bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear‐Accelerator‐Based Modified Radiosurgical Treatment of Pituitary Tumors in Cats: 11 Cases (1997–2008)
Authors: Sellon R.K. , Fidel J. , Houston R. , Gavin P.R.
Published: July 2009

Objective:Determine the efficacy and safety of a linear‐accelerator‐based single fraction radiosurgical approach to the treatment of pituitary tumors in cats.

Design:Retrospective study.

Animals:Eleven client‐owned cats referred for treatment of pituitary tumors causing neurological signs, or poorly controlled diabetes mellitus (DM) secondary either to acromegaly or pituitary‐dependent hyperadrenocortism.

Procedures:Cats underwent magnetic resonance imaging (MRI) of the brain to manually plan radiation therapy. After MRI, modified radiosurgery was performed by delivering a single large dose (15 or 20 Gy) of radiation while arcing a linear‐accelerator‐generated radiation beam around the cat's head with the pituitary mass at the center of the beam. Eight cats were treated once, 2 cats were treated twice, and 1 cat received 3 treatments. Treated cats were evaluated for improvement in endocrine function or resolution of neurological disease by review of medical records or contact with referring veterinarians and owners.

Results:Improvement in clinical signs occurred in 7/11 (63.6%) of treated cats. Five of 9 cats with poorly regulated DM had improved insulin responses, and 2/2 cats with neurological signs had clinical improvement. There were no confirmed acute or late adverse radiation effects. The overall median survival was 25 months (range, 1–60), and 3 cats were still alive.

Conclusions and Clinical Importance:Single fraction modified radiosurgery is a safe and effective approach to the treatment of pituitary tumors in cats.
THE MIXING OF THE SCALAR–ISOSCALAR STATES f0(1370), f0(1500) AND f0(1710)
Authors: CHEN JIANXING , ZHANG LIMEI , XIA HUANYU
Published: July 2009

Motivated by the chiral suppression in the mixing between a scalar glueball and quarkonia, we have investigated the mixing of three important candidates of glueballs: f0(1370), f0(1500) and f0(1710), with their latest two-body pseudoscalar meson decay data in a simple decay model. In our work, we utilize a general mass matrix, in which the chiral suppression parameter a and the direct mixing r between |S〉 and |N〉 are introduced as free parameters. The most hopeful result in our fits suggests that the f0(1710) is mainly the mixing of |G〉 and |S〉, the f0(1370) has almost equal |G〉, |S〉 and |N〉 components, and the f0(1500) is mainly the mixing of |S> and |N> with sizable glueball component. We find that r is reasonably small as expected, the chiral suppression parameter a can be small which suggests the chiral suppression in the mixing between glueball and quarkonia is necessary to be considered, and the SU(3) symmetry is respected in decay processes.
KINEMATICAL ANALOGY FOR MARGINAL DYON DECAY
Authors: MUKHERJEE ANINDYA , MUKHI SUNIL , NIGAM RAHUL
Published: July 2009

We describe a kinematical analogy for the marginal decay of ¼-BPS dyons in four-dimensional [Formula: see text] string compactifications. In this analogy, the electric and magnetic charges play the role of spatial momenta, the BPS mass plays the role of energy, and ½BPS dyons correspond to massless particles. Using SO(12, 1) "Lorentz" invariance and standard kinematical formulas in particle physics, we provide simple derivations of the curves of marginal stability. We also show how these curves map into the momentum ellipsoid, and propose some applications of this analogy.
ENTROPY OF EXTREMAL WARPED BLACK HOLES
Authors: MYUNG YUN SOO
Published: July 2009

We study the entropy of extremal warped black hole obtained from the topologically massive gravity with a negative cosmological constant of Λ = -1/l2. We compare the entropy Se = πα/3G from the Wald formalism with Sw = πl u /3G from the entropy function approach. These are the same if α = l u. Also we obtain the same Cardy formula when Je = l3 q with Je the angular momentum and q the conserved quantity.
AUTOMATIC INSERTION OF A TURBULENCE MODEL IN THE FINITE ELEMENT DISCRETIZATION OF THE NAVIER–STOKES EQUATIONS
Authors: BERNARDI CHRISTINE , CHACÓN REBOLLO TOMÁS , HECHT FRÉDÉRIC , LEWANDOWSKI ROGER
Published: July 2009

We consider the finite element discretization of the Navier–Stokes equations locally coupled with the equation for the turbulent kinetic energy through an eddy viscosity. We prove a posteriori error estimates which allow to automatically determine the zone where the turbulent kinetic energy must be inserted in the Navier–Stokes equations and also to perform mesh adaptivity in order to optimize the discretization of these equations. Numerical results confirm the interest of such an approach.
THE EASTWOOD–SINGER GAUGE IN EINSTEIN SPACES
Authors: ESPOSITO GIAMPIERO , ROYCHOWDHURY RAJU
Published: July 2009

Electrodynamics in curved space-time can be studied in the Eastwood–Singer gauge, which has the advantage of respecting the invariance under conformal rescalings of the Maxwell equations. Such a construction is here studied in Einstein spaces, for which the Ricci tensor is proportional to the metric. The classical field equations for the potential are then equivalent to first solving a scalar wave equation with cosmological constant, and then solving a vector wave equation where the inhomogeneous term is obtained from the gradient of the solution of the scalar wave equation. The Eastwood–Singer condition leads to a field equation on the potential which is preserved under gauge transformations provided that the scalar function therein obeys a fourth-order equation where the highest-order term is the wave operator composed with itself. The second-order scalar equation is here solved in de Sitter space-time, and also the fourth-order equation in a particular case, and these solutions are found to admit an exponential decay at large time provided that square-integrability for positive time is required. Last, the vector wave equation in the Eastwood–Singer gauge is solved explicitly when the potential is taken to depend only on the time variable.
A REVIEW ON THE GEOMETRIC FORMULATION OF TOLMAN–BONDI EQUATIONS IN GENERAL RELATIVITY
Authors: BOCHICCHIO IVANA , FRANCAVIGLIA MAURO , LASERRA ETTORE
Published: July 2009

This work is focused on spherically symmetric space-times. More precisely, geometric and structural properties of spatially spherical shells of a dust universe are analyzed in detail considering recent results of our research. Moreover, exact solutions, obtained for constant Ricci principal curvatures, are inferred and qualitatively analyzed through suitable classic analogies.
APPLICATIONS OF LIE SYSTEMS IN DISSIPATIVE MILNE–PINNEY EQUATIONS
Authors: CARIÑENA JOSÉ F. , DE LUCAS JAVIER
Published: July 2009

We use the geometric approach to the theory of Lie systems of differential equations in order to study dissipative Ermakov systems. We prove that there is a superposition rule for solutions of such equations. This fact enables us to express the general solution of a dissipative Milne–Pinney equation in terms of particular solutions of a system of second-order linear differential equations and a set of constants.
Akt1 mediates purinergic-dependent NOS3 activation in thick ascending limbs
Authors: Silva Guillermo B. , Garvin Jeffrey L.
Published: July 2009

Extracellular ATP regulates many physiological processes via release of nitric oxide (NO). ATP stimulates NO in thick ascending limbs (TALs), but the signaling cascade involved in the cells of this nephron segment, as well as many other types of cells, is poorly understood. We hypothesized that ATP enhances NO synthase (NOS) activity by stimulating PI3 kinase and Akt. We measured 1) NO in TALs using the NO-sensitive dye DAF-2 DA and 2) Akt activity by fluorescence resonance energy transfer and phosphorylation of Akt isoforms. ATP (100 μM) stimulated NO in wild-type mice [26 ± 4 arbitrary units (AU)], but not in NOS3 −/− mice (2 ± 2 AU; P < 0.04). In the presence of the NOS1- and NOS2-selective inhibitors 7-NI and 1400W, ATP stimulated NO by 30 ± 2 and 33 ± 3 AU, respectively (not significant vs. control). In the presence of the PI3 kinase inhibitor LY294002, ATP-increased NO was reduced by 85% (5 ± 2 vs. 28 ± 4 AU; P < 0.02). ATP alone increased Akt activity and this effect was significantly blocked by suramin, a P2 receptor antagonist. In the presence of an Akt-selective inhibitor, ATP-induced NO was blocked by 90 ± 4%. ATP significantly stimulated Akt1 phosphorylation at Ser473 by 91 ± 13%, whereas Akt2 phosphorylation remained unchanged and Akt3 phosphorylation decreased. In vivo transduction of TALs with a dominant-negative Akt1 significantly decreased ATP-induced NO by 88 ± 6%. We concluded that ATP increases NOS3-derived NO via Akt1 activation in the TAL.
Membrane Capacitance Measurements Revisited: Dependence of Capacitance Value on Measurement Method in Nonisopotential Neurons
Authors: Golowasch Jorge , Thomas Gladis , Taylor Adam L. , Patel Arif , Pineda Arlene , Khalil Christopher , Nadim Farzan
Published: July 2009

During growth or degeneration neuronal surface area can change dramatically. Measurements of membrane protein concentration, as in ion channel or ionic conductance density, are often normalized by membrane capacitance, which is proportional to the surface area, to express changes independently from cell surface variations. Several electrophysiological protocols are used to measure cell capacitance, all based on the assumption of membrane isopotentiality. Yet, most neurons violate this assumption because of their complex anatomical structure, raising the question of which protocol yields measurements that are closest to the actual total membrane capacitance. We measured the capacitance of identified neurons from crab stomatogastric ganglia using three different protocols: the current-clamp step, the voltage-clamp step, and the voltage-clamp ramp protocols. We observed that the current-clamp protocol produced significantly higher capacitance values than those of either voltage-clamp protocol. Computational models of various anatomical complexities suggest that the current-clamp protocol can yield accurate capacitance estimates. In contrast, the voltage-clamp protocol estimates rapidly deteriorate as isopotentiality is reduced. We provide a mathematical description of these results by analyzing a simple two-compartment model neuron to facilitate an intuitive understanding of these methods. Together, the experiments, modeling, and mathematical analysis indicate that accurate total membrane capacitance measurements cannot be obtained with voltage-clamp protocols in nonisopotential neurons. Furthermore, although current-clamp steps can theoretically yield accurate measurements, experimentalists should be aware of limitations imposed by step duration and numerical errors during fitting procedures to obtain the membrane time constant.
Current Source Density Profiles of Stimulus-Specific Adaptation in Rat Auditory Cortex
Authors: Szymanski Francois D. , Garcia-Lazaro Jose A. , Schnupp Jan W. H.
Published: July 2009

Neurons in primary auditory cortex (A1) are known to exhibit a phenomenon known as stimulus-specific adaptation (SSA), which means that, when tested with pure tones, they will respond more strongly to a particular frequency if it is presented as a rare, unexpected “oddball” stimulus than when the same stimulus forms part of a series of common, “standard” stimuli. Although SSA has occasionally been observed in midbrain neurons that form part of the paraleminscal auditory pathway, it is thought to be weak, rare, or nonexistent among neurons of the leminscal pathway that provide the main afferent input to A1, so that SSA seen in A1 is likely generated within A1 by local mechanisms. To study the contributions that neural processing within the different cytoarchitectonic layers of A1 may make to SSA, we recorded local field potentials in A1 of the rat in response to standard and oddball tones and subjected these to current source density analysis. Although our results show that SSA can be observed throughout all layers of A1, right from the earliest part of the response, there are nevertheless significant differences between layers, with SSA becoming significantly stronger as stimulus-related activity passes from the main thalamorecipient layers III and IV to layer V.
Genetic analysis of daily physical activity using a mouse chromosome substitution strain
Authors: Yang He S. , Vitaterna Martha H. , Laposky Aaron D. , Shimomura Kazuhiro , Turek Fred W.
Published: July 2009

There is considerable evidence for a genetic basis underlying individual differences in spontaneous physical activity in humans and animals. Previous publications indicate that the physical activity level and pattern vary among inbred strains of mice and identified a genomic region on chromosome 13 as quantitative trait loci (QTL) for physical activity. To confirm and further characterize the role of chromosome 13 in regulating daily physical activity level and pattern, we conducted a comprehensive phenotypic study in the chromosome 13 substitution strain (CSS-13) in which the individual chromosome 13 from the A/J strain was substituted into an otherwise complete C57BL/6J (B6) genome. The B6 and A/J parental strains exhibited pronounced differences in daily physical activity, sleep-wake structure, circadian period and body weight. Here we report that a single A/J chromosome 13 in the context of a B6 genetic background conferred a profound reduction in both total cage activity and wheel-running activity under a 14:10-h light-dark cycle, as well as in constant darkness, compared with B6 controls. Additionally, CSS-13 mice differed from B6 controls in the diurnal distribution of activity and the day-to-day variability in activity onset. We further performed a linkage analysis and mapped a significant QTL on chromosome 13 regulating the daily wheel running activity level in mice. Taken together, our findings indicate a QTL on chromosome 13 with dramatic and specific effects on daily voluntary physical activity, but not on circadian period, sleep, or other aspects of activity that are different between B6 and A/J strains.
Pleiotropic effects of negative energy balance in the postpartum dairy cow on splenic gene expression: repercussions for innate and adaptive immunity
Authors: Morris D. G. , Waters S. M. , McCarthy S. D. , Patton J. , Earley B. , Fitzpatrick R. , Murphy J. J. , Diskin M. G. , Kenny D. A. , Brass A. , Wathes D. C.
Published: July 2009

Increased energy demands to support lactation, coupled with lowered feed intake capacity results in negative energy balance (NEB) and is typically characterized by extensive mobilization of body energy reserves in the early postpartum dairy cow. The catabolism of stored lipid leads to an increase in the systemic concentrations of nonesterified fatty acids (NEFA) and β-hydroxy butyrate (BHB). Oxidation of NEFA in the liver result in the increased production of reactive oxygen species and the onset of oxidative stress and can lead to disruption of normal metabolism and physiology. The immune system is depressed in the peripartum period and early lactation and dairy cows are therefore more vulnerable to bacterial infections causing mastitis and or endometritis at this time. A bovine Affymetrix oligonucleotide array was used to determine global gene expression in the spleen of dairy cows in the early postpartum period. Spleen tissue was removed post mortem from five severe NEB (SNEB) and five medium NEB (MNEB) cows 15 days postpartum. SNEB increased systemic concentrations of NEFA and BHB, and white blood cell and lymphocyte numbers were decreased in SNEB animals. A total of 545 genes were altered by SNEB. Network analysis using Ingenuity Pathway Analysis revealed that SNEB was associated with NRF2-mediated oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, natural killer cell signaling, p53 signaling, downregulation of IL-15, BCL-2, and IFN-γ; upregulation of BAX and CHOP and increased apoptosis with a potential negative impact on innate and adaptive immunity.
Surface Roughness of CoCr and ZrO2 Femoral Heads with Metal Transfer: A Retrieval and Wear Simulator Study
Authors: Eberhardt Alan W. , McKee R. Travis , Cuckler John M. , Peterson Donald W. , Beck Preston R. , Lemons Jack E.
Published: July 2009

Metal transfer to femoral heads may result from impingement against the metallic acetabular shell following subluxation/dislocation, or when metallic debris enters the articulation zone. Such transfers roughen the head surface, increasing polyethylene wear in total hip replacements. Presently, we examined the surface roughness of retrieved femoral heads with metallic transfer. Profilometry revealed roughness averages in regions of metal transfer averaging 0.380 μm for CoCr and 0.294 μm for ZrO2 which were one order of magnitude higher than those from non‐implanted controls. Scanning electron microscopy (SEM) revealed adherent transfers on these retrievals, with titanium presence confirmed by electron dispersive spectroscopy. Due to the concern for increased wear, metal transfer was induced on non‐implanted heads, which were then articulated against flat polyethylene discs in multidirectional sliding wear tests. Increased polyethylene wear was associated with these specimens as compared to unaltered controls. SEM imaging provided visual evidence that the transfers remained adherent following the wear tests. Pre‐ and post‐test roughness averages exceeded 1 μm for both the CoCr and ZrO2 heads. Overall, these results suggest that metal transfer increases the surface roughness of CoCr and ZrO2 femoral heads and that the transfers may remain adherent following articulation against polyethylene, leading to increased polyethylene wear.
Duodenal Bulb Mucosa with Hypertrophic Gastric Oxyntic Heterotopia in Patients with Zollinger Ellison Syndrome
Authors: Kohan Emil , Oh David , Wang Hank , Hazany Salar , Ohning Gordon , Pisegna Joseph R.
Published: July 2009

Objectives. Zollinger-Ellison Syndrome (ZES) results in hypersecretion of gastric acid (via gastrinoma) leading to peptic ulcers, diarrhea, and abdominal pain. We describe the novel discovery of hypertrophic, heterotopic gastric mucosa in the proximal duodenal bulb in patients with ZES, which we hypothesize results in an increased incidence of postbulbar ulcers in patients with ZES (a mechanism previously unreported). We determined the incidence of the novel finding of duodenal gastric oxyntic hypertrophic heterotopia (GOH) in patients with ZES.Methods. Seven patients with ZES were enrolled. The diagnosis of ZES was established by hypergastrinemia, gastric acid hypersecretion, and a positive secretin test or based on biopsy specimens (evaluated via tissue staining). Basal acid output (BAO) and baseline gastrin secretion were determined by established methods. Endoscopic examinations with methylene blue staining and biopsy of the gastric and duodenal mucosa were conducted in all patients every 3–6 months for an average of 5 years.Results. The duodenal mucosa demonstrated hypertrophic GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. Biopsies from the bowel mucosa demonstrated patchy replacement of surface epithelium by gastric-type epithelium with hypertrophic oxyntic glands in the lamina propria in 5 patients. Two of the patients had no evidence of GOH in the duodenal bulb. Patients with GOH had an average serum gastrin level of 1245 pg/mL and BAO of 2.92 mEq/hr versus 724 pg/mL and 0.8 mEq/hr in patients without GOH.Conclusions. This study demonstrated the presence of duodenal mucosa with GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. The presence of hypertrophic and heterotopic gastric mucosa is proposed to result from increased gastrin levels and may contribute to the increased incidence of postbulbar ulcers in these patients.
Survival Following Rectal Impalement through the Pelvic, Abdominal, and Thoracic Cavities: A Case Report
Authors: Moncure Michael , Konie Jared A. , Kretzer Adam B. , DiPasco Peter J. , Braxton Carla C.
Published: July 2009

Impalement injuries are a unique form of penetrating trauma and are typically associated with a fall onto the object (Steele, 2006). We present the case of a 45-year-old man who reportedly slipped in his bathtub and fell onto a broomstick. Radiographic examination revealed a slender mass extending from his rectum to the right side of his neck. A review of English literature suggests that this is the second reported case in the last 100 years describing the successful management of an impalement injury traversing the pelvic, abdominal, and thoracic cavities. The management of this case is described.
Surface Plasmons and Surface Enhanced Raman Spectra of Aggregated and Alloyed Gold‐Silver Nanoparticles
Authors: Fleger Y. , Rosenbluh M.
Published: July 2009

Effects of size, morphology, and composition of gold and silver nanoparticles on surface plasmon resonance (SPR) and surface enhanced Raman spectroscopy (SERS) are studied with the purpose of optimizing SERS substrates. Various gold and silver films made by evaporation and subsequent annealing give different morphologies and compositions of nanoparticles and thus different position of the SPR peak. SERS measurements of 4‐mercaptobenzoic acid obtained from these films reveal that the proximity of the SPR peak to the exciting laser wavelength is not the only factor leading to the highest Raman enhancement. Silver nanoparticles evaporated on top of larger gold nanoparticles show higher SERS than gold‐silver alloyed nanoparticles, in spite of the fact that the SPR peak of alloyed nanoparticles is narrower and closer to the excitation wavelength. The highest Raman enhancement was obtained for substrates with a two‐peak particle size distribution for excitation wavelengths close to the SPR.
Rotations in the Space of Split Octonions
Authors: Gogberashvili Merab
Published: July 2009

The geometrical application of split octonions is considered. The new representation of products of the basis units of split octonionic having David′s star shape (instead of the Fano triangle) is presented. It is shown that active and passive transformations of coordinates in octonionic “eight‐space” are not equivalent. The group of passive transformations that leave invariant the pseudonorm of split octonions is SO(4, 4), while active rotations are done by the direct product of O(3, 4)‐boosts and real noncompact form of the exceptional group G2. In classical limit, these transformations reduce to the standard Lorentz group.
On the Recursive Sequence xn=A+xn−kp/xn−1r
Authors: Sun Fangkuan , Yang Xiaofan , Zhang Chunming
Published: July 2009

This paper studies the dynamic behavior of the positive solutions to the difference equation , n = 1, 2, …, where A, p, and r are positive real numbers, and the initial conditions are arbitrary positive numbers. We establish some results regarding the stability and oscillation character of this equation for p ∈ (0, 1).
Uniqueness of Entire Functions Sharing Polynomials with Their Derivatives
Authors: Qi Jianming , Lü Feng , Chen Ang
Published: July 2009

We use the theory of normal families to prove the following. Let Q1(z) = a1zp + a1,p−1zp−1 + ⋯+a1,0 and Q2(z) = a2zp + a2,p−1zp−1 + ⋯+a2,0 be two polynomials such that deg Q1 = deg Q2 = p (where p is a nonnegative integer) and a1, a2(a2 ≠ 0) are two distinct complex numbers. Let f(z) be a transcendental entire function. If f(z) and f′(z) share the polynomial Q1(z) CM and if f(z) = Q2(z) whenever f′(z) = Q2(z), then f ≡ f′. This result improves a result due to Li and Yi.
Mood Disorder Due to a General Medical Condition with Manic Features
Authors: Oliveira J. P. , Morais S. L. , Araújo D. , Carlotti C. G. , Colli B. O. , Crippa J. A. S. , Cecílio Hallak J. E.
Published: July 2009

This case report describes a patient with manic and psychotic symptoms who had a history of neurocysticercosis and presented with an episode of hypertensive hydrocephalus in 2003. Despite her history, she was initially treated for primary psychiatric disease.
Stimulating the GPR30 Estrogen Receptor with a Novel Tamoxifen Analogue Activates SF-1 and Promotes Endometrial Cell Proliferation
Authors: Lin Benjamin C. , Suzawa Miyuki , Blind Raymond D. , Tobias Sandra C. , Bulun Serdar E. , Scanlan Thomas S. , Ingraham Holly A.
Published: July 2009

Estrogens and selective estrogen receptor (ER) modulators such as tamoxifen are known to increase uterine cell proliferation. Mounting evidence suggests that estrogen signaling is mediated not only by ERα and ERβ nuclear receptors, but also by GPR30 (GPER), a seven transmembrane (7TM) receptor. Here, we report that primary human endometriotic H-38 cells express high levels of GPR30 with no detectable ERα or ERβ. Using a novel tamoxifen analogue, STX, which activates GPR30 but not ERs, significant stimulation of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways was observed in H-38 cells and in Ishikawa endometrial cancer cells expressing GPR30; a similar effect was observed in JEG3 choriocarcinoma cells. STX treatment also increased cellular pools of phosphatidylinositol (3,4,5) triphosphate, a proposed ligand for the nuclear hormone receptor SF-1 (NR5A1). Consistent with these findings, STX, tamoxifen, and the phytoestrogen genistein were able to increase SF-1 transcription, promote Ishikawa cell proliferation, and induce the SF-1 target gene aromatase in a GPR30-dependent manner. Our findings suggest a novel signaling paradigm that is initiated by estrogen activation of the 7TM receptor GPR30, with signal transduction cascades (PI3K and MAPK) converging on nuclear hormone receptors (SF-1/LRH-1) to modulate their transcriptional output. We propose that this novel GPR30/SF-1 pathway increases local concentrations of estrogen, and together with classic ER signaling, mediate the proliferative effects of synthetic estrogens such as tamoxifen, in promoting endometriosis and endometrial cancers. [Cancer Res 2009;69(13):5415–23]
Kinome Profiling in Pediatric Brain Tumors as a New Approach for Target Discovery
Authors: Sikkema Arend H. , Diks Sander H. , den Dunnen Wilfred F.A. , ter Elst Arja , Scherpen Frank J.G. , Hoving Eelco W. , Ruijtenbeek Rob , Boender Piet J. , de Wijn Rik , Kamps Willem A. , Peppelenbosch Maikel P. , de Bont Eveline S.J.M.
Published: July 2009

Progression in pediatric brain tumor growth is thought to be the net result of signaling through various protein kinase-mediated networks driving cell proliferation. Defining new targets for treatment of human malignancies, without a priori knowledge on aberrant cell signaling activity, remains exceedingly complicated. Here, we introduce kinome profiling using flow-through peptide microarrays as a new concept for target discovery. Comprehensive tyrosine kinase activity profiles were identified in 29 pediatric brain tumors using the PamChip kinome profiling system. Previously reported activity of epidermal growth factor receptor, c-Met, and vascular endothelial growth factor receptor in pediatric brain tumors could be appreciated in our array results. Peptides corresponding with phosphorylation consensus sequences for Src family kinases showed remarkably high levels of phosphorylation compared with normal tissue types. Src activity was confirmed applying Phos-Tag SDS-PAGE. Furthermore, the Src family kinase inhibitors PP1 and dasatinib induced substantial tumor cell death in nine pediatric brain tumor cell lines but not in control cell lines. Thus, this study describes a new high-throughput technique to generate clinically relevant tyrosine kinase activity profiles as has been shown here for pediatric brain tumors. In the era of a rapidly increasing number of small-molecule inhibitors, this approach will enable us to rapidly identify new potential targets in a broad range of human malignancies. [Cancer Res 2009;69(14):5987–95]
Active Notch1 Confers a Transformed Phenotype to Primary Human Melanocytes
Authors: Pinnix Chelsea C. , Lee John T. , Liu Zhao-Jun , McDaid Ronan , Balint Klara , Beverly Levi J. , Brafford Patricia A. , Xiao Min , Himes Benjamin , Zabierowski Susan E. , Yashiro-Ohtani Yumi , Nathanson Katherine L. , Bengston Ana , Pollock Pamela M. , Weeraratna Ashani T. , Nickoloff Brian J. , Pear Warren S. , Capobianco Anthony J. , Herlyn Meenhard
Published: July 2009

The importance of mitogen-activated protein kinase signaling in melanoma is underscored by the prevalence of activating mutations in N-Ras and B-Raf, yet clinical development of inhibitors of this pathway has been largely ineffective, suggesting that alternative oncogenes may also promote melanoma. Notch is an interesting candidate that has only been correlated with melanoma development and progression; a thorough assessment of tumor-initiating effects of activated Notch on human melanocytes would clarify the mounting correlative evidence and perhaps identify a novel target for an otherwise untreatable disease. Analysis of a substantial panel of cell lines and patient lesions showed that Notch activity is significantly higher in melanomas than their nontransformed counterparts. The use of a constitutively active, truncated Notch transgene construct (NIC) was exploited to determine if Notch activation is a “driving” event in melanocytic transformation or instead a “passenger” event associated with melanoma progression. NIC-infected melanocytes displayed increased proliferative capacity and biological features more reminiscent of melanoma, such as dysregulated cell adhesion and migration. Gene expression analyses supported these observations and aided in the identification of MCAM, an adhesion molecule associated with acquisition of the malignant phenotype, as a direct target of Notch transactivation. NIC-positive melanocytes grew at clonal density, proliferated in limiting media conditions, and also exhibited anchorage-independent growth, suggesting that Notch alone is a transforming oncogene in human melanocytes, a phenomenon not previously described for any melanoma oncogene. This new information yields valuable insight into the basic epidemiology of melanoma and launches a realm of possibilities for drug intervention in this deadly disease. [Cancer Res 2009;69(13):5312–20]
Differential Response of Glioma Cells to FOXO1-Directed Therapy
Authors: Lau Cara J. , Koty Zaf , Nalbantoglu Josephine
Published: July 2009

Gliomas are the most common adult primary brain tumors, and the most malignant form, glioblastoma multiforme, is invariably fatal. The phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway is altered in most glioblastoma multiforme. PTEN, an important negative regulator of the PI3K-Akt pathway, is also commonly mutated in glioma, leading to constitutive activation of Akt. One ultimate consequence is phosphorylation and inactivation of FOXO forkhead transcription factors that regulate genes involved in apoptosis, cell cycle arrest, nutrient availability, DNA repair, stress, and angiogenesis. We tested the ability of a mutant FOXO1 factor that is not subject to Akt phosphorylation to overcome dysregulated PI3K-Akt signaling in two PTEN-null glioma cell lines, U87 and U251. Adenovirus-mediated gene transfer of the mutant FOXO1 successfully restored cell cycle arrest and induced cell death in vitro and prolonged survival in vivo in xenograft models of human glioma (33% survival at 1 year of animals bearing U251 tumors). However, U87 were much more resistant than U251 to mutant FOXO1-induced death, showing evidence of increased nuclear export and Akt-independent phosphorylation of FOXO1 at S249. A cyclin-dependent kinase 2 inhibitor decreased phosphorylation of S249 and rendered U87 cells significantly more susceptible to mutant FOXO1-induced death. Our results indicate that targeting FOXO1, which is at the convergence point of several growth factor receptor tyrosine kinase pathways, can effectively induce glioma cell death and inhibit tumor growth. They also highlight the importance of Akt-independent phosphorylation events in the nuclear export of FOXO1. [Cancer Res 2009;69(13):5433–40]
β1 Integrin Cytoplasmic Variants Differentially Regulate Expression of the Antiangiogenic Extracellular Matrix Protein Thrombospondin 1
Authors: Goel Hira Lal , Moro Loredana , Murphy-Ullrich Joanne E. , Hsieh Chung-Cheng , Wu Chin-Lee , Jiang Zhong , Languino Lucia R.
Published: July 2009

β1 integrins play an important role in regulating cell proliferation and survival. Using small interfering RNA or an inhibitory antibody to β1, we show here that, in vivo, β1 integrins are essential for prostate cancer growth. Among the five known β1 integrin cytoplasmic variants, two have been shown to differentially affect prostate cell functions. The β1A variant promotes normal and cancer cell proliferation, whereas the β1C variant, which is down-regulated in prostate cancer, inhibits tumor growth and appears to have a dominant effect on β1A. To investigate the mechanism by which β1C inhibits the tumorigenic potential of β1A, we analyzed changes in gene expression in cells transfected with either β1C or β1A. The results show that β1C expression increases the levels of an extracellular matrix protein, thrombospondin 1 (TSP1), an angiogenesis inhibitor. TSP1 protein levels are increased upon β1C expression in prostate cancer cells as well as in β1-null GD25 cells. We show that TSP1 does not affect proliferation, apoptosis, or anchorage-independent growth of prostate cancer cells. In contrast, the newly synthesized TSP1, secreted by prostate cancer cells expressing β1C, prevents proliferation of endothelial cells. In conclusion, our novel findings indicate that expression of the β1C integrin variant in prostate glands prevents cancer progression by up-regulation of TSP1 levels and inhibition of angiogenesis. [Cancer Res 2009;69(13):5374–82]
microRNA miR-196a-2 and Breast Cancer: A Genetic and Epigenetic Association Study and Functional Analysis
Authors: Hoffman Aaron E. , Zheng Tongzhang , Yi Chunhui , Leaderer Derek , Weidhaas Joanne , Slack Frank , Zhang Yawei , Paranjape Trupti , Zhu Yong
Published: July 2009

Increasing evidence has suggested that microRNAs (miRNA) play an important role in tumorigenesis. As transcriptional regulators, altered miRNA expression may affect many cancer-related biological pathways, indicating that miRNAs can function as tumor suppressors and/or oncogenes. We first performed a genetic association analysis by screening genetic variants in 15 miRNA genes and detected that a common sequence variant in hsa-miR-196a-2 (rs11614913, C→T) was significantly associated with decreased breast cancer risk (for homozygous variant: odds ratio, 0.44; 95% confidence interval, 0.28-0.70). Hypermethylation of a CpG island upstream (-700 bp) of the miR-196a-2 precursor was also associated with reduced breast cancer risk (odds ratio, 0.35; 95% confidence interval, 0.15-0.81). By delivering expression vectors containing either wild-type or mutant precursors of miR-196a-2 into breast cancer cells, we showed that this variant led to less efficient processing of the miRNA precursor to its mature form as well as diminished capacity to regulate target genes. A whole-genome expression microarray was done and a pathway-based analysis identified a cancer-relevant network formed by genes significantly altered following enforced expression of miR-196a-2. Mutagenesis analysis further showed that cell cycle response to mutagen challenge was significantly enhanced in cells treated with variant miR-196a-2 compared with cells treated with the wild-type. Taken together, our findings suggest that miR-196a-2 might have a potentially oncogenic role in breast tumorigenesis, and the functional genetic variant in its mature region could serve as a novel biomarker for breast cancer susceptibility. [Cancer Res 2009;69(14):5970–7]
T-Regulatory Cells Shift from a Protective Anti-Inflammatory to a Cancer-Promoting Proinflammatory Phenotype in Polyposis
Authors: Gounaris Elias , Blatner Nichole R. , Dennis Kristen , Magnusson Fay , Gurish Michael F. , Strom Terry B. , Beckhove Philipp , Gounari Fotini , Khazaie Khashayarsha
Published: July 2009

T-regulatory (Treg) cells play a major role in cancer by suppressing protective antitumor immune responses. A series of observations (from a single laboratory) suggest that Treg cells are protective in cancer by virtue of their ability to control cancer-associated inflammation in an interleukin (IL)-10–dependent manner. Here, we report that the ability of Treg cells to produce IL-10 and control inflammation is lost in the course of progressive disease in a mouse model of hereditary colon cancer. Treg cells that expand in adenomatous polyps no longer produce IL-10 and instead switch to production of IL-17. Aberrant Treg cells from polyp-ridden mice promote rather than suppress focal mastocytosis, a critical tumor-promoting inflammatory response. The cells, however, maintain other Treg characteristics, including their inability to produce IL-2 and ability to suppress proliferation of stimulated CD4 T cells. By promoting inflammation and suppressing T-helper functions, these cells act as a double-edged knife propagating tumor growth. [Cancer Res 2009;69(13):5490–7]
A “Vascular Normalization Index” as Potential Mechanistic Biomarker to Predict Survival after a Single Dose of Cediranib in Recurrent Glioblastoma Patients
Authors: Sorensen A. Gregory , Batchelor Tracy T. , Zhang Wei-Ting , Chen Poe-Jou , Yeo Priscilla , Wang Meiyun , Jennings Dominique , Wen Patrick Y. , Lahdenranta Johanna , Ancukiewicz Marek , di Tomaso Emmanuelle , Duda Dan G. , Jain Rakesh K.
Published: July 2009

Early imaging or blood biomarkers of tumor response are desperately needed to customize antiangiogenic therapy for cancer patients. Anti–vascular endothelial growth factor (VEGF) therapy can “normalize” brain tumor vasculature by decreasing vessel diameter and permeability, and thinning the abnormally thick basement membrane. We hypothesized that the extent of vascular normalization will be predictive of outcome of anti-VEGF therapy in glioblastoma. We used advanced magnetic resonance imaging methods to monitor vascular parameters and treatment response in 31 recurrent glioblastoma patients enrolled in a phase II trial of cediranib, an oral pan-VEGF receptor tyrosine kinase inhibitor. We evaluated the correlation between clinical outcome and magnetic resonance imaging–measured changes in vascular permeability/flow (i.e., Ktrans) and in microvessel volume, and the change of circulating collagen IV levels, all after a single dose of cediranib. Here, we show that evaluation of biomarkers as early as after one day of anti-VEGF therapy with cediranib is predictive of response in patients with recurrent glioblastoma. Changes in Ktrans, microvessel volume, and circulating collagen IV correlated with duration of overall survival and/or progression-free survival (P < 0.05). When we combined these three parameters into a “vascular normalization index,” we found that it closely associated with overall survival (ρ = 0.54; P = 0.004) and progression-free survival (ρ = 0.6; P = 0.001). The vascular normalization index described here should be validated in randomized clinical trials. [Cancer Res 2009;69(13):5296–300]
MDA-MB-435 and M14 Cell Lines: Identical but not M14 Melanoma?
Authors: Chambers Ann F.
Published: July 2009

A controversy has arisen over the past several years about the true origin of the human MDA-MB-435 cell line. Originally described as a human breast cancer cell line, subsequent expression array studies instead suggested a gene expression profile consistent with a melanoma origin. Subsequent karyotype and comparative genomic hybridization studies supported the idea that current stocks of both MDA-MB-435 cells and M14 melanoma cells must be identical cell lines, and the conclusion was drawn that both cell lines were in fact M14 melanoma cells. However, an alternate conclusion based on these data is that both cell lines are indeed identical, but are in fact MDA-MB-435 breast cancer cells. There is evidence that many cell lines can display “lineage infidelity” and that assignment to tissue type is unreliably made based on expression patterns. Evidence from the literature is presented here that is inconsistent with both lines being of M14 melanoma origin, but rather is consistent with both cell lines being of MDA-MB-435 breast cancer origin. [Cancer Res 2009;69(13):5292–3]
Base excision repair of reactive oxygen species–initiated 7,8-dihydro-8-oxo-2′-deoxyguanosine inhibits the cytotoxicity of platinum anticancer drugs
Authors: Preston Thomas J. , Henderson Jeffrey T. , McCallum Gordon P. , Wells Peter G.
Published: July 2009

Anticancer therapy with cisplatin and oxaliplatin is limited by toxicity and onset of tumor resistance. Both drugs form platinum-DNA cross-linked adducts, and cisplatin causes oxidative DNA damage including the 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG) lesion. To assess oxidative DNA damage as a mechanism of cisplatin and oxaliplatin cytotoxicity, 8-oxodG–directed base excision repair was stably enhanced in human embryonic kidney cells by FLAG-tagged expression of human oxoguanine glycosylase 1 (α-OGG1) or its functional homologue, Escherichia coli formamidopyrimidine glycosylase (fpg). Both drugs increased reactive oxygen species and 8-oxodG levels, and cytotoxicity was decreased by antioxidant pretreatment. Ectopic expression of α-OGG1 or fpg in cell clones increased nuclear and mitochondrial 8-oxodG repair, and reduced death by reactive oxygen species initiators (H2O2, menadione) and both platinum drugs. Exposure to oxaliplatin caused a more marked and sustained block of cell proliferation than exposure to cisplatin. We conclude that the 8-oxodG lesion is cytotoxic, and base excision repair a likely determinant of risk. The greater antitumor efficacy of oxaliplatin seems unrelated to oxidative DNA damage, suggesting a novel strategy for improving the therapeutic index in cancer therapy. [Mol Cancer Ther 2009;8(7):2015–26]
GSK1070916, a potent Aurora B/C kinase inhibitor with broad antitumor activity in tissue culture cells and human tumor xenograft models
Authors: Hardwicke Mary Ann , Oleykowski Catherine A. , Plant Ramona , Wang Jamin , Liao Qiaoyin , Moss Katherine , Newlander Ken , Adams Jerry L. , Dhanak Dashyant , Yang Jingsong , Lai Zhihong , Sutton David , Patrick Denis
Published: July 2009

The protein kinases, Aurora A, B, and C have critical roles in the regulation of mitosis and are frequently overexpressed or amplified in human tumors. GSK1070916, is a novel ATP competitive inhibitor that is highly potent and selective for Aurora B/C kinases. Human tumor cells treated with GSK1070916 show dose-dependent inhibition of phosphorylation on serine 10 of Histone H3, a substrate specific for Aurora B kinase. Moreover, GSK1070916 inhibits the proliferation of tumor cells with EC50 values of <10 nmol/L in over 100 cell lines spanning a broad range of tumor types. Although GSK1070916 has potent activity against proliferating cells, a dramatic shift in potency is observed in primary, nondividing, normal human vein endothelial cells, consistent with the proposed mechanism. We further determined that treated cells do not arrest in mitosis but instead fail to divide and become polyploid, ultimately leading to apoptosis. GSK1070916 shows dose-dependent inhibition of phosphorylation of an Aurora B–specific substrate in mice and consistent with its broad cellular activity, has antitumor effects in 10 human tumor xenograft models including breast, colon, lung, and two leukemia models. These results show that GSK1070916 is a potent Aurora B/C kinase inhibitor that has the potential for antitumor activity in a wide range of human cancers. [Mol Cancer Ther 2009;8(7):1808–17]
Folate-mediated intracellular drug delivery increases the anticancer efficacy of nanoparticulate formulation of arsenic trioxide
Authors: Chen Haimei , Ahn Richard , Van den Bossche Jeroen , Thompson David H. , O'Halloran Thomas V.
Published: July 2009

Arsenic trioxide (As2O3) is a frontline drug for treatment of acute promyelocytic leukemia and is in clinical trials for treatment of other malignancies, including multiple myeloma; however, efforts to expand clinical utility to solid tumors have been limited by toxicity. Nanoparticulate forms of As2O3 encapsulated in 100-nm-scale, folate-targeted liposomes have been developed to lower systematic toxicity and provide a platform for targeting this agent. The resultant arsenic “nanobins” are stable under physiologic conditions but undergo triggered drug release when the pH is lowered to endosomal/lysosomal levels. Cellular uptake and antitumor efficacy of these arsenic liposomes have been evaluated in folate receptor (FR)–positive human nasopharyngeal (KB) and cervix (HeLa) cells, as well as FR-negative human breast (MCF-7) tumor cells through confocal microscopy, inductively coupled plasma mass spectroscopy, and cytotoxicity studies. Uptake of folate-targeted liposomal arsenic by KB cells was three to six times higher than that of free As2O3 or nontargeted liposomal arsenic; the enhanced uptake occurs through folate-mediated endocytosis, leading to a 28-fold increase in cytotoxicity. In contrast, tumor cells with lower FR density on the surface (HeLa and MCF-7) showed much less uptake of the folate-targeted drug and lower efficacy. In cocultures of KB and MCF-7 cells, the folate-targeted arsenic liposomes were exclusively internalized by KB cells, showing high targeting specificity. Our studies further indicate that folate-targeted delivery of As2O3 with coencapsulated nickel(II) ions (as a nontoxic adjuvant) potentiates the As2O3 efficacy in relatively insensitive solid tumor–derived cells and holds the promise of improving drug therapeutic index. [Mol Cancer Ther 2009;8(7):1955–63]
Inhibition of vascular endothelial growth factor reduces angiogenesis and modulates immune cell infiltration of orthotopic breast cancer xenografts
Authors: Roland Christina L. , Dineen Sean P. , Lynn Kristi D. , Sullivan Laura A. , Dellinger Michael T. , Sadegh Leila , Sullivan James P. , Shames David S. , Brekken Rolf A.
Published: July 2009

Vascular endothelial growth factor (VEGF) is a primary stimulant of angiogenesis and is a macrophage chemotactic protein. Inhibition of VEGF is beneficial in combination with chemotherapy for some breast cancer patients. However, the mechanism by which inhibition of VEGF affects tumor growth seems to involve more than its effect on endothelial cells. In general, increased immune cell infiltration into breast tumors confers a worse prognosis. We have shown previously that 2C3, a mouse monoclonal antibody that prevents VEGF from binding to VEGF receptor 2 (VEGFR2), decreases tumor growth, angiogenesis, and macrophage infiltration into pancreatic tumors and therefore hypothesized that r84, a fully human IgG that phenocopies 2C3, would similarly affect breast tumor growth and immune cell infiltration. In this study, we show that anti-VEGF therapy with bevacizumab, 2C3, or r84 inhibits the growth of established orthotopic MDA-MB-231 breast tumors in severe combined immunodeficiency (SCID) mice, reduces tumor microvessel density, limits the infiltration of tumor-associated macrophages, but is associated with elevated numbers of tumor-associated neutrophils. In addition, we found that treatment with r84 reduced the number of CD11b+Gr1+ double-positive cells in the tumor compared with tumors from control-treated animals. These results show that selective inhibition of VEGFR2 with an anti-VEGF antibody is sufficient for effective blockade of the protumorigenic activity of VEGF in breast cancer xenografts. These findings further define the complex molecular interactions in the tumor microenvironment and provide a translational tool that may be relevant to the treatment of breast cancer. [Mol Cancer Ther 2009;8(7):1761–71]