bluuebunny/crossref_metadata_2025 huggingface dataset:
Prolactin independent rescue of mouse corpus luteum life span: identification of prolactin and luteinizing hormone target genes
Authors: Bachelot Anne , Beaufaron Julie , Servel Nathalie , Kedzia Cécile , Monget Philippe , Kelly Paul A. , Gibori Geula , Binart Nadine
Published: June 2009

The corpus luteum (CL) plays a central role in the maintenance of pregnancy in rodents, mainly by secreting progesterone. Female mice lacking prolactin (PRL) receptor (R) are sterile due to a failure of embryo implantation, which is a consequence of decreased luteinizing hormone (LH) receptor expression in the CL and inadequate levels of progesterone. We attempted to treat PRLR−/− females with human chorionic gonadotropin (hCG) and showed a de novo expression of LHR mRNA in the corpora lutea. Binding analysis confirmed that the LHR in hCG-treated PRLR−/− animals was functional. This was accompanied with increased expression of steroidogenic enzymes involved in progesterone synthesis. Despite these effects, no embryo implantation was observed because of high expression of 20α-hydroxysteroid dehydrogenase. To better appreciate the molecular mechanisms underlying maintenance of the CL, a series of mRNA expression-profiling experiments was performed on isolated corpora lutea of PRLR−/− and hCG-treated PRLR−/− mice. This approach revealed several novel candidate genes with potentially pivotal roles in ovarian function, among them, p27, VE-cadherin, Pten, and sFRP-4, a member of the Wnt/frizzled family. This study showed the differential role of PRL and LH in CL function and identified new targets of these hormones in luteal cells.
Discharge properties of cardiac and renal sympathetic nerves and their impaired responses to changes in blood volume in heart failure
Authors: Ramchandra R. , Hood S. G. , Frithiof R. , May C. N.
Published: June 2009

Sympathetic nerve activity (SNA) consists of discharges that vary in amplitude and frequency, reflecting the level of recruitment of nerve fibers and the rhythmic generation and entrainment of activity by the central nervous system. It is unknown whether selective changes in these amplitude and frequency components account for organ-specific changes in SNA in response to alterations in blood volume or for the impaired SNA responses to volume changes in heart failure (HF). To address these questions, we measured cardiac SNA (CSNA) and renal SNA (RSNA) simultaneously in conscious, normal sheep and sheep in HF induced by rapid ventricular pacing. Volume expansion decreased CSNA (−62 ± 10%, P < 0.05) and RSNA (−59 ± 10%, P < 0.05) equally ( n = 6). CSNA decreased as a result of a reduction in burst frequency, whereas RSNA fell because of falls in burst frequency and amplitude. Hemorrhage increased CSNA (+74 ± 9%, P < 0.05) more than RSNA (+21 ± 5%, P < 0.09), in both cases because of increased burst frequency, whereas burst amplitude decreased. In HF, burst frequency of CSNA (from 26 ± 3 to 75 ± 3 bursts/min) increased more than that of RSNA (from 63 ± 4 to 79 ± 4 bursts/min). In HF, volume expansion caused no change in CSNA and an attenuated decrease in RSNA, due entirely to decreased burst amplitude. Hemorrhage did not significantly increase SNA in either nerve in HF. These findings support the concept that the number of sympathetic fibers recruited and their firing frequency are controlled independently. Furthermore, afferent stimuli, such as changes in blood volume, cause organ-specific responses in each of these components, which are also selectively altered in HF.
Long-term therapeutic effect of vitamin D analog doxercalciferol on diabetic nephropathy: strong synergism with AT1 receptor antagonist
Authors: Zhang Yan , Deb Dilip K. , Kong Juan , Ning Gang , Wang Yurong , Li George , Chen Yunzi , Zhang Zhongyi , Strugnell Stephen , Sabbagh Yves , Arbeeny Cynthia , Li Yan Chun
Published: June 2009

The intrarenal renin-angiotensin system (RAS) plays a key role in the development of diabetic nephropathy. Recently, we showed that combination therapy with an AT1 receptor blocker (ARB) and an activated vitamin D analog produced excellent synergistic effects against diabetic nephropathy, as a result of blockade of the ARB-induced compensatory renin increase. Given the diversity of vitamin D analogs, here we used a pro-drug vitamin D analog, doxercalciferol (1α-hydroxyvitamin D2), to further test the efficacy of the combination strategy in long-term treatment. Streptozotocin-induced diabetic DBA/2J mice were treated with vehicle, losartan, doxercalciferol (0.4 and 0.6 μg/kg), or losartan and doxercalciferol combinations for 20 wk. Vehicle-treated diabetic mice developed progressive albuminuria and glomerulosclerosis. Losartan alone moderately ameliorated kidney injury, with renin being drastically upregulated. A similar therapeutic effect was seen with doxercalciferol alone, which markedly suppressed renin and angiotensinogen expression. The losartan and doxercalciferol combination most effectively prevented albuminuria, restored glomerular filtration barrier structure, and dramatically reduced glomerulosclerosis in a dose-dependent manner. These effects were accompanied by blockade of intrarenal renin upregulation and ANG II accumulation. These data demonstrate an excellent therapeutic potential for doxercalciferol in diabetic renal disease and confirm the concept that blockade of the compensatory renin increase enhances the efficacy of RAS inhibition and produces synergistic therapeutic effects in combination therapy.
Single-Unit Stability Using Chronically Implanted Multielectrode Arrays
Authors: Dickey Adam S. , Suminski Aaron , Amit Yali , Hatsopoulos Nicholas G.
Published: June 2009

The use of chronic intracortical multielectrode arrays has become increasingly prevalent in neurophysiological experiments. However, it is not obvious whether neuronal signals obtained over multiple recording sessions come from the same or different neurons. Here, we develop a criterion to assess single-unit stability by measuring the similarity of 1) average spike waveforms and 2) interspike interval histograms (ISIHs). Neuronal activity was recorded from four Utah arrays implanted in primary motor and premotor cortices in three rhesus macaque monkeys during 10 recording sessions over a 15- to 17-day period. A unit was defined as stable through a given day if the stability criterion was satisfied on all recordings leading up to that day. We found that 57% of the original units were stable through 7 days, 43% were stable through 10 days, and 39% were stable through 15 days. Moreover, stable units were more likely to remain stable in subsequent recording sessions (i.e., 89% of the neurons that were stable through four sessions remained stable on the fifth). Using both waveform and ISIH data instead of just waveforms improved performance by reducing the number of false positives. We also demonstrate that this method can be used to track neurons across days, even during adaptation to a visuomotor rotation. Identifying a stable subset of neurons should allow the study of long-term learning effects across days and has practical implications for pooling of behavioral data across days and for increasing the effectiveness of brain–machine interfaces.
Differential Response Patterns in the SI Barrel and Septal Compartments During Mechanical Whisker Stimulation
Authors: Chakrabarti Shubhodeep , Alloway Kevin D.
Published: June 2009

A growing body of evidence suggests that the barrel and septal regions in layer IV of rat primary somatosensory (SI) cortex may represent separate processing channels. To assess this view, pairs of barrel and septal neurons were recorded simultaneously in the anesthetized rat while a 4 × 4 array of 16 whiskers was mechanically stimulated at 4, 8, 12, and 16 Hz. Compared with barrel neurons, regular-spiking septal neurons displayed greater increases in response latencies as the frequency of whisker stimulation increased. Cross-correlation analysis indicated that the incidence and strength of neuronal coordination varied with the relative spatial configuration (within vs. across rows) and compartmental location (barrel vs. septa) of the recorded neurons. Barrel and septal neurons were strongly coordinated if both neurons were in close proximity and resided in the same row. Some barrel neurons were weakly coordinated, but only if they resided in the same row. By contrast, the strength of coordination among pairs of septal neurons did not vary with their spatial proximity or their spatial configuration within the arcs and rows of the barrel field. These differential responses provide further support for the view that the barrel and septal regions represent the cortical gateway for processing streams that encode specific aspects of the sensorimotor information associated with whisking behavior.
Lasp1gene disruption is linked to enhanced cell migration and tumor formation
Authors: Zhang Han , Chen Xunsheng , Bollag Wendy B. , Bollag Roni J. , Sheehan Daniel J. , Chew Catherine S.
Published: June 2009

Lasp1 is an actin-binding, signaling pathway-regulated phosphoprotein that is overexpressed in several cancers. siRNA knockdown in cell lines retards cell migration, suggesting the possibility that Lasp1 upregulation influences cancer metastasis. Herein, we utilized a recently developed gene knockout model to assess the role of Lasp1 in modulating nontransformed cell functions. Wound healing and tumor initiation progressed more rapidly in Lasp1−/−mice compared with Lasp1+/+controls. Embryonic fibroblasts (MEFs) derived from Lasp1−/−mice also migrated more rapidly in vitro. These MEFs characteristically possessed increased focal adhesion numbers and displayed more rapid attachment compared with wild-type MEFs. Differential microarray analyses revealed alterations in message expression for proteins implicated in cell migration, adhesion, and cytoskeletal organization. Notably, the focal adhesion protein, lipoma preferred partner (LPP), a zyxin family member and putative Lasp1 binding protein, was increased about twofold. Because LPP gene disruption reduces cell migration, we hypothesize that LPP plays a role in enhancing the migratory capacity of Lasp1−/−MEFs, perhaps by modifying the subcellular localization of other motility-associated proteins. The striking contrast in the functional effects of loss of Lasp1 in innate cells compared with cell lines reveals distinct differences in mechanisms of motility and attachment in these models.
Longitudinal system-based analysis of transcriptional responses to type I interferons
Authors: Pappas D. J. , Coppola G. , Gabatto P. A. , Gao F. , Geschwind D. H. , Oksenberg J. R. , Baranzini S. E.
Published: June 2009

Type I interferons (IFNs) are pleiotropic cytokines that modulate both innate and adaptive immune responses. They have been used to treat autoimmune disorders, cancers, and viral infection and have been demonstrated to elicit differential responses within cells, despite sharing a single receptor. The molecular basis for such differential responses has remained elusive. To identify the mechanisms underlying differential type I IFN signaling, we used whole genome microarrays to measure longitudinal transcriptional events within human CD4+T cells treated with IFN-α2bor IFN-β1a. We identified differentially regulated genes, analyzed them for the enrichment of known promoter elements and pathways, and constructed a network module based on weighted gene coexpression network analysis (WGCNA). WGCNA uses advanced statistical measures to find interconnected modules of correlated genes. Overall, differential responses to IFN in CD4+T cells related to three dominant themes: migration, antigen presentation, and the cytotoxic response. For migration, WGCNA identified subtype-specific regulation of pre-mRNA processing factor 4 homolog B and eukaryotic translation initiation factor 4A2, which work at various levels within the cell to affect the expression of the chemokine CCL5. WGCNA also identified sterile α-motif domain-containing 9-like ( SAMD9L) as critical in subtype-independent effects of IFN treatment. RNA interference of SAMD9L expression enhanced the migratory phenotype of activated T cells treated with IFN-β compared with controls. Through the analysis of the dynamic transcriptional events after differential IFN treatment, we were able to identify specific signatures and to uncover novel genes that may underpin the type I IFN response.
Modified Neural Network Algorithms for Predicting Trading Signals of Stock Market Indices
Authors: Tilakaratne C. D. , Mammadov M. A. , Morris S. A.
Published: June 2009

The aim of this paper is to present modified neural network algorithms to predict whether it is best to buy, hold, or sell shares (trading signals) of stock market indices. Most commonly used classification techniques are not successful in predicting trading signals when the distribution of the actual trading signals, among these three classes, is imbalanced. The modified network algorithms are based on the structure of feedforward neural networks and a modified Ordinary Least Squares (OLSs) error function. An adjustment relating to the contribution from the historical data used for training the networks and penalisation of incorrectly classified trading signals were accounted for, when modifying the OLS function. A global optimization algorithm was employed to train these networks. These algorithms were employed to predict the trading signals of the Australian All Ordinary Index. The algorithms with the modified error functions introduced by this study produced better predictions.
The Adsorption Properties of Bacillus atrophaeus Spores on Single‐Wall Carbon Nanotubes
Authors: Cortes P. , Deng S. , Smith G. B.
Published: June 2009

An adsorption equilibrium and a kinetic study of Bacillus atrophaeus on Single‐Wall Carbon Nanotubes (SWCNTs) were here performed to provide the basis for developing biosensor devices for detecting threatening micro‐organisms in water supply systems. B. atrophaeus spores and carbon nanotubes were subjected to a batch adsorption process to document their equilibria and kinetics. Here, commercial nanotubes were either studied as received or were acid‐purified before adsorption experiments. The Bacillus spores appear to show higher affinity towards the purified nanotubes than to the as‐received nanomaterial. The effective diffusivity of the spores onto the purified nanotubes was found to be approximately 30 percent higher than onto the as‐received nanotubes. It seems that the removal of amorphous carbon from the as‐received nanotubes through a purification process yielded an intimate nantoubes‐spore interaction as revealed by transmission electron microscopy. Freundlich model successfully correlated the adsorption equilibrium data for the nanotubes‐spore interaction. Transmission electron micrographs showed extensive contact between the Bacillus and the purified nanotubes, but the association appeared less intimate between the spores and the as‐received nanotubes.
Existence of Positive Solutions to Singular p‐Laplacian General Dirichlet Boundary Value Problems with Sign Changing Nonlinearity
Authors: Wei Qiying , Su You-Hui , Li Subei , Yan Xing-Xue
Published: June 2009

By using the well‐known Schauder fixed point theorem and upper and lower solution method, we present some existence criteria for positive solution of an m‐point singular p‐Laplacian dynamic equation on time scales with the sign changing nonlinearity. These results are new even for the corresponding differential (𝕋 = ℝ) and difference equations (𝕋 = ℤ), as well as in general time scales setting. As an application, an example is given to illustrate the results.
Fuzzy Stability of Jensen‐Type Quadratic Functional Equations
Authors: Jang Sun-Young , Lee Jung Rye , Park Choonkil , Shin Dong Yun
Published: June 2009

We prove the generalized Hyers‐Ulam stability of the following quadratic functional equations 2f((x + y)/2) + 2f((x − y)/2) = f(x) + f(y) and f(ax + ay) + (ax − ay) = 2a2f(x) + 2a2f(y) in fuzzy Banach spaces for a nonzero real number a with a ≠ ±1/2.
High‐Order Compact Implicit Difference Methods For Parabolic Equations in Geodynamo Simulation
Authors: Liu Don , Kuang Weijia , Tangborn Andrew
Published: June 2009

A series of compact implicit schemes of fourth and sixth orders are developed for solving differential equations involved in geodynamics simulations. Three illustrative examples are described to demonstrate that high‐order convergence rates are achieved while good efficiency in terms of fewer grid points is maintained. This study shows that high‐order
compact implicit difference methods provide high flexibility and good convergence in solving some special differential equations on nonuniform grids.
Quartz Crystal Microbalance as a Sensor to Characterize Macromolecular Assembly Dynamics
Authors: Kanazawa K. , Cho Nam-Joon
Published: June 2009

The quartz crystal microbalance sensor has a resonant frequency f and a quality factor Q which can be used to probe the properties of nanometer thick film loads. A recent review by Arnau (2008) has discussed many of the considerations necessary to accurately probe for these properties. To avoid needless duplication but to still provide an adequate background for the new user, we briefly outline the basic measurement methodologies and analytical techniques that were covered in the review. Details will be provided on some specific perspectives of the authors. For example, the special precautions necessary when dealing with soft films (polymeric and biological) under liquid are overviewed. To illustrate applications of the QCM technique, simple bilayer and vesicle behaviors are discussed, along with the structural transformation resulting from protein adsorption onto an intact vesicle adlayer. The amphipathic α‐helical (AH) peptide interaction is given as a particular example. Lastly, we summarize a top‐down approach to functionalize a surface with a cell membrane and to study its interaction with proteins.
Real Time Animation of Trees Based on BBSC in Computer Games
Authors: Ao Xuefeng , Wu Zhongke , Zhou Mingquan
Published: June 2009

That researchers in
the field of computer games usually find it is
difficult to simulate the motion of actual 3D
model trees lies in the fact that the tree model
itself has very complicated structure, and many
sophisticated factors need to be considered
during the simulation. Though there are some
works on simulating 3D tree and its motion, few
of them are used in computer games due to the
high demand for real‐time in computer games. In
this paper, an approach of animating trees in
computer games based on a novel tree model
representation—Ball B‐Spline Curves
(BBSCs) are proposed. By taking advantage of the
good features of the BBSC‐based model, physical
simulation of the motion of leafless trees with
wind blowing becomes easier and more efficient.
The method can generate realistic 3D tree
animation in real‐time, which meets the high
requirement for real time in computer
games.
Smad2 and Smad3 Phosphorylated at Both Linker and COOH-Terminal Regions Transmit Malignant TGF-β Signal in Later Stages of Human Colorectal Cancer
Authors: Matsuzaki Koichi , Kitano Chiaki , Murata Miki , Sekimoto Go , Yoshida Katsunori , Uemura Yoshiko , Seki Toshihito , Taketani Shigeru , Fujisawa Jun-ichi , Okazaki Kazuichi
Published: June 2009

Transforming growth factor (TGF)-β initially inhibits growth of mature epithelial cells. Later, however, autocrine TGF-β signaling acts in concert with the Ras pathway to induce a proliferative and invasive phenotype. TGF-β activates not only TGF-β type I receptor (TβRI) but also Ras-associated kinases, which differentially phosphorylate the mediators Smad2 and Smad3 to create distinct phosphorylated forms: COOH-terminally phosphorylated Smad2/3 (pSmad2C and pSmad3C) and both linker and COOH-terminally phosphorylated Smad2/3 (pSmad2L/C and pSmad3L/C). In this study, we investigated actions of pSmad2L/C and pSmad3L/C in cancer progression. TGF-β inhibited cell growth by down-regulating c-Myc oncoprotein through the pSmad2C and pSmad3C pathway; TGF-β signaling, in turn, enhanced cell growth by up-regulating c-Myc through the cyclin-dependent kinase (CDK) 4–dependent pSmad2L/C and pSmad3L/C pathways in cell nuclei. Alternatively, TβRI and c-Jun NH2-terminal kinase (JNK) together created cytoplasmic pSmad2L/C, which entered the nucleus and stimulated cell invasion, partly by up-regulating matrix metalloproteinase-9. In 20 clinical samples, pSmad2L/C and pSmad3L/C showed nuclear localization at invasion fronts of all TGF-β–producing human metastatic colorectal cancers. In vitro kinase assay confirmed that nuclear CDK4 and cytoplasmic JNK obtained from the tumor tissue could phosphorylate Smad2 or Smad3 at their linker regions. We suggest that CDK4, together with JNK, alters tumor-suppressive TGF-β signaling to malignant characteristics in later stages of human colorectal cancer. The linker phosphorylation of Smad2 and Smad3 may represent a target for intervention in human metastatic cancer. [Cancer Res 2009;69(13):5321–30]
Ferritin Heavy Chain–Mediated Iron Homeostasis and Subsequent Increased Reactive Oxygen Species Production Are Essential for Epithelial-Mesenchymal Transition
Authors: Zhang Ke-Hua , Tian Hong-Yu , Gao Xia , Lei Wei-Wei , Hu Ying , Wang Dong-Mei , Pan Xin-Chao , Yu Mei-Lan , Xu Gen-Jun , Zhao Fu-Kun , Song Jian-Guo
Published: June 2009

The epithelial-mesenchymal transition (EMT) plays a critical role in tumor progression. To obtain a broad view of the molecules involved in EMT, we carried out a comparative proteomic analysis of transforming growth factor-β1 (TGF-β1)–induced EMT in AML-12 murine hepatocytes. A total of 36 proteins with significant alterations in abundance were identified. Among these proteins, ferritin heavy chain (FHC), a cellular iron storage protein, was characterized as a novel modulator in TGF-β1–induced EMT. In response to TGF-β1, there was a dramatic decrease in the FHC levels, which caused iron release from FHC and, therefore, increased the intracellular labile iron pool (LIP). Abolishing the increase in LIP blocked TGF-β1–induced EMT. In addition, increased LIP levels promoted the production of reactive oxygen species (ROS), which in turn activated p38 mitogen-activated protein kinase. The elimination of ROS inhibited EMT, whereas H2O2 treatment rescued TGF-β1–induced EMT in cells in which the LIP increase was abrogated. Overexpression of exogenous FHC attenuated the increases in LIP and ROS production, leading to a suppression of EMT. We also showed that TGF-β1–mediated down-regulation of FHC occurs via 3′ untranslated region–dependent repression of the translation of FHC mRNA. Moreover, we found that FHC down-regulation is an event that occurs between the early and highly invasive advanced stages in esophageal adenocarcinoma and that depletion of LIP or ROS suppresses the migration of tumor cells. Our data show that cellular iron homeostasis regulated by FHC plays a critical role in TGF-β1–induced EMT. [Cancer Res 2009;69(13):5340–8]
[6]-Gingerol Suppresses Colon Cancer Growth by Targeting Leukotriene A4 Hydrolase
Authors: Jeong Chul-Ho , Bode Ann M. , Pugliese Angelo , Cho Yong-Yeon , Kim Hong-Gyum , Shim Jung-Hyun , Jeon Young-Jin , Li Honglin , Jiang Hualiang , Dong Zigang
Published: June 2009

[6]-Gingerol, a natural component of ginger, exhibits anti-inflammatory and antitumorigenic activities. Despite its potential efficacy in cancer, the mechanism by which [6]-gingerol exerts its chemopreventive effects remains elusive. The leukotriene A4 hydrolase (LTA4H) protein is regarded as a relevant target for cancer therapy. Our in silico prediction using a reverse-docking approach revealed that LTA4H might be a potential target of [6]-gingerol. We supported our prediction by showing that [6]-gingerol suppresses anchorage-independent cancer cell growth by inhibiting LTA4H activity in HCT116 colorectal cancer cells. We showed that [6]-gingerol effectively suppressed tumor growth in vivo in nude mice, an effect that was mediated by inhibition of LTA4H activity. Collectively, these findings indicate a crucial role of LTA4H in cancer and also support the anticancer efficacy of [6]-gingerol targeting of LTA4H for the prevention of colorectal cancer. [Cancer Res 2009;69(13):5584–91]
Vaccination with Recombinant NY-ESO-1 Protein Elicits Immunodominant HLA-DR52b-restricted CD4+ T Cell Responses with a Conserved T Cell Receptor Repertoire
Authors: Bioley Gilles , Dousset Christelle , Yeh Alice , Dupont Bo , Bhardwaj Nina , Mears Gregory , Old Lloyd J. , Ayyoub Maha , Valmori Danila
Published: June 2009

Purpose: ESO is a tumor-specific antigen with wide expression in human tumors of different histologic types and remarkable spontaneous immunogenicity. We have previously shown that specific TH1 and antibody responses can be elicited in patients with no detectable preexisting immune responses by vaccination with rESO administered with Montanide ISA-51 and CpG ODN 7909. The purpose of the present study was to characterize vaccine-induced ESO-specific CD4+ T cell responses.

Experimental Design: We generated CD4+ T cell clones from patient C2, who had the highest CD4+ T cell response to the vaccine, and analyzed their fine specificity and HLA class II restriction to determine the recognized epitope. We then assessed the response to the identified epitope in all vaccinated patients expressing the corresponding HLA class II allele.

Results: We found that ESO-specific CD4+ T cell clones from patient C2 recognize peptide ESO119-143 (core region 123-137) presented by HLA-DR52b (HLA-DRB3*0202), a MHC class II allele expressed by about half of Caucasians. Importantly, following vaccination, all patients expressing DR52b developed significant responses to the identified epitope, accounting for, on average, half of the total CD4+ T cell responses to the 119-143 immunodominant region. In addition, analysis of ESO-specific DR52b-restricted CD4+ T cells at the clonal level revealed significant conservation of T cell receptor usage among different individuals.

Conclusions: The identification of a DR52b-restricted epitope from ESO that is immunodominant in the context of vaccine-elicited immune responses is instrumental for the immunologic monitoring of vaccination trials targeting this important tumor antigen.
Narciclasine, a plant growth modulator, activates Rho and stress fibers in glioblastoma cells
Authors: Lefranc Florence , Sauvage Sébastien , Van Goietsenoven Gwendoline , Mégalizzi Véronique , Lamoral-Theys Delphine , Debeir Olivier , Spiegl-Kreinecker Sabine , Berger Walter , Mathieu Véronique , Decaestecker Christine , Kiss Robert
Published: June 2009

Cell motility and resistance to apoptosis characterize glioblastoma multiforme growth and malignancy. Narciclasine, a plant growth modulator, could represent a powerful new weapon targeting the Achilles' heel of glioblastoma multiforme and may offer the potential to better combat these devastating malignancies. The in vitro effects of narciclasine on cell proliferation, morphology, actin cytoskeleton organization, and the Rho/Rho kinase/LIM kinase/cofilin pathway and its antitumor activity in vivo have been determined in models of human glioblastoma multiforme. Narciclasine impairs glioblastoma multiforme growth by markedly decreasing mitotic rates without inducing apoptosis. The compound also modulates the Rho/Rho kinase/LIM kinase/cofilin signaling pathway, greatly increasing GTPase RhoA activity as well as inducing actin stress fiber formation in a RhoA-dependent manner. Lastly, the treatment of human glioblastoma multiforme orthotopic xenograft- bearing mice with nontoxic doses of narciclasine significantly increased their survival. Narciclasine antitumor effects were of the same magnitude as those of temozolomide, the drug associated with the highest therapeutic benefits in treating glioblastoma multiforme patients. Our results show for the first time that narciclasine, a plant growth modulator, activates Rho and stress fibers in glioblastoma multiforme cells and significantly increases the survival of human glioblastoma multiforme preclinical models. This statement is made despite the recognition that to date, irrespective of treatment, no single glioblastoma multiforme patient has been cured. [Mol Cancer Ther 2009;8(7):1739–50]
Ligand, receptor, and cell type–dependent regulation ofABCA1andABCG1mRNA in prostate cancer epithelial cells
Authors: Trasino Steven E. , Kim Young S. , Wang Thomas T.Y.
Published: June 2009

Recent evidence suggests that the liver X receptor (LXR) is a potential anticancer target in prostate carcinoma. There is little characterization, however, of which of the two LXR isoforms, LXRα or LXRβ, regulates the LXR-responsive genes ATP-binding cassette subfamily members A1 (ABCA1) and G1 (ABCG1) in transformed prostatic epithelial cells. In this study, small interfering RNA (siRNA) was used to determine whether LXRα or LXRβ is involved in regulating ABCA1 and ABCG1 mRNA expression in LNCaP and PC-3 cells. Treatment of both cell lines with the synthetic LXR ligand T0901317 and oxysterols: 25-hydroxycholesterol (25HC) and 24(S), 25-epoxycholesterol (24,25EC), resulted in more than a 10-fold increase of ABCA1 and ABCG1 mRNA expression. Transfection of LNCaP cells with siRNA against either LXRβ or LXRα failed to inhibit T0901317 and 25HC-mediated increase of ABCA1 mRNA. siRNA silencing of LXRβ did, however, inhibit ABCA1 mRNA expression in 24,25EC-treated LNCaP cells. In contrast, LXRβ siRNA inhibited T0901317, 25HC, and 24,25EC induction of ABCA1 mRNA in PC-3 cells and ABCG1 mRNA in both LNCaP and PC-3 cells. Additional experiments revealed that T0901317 and 25HC induction of ABCA1 mRNA expression was significantly inhibited by the p38 stress kinase antagonist SB202190 and PKA inhibitor H89. Our study is the first to show that LXRβ, but not LXRα, is the major regulatory isoform of ABCG1 mRNA expression in LNCaP and PC-3 cells. Our study also reveals that ABCA1 gene expression is differentially regulated by synthetic and natural LXR ligands, possibly involving kinase mediated signal transduction. [Mol Cancer Ther 2009;8(7):1934–45]
Identification of a Novel DNA Binding Site and a Transcriptional Target for Activating Transcription Factor 5 in C6 Glioma and MCF-7 Breast Cancer Cells
Authors: Li Guangfu , Li Wenhong , Angelastro James M. , Greene Lloyd A. , Liu David X.
Published: June 2009

Recent reports indicate that the activating transcription factor 5 (ATF5) is required for the survival of cancer cells but not for noncancer cells. However, the mechanisms by which ATF5 regulates genes and promotes cell survival are not clear. Using a cyclic amplification and selection of targets (CASTing) approach, we identified a novel ATF5 consensus DNA binding sequence. We show in C6 glioma and MCF-7 breast cancer cells that ATF5 occupies this sequence and that ATF5 activates reporter gene expression driven by this site. Conversely, reporter activity is diminished when ATF5 activity is blocked or when ATF5 expression is down-regulated by serum withdrawal. We further show that early growth response factor 1 (Egr-1), whose promoter contains two adjacent ATF5 consensus binding sites at a conserved promoter position in rat, mouse, and human, is targeted and regulated by ATF5 in C6 and MCF-7 cells. These data provide new insight on the mechanisms by which ATF5 promotes gene regulation and cancer-specific cell survival. (Mol Cancer Res 2009;7(6):933–43)
Down-Regulation of 3-Phosphoinositide–Dependent Protein Kinase-1 Levels Inhibits Migration and Experimental Metastasis of Human Breast Cancer Cells
Authors: Liu Ying , Wang Jingna , Wu Min , Wan Wuzhou , Sun Ronghua , Yang De , Sun Xiangjun , Ma Dalong , Ying Guoguang , Zhang Ning
Published: June 2009

High expression of 3-phosphoinositide–dependent protein kinase-1 (PDK1) has been detected in various invasive cancers. In the current study, we investigated its role in cancer cell migration and experimental metastasis. Down-regulation of PDK1 expression by small interference RNA markedly inhibited spontaneous migration and epidermal growth factor (EGF)–induced chemotaxis of human breast cancer cells. The defects were rescued by expressing wild-type PDK1. PDK1-depleted cells showed impaired EGF-induced actin polymerization and adhesion, probably due to a decrease in phosphorylation of LIM kinase/cofilin and integrin β1. Confocal microscopy revealed that EGF induced cotranslocation of PDK1 with Akt and protein kinase Cζ (PKCζ), regulators of LIM kinase, and integrin β1. Furthermore, PDK1 depletion dampened EGF-induced phosphorylation and translocation of Akt and PKCζ, suggesting that Akt and PKCζ functioned downstream of PDK1 in the chemotactic signaling pathway. In severe combined immunodeficiency mice, PDK1-depleted human breast cancer cells formed more slowly growing tumors and were defective in extravasation to mouse lungs after i.v. injection. Our results indicate that PDK1 plays an important role in regulating the malignant behavior of breast cancer cells, including their motility, through activation of Akt and PKCζ. Thus, PDK1, which increases its expression in cancer cells, can be used as a target for the development of novel therapies. (Mol Cancer Res 2009;7(6):944–54)
Calcineurin A–Binding Protein, a Novel Modulator of the Calcineurin-Nuclear Factor of Activated T-Cell Signaling Pathway, Is Overexpressed in Wilms' Tumors and Promotes Cell Migration
Authors: Nguyen Alana H.T. , Béland Mélanie , Gaitan Yaned , Bouchard Maxime
Published: June 2009

Current therapeutic strategies against Wilms' tumor (WT) reach 80% to 85% success rate. In spite of this, a remaining 15% to 20% of tumors relapse and are associated with increased metastasis and poor prognosis. To identify new regulators of WT progression, we screened for developmental target genes of Pax2, a key regulator of kidney development and a WT signature gene. We show that one of these target genes, calcineurin A–binding protein (CnABP), is coexpressed with Pax2 during kidney development and is overexpressed in >70% of WT samples analyzed. The CnABP gene encodes a novel protein product conserved in higher vertebrates. We show that CnABP promotes cell proliferation and migration in cell culture experiments. Biochemical analyses additionally identified an interaction between CnABP and calcineurin Aβ, the catalytic subunit of the calcium-responsive serine/threonine phosphatase calcineurin. We show that this interaction leads to the inhibition of calcineurin phosphatase activity and prevents nuclear factor of activated T-cell (NFAT) nuclear translocation. Inhibition of NFAT nuclear localization results in decreased NFAT transcriptional response. Together, these data identify a new modulator of calcineurin signaling up-regulated in WTs. (Mol Cancer Res 2009;7(6):821–31)
Effects of Raf Kinase Inhibitor Protein Expression on Metastasis and Progression of Human Breast Cancer
Authors: Li Hong Zhao , Gao Yan , Zhao Xiu Lan , Liu Yi Xin , Sun Bao Cun , Yang Jie , Yao Zhi
Published: June 2009

Raf kinase inhibitor protein (RKIP) has been shown to be a metastasis suppressor in many kinds of malignant tumors. But its function in breast cancer was not yet clarified completely. We detected RKIP expression in clinical samples of primary breast cancer, breast cancer metastases, and in different breast cancer cells. Compared with the normal breast epithelia, benign breast epithelia, or in situ ductal carcinoma, the expression level of RKIP is decreased in invasive carcinoma and significantly reduced or lost in the metastasis lymph node matched to the invasive carcinoma. To explore the potential role of RKIP in breast cancer metastasis, we studied the effect of RKIP on the malignant phenotypes of the breast cancer cells with ectopically overexpression or knockdown of RKIP. Cell proliferation, soft-agar colony formation, in vitro adhesion assay, invasion, and migation assays were done to examine the malignant phenotypes of the transfected cells. Consequently, RKIP has no effect on in vitro proliferation rate or colony-forming ability of MDA-MB-435 cells. In vitro cell invasion and migration assays indicated that the RKIP expression was inversely associated with the invasiveness of MDA-MB-435 cells. Consistent with these results, in the orthotopic murine models, we observed that overexpression of RKIP in breast cancer cells impaired invasiveness and metastasis, whereas down-regulation of RKIP expression promoted invasiveness and metastasis. These results indicate that RKIP is a metastasis suppressor gene of human breast cancer. (Mol Cancer Res 2009;7(6):832–40)
Ceramide Regulates Gemcitabine-Induced Senescence and Apoptosis in Human Pancreatic Cancer Cell Lines
Authors: Modrak David E. , Leon Evelyn , Goldenberg David M. , Gold David V.
Published: June 2009

Bioactive sphingolipids are potent intracellular signaling molecules having profound effects on cell death, growth, and differentiation. Pharmacologic manipulation of sphingolipid levels could have a significant effect on the induction of apoptosis by anticancer agents, and thus, improve treatment efficacy. We observed that gemcitabine cannot completely kill AsPc1 and Panc1 human pancreatic cancer cells in culture; even at high concentrations of gemcitabine, 30% to 40% of the cells remain viable. By adding sphingomyelin to the culture medium, gemcitabine-induced cell death increased synergistically to >90%. Panc1 cells that survived high concentrations of gemcitabine had an increase in β-galactosidase activity, a marker of senescence. The inclusion of sphingomyelin with gemcitabine reduced β-galactosidase activity, as compared with cells treated with gemcitabine alone. Expression of p21waf1/cip1 in both cell lines exposed to sphingomyelin, gemcitabine, and gemcitabine + sphingomyelin varied relative to the untreated group. C8-ceramide induced both cell death and senescence in a dose-dependent manner. These results indicate that gemcitabine induces senescence in pancreatic cancer cells and that sphingomyelin-enhanced chemosensitivity is achieved through reducing the induction of senescence by redirecting the cell to enter the apoptotic pathway. Ceramide levels seem to be critical to this decision, with cell cycle progression being uninhibited at low ceramide levels, senescence induced at moderate levels, and apoptosis initiated at high levels. Our results provide further evidence that targeting the sphingolipid metabolism is a means of enhancing the efficacy of chemotherapeutic agents. (Mol Cancer Res 2009;7(6):890–6)
Zebrafish Hagoromo Mutants Up-Regulate fgf8 Postembryonically and Develop Neuroblastoma
Authors: Amsterdam Adam , Lai Kevin , Komisarczuk Anna Z. , Becker Thomas S. , Bronson Roderick T. , Hopkins Nancy , Lees Jacqueline A.
Published: June 2009

We screened an existing collection of zebrafish insertional mutants for cancer susceptibility by histologic examination of heterozygotes at 2 years of age. As most mutants had no altered cancer predisposition, this provided the first comprehensive description of spontaneous tumor spectrum and frequency in adult zebrafish. Moreover, the screen identified four lines, each carrying a different dominant mutant allele of Hagoromo previously linked to adult pigmentation defects, which develop tumors with high penetrance and that histologically resemble neuroblastoma. These tumors are clearly neural in origin, although they do not express catecholaminergic neuronal markers characteristic of human neuroblastoma. The zebrafish tumors result from inappropriate maintenance of a cell population within the cranial ganglia that are likely neural precursors. These neoplasias typically remain small but they can become highly aggressive, initially traveling along cranial nerves, and ultimately filling the head. The developmental origin of these tumors is highly reminiscent of human neuroblastoma. The four mutant Hagoromo alleles all contain viral insertions in the fbxw4 gene, which encodes an F-box WD40 domain–containing protein. However, although one allele clearly reduced the levels of fbxw4 mRNA, the other three insertions had no detectable effect on fbw4 expression. Instead, we showed that all four mutations result in the postembryonic up-regulation of the neighboring gene, fibroblast growth factor 8 (fgf8). Moreover, fgf8 is highly expressed in the tumorigenic lesions. Although fgf8 overexpression is known to be associated with breast and prostate cancer in mammals, this study provides the first evidence that fgf8 misregulation can lead to neural tumors. (Mol Cancer Res 2009;7(6):841–50)
CD151 Regulates Tumorigenesis by Modulating the Communication between Tumor Cells and Endothelium
Authors: Sadej Rafal , Romanska Hanna , Baldwin Gouri , Gkirtzimanaki Katerina , Novitskaya Vera , Filer Andrew D. , Krcova Zuzana , Kusinska Renata , Ehrmann Jiri , Buckley Christopher D. , Kordek Radzisław , Potemski Piotr , Eliopoulos Aristides G. , Lalani El-Nasir , Berditchevski Fedor
Published: June 2009

The tetraspanin CD151 forms stoichiometric complexes with laminin-binding integrins (e.g., α3β1, α6β1, and α6β4) and regulates their ligand-binding and signaling functions. We have found that high expression of CD151 in breast cancers is associated with decreased overall survival (3.44-fold higher risk of death). Five-year estimated survival rates were 45.8% (95% confidence interval, 16.4-71.4%) for CD151-positive patients and 79.9% (95% confidence interval, 62.2-90.0%) for CD151-negative patients. Furthermore, CD151 was positively associated with axillary lymph node involvement. To study the biological significance of this observation, we investigated the contribution of CD151 in breast cancer tumorigenesis using MDA-MB-231 cells as a model system. Stable down-regulation of this tetraspanin by short-hairpin RNA decreased the tumorigenicity of these cells in mice. Detailed immunohistologic analysis of CD151(+) and CD151(−) xenografts showed differences in tumor vascular pattern. Vascularization observed at the subcutaneous border of the CD151(+) tumors was less pronounced or absent in the CD151(−) xenografts. In vitro experiments have established that depletion of CD151 did not affect the inherent proliferative capacity of breast cancer cells in three-dimensional extracellular matrices, but modified their responses to endothelial cells in coculture experiments. The modulatory activity of CD151 was dependent on its association with both α3β1 and α6β4 integrins. These data point to a new role of CD151 in tumorigenesis, whereby it functions as an important regulator of communication between tumor cells and endothelial cells. These results also identify CD151 as a potentially novel prognostic marker and target for therapy in breast cancer. (Mol Cancer Res 2009;7(6):787–98)
Thiacremonone Augments Chemotherapeutic Agent–Induced Growth Inhibition in Human Colon Cancer Cells through Inactivation of Nuclear Factor-κB
Authors: Ban Jung Ok , Lee Hee Soon , Jeong Heon-Sang , Song Sugkil , Hwang Bang Yeon , Moon Dong Cheul , Yoon Do Young , Han Sang Bae , Hong Jin Tae
Published: June 2009

Chemotherapeutic strategies commonly use multiple agents to overcome drug resistance and to lower drug toxicity. Activation of nuclear factor-κB (NF-κB) is implicated in drug resistance in cancer cells. Previously, we reported that thiacremonone, a novel sulfur compound isolated from garlic, inhibited NF-κB and cancer cell growth with IC50 values about 100 μg/mL in colon cancer cells. In the present study, we tested whether thiacremonone could increase susceptibility of cancer cells to chemotherapeutics through inactivation of NF-κB. Colon cancer cells were cotreated with thiacremonone (50 μg/mL, half dose of IC50) and lower doses of each chemotherapeutic agent (half dose of IC50) for 24 hours. NF-κB activity was completely abrogated in cells treated with a combination of thiacremonone and docetaxel, whereas thiacremonone on its own did not alter NF-κB activity. This combined drug effect was also found with other anticancer drugs in colon cancer and in other cancer cells. In good correlation with inhibition of cell growth and NF-κB activity, the combination treatment also regulated NF-κB target genes. Oral treatment of mice with thiacremonone (1 mg/kg) by administering it in drinking water for 4 weeks significantly augmented docetaxel (1 mg/kg, i.p., four times)–induced decrease of tumor growth accompanied with regulation of NF-κB activity and NF-κB target genes. These results warrant carefully designed clinical studies investigating the combination of thiacremonone and commonly used chemotherapeutic agents for the treatment of human cancers. (Mol Cancer Res 2009;7(6):870–9)
Social- and Behavioral-Specific Genetic Effects on Blood Pressure Traits
Authors: Franceschini Nora , Rose Kathryn M. , Storti Kristi L. , Rutherford Sue , Voruganti V. Saroja , Laston Sandy , Göring Harald H.H. , Dyer Thomas D. , Umans Jason G. , Lee Elisa T. , Best Lyle G. , Fabsitz Richard R. , Cole Shelley A. , MacCluer Jean W. , North Kari E.
Published: June 2009

Background—

Population studies have demonstrated an important role of social, behavioral, and environmental factors in blood pressure (BP) levels. Accounting for the genetic interaction of these factors may help to identify common BP susceptibility alleles.

Methods and Results—

We studied the interaction of additive genetic effects and behavioral (physical activity, smoking, alcohol use) and socioeconomic (education) factors on BP in ≈3600 American Indian participants of the Strong Heart Family Study, using variance component models. The mean and SD of resting systolic and diastolic BPs were 123�17 and 76�11 mm Hg, respectively. We detected evidence for distinct genetic effects on diastolic BP among ever smokers compared with never smokers (
P
=0.01). For alcohol intake, we observed significant genotype-by-environment interactions on diastolic (ρg=0.10,
P
=0.0003) and on systolic BPs (ρg=0.59,
P
=0.0008) among current drinkers compared with former or never drinkers. We also detected genotype-by-physical activity interactions on diastolic BP (ρg=0.35,
P
=0.0004). Finally, there was evidence for distinct genetic effects on diastolic BP among individuals with less than high school education compared with those with 12 or more years of education (ρg=0.41,
P
=0.02).

Conclusions—

Our findings suggest that behavioral and socioeconomic factors can modify the genetic effects on BP phenotypes. Accounting for context dependent factors may help us to better understand the complexities of the gene effects on BP and other complex phenotypes with high levels of genetic heterogeneity.