bluuebunny/crossref_metadata_2025 huggingface dataset:
The Supercollider: The Pre-Texas Days — A Personal Recollection of Its Birth and Berkeley Years
Authors: Wojcicki Stanley
Published: October 2008

This article describes the beginnings of the Superconducting Super Collider (SSC). The narrative starts in the early 1980s with the discussion of the process that led to the recommendation by the US high energy physics community to initiate work on a multi-TeV hadron collider. The article then describes the formation in 1984 of the Central Design Group (CDG) charged with directing and coordinating the SSC R&D and subsequent activities which led in early 1987 to the SSC endorsement by President Reagan. The last part of the article deals with the site selection process, steps leading to the initial Congressional appropriation of the SSC construction funds and the creation of the management structure for the SSC Laboratory.
Attenuation of depression of muscle protein synthesis induced by lipopolysaccharide, tumor necrosis factor, and angiotensin II by β-hydroxy-β-methylbutyrate
Authors: Eley Helen L. , Russell Steven T. , Tisdale Michael J.
Published: October 2008

β-Hydroxy-β-methylbutyrate (HMB; 50 μM) has been shown to attenuate the depression in protein synthesis in murine myotubes in response to lipopolysaccharide (LPS), tumor necrosis factor-α (TNF-α) with or without interferon-γ (IFN-γ), and angiotensin II (ANG II). The mechanism for the depression of protein synthesis by all three agents was the same and was attributed to activation of double-stranded RNA-dependent protein kinase (PKR) with the subsequent phosphorylation of eukaryotic initiation factor 2 (eIF2) on the α-subunit as well as increased phosphorylation of the elongation factor (eEF2). Myotubes expressing a catalytically inactive PKR variant, PKRΔ6, showed no depression of protein synthesis in response to either LPS or TNF-α, confirming the importance of PKR in this process. There was no effect of any of the agents on phosphorylation of mammalian target of rapamycin (mTOR) or initiation factor 4E-binding protein (4E-BP1), and thus no change in the amount of eIF4E bound to 4E-BP1 or the concentration of the active eIF4E·eIF4G complex. HMB attenuated phosphorylation of eEF2, possibly by increasing phosphorylation of mTOR, and also attenuated phosphorylation of eIF2α by preventing activation of PKR. These results suggest that HMB may be effective in attenuating muscle atrophy in a range of catabolic conditions.
25-Hydroxycholesterol-3-sulfate regulates macrophage lipid metabolism via the LXR/SREBP-1 signaling pathway
Authors: Ma Yongjie , Xu Leyuan , Rodriguez-Agudo Daniel , Li Xiaobo , Heuman Douglas M. , Hylemon Phillip B. , Pandak William M. , Ren Shunlin
Published: October 2008

The oxysterol receptor LXR is a key transcriptional regulator of lipid metabolism. LXR increases expression of SREBP-1, which in turn regulates at least 32 genes involved in lipid synthesis and transport. We recently identified 25-hydroxycholesterol-3-sulfate (25HC3S) as an important regulatory molecule in the liver. We have now studied the effects of 25HC3S and its precursor, 25-hydroxycholesterol (25HC), on lipid metabolism as mediated by the LXR/SREBP-1 signaling in macrophages. Addition of 25HC3S to human THP-1-derived macrophages markedly decreased nuclear LXR protein levels. 25HC3S administration was followed by dose- and time-dependent decreases in SREBP-1 mature protein and mRNA levels. 25HC3S decreased the expression of SREBP-1-responsive genes, acetyl-CoA carboxylase-1, and fatty acid synthase (FAS) as well as HMGR and LDLR, which are key proteins involved in lipid metabolism. Subsequently, 25HC3S decreased intracellular lipids and increased cell proliferation. In contrast to 25HC3S, 25HC acted as an LXR ligand, increasing ABCA1, ABCG1, SREBP-1, and FAS mRNA levels. In the presence of 25HC3S, 25HC, and LXR agonist T0901317, stimulation of LXR targeting gene expression was repressed. We conclude that 25HC3S acts in macrophages as a cholesterol satiety signal, downregulating cholesterol and fatty acid synthetic pathways via inhibition of LXR/SREBP signaling. A possible role of oxysterol sulfation is proposed.
Mice lacking the PACAP type I receptor have impaired photic entrainment and negative masking
Authors: Hannibal Jens , Brabet Philippe , Fahrenkrug Jan
Published: October 2008

The retinohypothalamic tract (RHT) is a retinofugal neuronal pathway which, in mammals, mediates nonimage-forming vision to various areas in the brain involved in circadian timing, masking behavior, and regulation of the pupillary light reflex. The RHT costores the two neurotransmitters glutamate and pituitary adenylate cyclase activating peptide (PACAP), which in a rather complex interplay are mediators of photic adjustment of the circadian system. To further characterize the role of PACAP/PACAP receptor type 1 (PAC1) receptor signaling in light entrainment of the clock and in negative masking behavior, we extended previous studies in mice lacking the PAC1 receptor (PAC1 KO) by examining their phase response to single light pulses using Aschoff type II regime, their ability to entrain to non-24-h light-dark (LD) cycles and large phase shifts of the LD cycle (jet lag), as well as their negative masking response during different light intensities. A prominent finding in PAC1 KO mice was a significantly decreased phase delay of the endogenous rhythm at early night. In accordance, PAC1 KO mice had a reduced ability to entrain to T cycles longer than 26 h and needed more time to reentrain to large phase delays, which was prominent at low light intensities. The data obtained at late night indicated that PACAP/PAC1 receptor signaling is less important during the phase-advancing part of the phase-response curve. Finally, the PAC1 KO mice showed impaired negative masking behavior at low light intensities. Our findings substantiate a role for PACAP/PAC1 receptor signaling in nonimage-forming vision and indicate that the system is particularly important at lower light intensities.
Alcohol Impairs Long-Term Depression at the Cerebellar Parallel Fiber–Purkinje Cell Synapse
Authors: Belmeguenai Amor , Botta Paolo , Weber John T. , Carta Mario , De Ruiter Martijn , De Zeeuw Chris I. , Valenzuela C. Fernando , Hansel Christian
Published: October 2008

Acute alcohol consumption causes deficits in motor coordination and gait, suggesting an involvement of cerebellar circuits, which play a role in the fine adjustment of movements and in motor learning. It has previously been shown that ethanol modulates inhibitory transmission in the cerebellum and affects synaptic transmission and plasticity at excitatory climbing fiber (CF) to Purkinje cell synapses. However, it has not been examined thus far how acute ethanol application affects long-term depression (LTD) and long-term potentiation (LTP) at excitatory parallel fiber (PF) to Purkinje cell synapses, which are assumed to mediate forms of cerebellar motor learning. To examine ethanol effects on PF synaptic transmission and plasticity, we performed whole cell patch-clamp recordings from Purkinje cells in rat cerebellar slices. We found that ethanol (50 mM) selectively blocked PF–LTD induction, whereas it did not change the amplitude of excitatory postsynaptic currents at PF synapses. In contrast, ethanol application reduced voltage-gated calcium currents and type 1 metabotropic glutamate receptor (mGluR1)–dependent responses in Purkinje cells, both of which are involved in PF–LTD induction. The selectivity of these effects is emphasized by the observation that ethanol did not impair PF–LTP and that PF–LTP could readily be induced in the presence of the group I mGluR antagonist AIDA or the mGluR1a antagonist LY367385. Taken together, these findings identify calcium currents and mGluR1-dependent signaling pathways as potential ethanol targets and suggest that an ethanol-induced blockade of PF–LTD could contribute to the motor coordination deficits resulting from alcohol consumption.
Relationship Between Color Discrimination and Neural Responses in the Inferior Temporal Cortex of the Monkey
Authors: Matsumora Takehiro , Koida Kowa , Komatsu Hidehiko
Published: October 2008

Earlier studies suggest that the inferior temporal (IT) cortex of the monkey plays a key role in color discrimination. Here, we examined the quantitative relationship between color judgment in monkeys and the responses of color-selective neurons in the anterior part of the IT cortex (area TE) by comparing neuronal activity and behavior recorded simultaneously while the monkeys performed a color-judgment task. We first compared the abilities of single neurons and monkeys to discriminate color. To calculate a neuron's ability to discriminate color, we computed a neurometric function using receiver-operating-characteristics analysis. We then compared the neural and behavioral thresholds for color discrimination and found that, in general, the neural threshold was higher than the behavioral threshold, although occasionally the reverse was true. Variation in the neural threshold across the color space corresponded well with that of the behavioral threshold. We then calculated the choice probability (CP), which is a measure of the correlation between the trial-to-trial fluctuations in neuronal responses and the monkeys' color judgment. On average, CPs were slightly but significantly greater than 0.5, indicating the activities of these TE neurons correlate positively with the monkeys' color judgment. This suggests that individual color-selective TE neurons only weakly contribute to color discrimination and that a large population of color-selective TE neurons contribute to the performance of color discrimination.
TMS Over the Intraparietal Sulcus Induces Perceptual Fading
Authors: Kanai Ryota , Muggleton Neil G. , Walsh Vincent
Published: October 2008

During prolonged fixation, visual objects presented in the periphery of the visual field often fade from awareness. This phenomenon, known as the Troxler effect, has been largely attributed to adaptation of neurons responding to peripheral targets. Here, we hypothesized that perceptual disappearance might result from degeneration of feedback from attention-related cortical areas to early visual areas and that visual transients disrupt the feedback loop sustaining low-level signals and thereby trigger perceptual fading. We examined this hypothesis by briefly disrupting the functions of attention-related regions in the intraparietal sulcus (IPS) using transcranial magnetic stimulation (TMS). The hypothesis predicted that temporary disruption of IPS would trigger perceptual disappearances. We measured perceptual disappearance using a task in which participants were asked to discriminate the presence or absence (fading) of a peripheral green target immediately after a TMS pulse. On one half of the trials, the target remained on the screen until the end of a trial, and on the other half of the trials, it gradually faded. The results of this experiment show that brief disruption of the IPS with a single pulse TMS is sufficient to trigger perceptual disappearance. TMS over the IPS resulted in a fewer reports of continuous percepts (i.e., more fading) without changes in the perception of physically fading stimuli. Our control experiment shows the loss of sensitivity is not caused by suppression of microsaccades in response to the sound produced by TMS. This study supports the idea that conscious visual perception requires a coupling between the early visual areas representing sensory data and the parietal areas subserving spatial localization functions.
Mechanical strain activates a program of genes functionally involved in paracrine signaling of angiogenesis
Authors: Yang Ru , Amir Jawaria , Liu Haibo , Chaqour Brahim
Published: October 2008

Studies were performed to examine the extent to which mechanical stimuli mediate control of angiogenesis in bladder cells both in vitro and in vivo. Differential gene expression between control nonstretched and cyclically stretched bladder smooth muscle cells was assessed using oligonucleotide microarrays and pathway analysis by the web tool Fast Assignment and Transference of Information (FatiGO). Data showed that a substantial proportion (33 of 86) of mechanically responsive genes were angiogenesis-related and include cytokines, growth-related factors, adhesion proteins, and matricellular, signal transduction, extracellular matrix (ECM), and inflammatory molecules. Integrative knowledge of protein-protein interactions revealed that 12 mechano-sensitive gene-encoded proteins have interacting partner(s) in the vascular system confirming their potential role in paracrine regulation of angiogenesis. Angiogenic genes include matricellular proteins such as Cyr61/CCN1, CTGF/CCN2 and tenascin C, components of the VEGF and IGF systems, ECM proteins such as type I collagen and proteoglycans, and matrix metalloproteinases. In an in vivo model of bladder overdistension, 5 of 11 mechano-responsive angiogenic genes, independently tested by real-time PCR, were upregulated as a result of pressure overload including Cyr61/CCN1, CTGF/CCN2, MCP-1, VEGF-A, MMP-1, and midkine. Meanwhile, the molecular anatomy of angiogenic gene promoters reveals the presence of GA box-binding for the myc-associated zinc finger protein, MAZ, often found adjacent to binding sites for mechano-responsive transcription factors (e.g., NF-κB), suggesting that the coordinated activity of these factors may induce selective angiogenic gene transcription. These data suggest that mechanical control of angiogenic genes is an integral part of the adaptive and plasticity responses to mechanical overload.
Prostaglandins, NSAIDs, and Gastric Mucosal Protection: Why Doesn't the Stomach Digest Itself?
Authors: Wallace John L.
Published: October 2008

Except in rare cases, the stomach can withstand exposure to highly concentrated hydrochloric acid, refluxed bile salts, alcohol, and foodstuffs with a wide range of temperatures and osmolarity. This is attributed to a number of physiological responses by the mucosal lining to potentially harmful luminal agents, and to an ability to rapidly repair damage when it does occur. Since the discovery in 1971 that prostaglandin synthesis could be blocked by aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), there has been great interest in the contribution of prostaglandins to gastric mucosal defense. Prostaglandins modulate virtually every aspect of mucosal defense, and the importance of this contribution is evident by the increased susceptibility of the stomach to injury following ingestion of an NSAID. With chronic ingestion of these drugs, the development of ulcers in the stomach is a significant clinical concern. Research over the past two decades has helped to identify some of the key events triggered by NSAIDs that contribute to ulcer formation and/or impair ulcer healing. Recent research has also highlighted the fact that the protective functions of prostaglandins in the stomach can be carried out by other mediators, in particular the gaseous mediators nitric oxide and hydrogen sulfide. Better understanding of the mechanisms through which the stomach is able to resist injury in the presence of luminal irritants is helping to drive the development of safer anti-inflammatory drugs, and therapies to accelerate and improve the quality of ulcer healing.
Exercise-Induced Oxidative Stress: Cellular Mechanisms and Impact on Muscle Force Production
Authors: Powers Scott K. , Jackson Malcolm J.
Published: October 2008

The first suggestion that physical exercise results in free radical-mediated damage to tissues appeared in 1978, and the past three decades have resulted in a large growth of knowledge regarding exercise and oxidative stress. Although the sources of oxidant production during exercise continue to be debated, it is now well established that both resting and contracting skeletal muscles produce reactive oxygen species and reactive nitrogen species. Importantly, intense and prolonged exercise can result in oxidative damage to both proteins and lipids in the contracting myocytes. Furthermore, oxidants can modulate a number of cell signaling pathways and regulate the expression of multiple genes in eukaryotic cells. This oxidant-mediated change in gene expression involves changes at transcriptional, mRNA stability, and signal transduction levels. Furthermore, numerous products associated with oxidant-modulated genes have been identified and include antioxidant enzymes, stress proteins, DNA repair proteins, and mitochondrial electron transport proteins. Interestingly, low and physiological levels of reactive oxygen species are required for normal force production in skeletal muscle, but high levels of reactive oxygen species promote contractile dysfunction resulting in muscle weakness and fatigue. Ongoing research continues to probe the mechanisms by which oxidants influence skeletal muscle contractile properties and to explore interventions capable of protecting muscle from oxidant-mediated dysfunction.
CFD Simulation of Polydispersed Bubbly Two‐Phase Flow Around an Obstacle
Authors: Krepper E. , Ruyer P. , Beyer M. , Lucas D. , Prasser H.-M. , Seiler N.
Published: October 2008

This paper concerns the model of a polydispersed bubble population in the frame of an ensemble averaged two‐phase flow formulation.
The ability of the moment density approach to represent bubble population size distribution within a multi‐dimensional CFD code based on the two‐fluid model is studied.
Two different methods describing the polydispersion are presented: (i) a moment density method, developed at IRSN,
to model the bubble size distribution function and (ii) a population balance method considering several different velocity fields of the gaseous phase.
The first method is implemented in the Neptune_CFD code, whereas the second method is implemented in the CFD code ANSYS/CFX.
Both methods consider coalescence and breakup phenomena and momentum interphase transfers related to drag and lift forces. Air‐water bubbly flows in a vertical pipe with obstacle of the TOPFLOW experiments series performed at FZD are then used as simulations test cases. The numerical results, obtained with Neptune_CFD and with ANSYS/CFX, allow attesting the validity of the approaches. Perspectives concerning the improvement of the models, their validation, as well as the extension of their applicability range are discussed.
Modeling of Multisize Bubbly Flow and Application to the Simulation of Boiling Flows with the Neptune_CFD Code
Authors: Morel Christophe , Laviéville Jérôme M.
Published: October 2008

This paper describes the modeling of boiling multisize bubbly flows and its application to the simulation of the DEBORA experiment. We follow the method proposed originally by Kamp, assuming a given mathematical expression for the bubble diameter pdf. The original model is completed by the addition of some new terms for vapor compressibility and phase change. The liquid‐to‐interface heat transfer term, which essentially determines the bubbles condensation rate in the DEBORA experiment, is also modeled with care. First numerical results realized with the Neptune_CFD code are presented and discussed.
Suppression of the Negative Regulator LRIG1 Contributes to ErbB2 Overexpression in Breast Cancer
Authors: Miller Jamie K. , Shattuck David L. , Ingalla Ellen Q. , Yen Lily , Borowsky Alexander D. , Young Lawrence J.T. , Cardiff Robert D. , Carraway Kermit L. , Sweeney Colleen
Published: October 2008

The ErbB2 receptor tyrosine kinase is overexpressed in ∼25% of breast tumors and contributes to poor patient prognosis and therapeutic resistance. Here, we examine the role of the recently discovered ErbB negative regulator LRIG1 in ErbB2+ breast cancer. We observe that LRIG1 protein levels are significantly suppressed in ErbB2-induced mammary tumors in transgenic mice as well as in the majority of ErbB2+ human breast tumors. These observations raise the possibility that LRIG1 loss could contribute to the initiation or growth of ErbB2+ breast tumors. RNA interference–mediated knockdown of endogenous LRIG1 in the ErbB2-overexpressing breast tumor cell lines MDA-MB-453 and BT474 further elevates ErbB2 in these cells and augments cellular proliferation. In contrast, ectopic expression of LRIG1 reverses these trends. Interestingly, we observe that LRIG1 protein levels are suppressed in response to ErbB receptor activation in breast tumor cells but are unaffected by ErbB activation in immortalized nontransformed breast epithelial cells. Our observations indicate that the suppression of LRIG1 protein levels is a common feature of breast tumors. Moreover, our observations point to the existence of a feed-forward regulatory loop in breast tumor cells where aberrant ErbB2 signaling suppresses LRIG1 protein levels, which in turn contributes to ErbB2 overexpression. [Cancer Res 2008;68(20):8286–94]
The Polarity Protein Par6 Induces Cell Proliferation and Is Overexpressed in Breast Cancer
Authors: Nolan Marissa E. , Aranda Victoria , Lee Sangjun , Lakshmi Balasubramanian , Basu Srinjan , Allred D. Craig , Muthuswamy Senthil K.
Published: October 2008

The polarity protein complex Par6/atypical protein kinase (aPKC)/Cdc42 regulates polarization processes during epithelial morphogenesis, astrocyte migration, and axon specification. We, as well as others, have shown that this complex is also required for disruption of apical-basal polarity during the oncogene ErbB2-induced transformation and transforming growth factor β–induced epithelial-mesenchymal transition of mammary epithelial cells. Here, we report that expression of Par6 by itself in mammary epithelial cells induces epidermal growth factor–independent cell proliferation and development of hyperplastic three-dimensional acini without affecting apical-basal polarity. This is dependent on the ability of Par6 to interact with aPKC and Cdc42, but not Lgl and Par3, and its ability to promote sustained activation of MEK/ERK signaling. Down-regulation of Cdc42 or aPKC expression suppresses the ability of Par6 to induce proliferation, demonstrating that Par6 promotes cell proliferation by interacting with aPKC and Cdc42. We also show that Par6 is overexpressed in breast cancer–derived cell lines and in both precancerous breast lesions and advanced primary human breast cancers, suggesting that Par6 overexpression regulates tumor initiation and progression. Thus, in addition to regulating cell polarization processes, Par6 is an inducer of cell proliferation in breast epithelial cells. [Cancer Res 2008;68(20):8201–9]
Ultrasound Imaging of Apoptosis in Tumor Response: Novel Preclinical Monitoring of Photodynamic Therapy Effects
Authors: Banihashemi Behzad , Vlad Roxana , Debeljevic Branislav , Giles Anoja , Kolios Michael C. , Czarnota Gregory J.
Published: October 2008

High-frequency ultrasound is a novel method to detect apoptotic cell death based on changes in cell morphology that cause alterations in the viscoelastic and, consequently, the acoustic properties of cell ensembles and tissues. In this study, we evaluated the first preclinical tumor-based use of high-frequency ultrasound spectroscopy to noninvasively monitor tumor treatment by following xenograft malignant melanoma tumor responses to photodynamic therapy (PDT) in vivo. We observed a time-dependant increase in ultrasound backscatter variables after treatment. The observed increases in spectroscopic variables correlated with morphologic findings, indicating increases in apoptotic cell death, which peaked at 24 hours after PDT. We analyzed the changes in spectral slope and backscatter in relation to apoptosis and histologic variations in cell nuclear size. Changes in spectral slope strongly correlated with the changes in mean nuclear size over time, associated with apoptosis, after PDT (P < 0.05). At 48 hours, a decrease in ultrasound backscatter was observed, which could be explained by an increase in cell nuclear degradation. In summary, we show that high-frequency ultrasound spectroscopic variables can be used noninvasively to monitor response after treatment in a preclinical tumor cancer model. These findings provide a foundation for future investigations regarding the use of ultrasound to monitor and aid the customization of treatments noninvasively based on responses to specific interventions. [Cancer Res 2008;68(20):8590–6]
Down-regulation of Inhibition of Differentiation-1 via Activation of Activating Transcription Factor 3 and Smad Regulates REIC/Dickkopf-3–Induced Apoptosis
Authors: Kashiwakura Yuji , Ochiai Kazuhiko , Watanabe Masami , Abarzua Fernando , Sakaguchi Masakiyo , Takaoka Munenori , Tanimoto Ryuta , Nasu Yasutomo , Huh Nam-ho , Kumon Hiromi
Published: October 2008

REIC/Dickkopf-3 (Dkk-3), a tumor suppressor gene, has been investigated in gene therapy studies. Our previous study suggested that REIC/Dkk-3–induced apoptosis mainly resulted from phosphorylation of c-Jun-NH2 kinase (JNK) in prostate cancer cells. However, the precise mechanisms, especially the molecular mechanisms regulating JNK phosphorylation, remain unclear. In this study, we investigated the mechanisms participating in JNK phosphorylation in the context of a refractory cancer disease, malignant mesothelioma (MM). Adenovirus-mediated overexpression of REIC/Dkk-3 induced apoptosis mainly through JNK activation in immortalized MM cells (211H cells). Interestingly, transcriptional down-regulation of inhibition of differentiation-1 (Id-1) was detected in REIC/Dkk-3–overexpressed 211H cells. Moreover, restoration of Id-1 expression antagonized REIC/Dkk-3–induced JNK phosphorylation and apoptosis. Mutagenesis experiments with the 2.1-kb human Id-1 promoter revealed that activating transcription factor 3 (ATF3) and Smad interaction, with their respective binding motifs, was essential for REIC/Dkk-3–mediated suppression of Id-1 promoter activity. ATF3 activation was probably induced by endoplasmic reticulum stress. Finally, we showed strong antitumor effects from REIC/Dkk-3 gene transfer into the pleural cavity in an orthotopic MM mouse model. Relative to control tumor tissue, REIC/Dkk-3–treated tumor tissue showed down-regulated expression of Id-1 mRNA, enhanced expression of phosphorylated JNK, and an increased number of apoptotic cells. In summary, we first showed that both ATF3 and Smad were crucially and synergistically involved in down-regulation of Id-1, which regulated JNK phosphorylation in REIC/Dkk-3–induced apoptosis. Thus, gene therapy with REIC/Dkk-3 may be a promising therapeutic tool for MM. [Cancer Res 2008;68(20):8333–41]
Hyperpolarized 13C Lactate, Pyruvate, and Alanine: Noninvasive Biomarkers for Prostate Cancer Detection and Grading
Authors: Albers Mark J. , Bok Robert , Chen Albert P. , Cunningham Charles H. , Zierhut Matt L. , Zhang Vickie Yi , Kohler Susan J. , Tropp James , Hurd Ralph E. , Yen Yi-Fen , Nelson Sarah J. , Vigneron Daniel B. , Kurhanewicz John
Published: October 2008

An extraordinary new technique using hyperpolarized 13C-labeled pyruvate and taking advantage of increased glycolysis in cancer has the potential to improve the way magnetic resonance imaging is used for detection and characterization of prostate cancer. The aim of this study was to quantify, for the first time, differences in hyperpolarized [1-13C] pyruvate and its metabolic products between the various histologic grades of prostate cancer using the transgenic adenocarcinoma of mouse prostate (TRAMP) model. Fast spectroscopic imaging techniques were used to image lactate, alanine, and total hyperpolarized carbon (THC = lactate + pyruvate + alanine) from the entire abdomen of normal mice and TRAMP mice with low- and high-grade prostate tumors in 14 s. Within 1 week, the mice were dissected and the tumors were histologically analyzed. Hyperpolarized lactate SNR levels significantly increased (P < 0.05) with cancer development and progression (41 ± 11, 74 ± 17, and 154 ± 24 in normal prostates, low-grade primary tumors, and high-grade primary tumors, respectively) and had a correlation coefficient of 0.95 with the histologic grade. In addition, there was minimal overlap in the lactate levels between the three groups with only one of the seven normal prostates overlapping with the low-grade primary tumors. The amount of THC, a possible measure of substrate uptake, and hyperpolarized alanine also increased with tumor grade but showed more overlap between the groups. In summary, elevated hyperpolarized lactate and potentially THC and alanine are noninvasive biomarkers of prostate cancer presence and histologic grade that could be used in future three-dimensional 13C spectroscopic imaging studies of prostate cancer patients. [Cancer Res 2008;68(20):8607–15]
Up-regulation of Inflammatory Signalings by Areca Nut Extract and Role ofCyclooxygenase-2−1195G>A Polymorphism Reveal Risk of Oral Cancer
Authors: Chiang Shang-Lun , Chen Ping-Ho , Lee Chien-Hung , Ko Albert Min-Shan , Lee Ka-Wo , Lin Ying-Chu , Ho Pei-Shan , Tu Hung-Pin , Wu Deng-Chyang , Shieh Tien-Yu , Ko Ying-Chin
Published: October 2008

Because the mRNA expression of cyclooxygenase-2 (COX-2) is up-regulated by arecoline in human gingival fibroblasts, as shown in our previous study, we further investigated the mRNA expression level of COX-2 and its upstream effectors in three oral epithelial carcinoma cell lines (KB, SAS, and Ca9-22) by using areca nut extract (ANE) and saliva-reacted ANE (sANE). A case-control study of 377 oral squamous cell carcinoma (OSCC) patients and 442 controls was conducted to evaluate the gene-environment interaction between COX-2 promoter polymorphisms and substance use of alcohol, betel quid, and cigarettes (ABC) in risk of OSCC. The heterogeneous characteristics of the oral site and the COX-2 −1195G>A polymorphism in these cell lines showed diverse inflammatory response (KB≫Ca9-22>SAS) after 24-hour ANE/sANE treatments, and the COX-2 up-regulation might be mostly elicited from alternative nuclear factor-κB activation. In the case-control study, betel chewing [adjusted odds ratios (aOR), 42.2] posed a much higher risk of OSCC than alcohol drinking and cigarette smoking (aORs, 2.4 and 1.8, respectively), whereas the COX-2 −1195A/A homozygote presented a potential genetic risk (OR, 1.55). The strongest joint effect for OSCC was seen in betel chewers with −1195A/A homozygote (aOR, 79.44). In the non–betel chewing group, the −1195A/G and A/A genotypes together with the combined use of alcohol and cigarettes increased risk to 15.1-fold and 32.1-fold, respectively, compared with the G/G genotype without substance use. Taken together, these findings illustrate a valuable insight into the potential role of the COX-2 promoter region in contributing to the development of betel-related OSCC, including ANE/sANE–induced transcriptional effects and enhanced joint effects of COX-2 −1195A allele with substance use of ABC. [Cancer Res 2008;68(20):8489–98]
Transforming Growth Factor-β1 and CD105 Promote the Migration of Hepatocellular Carcinoma–Derived Endothelium
Authors: Benetti Anna , Berenzi Angiola , Gambarotti Marco , Garrafa Emirena , Gelati Maurizio , Dessy Enrico , Portolani Nazario , Piardi Tullio , Giulini Stefano Maria , Caruso Arnaldo , Invernici Gloria , Parati Eugenio Agostino , Nicosia Roberto , Alessandri Giulio
Published: October 2008

Hepatocellular carcinoma (HCC) is one of most malignant and aggressive human tumors. Transforming growth factor-β1 (TGF-β1) and its coreceptor CD105 have been shown to contribute to HCC malignant progression. TGF-β1 and CD105 have also been implicated in angiogenesis, but their role in the vascularization of HCC has not been investigated. To fill this gap, we studied the effect of TGF-β1 and CD105 on HCC-derived endothelium. By using immunomagnetic beads, we isolated and cultured endothelial cells (ECs) from HCC (HCC-EC) and adjacent nonneoplastic tissue (nNL-ECs) obtained from 24 liver biopsies. HCC and nNL biopsies were also analyzed by immunohistochemistry for the expression of CD105, TGF-β1, Ve-cadherin (Ve-cad), CD44, β-catenin, and E-cadherin. Compared with nNL-ECs, HCC-ECs had higher expression of CD105, enhanced spontaneous motility, and greater capacity to migrate in response to TGF-β1 (5 ng/mL), particularly in the presence of a fibronectin matrix. The chemotactic effect of TGF-β1 was blocked by anti-CD105 antibodies and correlated with the grade of HCC malignancy. Histologic examination of HCC biopsies showed that HCCs with the worse malignant features had the highest expression of TGF-β1, CD105, and angiogenic markers (Ve-cad and CD44). Because CD105 was highly expressed in microvessels at the tumor periphery and TGF-β1 staining was only found in neoplastic hepatocytes, we conclude that HCC-derived TGF-β1 may act as a chemoattractant for CD105-expressing ECs and as a promoter of tumor angiogenesis. Thus, drugs that selectively target the TGF-β1/CD105 axis may interfere with HCC-related angiogenesis and HCC progression. [Cancer Res 2008;68(20):8626–34]
Utilization of Pathway Signatures to Reveal Distinct Types of B Lymphoma in the Eμ-myc Model and Human Diffuse Large B-Cell Lymphoma
Authors: Mori Seiichi , Rempel Rachel E. , Chang Jeffrey T. , Yao Guang , Lagoo Anand S. , Potti Anil , Bild Andrea , Nevins Joseph R.
Published: October 2008

The Eμ-myc transgenic mouse has provided a valuable model for the study of B-cell lymphoma. Making use of gene expression analysis and, in particular, expression signatures of cell signaling pathway activation, we now show that several forms of B lymphoma can be identified in the Eμ-myc mice associated with time of tumor onset. Furthermore, one form of Eμ-myc tumor with pre-B character is shown to resemble human Burkitt lymphoma, whereas others exhibit more differentiated B-cell characteristics and show similarity with human diffuse large B-cell lymphoma in the pattern of gene expression, as well as oncogenic pathway activation. Importantly, we show that signatures of oncogenic pathway activity provide further dissection of the spectrum of diffuse large B-cell lymphoma, identifying a subset of patients who have very poor prognosis and could benefit from more aggressive or novel therapeutic strategies. Taken together, these studies provide insight into the complexity of the oncogenic process and a novel strategy for dissecting the heterogeneity of B lymphoma. [Cancer Res 2008;68(20):8525–34]
Allergic Pulmonary Inflammation Promotes the Recruitment of Circulating Tumor Cells to the Lung
Authors: Taranova Anna G. , Maldonado David , Vachon Celine M. , Jacobsen Elizabeth A. , Abdala-Valencia Hiam , McGarry Michael P. , Ochkur Sergei I. , Protheroe Cheryl A. , Doyle Alfred , Grant Clive S. , Cook-Mills Joan , Birnbaumer Lutz , Lee Nancy A. , Lee James J.
Published: October 2008

Allergen-induced respiratory inflammation facilitates and/or elicits the extravasation of proinflammatory leukocytes by well-understood mechanisms that mediate the movement of multiple cell types. The nonspecific character of these pathways led us to hypothesize that circulating cancer cells use similar mechanisms, promoting secondary tumor formation at distal sites. To test this hypothesis, the frequency of metastasis to the lung as a function of allergic pulmonary inflammation was assessed following the i.v. injection of B16-F10 melanoma cells in mice. These studies showed that allergen-induced pulmonary inflammation resulted in a >3-fold increase in lung metastases. This increase was dependent on CD4+ T-cell activities; however, it occurred independent of the induced eosinophilia associated with allergen provocation. Interventional strategies showed that existing therapeutic modalities for asthma, such as inhaled corticosteroids, were sufficient to block the enhanced pulmonary recruitment of cancer cells from circulation. Additional mechanistic studies further suggested that the ability of circulating cancer cells to extravasate to surrounding lung tissues was linked to the activation of the vascular endothelium via one or more Gαi-coupled receptors. Interestingly, a survey of a clinical breast cancer surgical database showed that the incidence of asthma was higher among patients with lung metastases. Thus, our data show that allergic respiratory inflammation may represent a risk factor for the development of lung metastases and suggest that amelioration of the pulmonary inflammation associated with asthma will have a direct and immediate benefit to the 7% to 8% of breast cancer patients with this lung disease. [Cancer Res 2008;68(20):8582–9]
Characterization of Naturally Occurring HPV16 Integration Sites Isolated from Cervical Keratinocytes under Noncompetitive Conditions
Authors: Dall Keltie L. , Scarpini Cinzia G. , Roberts Ian , Winder David M. , Stanley Margaret A. , Muralidhar Balaji , Herdman M. Trent , Pett Mark R. , Coleman Nicholas
Published: October 2008

As the high-risk human papillomavirus (HPV) integrants seen in anogenital carcinomas represent the end-point of a clonal selection process, we used the W12 model to study the naturally occurring integration events that exist in HPV16-infected cervical keratinocytes before integrant selection. We performed limiting dilution cloning to identify integrants present in cells that also maintain episomes. Such integrants arise in a natural context and exist in a noncompetitive environment, as they are transcriptionally repressed by episome-derived E2. We found that integration can occur at any time during episome maintenance, providing biological support for epidemiologic observations that persistent HPV infection is a major risk factor in cervical carcinogenesis. Of 24 different integration sites isolated from a single nonclonal population of W12, 12 (50%) occurred within chromosome bands containing a common fragile site (CFS), similar to observations for selected integrants in vivo. This suggests that such regions represent relatively accessible sites for insertion of foreign DNA, rather than conferring a selective advantage when disrupted. Interestingly, however, integrants and CFSs did not accurately colocalize. We further observed that local DNA rearrangements occur frequently and rapidly after the integration event. The majority of integrants were in chromosome bands containing a cancer-associated coding gene or microRNA, indicating that integration occurs commonly in these regions, regardless of selective pressure. The cancer-associated genes were generally a considerable distance from the integration site, and there was no evidence for altered expression of nine strong candidate genes. These latter observations do not support an important role for HPV16 integration in causing insertional mutagenesis. [Cancer Res 2008;68(20):8249–59]
Cell Motility in Chronic Lymphocytic Leukemia: Defective Rap1 and αLβ2 Activation by Chemokine
Authors: Till Kathleen J. , Harris Robert J. , Linford Andrea , Spiller David G. , Zuzel Mirko , Cawley John C.
Published: October 2008

Chemokine-induced activation of α4β1 and αLβ2 integrins (by conformational change and clustering) is required for lymphocyte transendothelial migration (TEM) and entry into lymph nodes. We have previously reported that chemokine-induced TEM is defective in chronic lymphocytic leukemia (CLL) and that this defect is a result of failure of the chemokine to induce polar clustering of αLβ2; engagement of α4β1 and autocrine vascular endothelial growth factor (VEGF) restore clustering and TEM. The aim of the present study was to characterize the nature of this defect in αLβ2 activation and determine how it is corrected. We show here that the αLβ2 of CLL cells is already in variably activated conformations, which are not further altered by chemokine treatment. Importantly, such treatment usually does not cause an increase in the GTP-loading of Rap1, a GTPase central to chemokine-induced activation of integrins. Furthermore, we show that this defect in Rap1 GTP-loading is at the level of the GTPase and is corrected in CLL cells cultured in the absence of exogenous stimuli, suggesting that the defect is the result of in vivo stimulation. Finally, we show that, because Rap1-induced activation of both α4β1 and αLβ2 is defective, autocrine VEGF and chemokine are necessary to activate α4β1 for ligand binding. Subsequently, this binding and both VEGF and chemokine stimulation are all needed for αLβ2 activation for motility and TEM. The present study not only clarifies the nature of the αLβ2 defect of CLL cells but is the first to implicate activation of Rap1 in the pathophysiology of CLL. [Cancer Res 2008;68(20):8429–36]
Black Cohosh Increases Metastatic Mammary Cancer in Transgenic Mice Expressing c-erbB2
Authors: Davis Vicki L. , Jayo Manuel J. , Ho Arline , Kotlarczyk Mary P. , Hardy Mary L. , Foster Warren G. , Hughes Claude L.
Published: October 2008

Black cohosh is an herbal extract that is often used as an alternative to estrogen-based replacement therapies to treat hot flushes that frequently accompany the transition to menopause. Although cancer-free women as well as breast cancer patients and survivors use black cohosh to relieve vasomotor symptoms, there is limited information on its potential to influence breast cancer development or progression. Therefore, in this study, the effects of black cohosh on mammary tumorigenesis were investigated in the MMTV-neu mouse model due to its similarities to HER2+ breast cancer, including stochastic development of mammary tumors, which frequently progress to metastatic disease. Using an adjusted dose for the mice to correlate to the recommended dose in women (40 mg/d), no differences were detected in the incidence or onset of mammary tumors in black cohosh–treated versus control females. The lack of effect on mammary tumor development suggests that black cohosh would not influence breast cancer risk if given to women before tumor formation. In contrast, black cohosh significantly increased the incidence of lung metastases in tumor-bearing animals compared with mice fed the isoflavone-free control diet. Additional studies will be needed to correlate these findings to women taking different black cohosh products at various times during breast cancer development; however, these results suggest caution for women using black cohosh, especially for extended periods of time. As metastatic progression is linked to patient survival, these data stress the importance of investigating how women's therapies influence all stages of mammary tumorigenesis, particularly for assessing their safety. [Cancer Res 2008;68(20):8377–83]
Novel Designs of Multivalent Anti-CD20 Humanized Antibodies as Improved Lymphoma Therapeutics
Authors: Rossi Edmund A. , Goldenberg David M. , Cardillo Thomas M. , Stein Rhona , Wang Yang , Chang Chien-Hsing
Published: October 2008

Multivalent antibodies, either monospecific or bispecific, may improve the efficacy of current therapeutic interventions involving a single monoclonal antibody (mAb). We have applied the Dock-and-Lock (DNL) method, a new platform technology for the site-specific and covalent assembly of modular components into stably tethered complexes of defined composition, to prepare a hexavalent, anti-CD20 antibody, designated Hex-hA20, which comprises six Fabs with one Fc. We show that Hex-hA20 retains the binding activity of all six Fabs, associates with CD20 in lipid rafts, affects antibody-dependent cell-mediated cytotoxicity, but not complement-dependent cytotoxicity, and inhibits proliferation of Daudi, Raji, and Ramos cells in vitro at subnanomolar concentrations without the need for a cross-linking antibody. In addition, Hex-hA20 induces strong homotypical adhesion and is inefficient in stimulating calcium mobilization. Thus, Hex-hA20 exhibits biological properties attributable to both type I and type II anti-CD20 mAbs, as exemplified by rituximab and tositumomab, respectively. Although Hex-hA20 has a short serum half-life, it shows antitumor efficacy in tumor-bearing mice comparable with veltuzumab at equivalent doses. The versatile DNL method was also applied to generate two other multivalent anti-CD20 antibodies without the Fc region, Tri-hA20 and Tetra-hA20, comprising three and four Fabs of veltuzumab, respectively. Similar to Hex-hA20, these were purified to near homogeneity and shown to have potent antiproliferative activity in vitro, thus indicating the need for clustering three or more CD20 molecules on the cell surface to induce growth inhibition. [Cancer Res 2008;68(20):8384–92]
Arsenic Exposure In utero Exacerbates Skin Cancer Response in Adulthood with Contemporaneous Distortion of Tumor Stem Cell Dynamics
Authors: Waalkes Michael P. , Liu Jie , Germolec Dori R. , Trempus Carol S. , Cannon Ronald E. , Tokar Erik J. , Tennant Raymond W. , Ward Jerrold M. , Diwan Bhalchandra A.
Published: October 2008

Arsenic is a carcinogen with transplacental activity that can affect human skin stem cell population dynamics in vitro by blocking exit into differentiation pathways. Keratinocyte stem cells (KSC) are probably a key target in skin carcinogenesis. Thus, we tested the effects of fetal arsenic exposure in Tg.AC mice, a strain sensitive to skin carcinogenesis via activation of the v-Ha-ras transgene likely in KSCs. After fetal arsenic treatment, offspring received topical 12-O-tetradecanoyl phorbol-13-acetate (TPA) through adulthood. Arsenic alone had no effect, whereas TPA alone induced papillomas and squamous cell carcinomas (SCC). However, fetal arsenic treatment before TPA increased SCC multiplicity 3-fold more than TPA alone, and these SCCs were much more aggressive (invasive, etc.). Tumor v-Ha-ras levels were 3-fold higher with arsenic plus TPA than TPA alone, and v-Ha-ras was overexpressed early on in arsenic-treated fetal skin. CD34, considered a marker for both KSCs and skin cancer stem cells, and Rac1, a key gene stimulating KSC self-renewal, were greatly increased in tumors produced by arsenic plus TPA exposure versus TPA alone, and both were elevated in arsenic-treated fetal skin. Greatly increased numbers of CD34-positive probable cancer stem cells and marked overexpression of RAC1 protein occurred in tumors induced by arsenic plus TPA compared with TPA alone. Thus, fetal arsenic exposure, although by itself oncogenically inactive in skin, facilitated cancer response in association with distorted skin tumor stem cell signaling and population dynamics, implicating stem cells as a target of arsenic in the fetal basis of skin cancer in adulthood. [Cancer Res 2008;68(20):8278–85]
A SNP in a let-7 microRNA Complementary Site in the KRAS 3′ Untranslated Region Increases Non–Small Cell Lung Cancer Risk
Authors: Chin Lena J. , Ratner Elena , Leng Shuguang , Zhai Rihong , Nallur Sunitha , Babar Imran , Muller Roman-Ulrich , Straka Eva , Su Li , Burki Elizabeth A. , Crowell Richard E. , Patel Rajeshvari , Kulkarni Trupti , Homer Robert , Zelterman Daniel , Kidd Kenneth K. , Zhu Yong , Christiani David C. , Belinsky Steven A. , Slack Frank J. , Weidhaas Joanne B.
Published: October 2008

Lung cancer is the leading cause of cancer deaths worldwide, yet few genetic markers of lung cancer risk useful for screening exist. The let-7 family-of-microRNAs (miRNA) are global genetic regulators important in controlling lung cancer oncogene expression by binding to the 3′ untranslated regions of their target mRNAs. The purpose of this study was to identify single nucleotide polymorphisms (SNP) that could modify let-7 binding and to assess the effect of such SNPs on target gene regulation and risk for non–small cell lung cancer (NSCLC). let-7 complementary sites (LCS) were sequenced in the KRAS 3′ untranslated region from 74 NSCLC cases to identify mutations and SNPs that correlated with NSCLC. The allele frequency of a previously unidentified SNP at LCS6 was characterized in 2,433 people (representing 46 human populations). The frequency of the variant allele is 18.1% to 20.3% in NSCLC patients and 5.8% in world populations. The association between the SNP and the risk for NSCLC was defined in two independent case-control studies. A case-control study of lung cancer from New Mexico showed a 2.3-fold increased risk (confidence interval, 1.1–4.6; P = 0.02) for NSCLC cancer in patients who smoked <40 pack-years. This association was validated in a second independent case-control study. Functionally, the variant allele results in KRAS overexpression in vitro. The LCS6 variant allele in a KRAS miRANA complementary site is significantly associated with increased risk for NSCLC among moderate smokers and represents a new paradigm for let-7 miRNAs in lung cancer susceptibility. [Cancer Res 2008;68(20):8535–40]