Properties and Photovoltaic Performance
Authors: Hafez Hoda S. , Saif M. , McLeskey, James T. , Abdel-Mottaleb M. S. A. , Yahia I. S. , Story T. , Knoff W.
Published: February 2010

Pure and Gd3+‐doped titanate nanotubes (TNTs) materials were
synthesized by a hydrothermal method. Their morphology, optical
properties, thermal stability, and magnetic properties were
characterized by X‐ray diffraction (XRD), transmission electron
microscope (TEM), UV‐Vis spectroscopy, thermal analysis, and
magnetic measurements. It was found that doping renders Gd3+‐TNT visible light active and results in smaller
crystallite size and larger surface area as well as higher thermal
stability compared to pure titanate nanotubes. The estimated
magnetic moments point to presence of weak antiferromagnetic
interaction. Application of the prepared Gd3+‐TNT for modifying conventional photoanodes in polymer
solar cells was attempted. Preliminary results show slightly
improved photovoltaic energy conversion efficiency in the devices
containing the newly designed Gd3+‐doped nanotubes.
Mathematical Programming Approaches to Classification Problems
Authors: Smaoui Soulef , Chabchoub Habib , Aouni Belaid
Published: February 2010

Discriminant Analysis (DA) is widely applied in many fields. Some recent researches raise the fact that standard DA assumptions, such as a normal distribution of data and equality of the variance-covariance matrices, are not always satisfied. A Mathematical Programming approach (MP) has been frequently used in DA and can be considered a valuable alternative to the classical models of DA. The MP approach provides more flexibility for the process of analysis. The aim of this paper is to address a comparative study in which we analyze the performance of three statistical and some MP methods using linear and nonlinear discriminant functions in two-group classification problems. New classification procedures will be adapted to context of nonlinear discriminant functions. Different applications are used to compare these methods including the Support Vector Machines- (SVMs-) based approach. The findings of this study will be useful in assisting decision-makers to choose the most appropriate model for their decision-making situation.
Analysis of Bio‐Obtainable Endocrine Disrupting Metals in River Water and Sediment, Sewage Influent/Effluent, Sludge, Leachate, and Concentrated Leachate, in the Irish Midlands Shannon Catchment
Authors: Reid Antoinette M. , Brougham Concepta A. , Fogarty Andrew M. , Roche James J.
Published: February 2010

The application of an acid digestion and subsequent solid‐phase extraction (SPE) procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs) in a variety of solid and liquid matrices. These included (solid) river sediment, leachate sediment and sewage sludge and also (liquid) river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and manganese (Mn), after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS). Mercury (Hg) in sediment and sludge was determined using cold‐vapour atomic fluorescence spectroscopy (AFS). For sewage sludge maximum values (mg/kgdw) of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg/kgdw) of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.
Phase Synchronization in Coupled Sprott Chaotic Systems Presented by Fractional Differential Equations
Authors: Erjaee G. H. , Alnasr M.
Published: February 2010

Phase synchronization occurs whenever a linearized system describing the evolution of the difference between coupled chaotic systems has at least one eigenvalue with zero real part. We illustrate numerical phase synchronization results and stability analysis for some coupled Sprott chaotic systems presented by fractional differential equations.
Immunity against Helminths: Interactions with the Host and the Intercurrent Infections
Authors: Moreau Emmanuelle , Chauvin Alain
Published: February 2010

Helminth parasites are of considerable medical and economic importance. Studies of the immune response against helminths are of great interest in understanding interactions between the host immune system and parasites. Effector immune mechanisms against tissue-dwelling helminths and helminths localized in the lumen of organs, and their regulation, are reviewed. Helminth infections are characterized by an association of Th2-like and Treg responses. Worms are able to persist in the host and are mainly responsible for chronic infection despite a strong immune response developed by the parasitized host. Two types of protection against the parasite, namely, premune and partial immunities, have been described. Immune responses against helminths can also participate in pathogenesis. Th2/Treg-like immunomodulation allows the survival of both host and parasite by controlling immunopathologic disorders and parasite persistence. Consequences of the modified Th2-like responses on co-infection, vaccination, and inflammatory diseases are discussed.
Does Kirk's Theorem Hold for Multivalued Nonexpansive Mappings?
Authors: Domínguez Benavides T , Gavira B
Published: February 2010

Fixed Point Theory for multivalued mappings has many useful applications in Applied Sciences, in particular, in Game Theory and Mathematical Economics. Thus, it is natural to try of extending the known fixed point results for single-valued mappings to the setting of multivalued mappings. Some theorems of existence of fixed points of single-valued mappings have already been extended to the multivalued case. However, many other questions remain still open, for instance, the possibility of extending the well-known Kirk's Theorem, that is: do Banach spaces with weak normal structure have the fixed point property (FPP) for multivalued nonexpansive mappings? There are many properties of Banach spaces which imply weak normal structure and consequently the FPP for single-valued mappings (for example, uniform convexity, nearly uniform convexity, uniform smoothness,…). Thus, it is natural to consider the following problem: do these properties also imply the FPP for multivalued mappings? In this way, some partial answers to the problem of extending Kirk's Theorem have appeared, proving that those properties imply the existence of fixed point for multivalued nonexpansive mappings. Here we present the main known results and current research directions in this subject. This paper can be considered as a survey, but some new results are also shown.
Increased Risk of Colon Cancer Associated with a Genetic Polymorphism of SMAD7
Authors: Slattery Martha L. , Herrick Jennifer , Curtin Karen , Samowitz Wade , Wolff Roger K. , Caan Bette J. , Duggan David , Potter John D. , Peters Ulrike
Published: February 2010

Genome-wide association studies (GWAS) have identified SMAD7 on 8q21 as being associated with colorectal cancer. We evaluated single nucleotide polymorphisms (SNP) in the SMAD7 gene, including rs4939827, rs12953717, and rs4464148, previously identified from GWAS in a large population-based case-control study of colon cancer. We observed that rs12953717 was associated with a statistically significant increased risk of colon cancer [odds ratio, 1.38; 95% confidence intervals (CI), 1.13–1.68; P linear trend < 0.01] for the TT genotype compared with the CC genotype, whereas the CC genotype of the rs4939827 SNP was inversely associated with colon cancer (0.77; 95% CI, 0.64–0.93) relative to the TT genotype. There were no significant differences in association for either of these polymorphisms when stratified by age, tumor site, sex, or family history. The odds ratios between SMAD7 and colon cancer among individuals reporting recent aspirin/nonsteroidal anti-inflammatory drug use was 0.60 (95% CI, 0.43–0.85) for the CC genotype of the rs4939827 polymorphism and 1.69 (95% CI, 1.20–2.38) for the TT genotype of the rs1295371 polymorphism. This result compares to odds ratios of 0.86 (95% CI, 0.68–1.09) for rs4939827 and 1.22 (95% CI, 0.96–1.56) among individuals who did not use aspirin/nonsteroidal anti-inflammatory drugs. An assessment of SMAD7 genotypes with tumor markers did not reveal any significant differences by KRAS2, TP53, CpG island methylator phenotype, or microsatellite instability status. No significant associations were observed for the rs4464148 SNP or other SNPs evaluated in the SMAD7. These results corroborate the findings of GWAS in colon cancer pointing to SMAD7 and reinforce interest in SNPs in this gene. Cancer Res; 70(4); 1479–85
Cell Surface Tetraspanin Tspan8 Contributes to Molecular Pathways of Exosome-Induced Endothelial Cell Activation
Authors: Nazarenko Irina , Rana Sanyukta , Baumann Alexandra , McAlear Jessica , Hellwig Andrea , Trendelenburg Michael , Lochnit Günter , Preissner Klaus T. , Zöller Margot
Published: February 2010

Tumor-derived exosomes containing the tetraspanin Tspan8 can efficiently induce angiogenesis in tumors and tumor-free tissues. However, little information exists on exosome–endothelial cell (EC) interactions or the proangiogenic role of tetraspanins, which are a constitutive component of exosomes. In this study, we used a rat adenocarcinoma model (AS-Tspan8) to explore the effects of exosomal Tspan8 on angiogenesis. Tspan8 contributed to a selective recruitment of proteins and mRNA into exosomes, including CD106 and CD49d, which were implicated in exosome-EC binding and EC internalization. We found that EC internalized Tspan8-CD49d complex–containing exosomes. Exosome uptake induced vascular endothelial growth factor (VEGF)–independent regulation of several angiogenesis-related genes, including von Willebrand factor, Tspan8, chemokines CXCL5 and MIF, chemokine receptor CCR1, and, together with VEGF, VEGF receptor 2. EC uptake of Tspan8-CD49d complex–containing exosomes was accompanied by enhanced EC proliferation, migration, sprouting, and maturation of EC progenitors. Unraveling these new pathways of exosome-initiated EC regulation could provide new options for therapeutic interference with tumor-induced angiogenesis. Cancer Res; 70(4); 1668–78
Inflammatory Processes Triggered by Helicobacter pylori Infection Cause Aberrant DNA Methylation in Gastric Epithelial Cells
Authors: Niwa Tohru , Tsukamoto Tetsuya , Toyoda Takeshi , Mori Akiko , Tanaka Harunari , Maekita Takao , Ichinose Masao , Tatematsu Masae , Ushijima Toshikazu
Published: February 2010

Altered patterns of DNA methylation associated with Helicobacter pylori (HP) infection of gastric epithelial cells are thought to contribute to gastric cancer risk. However, it is unclear whether this increased risk reflects an infection-associated inflammatory response or the infection itself. In this study, we sought to clarify mechanisms in a gerbil model of gastric cancer where we showed that HP infection is causally involved in induction of aberrant DNA methylation. By genome-wide screening, CpG islands that were aberrantly methylated in gerbil gastric cancer cell lines were isolated, and 10 islands were shown to be specifically methylated only in gastric mucosae infected with HP. By temporal analysis, methylation levels in gastric epithelial cells started to increase at 5 to 10 weeks after infection and reached high levels by 50 weeks. When HP was eradicated, methylation levels markedly decreased 10 and 20 weeks later, but they remained higher than those in gerbils that were not infected by HP. Expression levels of several inflammation-related genes (CXCL2, IL-1β, NOS2, and TNF-α) paralleled the temporal changes of methylation levels. Significantly suppressing inflammation with the immunosuppressive drug cyclosporin A did not affect colonization by HP but blocked the induction of altered DNA methylation. Our findings argue that DNA methylation alterations that occur in gastric mucosae after HP infection are composed of transient components and permanent components, and that it is the infection-associated inflammatory response, rather than HP itself, which is responsible for inducing the altered DNA methylation. Cancer Res; 70(4); 1430–40
Downregulation of Rap1GAP through Epigenetic Silencing and Loss of Heterozygosity Promotes Invasion and Progression of Thyroid Tumors
Authors: Zuo Hui , Gandhi Manoj , Edreira Martin M. , Hochbaum Daniel , Nimgaonkar Vishwajit L. , Zhang Ping , DiPaola James , Evdokimova Viktoria , Altschuler Daniel L. , Nikiforov Yuri E.
Published: February 2010

Thyroid cancer is the most common type of endocrine malignancy, encompassing tumors with various levels of invasive growth and aggressiveness. Rap1GAP, a Rap1 GTPase-activating protein, inhibits the RAS superfamily protein Rap1 by facilitating hydrolysis of GTP to GDP. In this study, we analyzed 197 thyroid tumor samples and showed that Rap1GAP was frequently lost or downregulated in various types of tumors, particularly in the most invasive and aggressive forms of thyroid cancer. The downregulation was due to promoter hypermethylation and/or loss of heterozygosity, found in the majority of thyroid tumors. Treatment with demethylating agent 5-aza-deoxycytidine and/or histone deacetylation inhibitor trichostatin A induced gene reexpression in thyroid cells. A genetic polymorphism, Y609C, was seen in 7% of thyroid tumors but was not related to gene downregulation. Loss of Rap1GAP expression correlated with tumor invasiveness but not with specific mutations activating the mitogen-activated protein kinase pathway. Rap1GAP downregulation was required in vitro for cell migration and Matrigel invasion. Recovery of Rap1GAP expression inhibited thyroid cell proliferation and colony formation. Overall, our findings indicate that epigenetic or genetic loss of Rap1GAP is very common in thyroid cancer, where these events are sufficient to promote cell proliferation and invasion. Cancer Res; 70(4); 1389–97
Cancer Biomarkers Defined by Autoantibody Signatures to Aberrant O-Glycopeptide Epitopes
Authors: Wandall Hans H. , Blixt Ola , Tarp Mads A. , Pedersen Johannes W. , Bennett Eric P. , Mandel Ulla , Ragupathi Govind , Livingston Phil O. , Hollingsworth Michael A. , Taylor-Papadimitriou Joyce , Burchell Joy , Clausen Henrik
Published: February 2010

Autoantibodies to cancer antigens hold promise as biomarkers for early detection of cancer. Proteins that are aberrantly processed in cancer cells are likely to present autoantibody targets. The extracellular mucin MUC1 is overexpressed and aberrantly glycosylated in many cancers; thus, we evaluated whether autoantibodies generated to aberrant O-glycoforms of MUC1 might serve as sensitive diagnostic biomarkers for cancer. Using an antibody-based glycoprofiling ELISA assay, we documented that aberrant truncated glycoforms were not detected in sera of cancer patients. An O-glycopeptide microarray was developed that detected IgG antibodies to aberrant O-glycopeptide epitopes in patients vaccinated with a keyhole limpet hemocyanin–conjugated truncated MUC1 peptide. We detected cancer-associated IgG autoantibodies in sera from breast, ovarian, and prostate cancer patients against different aberrent O-glycopeptide epitopes derived from MUC1. These autoantibodies represent a previously unaddressed source of sensitive biomarkers for early detection of cancer. The methods we have developed for chemoenzymatic synthesis of O-glycopeptides on microarrays may allow for broader mining of the entire cancer O-glycopeptidome. Cancer Res; 70(4); 1306–13
Surface Charge: A Key Determinant of Protein Localization and Function
Authors: Goldenberg Neil M. , Steinberg Benjamin E.
Published: February 2010

Electrostatic charge at the membrane surface has emerged as a crucial determinant of the localization and activation of many proteins containing polycationic domains in their amino acid sequence. The spatiotemporal regulation of surface charge, as well as the downstream effects of dysregulation of surface charge, may have a significant impact on many of the signaling molecules important to cancer biology such as K-ras. Cancer Res; 70(4); 1277–80
Irreversible Electroporation Therapy in the Liver: Longitudinal Efficacy Studies in a Rat Model of Hepatocellular Carcinoma
Authors: Guo Yang , Zhang Yue , Klein Rachel , Nijm Grace M. , Sahakian Alan V. , Omary Reed A. , Yang Guang-Yu , Larson Andrew C.
Published: February 2010

Irreversible electroporation (IRE) is an innovative local-regional therapy that involves delivery of intense electrical pulses to tissue to induce nanoscale cell membrane defects for tissue ablation. The purpose of this study was to investigate the feasibility of using IRE as a liver-directed ablation technique for the treatment of hepatocellular carcinoma (HCC). In the N1-S1 rodent model, hepatomas were grown in 30 Sprague-Dawley rats that were divided into treatment and control groups. For treatment groups, IRE electrodes were inserted and eight 100-μs 2,500-V pulses were applied to ablate the targeted tumor tissues. For both groups, magnetic resonance imaging scans were performed at baseline and 15-day follow-up intervals to determine tumor sizes (one-dimensional maximum diameter, Dmax; estimated two-dimensional cross-sectional area, Cmax) as a tactic to assess longitudinal outcomes. Additional groups of treated animals were sacrificed at 1-, 3-, and 7-day intervals posttherapy for pathology assessment of treatment response. Magnetic resonance images showed significant tumor size reductions within 15 days posttherapy (32 ± 31% Dmax and 52 ± 39% Cmax decreases compared with 110 ± 35% Dmax and 286 ± 125% Cmax increases for untreated tumors). Pathology correlation studies documented progression from poorly differentiated viable HCC tissues before treatment to extensive tumor necrosis and full regression in 9 of 10 treated rats 7 to 15 days after treatment. Our findings suggest that IRE can be an effective strategy for targeted ablation of liver tumors, prompting its further evaluation for HCC therapy. Cancer Res; 70(4); 1555–63
Gossypol Induces Apoptosis by Activating p53 in Prostate Cancer Cells and Prostate Tumor–Initiating Cells
Authors: Volate Suresh R. , Kawasaki Brian T. , Hurt Elaine M. , Milner John A. , Kim Young S. , White Jeffrey , Farrar William L.
Published: February 2010

Prostate cancer continues to represent a burgeoning medical problem in the United States. Recent studies suggest that gossypol, a bioactive phytochemical produced by cotton plants, is a promising agent against prostate cancer. The current studies were undertaken to examine the chemotherapeutic efficacy of gossypol on human prostate cancer cell lines and prostate tumor–initiating cells. Gossypol reduced the viability of three prostate cancer cell lines (LAPC4, PC3, and DU145) with an IC50 between 3 and 5 μmol/L. Additionally, gossypol was effective at inhibiting prostate tumor–initiating cell-driven tumor growth in a nonobese diabetic/severe combined immunodeficient xenograft model. Our integrated molecular profiling approach encompassing proteomics, activated transcription factors, and genomics suggests that the decrease in viability was associated with increased DNA damage and the induction of apoptosis. Exposure of DU145 cells to gossypol (1–10 μmol/L) resulted in the activation of 13 proteins and 7 transcription factors, and the expression of 17 genes involved in the mitochondrial pathway of apoptosis. These studies show for the first time that gossypol treatment induces DNA damage and activates p53. Collectively, these data support the use of gossypol as a novel agent for prostate cancer. Mol Cancer Ther; 9(2); 461–70
Molecular Evolutionary Analysis of Cancer Cell Lines
Authors: Zhang Yan , Italia Michael J. , Auger Kurt R. , Halsey Wendy S. , Van Horn Stephanie F. , Sathe Ganesh M. , Magid-Slav Michal , Brown James R. , Holbrook Joanna D.
Published: February 2010

With genome-wide cancer studies producing large DNA sequence data sets, novel computational approaches toward better understanding the role of mutations in tumor survival and proliferation are greatly needed. Tumors are widely viewed to be influenced by Darwinian processes, yet molecular evolutionary analysis, invaluable in other DNA sequence studies, has seen little application in cancer biology. Here, we describe the phylogenetic analysis of 353 cancer cell lines based on multiple sequence alignments of 3,252 nucleotides and 1,170 amino acids built from the concatenation of variant codons and residues across 494 and 523 genes, respectively. Reconstructed phylogenetic trees cluster cell lines by shared DNA variant patterns rather than cancer tissue type, suggesting that tumors originating from diverse histologies have similar oncogenic pathways. A well-supported clade of 91 cancer cell lines representing multiple tumor types also had significantly different gene expression profiles from the remaining cell lines according to statistical analyses of mRNA microarray data. This suggests that phylogenetic clustering of tumor cell lines based on DNA variants might reflect functional similarities in cellular pathways. Positive selection analysis revealed specific DNA variants that might be potential driver mutations. Our study shows the potential role of molecular evolutionary analyses in tumor classification and the development of novel anticancer strategies. Mol Cancer Ther; 9(2); 279–91
A Fully Human Insulin-Like Growth Factor-I Receptor Antibody SCH 717454 (Robatumumab) Has Antitumor Activity as a Single Agent and in Combination with Cytotoxics in Pediatric Tumor Xenografts
Authors: Wang Yaolin , Lipari Philip , Wang Xiaoying , Hailey Judith , Liang Lianzhu , Ramos Robert , Liu Ming , Pachter Jonathan A. , Bishop W. Robert , Wang Yan
Published: February 2010

The insulin-like growth factor-I receptor (IGF-IR) and its ligands (IGF-I and IGF-II) have been implicated in the growth, survival, and metastasis of a broad range of malignancies including pediatric tumors. Blocking the IGF-IR action is a potential cancer treatment. A fully human neutralizing monoclonal antibody, SCH 717454 (19D12, robatumumab), specific to IGF-IR, has shown potent antitumor effects in ovarian cancer in vitro and in vivo. In this study, SCH 717454 was evaluated in several pediatric solid tumors including neuroblastoma, osteosarcoma, and rhabdomyosarcoma. SCH 717454 is shown here to downregulate IGF-IR as well as inhibit IGF-IR and insulin receptor substrate-1 phosphorylation in pediatric tumor cells. IGF-IR and insulin receptor substrate-1 phosphorylation in the tumor cells. In vivo, SCH 717454 exhibits activity as a single agent and significantly inhibited growth of neuroblastoma, osteosarcoma, and rhabdomyosarcoma tumor xenografts. Combination of SCH 717454 with cisplatin or cyclophosphamide enhanced both the degree and the duration of the in vivo antitumor activity compared with single-agent treatments. Furthermore, SCH 717454 treatment markedly reduced Ki-67 expression and blood vessel formation in tumor xenografts, showing that the in vivo activity is derived from its inhibition of tumor cell proliferation and angiogenesis activity. Mol Cancer Ther; 9(2); 410–8
The Novel, Proteasome-Independent NF-κB Inhibitor V1810 Induces Apoptosis and Cell Cycle Arrest in Multiple Myeloma and Overcomes NF-κB–Mediated Drug Resistance
Authors: Meinel Felix G. , Mandl-Weber Sonja , Baumann Philipp , Leban Johann , Schmidmaier Ralf
Published: February 2010

Evidence is increasing that aberrant NF-κB activation is crucial for multiple myeloma pathophysiology and a promising target for new antimyeloma therapies. In this study, we assessed the in vitro antimyeloma activity of the novel NF-κB inhibitor V1810. Pharmacokinetics and toxicity were studied in vivo. In mice, V1810 plasma concentrations of 10 μmol/L can be reached without relevant toxicity. At this concentration, V1810 potently induces apoptosis in all four multiple myeloma cell lines assessed (IC50 = 5–12 μmol/L) as well as in primary multiple myeloma cells (IC50 = 5–40 μmol/L). Apoptosis induced by V1810 is associated with proteasome-independent inhibition of NF-κB signaling (41% relative reduction), downregulation of Mcl-1, and caspase 3 cleavage. In OPM2, U266, and RPMI-8226 cells, induction of apoptosis is accompanied by cell cycle arrest. Western blots revealed downregulation of Cdk4 as well as cyclin D1 (U266) or cyclin D2 (OPM2, NCI-H929, RPMI-8226), but not cyclin D3. Consistently, retinoblastoma protein was found to be hypophosphorylated. Furthermore, V1810 reverses NF-κB activation induced by the genotoxic drugs melphalan and doxorubicin. V1810 and melphalan synergistically decrease multiple myeloma cell viability. Taken together, the novel, proteasome-independent NF-κB inhibitor V1810 induces apoptosis and cell cycle arrest in multiple myeloma cells at a concentration range that can be achieved in vivo. Moreover, V1810 reverses NF-κB activation by alkylating drugs and overcomes NF-κB–mediated resistance to melphalan. Mol Cancer Ther; 9(2); 300–10
Reprogramming Murine Telomerase Rapidly Inhibits the Growth of Mouse Cancer Cells In vitro and In vivo
Authors: Xu Tong , Xu Yucheng , Liao Chun-Peng , Lau Roy , Goldkorn Amir
Published: February 2010

Telomerase plays a critical role in cancer, prompting the pursuit of various telomerase-based therapeutic strategies. One such strategy, telomerase interference, exploits the high telomerase activity in cancer cells and reprograms telomerase to encode “toxic” telomeres. To date, telomerase interference has been tested in human cancer cells xenografted into mice, an approach that does not recapitulate spontaneous malignancy and offers few insights about host toxicities, because human telomerase is targeted in a mouse host. To address these limitations, we designed and validated two new gene constructs specifically targeting mouse telomerase: mutant template mouse telomerase RNA (MT-mTer) and small interfering RNA against wild-type mouse telomerase RNA (α-mTer-siRNA). Using lentiviral delivery in mouse prostate cancer cells, we achieved α-mTer-siRNA–mediated knockdown of wild-type mTer (80% depletion) and concurrent overexpression of MT-mTer (50-fold). We showed that the two constructs effectively synergize to reprogram murine telomerase to add mutant instead of wild-type telomeric repeats, resulting in rapid telomeric uncapping (5-fold increase in DNA damage foci). This, in turn, led to rapid and significant apoptosis (>90% of cells) and growth inhibition in vitro (90% reduction in viable cell mass) and in vivo (75% reduction in tumor allograft wet weight). In summary, we have shown that mouse cancer cells are vulnerable to direct telomerase interference using novel murine telomerase-targeting constructs; this approach can now be used to study the true therapeutic potential of telomerase interference in mouse spontaneous cancer models. Mol Cancer Ther; 9(2); 438–49
A Novel E1B-55kD-Deleted Oncolytic Adenovirus Carrying Mutant KRAS-Regulated hdm2 Transgene Exerts Specific Antitumor Efficacy on Colorectal Cancer Cells
Authors: Liu Chin-Cheng , Liu Jin-Hwang , Wu Suh-Chin , Yen Chueh-Chuan , Chen Wei-Shone , Tsai Ying-Chieh
Published: February 2010

E1B-55kD-deleted adenoviruses have been used as conditionally replicative adenoviruses (CRAds) for therapeutic purposes in tumors with loss-of-function p53 mutation. To target cancer cells that harbor activating mutant KRAS (KRASaMut) but spare p53wild normal cells, we constructed and examined by reporter assays a KRASaMut but not p53-responsive promoter, the Δp53REP2 promoter. The Δp53REP2 promoter, derived from human double minute 2 (hdm2) P2 promoter with its p53 response elements being deleted, was used to regulate the expression of the hdm2 transgene in a novel E1B-55kD-deleted CRAd, the Ad-KRhdm2. The Ad-KRhdm2 selectively replicated in and exerted cytopathic effects on KRASaMut colorectal cancer cell lines (HCT116, LoVo, LS174T, LS123, and SW620), regardless of their p53 gene statuses, by forming plaques and exhibiting cytopathic effect in cultured cells. Ad-KRhdm2, like other E1B-55kD-deleted adenoviruses, also exerted selective cytopathic effects on tumor cells with loss-of-function p53 mutant. The multiplicities of infection of Ad-KRhdm2 required to decrease 50% viability of KRASaMut tumor cells cultured for 7 days were 440 to 3,400 times less than those of MRC5 normal fibroblasts and KRASwild/p53wild RKO tumor cells. Intratumoral injection of Ad-KRhdm2 vectors exhibited specific lytic activities in nude mouse xenografts of KRASaMut cell lines (LoVo, SW620, and LS174T) but not in xenografts of RKO cells. Transduction of KRASaMut/p53wild HCT116, LoVo, and LS174T cells by Ad-KRhdm2 significantly increased Hdm2 expression, decreased p53 level, and abolished the p53-transactivating p21Cip1 promoter activity. Ad-KRhdm2 has shown its therapeutic potential in KRASaMut cancer cells and warrants further clinical trials. Mol Cancer Ther; 9(2); 450–60
Biochemical Characterization of AMG 102: A Neutralizing, Fully Human Monoclonal Antibody to Human and Nonhuman Primate Hepatocyte Growth Factor
Authors: Burgess Teresa L. , Sun Jan , Meyer Susanne , Tsuruda Trace S. , Sun Jilin , Elliott Gary , Chen Qing , Haniu Mitsuru , Barron Will F. , Juan Todd , Zhang Ke , Coxon Angela , Kendall Richard L.
Published: February 2010

AMG 102 is a fully human monoclonal antibody that selectively targets and neutralizes hepatocyte growth factor/scatter factor (HGF/SF). A detailed biochemical and functional characterization of AMG 102 was done to support its clinical development for the treatment of cancers dependent on signaling through the HGF/SF:c-Met pathway. In competitive equilibrium binding experiments, AMG 102 bound to human and cynomolgus monkey HGF with affinities of approximately 19 pmol/L and 41 pmol/L, respectively. However, AMG 102 did not detect mouse or rabbit HGF on immunoblots. Immunoprecipitation experiments showed that AMG 102 preferentially bound to the mature, active form of HGF, and incubation of AMG 102/HGF complexes with kallikrein protease indicated that AMG 102 had no apparent effect on proteolytic processing of the inactive HGF precursor. AMG 102 inhibited human and cynomolgus monkey HGF-induced c-Met autophosphorylation in PC3 cells with IC50 values of 0.12 nmol/L and 0.24 nmol/L, respectively. AMG 102 also inhibited cynomolgus monkey HGF-induced migration of human MDA-MB-435 cells but not rat HGF-induced migration of mouse 4T1 cells. Epitope-mapping studies of recombinant HGF molecules comprising human/mouse chimeras and human-to-mouse amino acid substitutions showed that amino acid residues near the NH2-terminus of the β-chain are critical for AMG 102 binding. Bound AMG 102 protected one trypsin protease cleavage site near the NH2-terminus of the β-chain of human HGF, further substantiating the importance of this region for AMG 102 binding. Currently, AMG 102 is in phase II clinical trials in a variety of solid tumor indications. Mol Cancer Ther; 9(2); 400–9
Dependence on Phosphoinositide 3-Kinase and RAS-RAF Pathways Drive the Activity of RAF265, a Novel RAF/VEGFR2 Inhibitor, and RAD001 (Everolimus) in Combination
Authors: Mordant Pierre , Loriot Yohann , Leteur Céline , Calderaro Julien , Bourhis Jean , Wislez Marie , Soria Jean-Charles , Deutsch Eric
Published: February 2010

Activation of phosphatidylinositol-3-kinase (PI3K)-AKT and Kirsten rat sarcoma viral oncogene homologue (KRAS) can induce cellular immortalization, proliferation, and resistance to anticancer therapeutics such as epidermal growth factor receptor inhibitors or chemotherapy. This study assessed the consequences of inhibiting these two pathways in tumor cells with activation of KRAS, PI3K-AKT, or both. We investigated whether the combination of a novel RAF/vascular endothelial growth factor receptor inhibitor, RAF265, with a mammalian target of rapamycin (mTOR) inhibitor, RAD001 (everolimus), could lead to enhanced antitumoral effects in vitro and in vivo. To address this question, we used cell lines with different status regarding KRAS, PIK3CA, and BRAF mutations, using immunoblotting to evaluate the inhibitors, and MTT and clonogenic assays for effects on cell viability and proliferation. Subcutaneous xenografts were used to assess the activity of the combination in vivo. RAD001 inhibited mTOR downstream signaling in all cell lines, whereas RAF265 inhibited RAF downstream signaling only in BRAF mutant cells. In vitro, addition of RAF265 to RAD001 led to decreased AKT, S6, and Eukaryotic translation initiation factor 4E binding protein 1 phosphorylation in HCT116 cells. In vitro and in vivo, RAD001 addition enhanced the antitumoral effect of RAF265 in HCT116 and H460 cells (both KRAS mut, PIK3CA mut); in contrast, the combination of RAF265 and RAD001 yielded no additional activity in A549 and MDAMB231 cells. The combination of RAF and mTOR inhibitors is effective for enhancing antitumoral effects in cells with deregulation of both RAS-RAF and PI3K, possibly through the cross-inhibition of 4E binding protein 1 and S6 protein. Mol Cancer Ther; 9(2); 358–68
High Prevalence of Potential Drug-Drug Interactions for Psoriasis Patients Prescribed Methotrexate or Cyclosporine for Psoriasis: Associated Clinical and Economic Outcomes in Real-World Practice
Authors: Saurat Jean-Hilaire , Guérin Annie , Yu Andrew P. , Latremouille-Viau Dominick , Wu Eric Q. , Gupta Shiraz R. , Bao Yanjun , Mulani Parvez M.
Published: February 2010

Background: Methotrexate (MTX) and cyclosporine (CYC) may adversely interact with common medications in patients with psoriasis. Objective: Our purpose was to investigate the prevalence and outcomes of MTX/CYC polypharmacy. Methods: We evaluated rates of events that may be associated with drug-related toxicity, health care resource utilization and costs for patients with psoriasis in the Ingenix® Impact National Managed Care Database (1999–2007) who were exposed or not exposed to potential drug-drug interactions. Results: Among 4,583 (57.6%) exposed and 3,372 (42.4%) nonexposed patients, nonsteroidal anti-inflammatory drugs and antibiotics were the most common drugs with potential interactions. The exposed patients had significantly greater risks of developing renal [adjusted odds ratio (OR): 2.58; p = 0.0145], gastrointestinal (OR: 1.36; p = 0.0197) and pulmonary events (OR: 1.20; p = 0.0470), and significantly greater health care resource utilization (e.g. OR for inpatient and emergency department visits: 1.47; p < 0.0001) and costs (adjusted incremental cost: USD 1,722; p < 0.0001). Conclusions: MTX/CYC polypharmacy is prevalent in patients with psoriasis and associated with significant risks.
Linear IgA Disease: Successful Application of Immunoadsorption and Review of the Literature
Authors: Kasperkiewicz Michael , Meier Markus , Zillikens Detlef , Schmidt Enno
Published: February 2010

Linear IgA disease (LAD) is an autoimmune subepidermal blistering disorder characterized by IgA autoantibodies at the dermal-epidermal junction. Conventional first-line treatments include dapsone with or without oral glucocorticosteroids. Various other therapeutic approaches have been used in refractory patients. Immunoadsorption (IA) has been previously successfully applied in severe and/or otherwise treatment-resistant IgG-mediated immunobullous disorders. Here, we report a patient with a severe generalized LAD in whom adjuvant tryptophan IA was associated with rapid healing of skin lesions. Our observation suggests that IA may also be a helpful adjuvant treatment option for severe LAD.
Stress and Survival Pathways in the Mammalian Cochlea
Authors: Caelers Antje , Radojevic Vesna , Traenkle Jens , Brand Yves , Bodmer Daniel
Published: February 2010

Studies conducted over the last few years demonstrated that signaling pathways that operate in the organs of Corti (OC) play a central role in survival and death of hair cells. An important goal of molecular otology is to characterize these signaling pathways in normal inner ears and inner ears exposed to a variety of different forms of stress, such as ototoxic substances and noise overexposure. In this study, we used high-performance reverse protein microarray technology and phospho-specific antibodies to examine the activation status of defined molecules involved in cellular signaling. We demonstrate that reverse protein microarrays based on the highly sensitive planar-waveguide technology provide an effective and high-throughput means to assess the activation state of key molecules involved in apoptotic and prosurvival signaling in microdissected OC explants over time. In this study, we show that gentamicin and a specific NF-ĸB inhibitor increase the ratio of phospho-c-Jun/c-Jun in OC explants of postnatal rats soon after exposure to these drugs. In addition, we found a decrease in the phospho-Akt/Akt ratio in OC explants early after NF-ĸB inhibition. Finally, we observed an early and consistent decrease in the phospho-p38/p38 ratio in OC explants exposed to the NF-ĸB inhibitor and only a transient decrease in this ratio in OC examples after gentamicin exposure.
Molecular and Epidemiological Characteristics of Norovirus Associated with Community-Based Sporadic Gastroenteritis Incidents and Norovirus Outbreaks in Victoria, Australia, 2002–2007
Authors: Bruggink Leesa , Sameer Rizmina , Marshall John
Published: February 2010

Objectives: The molecular and epidemiological features of community-based norovirus-associated sporadic gastroenteritis incidents (NASGIs) are poorly understood. This study examined these features and compared the findings with studies of community-based and institutional norovirus-associated gastroenteritis outbreaks (NAGOs). Methods: Fecal specimens from NASGIs and NAGOs that occurred in Victoria, Australia (2002–2007) were tested for norovirus by reverse transcription-polymerase chain reaction methodology. Norovirus genotype was determined by nucleotide sequence analysis. Results: 106 community-based NASGIs, 116 community-based NAGOs and 902 institutional NAGOs were identified. The mean age and gender ratio of individuals associated with community-based NASGIs and community-based NAGOs were similar but differed from that found for institutional NAGOs. Although GII.4 was the predominant genotype associated with all three incident types, the mix of genotypes was similar for community-based NASGIs and community-based NAGOs but that for institutional NAGOs was different. All three incident types had a similar seasonal periodicity due to the pronounced seasonal periodicity of GII.4 incidents. Conclusions: The molecular and epidemiological features of noroviruses associated with community-based NASGIs and community-based NAGOs are similar but are different from those found for institutional NAGOs.
Appearance of HbeAg in an Occult Persistent Hepatitis B Virus Infection
Authors: Paparella Concetta , De Rosa Filomena , Longo Roberta , Cappiello Giuseppina , Ursitti Antonella , Rosa Marisa , Morosetti Massimo , Spanò Alberto
Published: February 2010

Occult hepatitis B virus infection (OBI) is characterized by the presence of ongoing viral replication with very low levels of viremia (<200 IU/ml), and negativity for HBsAg, while the so-called ‘false’ OBI with higher levels of HBV-DNA that are negative for HBsAg are usually due to the occurrence of mutations of the HBsAg sequence that may alter the recognition by some immunoassays. We describe here a case of occult HBV infection that combines both aspects. A male patient with severe systemic diseases, positive for anti-HBc and anti-HBs and negative for all other HBV markers, including HBsAg, since at least 4 years, showed a positivity for HBeAg at a follow-up control in November 2008; HBV-DNA testing by real-time PCR evidenced very low levels of viremia (<40 IU/ml), direct sequencing of the surface antigen-coding and Pol/RT coding regions allowed the identification of genotype D, serotype adw2, one immune escape mutation (G145R) and no drug resistance mutations. The positivity for HBeAg could be attributed to a superinfection in a naturally immune subject or to reactivation of a latent infection; the mutated virus had a reduced fitness and was therefore able to replicate only at low levels, resulting in a mild form of occult HBV infection.
Bioavailability of Buprenorphine from Crushed and Whole Buprenorphine (Subutex) Tablets
Authors: Simojoki Kaarlo , Lillsunde Pirjo , Lintzeris Nicholas , Alho Hannu
Published: February 2010

Background: Buprenorphine (Subutex) is the most abused opioid in Finland. In order to curb the abuse potential of this drug, many treatment centers and prisons crush Subutex tablets before administering them to patients. To date, there are no published studies comparing the efficacy and bioavailability of crushed and whole Subutex tablets. Methods: A total of 16 opioid-dependent patients stabilized on 24 mg of buprenorphine were enrolled in a double-blind, double-dummy, randomized cross-over study comparing crushed and whole buprenorphine tablets on a range of pharmacokinetic and pharmacodynamic variables. Buprenorphine tablets (either crushed or whole) and placebo tablets (either crushed or whole) were administered to subjects simultaneously. Buprenorphine and norbuprenorphine serum levels were measured at 30, 60, 90, 120, 180, 240 and 360 min, as well as 24 h, after tablet administration. After 1 week, the experiment was repeated in a cross-over design so that, by the end of the study, each patient had received the active drug (buprenorphine) as both crushed and whole tablets. Results: Pharmacokinetic parameters (mean serum levels, Cmax, Tmax, AUC) of buprenorphine or norbuprenorphine did not differ significantly between crushed and whole tablets, although serum levels were slightly higher after administration of the crushed tablets. There were also no significant differences in dissolution/absorption time, withdrawal signs or opiate craving. Conclusion: We conclude that crushing Subutex tablets does not significantly alter serum buprenorphine or norbuprenorphine levels or the drug’s clinical effect. Our results indicate that crushing Subutex tablets may be used as an alternative method to counter the risk of buprenorphine diversion.
Modern Classification of Acute Kidney Injury
Authors: Srisawat Nattachai , Hoste Eric E.A. , Kellum John A.
Published: February 2010

Acute kidney injury (AKI) is a common clinical syndrome defined as a sudden onset of reduced kidney function manifested by increased serum creatinine or a reduction in urine output. This clinical syndrome has been called by 25 different names and at least 35 definitions. As a result of this deficiency of standardized definition, reported incidences of AKI in the ICU range from 1 to 25% with mortality rates between 15 and 60%. This lack of a uniform definition not only leads to the conflicting reports in the literature but is also a major obstacle for research in the field. The recent consensus definition which was proposed by the ADQI group and expanded by AKIN has brought the RIFLE criteria and staging into position as the standard definition and diagnosis of this syndrome. The RIFLE criteria have been extensively validated in more than 550,000 patients worldwide.