bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Novel Epstein-Barr Virus MicroRNA Genes from Nasopharyngeal Carcinomas
Authors: Zhu Jia Yun , Pfuhl Thorsten , Motsch Natalie , Barth Stephanie , Nicholls John , Grässer Friedrich , Meister Gunter
Published: January 2009

MicroRNAs (miRNAs) represent a conserved class of small noncoding RNAs that are found in all higher eukaryotes as well as some DNA viruses. miRNAs are 20 to 25 nucleotides in length and have important regulatory functions in biological processes such as embryonic development, cell differentiation, hormone secretion, and metabolism. Furthermore, miRNAs have been implicated in the pathology of various diseases, including cancer. miRNA expression profiles not only classify different types of cancer but also may even help to characterize distinct tumor stages, therefore constituting a valuable tool for prognosis. Here we report the miRNA profile of Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) tissue samples characterized by cloning and sequencing. We found that all EBV miRNAs from the BART region are expressed in NPC tissues, whereas EBV miRNAs from the BHRF1 region are not found. Moreover, we identified two novel EBV miRNA genes originating from the BART region that have not been found in other tissues or cell lines before. We also identified three new human miRNAs which might be specific for nasopharyngeal tissues. We further show that a number of different cellular miRNAs, including miR-15a and miR-16, are up- or downregulated in NPC tissues compared to control tissues. We found that the tumor suppressor BRCA-1 is a target of miR-15a as well as miR-16, suggesting a miRNA role in NPC pathogenesis.
Vesicular Stomatitis Virus M Protein Mutant Stimulates Maturation of Toll-Like Receptor 7 (TLR7)-Positive Dendritic Cells through TLR-Dependent and -Independent Mechanisms
Authors: Ahmed Maryam , Mitchell Latoya M. , Puckett Shelby , Brzoza-Lewis Kristina L. , Lyles Douglas S. , Hiltbold Elizabeth M.
Published: January 2009

Wild-type (wt) vesicular stomatitis virus (VSV) strains stimulate plasmacytoid dendritic cells (pDC) through Toll-like receptor 7 (TLR7) and its adaptor molecule, MyD88. Granulocyte-macrophage colony-stimulating factor-derived DC (G-DC), which do not express TLR7, are unresponsive to wt VSV due to inhibition of cellular gene expression by the matrix (M) protein. In contrast to its recombinant wt (rwt) counterpart, an M protein mutant of VSV, rM51R-M virus, stimulates maturation of G-DC independently of MyD88. These results suggest that, as in the case of G-DC, rM51R-M virus may stimulate pDC by mechanisms distinct from that by rwt virus. Studies presented here demonstrate that both rwt and rM51R-M viruses induced maturation of TLR7-positive DC derived by culture in the presence of Flt3L (F-DC), with the subsequent expression of type I interferon (IFN). F-DC are a mixture of myeloid (CD11b
+
) and plasmacytoid (B220
+
) DC, both of which respond to TLR7 ligands. Separated CD11b
+
and B220
+
F-DC responded to both rwt and rM51R-M viruses. Both viruses were also defective at inhibiting host gene expression in F-DC, including the expression of genes involved in the antiviral response. The data from F-DC generated from IFN receptor knockout mice demonstrated that the maturation of F-DC induced by rwt virus was dependent on the type I IFN response, while maturation induced by rM51R-M virus was partially dependent on this molecule. Therefore, activation of the type I IFN pathway appears to be important for not only inducing an antiviral response but also for stimulating maturation of F-DC upon virus infection. Importantly, F-DC from TLR7 and MyD88 knockout mice did not undergo maturation in response to rwt virus, while maturation induced by rM51R-M virus was largely independent of both molecules. These results indicate that although both viruses induce F-DC maturation, F-DC detect and respond to rM51R-M virus by means that are distinct from rwt virus. Specifically, this mutant virus appears capable of inducing DC maturation in a wide variety of DC subsets through TLR-dependent and independent mechanisms.
Determinants of the Establishment of Human Immunodeficiency Virus Type 1 Latency
Authors: Duverger Alexandra , Jones Jennifer , May Jori , Bibollet-Ruche Frederic , Wagner Frederic A. , Cron Randall Q. , Kutsch Olaf
Published: January 2009

Recent research has emphasized the notion that human immunodeficiency virus type 1 (HIV-1) latency is controlled by a restrictive histone code at, or DNA methylation of, the integrated viral promoter (long terminal repeat [LTR]). The present concept of HIV-1 latency has essentially been patterned from the principles of cellular gene regulation. Here we introduce an experimental system that allows for the qualitative and quantitative kinetic study of latency establishment and maintenance at the population level. In this system, we find no evidence that HIV-1 latency establishment is the consequence of downregulation of initial active infection followed by the establishment of a restrictive histone code at the viral LTR. Latent infection was established following integration of the virus in the absence of viral gene expression (silent integration) and was a function of the NF-κB activation level in the host cell at the time of infection. In the absence of a role for epigenetic regulation, we demonstrate that transcriptional interference, a mechanism that has recently been suggested to add to the stabilization of HIV-1 latency, is the primary mechanism to govern latency maintenance. These findings provide direct experimental evidence that the high number of viral integration events (>90%) found in actively expressed genes of CD4+memory T cells from highly active antiretroviral therapy-suppressed patients represent indeed latent infection events and that transcriptional interference may be the primary mechanism to control HIV-1 latency in vivo. HIV-1 latency may thus not be governed by the principles of cellular gene regulation, and therapeutic strategies to deplete the pool of latently HIV-1-infected cells should be reconsidered.
Translocation of Incoming Pseudorabies Virus Capsids to the Cell Nucleus Is Delayed in the Absence of Tegument Protein pUL37
Authors: Krautwald Mirjam , Fuchs Walter , Klupp Barbara G. , Mettenleiter Thomas C.
Published: January 2009

After fusion of the envelope of herpesvirus particles with the host cell plasma membrane, incoming nucleocapsids are transported to nuclear pores. Inner tegument proteins pUL36, pUL37, and pUS3 remain attached to the nucleocapsid after entry and therefore might mediate interactions between the nucleocapsid and cellular microtubule-associated motor proteins during transport. To assay for the role of pUL37 in this process, we constructed a pUL37-deleted pseudorabies virus mutant, PrV-ΔUL37/UL35GFP, which expresses a fusion protein of green fluorescent protein (GFP) and the nonessential small capsid protein pUL35, resulting in the formation of fluorescently labeled capsids. Confocal laser-scanning microscopy of rabbit kidney cells infected with PrV-ΔUL37/UL35GFP revealed that, whereas penetration was not affected in the absence of pUL37, nuclear translocation of incoming particles was delayed by approximately 1 h compared to PrV-UL35GFP, but not abolished. In contrast, phenotypically complemented pUL37-containing virions of PrV-ΔUL37/UL35GFP exhibited wild type-like entry kinetics. Thus, the presence of pUL37 is required for rapid nuclear translocation of incoming nucleocapsids.
Age-Associated Aggravation of Clinical Disease after Primary Metapneumovirus Infection of BALB/c Mice
Authors: Darniot M. , Pitoiset C. , Petrella T. , Aho S. , Pothier P. , Manoha C.
Published: January 2009

Human metapneumovirus (hMPV) is associated with respiratory tract infections among children and adults. Because hMPV induces significant morbidity and mortality in the elderly, a model of hMPV infection in aged BALB/c mice was established. Young (8 weeks old) and aged (18 months old) mice were intranasally inoculated with hMPV. The infected mice showed respiratory dysfunction, as measured by plethysmography, a marked loss in weight (up to 24%), and severe histopathological abnormalities including bronchiolitis obliterans organizing pneumonia. However, clinical severity was far higher in the aged mice, and none of the young infected mice died. Although virus replication in the lung was greater in the older mice, clearance of virus was not delayed compared to young mice. Production of virus-specific antibody as well as neutralizing antibody was lower. Gamma interferon and monocyte chemotactic protein-1 levels in bronchoalveolar lavage fluid were significantly lower in older mice, whereas interleukin-6 and interleukin-4 levels were significantly higher. We observed by flow cytometry a significant increase in the CD4
+
T lymphocytes (
P
< 0.05) of the aged mice and no difference in CD8
+
T-cell recruitment to the respiratory tract between the two groups. The present study investigated the effects of aging on the immunopathogenesis of hMPV infection and suggests that CD4
+
T lymphocytes, the cytokine response, or a defect in humoral response may be associated with the increased disease severity observed in the aged mice.
Interaction of Epstein-Barr Virus BZLF1 C-Terminal Tail Structure and Core Zipper Is Required for DNA Replication but Not for Promoter Transactivation
Authors: McDonald Carol M. , Petosa Carlo , Farrell Paul J.
Published: January 2009

The Epstein-Barr virus (EBV) protein BZLF1 contains a bZIP DNA binding domain in which C-terminal tail residues fold back against a zipper region that forms a coiled coil and mediates dimerization. Point mutagenesis in the zipper region reveals the importance of individual residues within the
208
SSENDRLR
215
sequence that is conserved in C/EBP for transactivation and EBV DNA replication. The restoration of BZLF1 DNA replication activity by the complementation of two deleterious mutations (S208E and D236K) indicates that the interaction of the C-terminal tail and the core zipper is required for DNA replication, identifying a functional role for this structural feature unique to BZLF1.
Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr
Authors: Nummert Vilve , Piirsalu Mare , Vahur Signe , Travnikova Oksana , Koppel Ilmar A.
Published: January 2009

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.
A NOVEL HYPERCHAOTIC SYSTEM AND ITS COMPLEX DYNAMICS
Authors: WANG JIEZHI , CHEN ZENGQIANG , CHEN GUANRONG , YUAN ZHUZHI
Published: January 2009

This paper is concerned with a novel four-dimensional continuous autonomous hyperchaotic system, which is obtained by adding a simple dynamical state-feedback controller to a Lorenz-like three-dimensional autonomous chaotic system. This new system contains three parameters and each equation of the system has one quadratic cross-product term. Some basic properties of the system are studied first. Its complex dynamic behaviors are then analyzed by means of Lyapunov exponent (LE) spectrum, bifurcation diagrams, phase portraits and Poincaré sections. It is shown that the system has several large hyperchaotic regions. When the system is evolving in a hyperchaotic region, the two positive LEs are both large, which can be larger than 1 if the system parameters are taken appropriately. The pitchfork bifurcation of the system is finally analyzed by using the center manifold theorem.
DIGITAL SECURE-COMMUNICATION USING ROBUST HYPER-CHAOTIC SYSTEMS
Authors: CHEN SHIH-LIANG , CHANG SHU-MING , LIN WEN-WEI , HWANG TINGTING
Published: January 2009

In this paper, we propose a robust hyper-chaotic system that is suitable for digital secure-communication. The system consists of many coupled robust logistic maps that form a hyper-chaotic system. It has a higher degree of complexity than traditional discrete-time secure-communication systems that use only a single map. Moreover, the system has a very large parameter space which grows along with system precision. Hence, attacking the system by the method of map reconstruction in current computation technology is not feasible. Statistical analysis shows that the system achieves very high security level. Finally, two hardware architectures (multiple-cycle and pipelined) are proposed for area and performance optimization, respectively.
OPTIMAL CONTROL OF CHAOS IN NONLINEAR DRIVEN OSCILLATORS VIA LINEAR TIME-VARYING APPROXIMATIONS
Authors: HUGUES-SALAS O. , BANKS S. P.
Published: January 2009

An optimal chaos control procedure is proposed. The aim of using this method is to stabilize the chaotic behavior of forced continuous-time nonlinear systems by using an approximation sequence technique and linear optimal control. The idea of the approximation technique is to use a sequence of linear, time-varying equations to approximate the solution of nonlinear systems. In each of these equations, the linear-quadratic optimal tracking control is applied. The purpose is to find a linear time-varying feedback controller which produces an optimized trajectory that converges to a desired signal. This controller is then used in the original nonlinear system. As an example, the procedure is proved to work in the Duffing oscillator and the chaotic pendulum, in which the goal is to direct chaotic trajectories of these systems to a period-n orbit.
ROBUST LINEAR OUTPUT FEEDBACK CONTROL DESIGN FOR NONLINEAR CHAOTIC SYSTEMS VIA T–S FUZZY MODEL WITH H∞ SETTING
Authors: LI YEN-FANG , TSENG CHUNG-SHI
Published: January 2009

In this paper, the problem of H∞ control design is studied for a nonlinear chaotic system via its corresponding Takagi–Sugeno (T–S) fuzzy model. It is known that many nonlinear chaotic systems can be exactly represented by their corresponding T–S fuzzy models. First, in this study, the T–S fuzzy model is proposed to represent a class of nonlinear chaotic systems. Next, a linear output feedback control scheme, where only linear controller and linear observer are considered, with H∞ setting is proposed for the nonlinear chaotic system. Then, based on the T–S fuzzy model and the proposed linear control scheme, the H∞ controller design problem for nonlinear chaotic systems is characterized in terms of minimizing the attenuation level subject to some linear matrix inequalities (LMIs), which is also called eigenvalue problem (EVP), through the scanning of a positive parameter. Finally, the proposed control scheme is applied to a chaotic system, namely Chua's circuit, to illustrate the robust performance of the proposed linear controller and linear observer.
A ROBUST NONMODEL-BASED TECHNIQUE FOR STABILIZING CHAOTIC SYSTEMS WITH CONSTANT DISTURBANCE INPUT
Authors: ZAHER ASHRAF A. , ABU-REZQ ABDULNASSER
Published: January 2009

The stabilization of nonlinear systems that exhibit chaotic behavior is presented using notch-filter output feedback control. The effect of constant disturbance input and/or parametric uncertainty on the systems' performance is studied for a class of nonlinear systems where bifurcation analysis is used to illustrate the period-doubling route to chaos. The motivation for using the notch-filter in the feedback is to selectively damp-out portions of the closed-loop power spectrum, thus truncating period-doubling. Double-notch-filter feedback is introduced as a regulation scheme to bring the chaotic system to a steady state. The effect of using the fixed-parameters feedback on the equilibrium points is carefully studied, and a robust numerical parameter-tuning method is presented. The efficiency of this method is verified via simulations applied to a third-order uncertain nonlinear system that has typical applications in power generation and voltage control. A comparative study with a model-based recursive backstepping controller is carried out to highlight the advantages and limitations of the proposed control system.
NONSTANDARD ANALYSIS, FRACTAL PROPERTIES AND BROWNIAN MOTION
Authors: POTGIETER PAUL
Published: January 2009

In this paper I explore a nonstandard formulation of Hausdorff dimension. By considering an adapted form of the counting measure formulation of Lebesgue measure, I prove a nonstandard version of Frostman's lemma and find that Hausdorff dimension can be computed through a counting argument rather than by taking the infimum of a sum of certain covers. This formulation is then applied to obtain a simple proof of the doubling of the dimension of certain sets under a Brownian motion.
ANALYSIS ON A FRACTAL SET
Authors: RAUT SANTANU , DATTA DHURJATI PRASAD
Published: January 2009

The formulation of a new analysis on a zero measure Cantor set C(⊂I = [0,1]) is presented. A non-Archimedean absolute value is introduced in C exploiting the concept of relative infinitesimals and a scale invariant ultrametric valuation of the form log ε-1 (ε/x) for a given scale ε > 0 and infinitesimals 0 < x < ε, x ∈ I\C. Using this new absolute value, a valued (metric) measure is defined on C and is shown to be equal to the finite Hausdorff measure of the set, if it exists. The formulation of a scale invariant real analysis is also outlined, when the singleton {0} of the real line R is replaced by a zero measure Cantor set. The Cantor function is realized as a locally constant function in this setting. The ordinary derivative dx/dt in R is replaced by the scale invariant logarithmic derivative d log x/d log t on the set of valued infinitesimals. As a result, the ordinary real valued functions are expected to enjoy some novel asymptotic properties, which might have important applications in number theory and in other areas of mathematics.
SELF-ORGANIZED CRITICALITY IN ASYMMETRIC WARFARE
Authors: DOBIAS PETER
Published: January 2009

Two current conflicts, in Afghanistan and in Iraq were studied to identify a possibility of a critical behavior in an asymmetric conflict. The analysis was performed using temporal dependence of fatalities. The data included daily fatality information from the beginning of each of the conflicts until 31 December 2007. The results suggest that these examples of asymmetric, counter-insurgency warfare can possibly be characterized in terms of self-organized criticality (SOC). While SOC could be an attractor for such conflicts in general, not all asymmetric conflicts are actually at the point of criticality. The conflict in Afghanistan is an example of such a subcritical conflict. The conflict in Iraq, on the other hand is an example of an already critical system. The two types of conflict have in common the power-law dependence between the numbers of fatalities and the frequency of occurrences. However, while for a critical system the numbers of fatalities are correlated over time, for a subcritical system they are anti-correlated. From the point of view of counter-insurgency, the subcritical state is a preferred option. However, from the system point of view the two cases are just two different phases of the same type of a dynamical system.
CALCULUS ON FRACTAL SUBSETS OF REAL LINE — I: FORMULATION
Authors: PARVATE ABHAY , GANGAL A. D.
Published: January 2009

A new calculus based on fractal subsets of the real line is formulated. In this calculus, an integral of order α, 0 < α ≤ 1, called Fα-integral, is defined, which is suitable to integrate functions with fractal support F of dimension α. Further, a derivative of order α, 0 < α ≤ 1, called Fα-derivative, is defined, which enables us to differentiate functions, like the Cantor staircase, "changing" only on a fractal set. The Fα-derivative is local unlike the classical fractional derivative. The Fα-calculus retains much of the simplicity of ordinary calculus. Several results including analogues of fundamental theorems of calculus are proved.

The integral staircase function, which is a generalization of the functions like the Cantor staircase function, plays a key role in this formulation. Further, it gives rise to a new definition of dimension, the γ-dimension.

Spaces of Fα-differentiable and Fα-integrable functions are analyzed. Analogues of Sobolev Spaces are constructed on F and Fα-differentiability is generalized using Sobolev-like construction.

Fα-differential equations are equations involving Fα-derivatives. They can be used to model sublinear dynamical systems and fractal time processes, since sublinear behaviors are associated with staircase-like functions which occur naturally as their solutions. As examples, we discuss a fractal-time diffusion equation, and one-dimensional motion of a particle undergoing friction in a fractal medium.
MULTIFRACTAL BEHAVIORS IN FOREIGN EXCHANGE MARKETS
Authors: KIM SOO YONG , LIM GYUCHANG , CHANG KI-HO , KIM KUM LAN , LEE S. Y. , PARK IN HO , LEE DONG IN , YOU CHEOL-HWAN , KIM KYUNGSIK
Published: January 2009

A two-phase phenomenon in three financial exchange prices is studied. To understand the underlying mechanism for the formation of market prices, we perform the multifractal analysis and the detrended fluctuation analysis in terms of time series of market prices. We also examine higher order temporal correlations for the market price. Although the multifractal properties of market prices are obtained, it cannot be reproduced the binomial multiplicative process through that was used to understand fully developed turbulence.
CLUSTERING IN A SPATIAL SYSTEM OF SELF-AGGREGATING AGENTS
Authors: SHIN J. K. , SHIN G. S. , MANSURY Y. S.
Published: January 2009

We examine a dynamic spatial system of self-aggregating individuals that migrate under mutual gravitational attraction, forming clusters of varying sizes and distributions. To that end, we develop a computational model in which a frictional factor limits agent mobility, which in turn leads to the concentration of population in clusters. Our numerical results reveal that the clustering behavior of the system generates two distinct phases broken down by a phase transition. In the sub-critical phase, the spatial size-distribution of clusters follows the well-known exponential or power-law distribution. By contrast, in the super-critical phase the entire population converges into either a single giant cluster (a "Black-hole"), or a few large clusters ("Oligarchs"). In between these two phases, there exists a threshold critical level corresponding to a phase transition in which clusters abruptly enter a period of rapid growth. The key contribution of this study is to solve for the phase transition regime analytically. We also discuss the application of our results to study the development of cities, the evolution of languages, the growth of asteroids, and the emergence of monopoly and oligopoly.
Health Communication in the Latino Community: Issues and Approaches
Authors: Elder John P. , Ayala Guadalupe X. , Parra-Medina Deborah , Talavera Gregory A.
Published: January 2009

With reference to the Communication-Persuasion model, we describe various research issues and challenges when considering the health of Latinos, and implications for designing and evaluating health communication and behavior change efforts in this population. Latinos, collectively the nation's largest minority group, vary substantially in terms of socioeconomic and legal status, their country of origin and the extent of ongoing contact with that country, their region of residence within the United States, their generation status and levels of acculturation, and psychosocial factors. Health communication efforts with Latinos need to focus on family, cultural traditions, and collectivism while attending to acculturation, language, generation and national origin. The most extensive intervention topic in Latino health promotion has been the application of the lay health advisor model. This and other fundamental communication approaches, as well as audience and population characteristics, need to be considered within the context of dynamic and complex societal changes.
Sex, diabetes and the kidney
Authors: Maric Christine
Published: January 2009

The incidence and the rate of progression of nondiabetic renal disease is generally greater in men compared with age-matched women, suggesting that the female sex is protective and/or that the male sex is a risk factor for the development and progression of nondiabetic renal disease. In diabetes, even though the male sex still appears to be a risk factor, this relationship is not as strong as it is in nondiabetic renal disease. Experimental evidence suggests that both estrogens and androgens play an important role in the pathophysiology of renal disease. Thus one of the potential mechanisms for the absence of a clear sex difference in the setting of diabetes may be alterations in sex hormone levels. Indeed, studies suggest that diabetes is a state of an imbalance in sex hormone levels; however, whether these changes correlate with the decline in renal function associated with diabetes is unclear. Furthermore, diabetic renal disease rarely develops before puberty, and the onset of puberty accelerates microalbuminuria, supporting the idea of the involvement of sex hormones in the development and progression of the disease. However, other than a handful of experimental studies indicating that treatment with or removal of sex hormones alters the course of diabetic renal disease, very few studies have actually directly examined the correlation between sex hormones and the disease development and progression. Further studies are necessary to determine the precise contribution of sex hormones in the pathophysiology of diabetic renal disease to develop novel and potentially sex-specific therapeutic treatments.
Moderate exercise attenuates caspase-3 activity, oxidative stress, and inhibits progression of diabetic renal disease indb/dbmice
Authors: Ghosh S. , Khazaei M. , Moien-Afshari F. , Ang L. S. , Granville D. J. , Verchere C. B. , Dunn S. R. , McCue P. , Mizisin A. , Sharma K. , Laher I.
Published: January 2009

Diabetic nephropathy, the leading cause of end-stage renal disease, is characterized by a proapoptotic and prooxidative environment. The mechanisms by which lifestyle interventions, such as exercise, benefit diabetic nephropathy are unknown. We hypothesized that exercise inhibits early diabetic nephropathy via attenuation of the mitochondrial apoptotic pathway and oxidative damage. Type 2 diabetic db/db and normoglycemic wild-type mice were exercised for an hour everyday at a moderate intensity for 7 wk, following which renal function, morphology, apoptotic signaling, and oxidative stress were evaluated. Exercise reduced body weight, albuminuria, and pathological glomerular expansion in db/db mice independent of hyperglycemic status. Changes in renal morphology were also related to reduced caspase-3 (main effector caspase in renal apoptosis), caspase-8 (main initiator caspase of the “extrinsic” pathway) activities, and TNF-α expression. A role for the mitochondrial apoptotic pathway was unlikely as both caspase-9 activity (initiator caspase of this pathway) and expression of regulatory proteins such as Bax and Bcl-2 were unchanged. Kidneys from db/db mice also produced higher levels of superoxides and had greater oxidative damage concurrent with downregulation of superoxide dismutase (SOD) 1 and 3. Interestingly, although exercise also increased superoxides, there was also upregulation of multiple SODs that likely inhibited lipid (hydroperoxides) and protein (carbonyls and nitrotyrosine) oxidation in db/db kidneys. In conclusion, exercise can inhibit progression of early diabetic nephropathy independent of hyperglycemia. Reductions in caspase-3 and caspase-8 activities, with parallel improvements in SOD expression and reduced oxidative damage, could underlie the beneficial effects of exercise in diabetic kidney disease.
Acute hypertension provokes acute trafficking of distal tubule Na-Cl cotransporter (NCC) to subapical cytoplasmic vesicles
Authors: Lee Donna H. , Riquier Anne D. M. , Yang Li E. , Leong Patrick K. K. , Maunsbach Arvid B. , McDonough Alicia A.
Published: January 2009

When blood pressure (BP) is elevated above baseline, a pressure natriuresis-diuresis response ensues, critical to volume and BP homeostasis. Distal convoluted tubule Na+-Cl−cotransporter (NCC) is regulated by trafficking between the apical plasma membrane (APM) and subapical cytoplasmic vesicles (SCV). We aimed to determine whether NCC trafficking contributes to pressure diuresis by decreasing APM NCC or compensates for increased volume flow to the DCT by increasing APM NCC. BP was raised 50 mmHg (high BP) in rats by arterial constriction for 5 or 20–30 min, provoking a 10-fold diuresis at both times. Kidneys were excised, and NCC subcellular distribution was analyzed by 1) sorbitol density gradient fractionation and immunoblotting and 2) immunoelectron microscopy (immuno-EM). NCC distribution did not change after 5-min high BP. After 20–30 min of high BP, 20% of NCC redistributed from low-density, APM-enriched fractions to higher density, endosome-enriched fractions, and, by quantitative immuno-EM, pool size of APM NCC decreased 14% and SCV pool size increased. Because of the time lag of the response, we tested the hypothesis that internalization of NCC was secondary to the decrease in ANG II that accompanies high BP. Clamping ANG II at a nonpressor level by coinfusion of captopril (12 μg/min) and ANG II (20 ng·kg−1·min−1) during 30-min high BP reduced diuresis to eightfold and prevented redistribution of NCC from APM- to SCV-enriched fractions. We conclude that DCT NCC may participate in pressure natriuresis-diuresis by retraction out of apical plasma membranes and that the retraction is, at least in part, driven by the fall in ANG II that accompanies acute hypertension.
Behavioral Triggers of Skin Conductance Responses and Their Neural Correlates in the Primate Amygdala
Authors: Laine Christopher M. , Spitler Kevin M. , Mosher Clayton P. , Gothard Katalin M.
Published: January 2009

The amygdala plays a crucial role in evaluating the emotional significance of stimuli and in transforming the results of this evaluation into appropriate autonomic responses. Lesion and stimulation studies suggest involvement of the amygdala in the generation of the skin conductance response (SCR), which is an indirect measure of autonomic activity that has been associated with both emotion and attention. It is unclear if this involvement marks an emotional reaction to an external stimulus or sympathetic arousal regardless of its origin. We recorded skin conductance in parallel with single-unit activity from the right amygdala of two rhesus monkeys during a rewarded image viewing task and while the monkeys sat alone in a dimly lit room, drifting in and out of sleep. In both experimental conditions, we found similar SCR-related modulation of activity at the single-unit and neural population level. This suggests that the amygdala contributes to the production or modulation of SCRs regardless of the source of sympathetic arousal.
A Shortest‐Path Lyapunov Approach for Forward Decision Processes
Authors: Clempner Julio B.
Published: January 2009

In previous work, attention was restricted to tracking the net using a backward method that knows the target point beforehand (Bellmans′s equation), this work tracks the state‐space in a forward direction,
and a natural form of termination is ensured by an equilibrium point
p∗ (M(p∗) = S < ∞  and  p∗• = ∅). We consider dynamical systems governed by ordinary difference equations described by Petri nets. The
trajectory over the net is calculated forward using a discrete Lyapunov‐like function, considered as a distance function. Because a Lyapunov‐like function is a solution to a difference equation, it is constructed to respect
the constraints imposed by the system (a Euclidean metric does not consider these factors). As a result, we prove natural generalizations of the standard outcomes for the deterministic shortest‐path problem and
shortest‐path game theory.
Melanoma Antigen-11 Inhibits the Hypoxia-Inducible Factor Prolyl Hydroxylase 2 and Activates Hypoxic Response
Authors: Aprelikova Olga , Pandolfi Silvia , Tackett Sean , Ferreira Mark , Salnikow Konstantin , Ward Yvona , Risinger John I. , Barrett J. Carl , Niederhuber John
Published: January 2009

Activation of hypoxia-inducible factors (HIF), responsible for tumor angiogenesis and glycolytic switch, is regulated by reduced oxygen availability. Normally, HIF-α proteins are maintained at low levels, controlled by site-specific hydroxylation carried out by HIF prolyl hydroxylases (PHD) and subsequent proteasomal degradation via the von Hippel-Lindau ubiquitin ligase. Using a yeast two-hybrid screen, we identified an interaction between melanoma antigen-11 (MAGE-11) cancer-testis antigen and the major HIF-α hydroxylating enzyme PHD2. The interaction was confirmed by a pull-down assay, coimmunoprecipitation, and colocalization in both normoxic and hypoxic conditions. Furthermore, MAGE-9, the closest homologue of MAGE-11, was also found to interact with PHD2. MAGE-11 inhibited PHD activity without affecting protein levels. This inhibition was accompanied by stabilization of ectopic or endogenous HIF-1α protein. Knockdown of MAGE-11 by small interfering RNA results in decreased hypoxic induction of HIF-1α and its target genes. Inhibition of PHD by MAGE-11, and following activation of HIFs, is a novel tumor-associated HIF regulatory mechanism. This finding provides new insights into the significance of MAGE expression in tumors and may provide valuable tools for therapeutic intervention because of the restricted expression of the MAGE gene family in cancers, but not in normal tissues. [Cancer Res 2009;69(2):616–24]
Identification of Nuclear Export Inhibitors with Potent Anticancer Activity In vivo
Authors: Mutka Sarah C. , Yang Wen Qing , Dong Steven D. , Ward Shannon L. , Craig Darren A. , Timmermans Pieter B.M.W.M. , Murli Sumati
Published: January 2009

The export protein CRM1 is required for the nuclear export of a wide variety of cancer-related “cargo” proteins including p53, c-Abl, and FOXO-3A. Leptomycin B (LMB) is a highly specific inhibitor of CRM1 with significant in vitro potency but limited in vivo efficacy due to toxicity. We now report a series of semisynthetic LMB derivatives showing substantially improved therapeutic windows. Exposure of cancer cells to these compounds leads to a rapid and prolonged block of nuclear export and apoptosis. In contrast to what is observed in cancer cells, these agents induce cell cycle arrest, but not apoptosis, in normal lung fibroblasts. These new nuclear export inhibitors (NEI) maintain the high potency of LMB, are up to 16-fold better tolerated than LMB in vivo, and show significant efficacy in multiple mouse xenograft models. These NEIs show the potential of CRM1 inhibitors as novel and potent anticancer agents. [Cancer Res 2009;69(2):510–7]
Reversal of P-glycoprotein–Mediated Multidrug Resistance by the Murine Double Minute 2 Antagonist Nutlin-3
Authors: Michaelis Martin , Rothweiler Florian , Klassert Denise , von Deimling Andreas , Weber Kristoffer , Fehse Boris , Kammerer Bernd , Doerr Hans Wilhelm , Cinatl Jindrich
Published: January 2009

Murine double minute 2 (MDM2) negatively regulates the activity of the tumor suppressor protein p53. Nutlin-3 is a MDM2 inhibitor under preclinical investigation as nongenotoxic activator of the p53 pathway for cancer therapy. Here, nutlin-3 was evaluated for its activity alone or in combination with established chemotherapeutic drugs for antitumor action in chemosensitive and chemoresistant neuroblastoma and rhabdomyosarcoma cell lines. Effects of nutlin-3 single treatment were much more pronounced in p53 wild-type cell lines (IC50s <3 μmol/L) than in p53-mutated cell lines (IC50s >17 μmol/L). In sharp contrast to the expectations, nutlin-3 concentrations that did not affect viability of p53-mutated cell lines strongly increased the efficacy of vincristine in p53-mutated, P-glycoprotein (P-gp)–overexpressing cell lines (decrease in IC50s 92- to 3,434-fold). Similar results were obtained for other P-gp substrates. Moreover, nutlin-3 reduced efflux of rhodamine 123 and other fluorescence dyes that are effluxed by P-gp. Investigation of Madin-Darby canine kidney (MDCK) II cells stably transfected with plasmids encoding for P-gp (MDCKII MDR1) or multidrug resistance protein 1 (MRP-1, MDCKII MRP1) revealed that nutlin-3 not only interferes with P-gp but also affects MRP-1–mediated efflux. Kinetic studies and investigation of P-gp-ATPase activity showed that nutlin-3 is likely to act as a P-gp transport substrate. Examination of the nutlin-3 enantiomers nutlin-3a and nutlin-3b revealed that, in contrast to MDM2-inhibitory activity that is limited to nutlin-3a, both enantiomers similarly interfere with P-gp–mediated drug efflux. In conclusion, nutlin-3–induced inhibition of P-gp and MRP-1 was discovered as a novel anticancer mechanism of the substance in this report. [Cancer Res 2009;69(2):416–21]
Genome-Wide Linkage Analysis of TMPRSS2-ERG Fusion in Familial Prostate Cancer
Authors: Hofer Matthias D. , Kuefer Rainer , Maier Christiane , Herkommer Kathleen , Perner Sven , Demichelis Francesca , Paiss Thomas , Vogel Walter , Rubin Mark A. , Hoegel Josef
Published: January 2009

Fusion of the 5′-untranslated region of androgen-regulated TMPRSS2 promoter with ETS transcription factor family members is found frequently in prostate cancers, and recent work suggests that the most common TMPRSS2-ERG fusion is associated with an aggressive clinical phenotype compared with fusion-negative prostate cancer. Thus far, analysis of the fusion has been limited to sporadic cases of prostate cancer. In the current study, we explore for an enrichment of TMPRSS2-ERG fusion in familial prostate cancer. TMPRSS2-ERG fusion was identified using a break-apart fluorescence in situ hybridization assay on tissue microarrays. Presence of TMPRSS2-ERG fusion was associated with higher Gleason scores (P = 0.027). Of 75 patients with established history of prostate cancer, we detected the TMPRSS2-ERG fusion in 44 (59%) patients. Almost three quarters (73%) of fusion-positive patients accumulated within 16 specific families whereas only 27% were single fusion-positive cases within one family. Based on reported prevalence rates, we calculated a sibling recurrence risk ratio of up to 18.9. A subset (63%) of families with uniformly TMPRSS2-ERG–positive prostate cancer underwent a genome-wide linkage scan at 500 markers. This revealed several loci located on chromosomes #9, #18, and X that were suggestive of linkage to the TMPRSS2-ERG fusion-positive prostate cancer phenotype with linkage-of-disease scores up to 2.16 and nonparametric linkage scores up to 2.77. This suggests the presence of an inherited susceptibility to developing the TMPRSS2-ERG fusion. Given the association of TMPRSS2-ERG fusion and aggressive prostate cancer, close surveillance of relatives of patients with established fusion-positive prostate cancer or a family history of prostate cancer in general would be warranted. [Cancer Res 2009;69(4):640–6]
Thyroid Hormone Receptor β1 Acts as a Potent Suppressor of Tumor Invasiveness and Metastasis
Authors: Martínez-Iglesias Olaia , Garcia-Silva Susana , Tenbaum Stephan P. , Regadera Javier , Larcher Fernando , Paramio Jesus M. , Vennström Bjorn , Aranda Ana
Published: January 2009

Loss of thyroid hormone receptors (TR) is a common feature in some tumors, although their role in tumor progression is currently unknown. We show here that expression of TRβ1 in hepatocarcinoma and breast cancer cells reduces tumor growth, causes partial mesenchymal-to-epithelial cell transition, and has a striking inhibitory effect on invasiveness, extravasation, and metastasis formation in mice. In cultured cells, TRβ1 abolishes anchorage-independent growth and migration, blocks responses to epidermal growth factor, insulin-like growth factor-I, and transforming growth factor β, and regulates expression of genes that play a key role in tumorigenicity and metastatic growth. The receptor disrupts the mitogenic action of growth factors by suppressing activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling pathways that are crucial for cell proliferation and invasiveness. Furthermore, increased aggressiveness of skin tumors is found in genetically modified mice lacking TRs, further demonstrating the role of these receptors as inhibitors of tumor progression. These results define a novel role for the thyroid hormone receptor as a metastasis suppressor gene, providing a starting point for the development of novel therapeutic strategies for the treatment of human cancer. [Cancer Res 2009;69(2):501–9]
Inhibition of Peroxisome Proliferator-Activated Receptor γ Increases Estrogen Receptor–Dependent Tumor Specification
Authors: Yin Yuzhi , Yuan Hongyan , Zeng Xiao , Kopelovich Levy , Glazer Robert I.
Published: January 2009

Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that regulates gene transcription associated with intermediary metabolism, adipocyte differentiation, and tumor suppression and proliferation. To understand the role of PPARγ in tumorigenesis, transgenic mice were generated with mammary gland–directed expression of the dominant-negative transgene Pax8PPARγ. Transgenic mice were phenotypically indistinguishable from wild-type (WT) mice, but mammary epithelial cells expressed a greater percentage of CD29hi/CD24neg, CK5+, and double-positive CK14/CK18 cells. These changes correlated with reduced PTEN and increased Ras and extracellular signal-regulated kinase (ERK) and AKT activation. Although spontaneous tumorigenesis did not occur, transgenic animals were highly susceptible to progestin/7,12-dimethylbenz(a)anthracene–induced mammary carcinogenesis, which in contrast to WT mice resulted in a high tumor multiplicity and, most importantly, in the appearance of predominantly estrogen receptor α–positive (ER+) ductal adenocarcinomas. Tumors expressed a similar PTENlo/pERKhi/pAKThi phenotype as mammary epithelium and exhibited high activation of estrogen response element–dependent reporter gene activity. Tumorigenesis in MMTV-Pax8PPARγ mice was insensitive to the chemopreventive effect of a PPARγ agonist but was profoundly inhibited by the ER antagonist fulvestrant. These results reveal important new insights into the previously unrecognized role of PPARγ in the specification of mammary lineage and the development of ER+ tumors. [Cancer Res 2009;69(2):687–94]
Morelloflavone, a Biflavonoid, Inhibits Tumor Angiogenesis by Targeting Rho GTPases and Extracellular Signal-Regulated Kinase Signaling Pathways
Authors: Pang Xiufeng , Yi Tingfang , Yi Zhengfang , Cho Sung Gook , Qu Weijing , Pinkaew Decha , Fujise Ken , Liu Mingyao
Published: January 2009

Morelloflavone, a biflavonoid extracted from Garcinia dulcis, has shown antioxidative, antiviral, and anti-inflammatory properties. However, the function and the mechanism of this compound in cancer treatment and tumor angiogenesis have not been elucidated to date. In this study, we postulated that morelloflavone might have the ability to inhibit angiogenesis, the pivotal step in tumor growth, invasiveness, and metastasis. We showed that morelloflavone could inhibit vascular endothelial growth factor (VEGF)–induced cell proliferation, migration, invasion, and capillary-like tube formation of primary cultured human umbilical vascular endothelial cells in a dose-dependent manner. Morelloflavone effectively inhibited microvessel sprouting of endothelial cells in the mouse aortic ring assay and the formation of new blood microvessels induced by VEGF in the mouse Matrigel plug assay. Furthermore, morelloflavone inhibited tumor growth and tumor angiogenesis of prostate cancer cells (PC-3) in xenograft mouse tumor model in vivo, suggesting that morelloflavone inhibited tumorigenesis by targeting angiogenesis. To understand the underlying mechanism of morelloflavone on the inhibitory effect of tumor growth and angiogenesis, we showed that morelloflavone could inhibit the activation of both RhoA and Rac1 GTPases but have little effect on the activation of Cdc42 GTPase. Additionally, morelloflavone inhibited the phosphorylation and activation of Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase/ERK pathway kinases without affecting VEGF receptor 2 activity. Together, our results indicate that morelloflavone exerts antiangiogenic action by targeting the activation of Rho-GTPases and ERK signaling pathways. These findings are the first to reveal the novel functions of morelloflavone in tumor angiogenesis and its molecular basis for the anticancer action. [Cancer Res 2009;69(2):518–25]
Glycosaminoglycans as Potential Regulators of Osteoprotegerin Therapeutic Activity in Osteosarcoma
Authors: Lamoureux Francois , Picarda Gaëlle , Garrigue-Antar Laure , Baud'huin Marc , Trichet Valerie , Vidal André , Miot-Noirault Elisabeth , Pitard Bruno , Heymann Dominique , Rédini Françoise
Published: January 2009

Osteosarcoma is the most frequent primary bone malignant tumor that develops mainly in children and adolescents. Despite recent improvements in chemotherapy and surgery, survival rate is ∼50% after 5 years. Osteoprotegerin (OPG) is a potent inhibitor of osteoclast differentiation and activation, but its use as therapeutic agent in cancer-associated osteolysis remains controversial due to its ability to bind and inhibit the apoptotic effect of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) on tumor cells. The therapeutic effects of full-length OPG (1-401) and OPG 1-194 lacking its heparin-binding domain delivered by nonviral gene therapy were compared in a murine model of osteolytic osteosarcoma. Tumor incidence, progression, and associated bone lesions were significantly diminished in the OPG 1-194 group, but not in the OPG 1-401 group, compared with controls. As receptor activator of nuclear factor-κB ligand (RANKL), TRAIL, and glycosaminoglycans (GAG) were shown to be overexpressed in osteosarcoma environment compared with control tissue, OPG 1-401 bioactivity may be modulated by one of these protagonists. Surface plasmon resonance analyses performed with OPG, TRAIL, and GAGs revealed that TRAIL binds both forms of OPG with the same affinity. In addition, as OPG 1-194 and OPG 1-401 similarly inhibit TRAIL-induced apoptosis, it suggests that TRAIL is not involved in the modulation of OPG bioactivity. However, as GAGs inhibit OPG 1-401 but not OPG 1-194 binding to TRAIL or to RANKL, they may represent potent regulators of OPG availability and antitumor activity in bone tumor microenvironment. [Cancer Res 2009;69(2):526–36]