bluuebunny/crossref_metadata_2025 huggingface dataset:
PPARα inhibition modulates multiple reprogrammed metabolic pathways in kidney cancer and attenuates tumor growth
Authors: Abu Aboud Omran , Donohoe Dallas , Bultman Scott , Fitch Mark , Riiff Tim , Hellerstein Marc , Weiss Robert H.
Published: March 2015

Kidney cancer [renal cell carcinoma (RCC)] is the sixth-most-common cancer in the United States, and its incidence is increasing. The current progression-free survival for patients with advanced RCC rarely extends beyond 1–2 yr due to the development of therapeutic resistance. We previously identified peroxisome proliferator-activating receptor-α (PPARα) as a potential therapeutic target for this disease and showed that a specific PPARα antagonist, GW6471, induced apoptosis and cell cycle arrest at G0/G1 in RCC cell lines associated with attenuation of cell cycle regulatory proteins. We now extend that work and show that PPARα inhibition attenuates components of RCC metabolic reprogramming, capitalizing on the Warburg effect. The specific PPARα inhibitor GW6471, as well as a siRNA specific to PPARα, attenuates the enhanced fatty acid oxidation and oxidative phosphorylation associated with glycolysis inhibition, and PPARα antagonism also blocks the enhanced glycolysis that has been observed in RCC cells; this effect did not occur in normal human kidney epithelial cells. Such cell type-specific inhibition of glycolysis corresponds with changes in protein levels of the oncogene c- Myc and has promising clinical implications. Furthermore, we show that treatment with GW6471 results in RCC tumor growth attenuation in a xenograft mouse model, with minimal obvious toxicity, a finding associated with the expected on-target effects on c-Myc. These studies demonstrate that several pivotal cancer-relevant metabolic pathways are inhibited by PPARα antagonism. Our data support the concept that targeting PPARα, with or without concurrent inhibition of glycolysis, is a potential novel and effective therapeutic approach for RCC that targets metabolic reprogramming in this tumor.
Nickel suppresses the PACAP-induced increase in guinea pig cardiac neuron excitability
Authors: Tompkins John D. , Merriam Laura A. , Girard Beatrice M. , May Victor , Parsons Rodney L.
Published: March 2015

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a potent intercellular signaling molecule involved in multiple homeostatic functions. PACAP/PAC1 receptor signaling increases excitability of neurons within the guinea pig cardiac ganglia, making them a unique system to establish mechanisms underlying PACAP modulation of neuronal function. Calcium influx is required for the PACAP-increased cardiac neuron excitability, although the pathway is unknown. This study tested whether PACAP enhancement of calcium influx through either T-type or R-type channels contributed to the modulation of excitability. Real-time quantitative polymerase chain reaction analyses indicated transcripts for Cav3.1, Cav3.2, and Cav3.3 T-type isoforms and R-type Cav2.3 in cardiac neurons. These neurons often exhibit a hyperpolarization-induced rebound depolarization that remains when cesium is present to block hyperpolarization-activated nonselective cationic currents ( Ih). The T-type calcium channel inhibitors, nickel (Ni2+) or mibefradil, suppressed the rebound depolarization, and treatment with both drugs hyperpolarized cardiac neurons by 2–4 mV. Together, these results are consistent with the presence of functional T-type channels, potentially along with R-type channels, in these cardiac neurons. Fifty micromolar Ni2+, a concentration that suppresses currents in both T-type and R-type channels, blunted the PACAP-initiated increase in excitability. Ni2+ also blunted PACAP enhancement of the hyperpolarization-induced rebound depolarization and reversed the PACAP-mediated increase in excitability, after being initiated, in a subset of cells. Lastly, low voltage-activated currents, measured under perforated patch whole cell recording conditions and potentially flowing through T-type or R-type channels, were enhanced by PACAP. Together, our results suggest that a PACAP-enhanced, Ni2+-sensitive current contributes to PACAP-induced modulation of neuronal excitability.
ANG II modulation of cardiac growth and remodeling in immature fetal sheep
Authors: Sandgren Jeremy , Scholz Thomas D. , Segar Jeffrey L.
Published: March 2015

ANG II increases fetal blood pressure and stimulates fetal heart growth; however, little is known regarding its direct effects on cardiomyocytes in vivo. We sought to determine whether ANG II stimulates heart growth and cardiomyocyte hypertrophy and/or hyperplasia in utero in the immature fetal heart independent of the effects on cardiac afterload. In twin gestation, fetal sheep at ∼100 days gestation (term 145 days), one fetus received a chronic (6 days) infusion of ANG II alone (50 μg·kg−1·min−1) or ANG II plus nitroprusside (NTP) to attenuate the increase in blood pressure; noninstrumented twins served as controls. ANG II alone, but not ANG II + NTP resulted in a significant increase in heart mass (left and right ventricle + septum, corrected for body weight) compared with controls. ANG II, but not ANG II+NTP, also significantly increased cardiomyocyte area compared with control and increased the percentage of binucleated myocytes. ANG II with or without concomitant infusion of NTP increased cardiac PCNA expression, a marker of proliferation. Steady-state protein expression of terminal mitogen-activated protein kinases, cyclin B1, cyclin E1, and p21 were similar among groups. We conclude that in vivo, ANG II increases fetal cardiac mass via cardiomyocyte hypertrophy, differentiation, and to a lesser extent hyperplasia. The effects of ANG II on hypertrophy appear dependent upon the increase in blood pressure (mechanical load), whereas effects on proliferation are load-independent.
Pregnant rats treated with a high-fat/prooxidant Western diet with ANG II and TNF-α are resistant to elevations in blood pressure and renal oxidative stress
Authors: Cunningham Mark W. , West Crystal A. , Wen Xuerong , Deng Aihua , Baylis Chris
Published: March 2015

Oxidative stress and inflammation are risk factors for hypertension in pregnancy. Here, we examined the 24-h mean arterial pressure (MAP) via telemetry and the nitric oxide (NO) and redox systems in the kidney cortex, medulla, and aorta of virgin and pregnant rats treated with a high-fat/prooxidant Western diet (HFD), ANG II, and TNF-α. Female Sprague-Dawley rats were given a normal diet (ND) or a HFD for 8 wk before mating. Day 6 of pregnancy and age-matched virgins were implanted with minipumps infusing saline or ANG II (150 ng·kg−1·min−1) + TNF-α (75 ng/day) for 14 days. Groups consisted of Virgin + ND + Saline (V+ND) ( n = 7), Virgin + HFD +ANG II and TNF-α (V+HFD) ( n = 7), Pregnant + ND + Saline (P+ND) ( n = 6), and Pregnant + HFD + ANG II and TNF-α (P+HFD) ( n = 8). After day 6 of minipump implantation, V+HFD rats displayed an increase in MAP on days 7, 8, and 10–15 vs. V+ND rats. P+HFD rats, after day 6 of minipump implantation, showed an increase in MAP only on day 7 vs. P+ND rats. P+HFD rats had a normal fall in 24-h MAP, hematocrit, plasma protein concentration, and osmolality at late pregnancy. No change in kidney cortex, medulla, or aortic oxidative stress in P+HFD rats. P+HFD rats displayed a decrease in nNOSβ abundance, but no change in kidney cortex NOxcontent vs. P+ND rats. Pregnant rats subjected to a chronic HFD and prooxidant and proinflammatory insults have a blunted increase in 24-h MAP and renal oxidative stress. Our data suggest renal NO bioavailability is not altered in pregnant rats treated with a HFD, ANG II, and TNF-α.
End tidal-to-arterial CO2and O2gas gradients at low- and high-altitude during dynamic end-tidal forcing
Authors: Tymko Michael M. , Ainslie Philip N. , MacLeod David B. , Willie Chris K. , Foster Glen E.
Published: March 2015

We sought to characterize and quantify the performance of a portable dynamic end-tidal forcing (DEF) system in controlling the partial pressure of arterial CO2(PaCO2) and O2(PaO2) at low (LA; 344 m) and high altitude (HA; 5,050 m) during an isooxic CO2test and an isocapnic O2test, which is commonly used to measure ventilatory and vascular reactivity in humans ( n = 9). The isooxic CO2tests involved step changes in the partial pressure of end-tidal CO2(PetCO2) of −10, −5, 0, +5, and +10 mmHg from baseline. The isocapnic O2test consisted of a 10-min hypoxic step (PetO2= 47 mmHg) from baseline at LA and a 5-min euoxic step (PetO2= 100 mmHg) from baseline at HA. At both altitudes, PetO2and PetCO2were controlled within narrow limits (<1 mmHg from target) during each protocol. During the isooxic CO2test at LA, PetCO2consistently overestimated PaCO2( P < 0.01) at both baseline (2.1 ± 0.5 mmHg) and hypercapnia (+5 mmHg: 2.1 ± 0.7 mmHg; +10 mmHg: 1.9 ± 0.5 mmHg). This Pa-PetCO2gradient was approximately twofold greater at HA ( P < 0.05). At baseline at both altitudes, PetO2overestimated PaO2by a similar extent (LA: 6.9 ± 2.1 mmHg; HA: 4.5 ± 0.9 mmHg; both P < 0.001). This overestimation persisted during isocapnic hypoxia at LA (6.9 ± 0.6 mmHg) and during isocapnic euoxia at HA (3.8 ± 1.2 mmHg). Step-wise multiple regression analysis, on the basis of the collected data, revealed that it may be possible to predict an individual's arterial blood gases during DEF. Future research is needed to validate these prediction algorithms and determine the implications of end-tidal-to-arterial gradients in the assessment of ventilatory and/or vascular reactivity.
Triacylglyceride physiology in the short-finned eel,Anguilla australis—changes throughout early oogenesis
Authors: Damsteegt Erin L. , Falahatimarvast Ali , McCormick Sally P. A. , Lokman P. Mark
Published: March 2015

During certain stages in an animal's life cycle, energy requirements may exceed energy intake from the diet. The spawning migration of temperate eels is a textbook example of negative energy balance, forcing these fish to rely on stored fats (triacylglycerides) to provide their muscles with energy for swimming and their growing oocytes with the nutrients needed to develop and support healthy offspring. We predicted broad implications of this great need for endogenous triacylglycerides in terms of their packaging, transport, and ovarian uptake. To test this, serum lipid concentrations and transcript abundances of intestinal and hepatic triacylglyceride packagers and ovarian triacylglyceride modifiers and receivers were investigated throughout previtellogenesis (feeding phase) and into early vitellogenesis (fasting phase) in short-finned eels. A switch from exogenous to endogenous triacylglyceride packaging was seen as the liver upregulated transcript levels of apolipoprotein B and microsomal triacylglyceride transport protein and downregulated those of apolipoprotein E and lipoprotein lipase. In the intestine, the reverse response was observed. Furthermore, ovarian transcript abundances of triacylglyceride modifiers and receivers increased (apolipoprotein E, lipoprotein lipase, and vitellogenin receptor), indicative of increased triacylglyceride uptake during previtellogenesis. We propose that increased hepatic apolipoprotein B production is a conserved vertebrate response to prolonged periods of negative energy balance.
High affinity and temperature sensitivity of blood oxygen binding inPangasianodon hypophthalmusdue to lack of chloride-hemoglobin allosteric interaction
Authors: Damsgaard Christian , Phuong Le My , Huong Do Thi Thanh , Jensen Frank B. , Wang Tobias , Bayley Mark
Published: March 2015

Air-breathing fishes represent interesting organisms in terms of understanding the physiological changes associated with the terrestrialization of vertebrates, and, further, are of great socio-economic importance for aquaculture in Southeast Asia. To understand how environmental factors, such as high temperature, affect O2transport in air-breathing fishes, this study assessed the effects of temperature on O2binding of blood and Hb in the economically important air-breathing fish Pangasianodon hypophthalmus. To determine blood O2binding properties, blood was drawn from resting cannulated fishes and O2binding curves made at 25°C and 35°C. To determine the allosteric regulation and thermodynamics of Hb O2binding, Hb was purified, and O2equilibria were recorded at five temperatures in the absence and presence of ATP and Cl−. Whole blood had a high O2affinity (O2tension at half saturation P50= 4.6 mmHg at extracellular pH 7.6 and 25°C), a high temperature sensitivity of O2binding (apparent heat of oxygenation Δ Happ= −28.3 kcal/mol), and lacked a Root effect. Further, the data on Hb revealed weak ATP binding and a complete lack of Cl−binding to Hb, which, in part, explains the high O2affinity and high temperature sensitivity of blood O2binding. This study demonstrates how a potent mechanism for increasing O2affinity is linked to increased temperature sensitivity of O2transport and provides a basic framework for a better understanding of how hypoxia-adapted species will react to increasing temperatures.
Effects of tempol on baroreflex neural arc versus peripheral arc in normotensive and spontaneously hypertensive rats
Authors: Kawada Toru , Sata Yusuke , Shimizu Shuji , Turner Michael J. , Fukumitsu Masafumi , Sugimachi Masaru
Published: March 2015

Although oxidative redox signaling affects arterial pressure (AP) regulation via modulation of vascular tone and sympathetic nerve activity (SNA), it remains unknown which effect plays a dominant role in the determination of AP in vivo. Open-loop systems analysis of the carotid sinus baroreflex was conducted to separately quantify characteristics of the neural arc from baroreceptor pressure input to SNA and the peripheral arc from SNA to AP in normotensive Wistar-Kyoto (WKY; n = 8) and spontaneously hypertensive rats (SHR; n = 8). Responses in SNA and AP to a staircase-wise increase in carotid sinus pressure were examined before and during intravenous administration of the membrane-permeable superoxide dismutase mimetic tempol (30 mg/kg bolus followed by 30 mg·kg−1·h−1). Two-way ANOVA indicated that tempol significantly decreased the response range of SNA (from 89.1 ± 2.4% to 60.7 ± 2.5% in WKY and from 77.5 ± 3.2% to 56.9 ± 7.3% in SHR, P < 0.001) without affecting the lower plateau of SNA (from 12.5 ± 2.4% to 9.5 ± 2.5% in WKY, and from 28.8 ± 2.8% to 30.4 ± 5.7% in SHR, P = 0.800) in the neural arc. While tempol did not affect the peripheral arc characteristics in WKY, it yielded a downward change in the regression line of AP vs. SNA in SHR. In conclusion, oxidative redox signaling plays an important role, not only in the pathological AP elevation, but also in the baroreflex-mediated physiological AP regulation. The effect of modulating oxidative redox signaling on the peripheral arc contributed to the determination of AP in SHR but not in WKY.
ClC-K chloride channels: emerging pathophysiology of Bartter syndrome type 3
Authors: Andrini Olga , Keck Mathilde , Briones Rodolfo , Lourdel Stéphane , Vargas-Poussou Rosa , Teulon Jacques
Published: March 2015

The mutations in the CLCNKB gene encoding the ClC-Kb chloride channel are responsible for Bartter syndrome type 3, one of the four variants of Bartter syndrome in the genetically based nomenclature. All forms of Bartter syndrome are characterized by hypokalemia, metabolic alkalosis, and secondary hyperaldosteronism, but Bartter syndrome type 3 has the most heterogeneous presentation, extending from severe to very mild. A relatively large number of CLCNKB mutations have been reported, including gene deletions and nonsense or missense mutations. However, only 20 CLCNKB mutations have been functionally analyzed, due to technical difficulties regarding ClC-Kb functional expression in heterologous systems. This review provides an overview of recent progress in the functional consequences of CLCNKB mutations on ClC-Kb chloride channel activity. It has been observed that 1) all ClC-Kb mutants have an impaired expression at the membrane; and 2) a minority of the mutants combines reduced membrane expression with altered pH-dependent channel gating. Although further investigation is needed to fully characterize disease pathogenesis, Bartter syndrome type 3 probably belongs to the large family of conformational diseases, in which the mutations destabilize channel structure, inducing ClC-Kb retention in the endoplasmic reticulum and accelerated channel degradation.
Harvest and primary culture of the murine aldosterone-sensitive distal nephron
Authors: Labarca Mariana , Nizar Jonathan M. , Walczak Elisabeth M. , Dong Wuxing , Pao Alan C. , Bhalla Vivek
Published: March 2015

The aldosterone-sensitive distal nephron (ASDN) exhibits axial heterogeneity in structure and function from the distal convoluted tubule to the medullary collecting duct. Ion and water transport is primarily divided between the cortex and medulla of the ASDN, respectively. Transcellular transport in this segment is highly regulated in health and disease and is integrated across different cell types. We currently lack an inexpensive, high-yield, and tractable technique to harvest and culture cells for the study of gene expression and physiological properties of mouse cortical ASDN. To address this need, we harvested tubules bound to Dolichos biflorus agglutinin lectin-coated magnetic beads from the kidney cortex and characterized these cell preparations. We determined that these cells are enriched for markers of distal convoluted tubule, connecting tubule, and cortical collecting duct, including principal and intercalated cells. In primary culture, these cells develop polarized monolayers with high resistance (1,000-1,500 Ω * cm2) and maintain expression and activity of key channels. These cells demonstrate an amiloride-sensitive short-circuit current that can be enhanced with aldosterone and maintain measurable potassium and anion secretion. Our method can be easily adopted to study the biology of the ASDN and to investigate phenotypic differences between wild-type and transgenic mouse models.
Brain-wide analysis of electrophysiological diversity yields novel categorization of mammalian neuron types
Authors: Tripathy Shreejoy J. , Burton Shawn D. , Geramita Matthew , Gerkin Richard C. , Urban Nathaniel N.
Published: March 2015

For decades, neurophysiologists have characterized the biophysical properties of a rich diversity of neuron types. However, identifying common features and computational roles shared across neuron types is made more difficult by inconsistent conventions for collecting and reporting biophysical data. Here, we leverage NeuroElectro, a literature-based database of electrophysiological properties ( www.neuroelectro.org ), to better understand neuronal diversity, both within and across neuron types, and the confounding influences of methodological variability. We show that experimental conditions (e.g., electrode types, recording temperatures, or animal age) can explain a substantial degree of the literature-reported biophysical variability observed within a neuron type. Critically, accounting for experimental metadata enables massive cross-study data normalization and reveals that electrophysiological data are far more reproducible across laboratories than previously appreciated. Using this normalized dataset, we find that neuron types throughout the brain cluster by biophysical properties into six to nine superclasses. These classes include intuitive clusters, such as fast-spiking basket cells, as well as previously unrecognized clusters, including a novel class of cortical and olfactory bulb interneurons that exhibit persistent activity at theta-band frequencies.
Difference in perceptual and oculomotor responses revealed by apparent motion stimuli presented with an interstimulus interval
Authors: Nohara Shizuka , Kawano Kenji , Miura Kenichiro
Published: March 2015

To understand the mechanisms underlying visual motion analyses for perceptual and oculomotor responses and their similarities/differences, we analyzed eye movement responses to two-frame animations of dual-grating 3 f5 f stimuli while subjects performed direction discrimination tasks. The 3 f5 f stimulus was composed of two sinusoids with a spatial frequency ratio of 3:5 (3 f and 5 f), creating a pattern with fundamental frequency f. When this stimulus was shifted by 1/4 of the wavelength, the two components shifted 1/4 of their wavelengths and had opposite directions: the 5 f forward and the 3 f backward. By presenting the 3 f5 f stimulus with various interstimulus intervals (ISIs), two visual-motion-analysis mechanisms, low-level energy-based and high-level feature-based, could be effectively distinguished. This is because response direction depends on the relative contrast between the components when the energy-based mechanism operates, but not when the feature-based mechanism works. We found that when the 3 f5 f stimuli were presented with shorter ISIs (<100 ms), and 3 f component had higher contrast, both perceptual and ocular responses were in the direction of the pattern shift, whereas the responses were reversed when the 5 f had higher contrast, suggesting operation of the energy-based mechanism. On the other hand, the ocular responses were almost negligible with longer ISIs (>100 ms), whereas perceived directions were biased toward the direction of pattern shift. These results suggest that the energy-based mechanism is dominant in oculomotor responses throughout ISIs; however, there is a transition from energy-based to feature-tracking mechanisms when we perceive visual motion.
Is Acculturation Related to Obesity in Hispanic/Latino Adults? Results from the Hispanic Community Health Study/Study of Latinos
Authors: Isasi Carmen R. , Ayala Guadalupe X. , Sotres-Alvarez Daniela , Madanat Hala , Penedo Frank , Loria Catherine M. , Elder John P. , Daviglus Martha L. , Barnhart Janice , Siega-Riz Anna Maria , Van Horn Linda , Schneiderman Neil
Published: March 2015

Background.The study examined the association of obesity with acculturation in a large and diverse sample of US Hispanic/Latino adults.Methods.The Hispanic Community Health Study (HCHS)/Study of Latinos (SOL) is a community-based cohort study of Hispanic/Latino adults aged 18–74 years (N=16,415) from four urban areas. Height and weight were directly measured using a standardized protocol. Acculturation was assessed by the Short Acculturation Scale for Hispanics (SASH). Other immigration related variables included place of birth, length of residency in the US, and age at immigration. Odds ratios were calculated to assess the association of overweight, moderate obesity, and extreme obesity (≥40 kg/m2) with acculturation and sociodemographic variables.Results.The prevalence of obesity was 42.4% for women and 36.5% for men and varied by field center and Hispanic/Latino background. The strongest predictor of moderate and extreme obesity was length of residency in mainland US. This association was consistent across Hispanic/Latino backgrounds. Acculturation was not significantly associated with obesity.Discussion.The burden of obesity is high among Hispanic/Latino adults. The study findings suggest that prolonged exposure to the environments in these communities, rather than acculturation, is an important risk factor for obesity in this population.
Formulation, Optimization, and Characterization of Repaglinide Loaded Nanocrystal for Diabetes Therapy
Authors: Shinde Gajanan , Patel Mitesh , Mehta Manan , Kesarla Rajesh , Bangale Ganesh
Published: March 2015

The aim of the present investigation was to formulate and characterize nanocrystal formulation of Repaglinide for diabetes therapy. Formulation was done by high pressure homogenization. HPH pressure and cycles range were screened by preliminary batches (T1 and T2). 5, 8, and 10 cycles and 500 to 1500 bar pressure range had kept for further investigation. Taguchi design was used to optimize type of polymer, % polymer concentration, number of cycles, and HPH pressure for nanocrystal formulation. Formulations were characterized for particle size, zeta potential, and in vitro drug release. Optimized formulation (NC 3) showed particle size of 187 nm, zeta potential of −29.4 mv, and % drug release of 80.58% and it was used for further study. Data analysis proved significant effects of factors on responses. Polydispersity index (PDI) Analysis of optimized formulation were found to be 0.248. SEM showed nanocrystal aggregation of drug, may be due to water removal process. DSC showed slight change in crystallinity, may be due to the presence of PEG 4000. Stability study was carried out for 3 months. It indicated no significant change in particle size and zeta potential. However, further studies in higher animals and human being need to be performed before this formulation can be commercially exploited.
RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury
Authors: Oliveira-Freitas Vera L. , Thomaz Leonardo Dalla Giacomassa Rocha , Simoneti Lucas Elias Lise , Malfitano Christiane , De Angelis Kátia , Ulbrich Jane Maria , Schwartsmann Gilberto , Andrade Cristiano Feijó
Published: March 2015

RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI) by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR), RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P<0.001). The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P=0.005). Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P<0.013). No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β(P=0.159) and TNF-α(P=0.260), as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis.
Always Consider the Possibility of Opioid Induced Respiratory Depression in Patients Presenting with Hypercapnic Respiratory Failure Who Fail to Improve as Expected with Appropriate Therapy
Authors: Steynor Martin , MacDuff Andrew
Published: March 2015

Hypercapnic respiratory failure is a frequently encountered medical emergency. Two common causes are acute exacerbations of chronic obstructive pulmonary disease (COPD) and as a side effect of opioids. The two causes may coexist leading to diagnostic confusion and consequent delay in optimal management. We report a case of what was initially thought to be an exacerbation of COPD. The patient failed to improve with treatment as expected which led to the empirical administration of naloxone resulting in a dramatic reversal of her respiratory failure. The patient was subsequently discovered to be taking regular dihydrocodeine for chronic back pain.
CDK2 Inhibition Causes Anaphase Catastrophe in Lung Cancer through the Centrosomal Protein CP110
Authors: Hu Shanhu , Danilov Alexey V. , Godek Kristina , Orr Bernardo , Tafe Laura J. , Rodriguez-Canales Jaime , Behrens Carmen , Mino Barbara , Moran Cesar A. , Memoli Vincent A. , Mustachio Lisa Maria , Galimberti Fabrizio , Ravi Saranya , DeCastro Andrew , Lu Yun , Sekula David , Andrew Angeline S. , Wistuba Ignacio I. , Freemantle Sarah , Compton Duane A. , Dmitrovsky Ethan
Published: March 2015

Aneuploidy is frequently detected in human cancers and is implicated in carcinogenesis. Pharmacologic targeting of aneuploidy is an attractive therapeutic strategy, as this would preferentially eliminate malignant over normal cells. We previously discovered that CDK2 inhibition causes lung cancer cells with more than two centrosomes to undergo multipolar cell division leading to apoptosis, defined as anaphase catastrophe. Cells with activating KRAS mutations were especially sensitive to CDK2 inhibition. Mechanisms of CDK2-mediated anaphase catastrophe and how activated KRAS enhances this effect were investigated. Live-cell imaging provided direct evidence that following CDK2 inhibition, lung cancer cells develop multipolar anaphase and undergo multipolar cell division with the resulting progeny apoptotic. The siRNA-mediated repression of the CDK2 target and centrosome protein CP110 induced anaphase catastrophe of lung cancer cells. In contrast, CP110 overexpression antagonized CDK2 inhibitor–mediated anaphase catastrophe. Furthermore, activated KRAS mutations sensitized lung cancer cells to CDK2 inhibition by deregulating CP110 expression. Thus, CP110 is a critical mediator of CDK2 inhibition–driven anaphase catastrophe. Independent examination of murine and human paired normal–malignant lung tissues revealed marked upregulation of CP110 in malignant versus normal lung. Human lung cancers with KRAS mutations had significantly lower CP110 expression as compared with KRAS wild-type cancers. Thus, a direct link was found between CP110 and CDK2 inhibitor antineoplastic response. CP110 plays a mechanistic role in response of lung cancer cells to CDK2 inhibition, especially in the presence of activated KRAS mutations. Cancer Res; 75(10); 2029–38. ©2015 AACR.
MMP16 Mediates a Proteolytic Switch to Promote Cell–Cell Adhesion, Collagen Alignment, and Lymphatic Invasion in Melanoma
Authors: Tatti Olga , Gucciardo Erika , Pekkonen Pirita , Holopainen Tanja , Louhimo Riku , Repo Pauliina , Maliniemi Pilvi , Lohi Jouko , Rantanen Ville , Hautaniemi Sampsa , Alitalo Kari , Ranki Annamari , Ojala Päivi M. , Keski-Oja Jorma , Lehti Kaisa
Published: March 2015

Lymphatic invasion and accumulation of continuous collagen bundles around tumor cells are associated with poor melanoma prognosis, but the underlying mechanisms and molecular determinants have remained unclear. We show here that a copy-number gain or overexpression of the membrane-type matrix metalloproteinase MMP16 (MT3-MMP) is associated with poor clinical outcome, collagen bundle assembly around tumor cell nests, and lymphatic invasion. In cultured WM852 melanoma cells derived from human melanoma metastasis, silencing of MMP16 resulted in cell-surface accumulation of the MMP16 substrate MMP14 (MT1-MMP) as well as L1CAM cell adhesion molecule, identified here as a novel MMP16 substrate. When limiting the activities of these trans-membrane protein substrates toward pericellular collagen degradation, cell junction disassembly, and blood endothelial transmigration, MMP16 supported nodular-type growth of adhesive collagen-surrounded melanoma cell nests, coincidentally steering cell collectives into lymphatic vessels. These results uncover a novel mechanism in melanoma pathogenesis, whereby restricted collagen infiltration and limited mesenchymal invasion are unexpectedly associated with the properties of the most aggressive tumors, revealing MMP16 as a putative indicator of adverse melanoma prognosis. Cancer Res; 75(10); 2083–94. ©2015 AACR.
Decoy Receptor DcR1 Is Induced in a p50/Bcl3–Dependent Manner and Attenuates the Efficacy of Temozolomide
Authors: Mansour Nassir M. , Bernal Giovanna M. , Wu Longtao , Crawley Clayton D. , Cahill Kirk E. , Voce David J. , Balyasnikova Irina V. , Zhang Wei , Spretz Ruben , Nunez Luis , Larsen Gustavo F. , Weichselbaum Ralph R. , Yamini Bakhtiar
Published: March 2015

Temozolomide is used widely to treat malignant glioma, but the overall response to this agent is generally poor. Resistance to DNA-damaging drugs such as temozolomide has been related to the induction of antiapoptotic proteins. Specifically, the transcription factor NF-κB has been suggested to participate in promoting the survival of cells exposed to chemotherapy. To identify factors that modulate cytotoxicity in the setting of DNA damage, we used an unbiased strategy to examine the NF-κB–dependent expression profile induced by temozolomide. By this route, we defined the decoy receptor DcR1 as a temozolomide response gene induced by a mechanism relying upon p50/NF-κB1. A conserved NF-κB–binding sequence (κB-site) was identified in the proximal promoter and was demonstrated to be required for DcR1 induction by temozolomide. Loss-of-function and gain-of-function studies reveal that the atypical IκB protein, Bcl3, is also required for induction of DcR1 by temozolomide. Mechanistically, DcR1 attenuates temozolomide efficacy by blunting activation of the Fas receptor pathway in p53+/+ glioma cells. Intracranial xenograft studies show that DcR1 depletion in glioma cells enhances the efficacy of temozolomide. Taken together, our results show how DcR1 upregulation mediates temozolomide resistance and provide a rationale for DcR1 targeting as a strategy to sensitize gliomas to this widely used chemotherapy. Cancer Res; 75(10); 2039–48. ©2015 AACR.
Tenascin-C Protects Cancer Stem–like Cells from Immune Surveillance by Arresting T-cell Activation
Authors: Jachetti Elena , Caputo Sara , Mazzoleni Stefania , Brambillasca Chiara Svetlana , Parigi Sara Martina , Grioni Matteo , Piras Ignazio Stefano , Restuccia Umberto , Calcinotto Arianna , Freschi Massimo , Bachi Angela , Galli Rossella , Bellone Matteo
Published: March 2015

Precociously disseminated cancer cells may seed quiescent sites of future metastasis if they can protect themselves from immune surveillance. However, there is little knowledge about how such sites might be achieved. Here, we present evidence that prostate cancer stem–like cells (CSC) can be found in histopathologically negative prostate draining lymph nodes (PDLN) in mice harboring oncogene-driven prostate intraepithelial neoplasia (mPIN). PDLN-derived CSCs were phenotypically and functionally identical to CSC obtained from mPIN lesions, but distinct from CSCs obtained from frank prostate tumors. CSC derived from either PDLN or mPIN used the extracellular matrix protein Tenascin-C (TNC) to inhibit T-cell receptor–dependent T-cell activation, proliferation, and cytokine production. Mechanistically, TNC interacted with α5β1 integrin on the cell surface of T cells, inhibiting reorganization of the actin-based cytoskeleton therein required for proper T-cell activation. CSC from both PDLN and mPIN lesions also expressed CXCR4 and migrated in response to its ligand CXCL12, which was overexpressed in PDLN upon mPIN development. CXCR4 was critical for the development of PDLN-derived CSC, as in vivo administration of CXCR4 inhibitors prevented establishment in PDLN of an immunosuppressive microenvironment. Taken together, our work establishes a pivotal role for TNC in tuning the local immune response to establish equilibrium between disseminated nodal CSC and the immune system. Cancer Res; 75(10); 2095–108. ©2015 AACR.
Chronic Inflammation Induces a Novel Epigenetic Program That Is Conserved in Intestinal Adenomas and in Colorectal Cancer
Authors: Abu-Remaileh Monther , Bender Sebastian , Raddatz Günter , Ansari Ihab , Cohen Daphne , Gutekunst Julian , Musch Tanja , Linhart Heinz , Breiling Achim , Pikarsky Eli , Bergman Yehudit , Lyko Frank
Published: March 2015

Chronic inflammation represents a major risk factor for tumor formation, but the underlying mechanisms have remained largely unknown. Epigenetic mechanisms can record the effects of environmental challenges on the genome level and could therefore play an important role in the pathogenesis of inflammation-associated tumors. Using single-base methylation maps and transcriptome analyses of a colitis-induced mouse colon cancer model, we identified a novel epigenetic program that is characterized by hypermethylation of DNA methylation valleys that are characterized by low CpG density and active chromatin marks. This program is conserved and functional in mouse intestinal adenomas and results in silencing of active intestinal genes that are involved in gastrointestinal homeostasis and injury response. Further analyses reveal that the program represents a prominent feature of human colorectal cancer and can be used to correctly classify colorectal cancer samples with high accuracy. Together, our results show that inflammatory signals establish a novel epigenetic program that silences a specific set of genes that contribute to inflammation-induced cellular transformation. Cancer Res; 75(10); 2120–30. ©2015 AACR.
Manic Fringe Promotes a Claudin-Low Breast Cancer Phenotype through Notch-Mediated PIK3CG Induction
Authors: Zhang Shubing , Chung Wen-Cheng , Wu Guanming , Egan Sean E. , Miele Lucio , Xu Keli
Published: March 2015

Claudin-low breast cancer (CLBC) is a poor prognosis disease biologically characterized by stemness and mesenchymal features. These tumors disproportionately affect younger patients and women with African ancestry, causing significant morbidity and mortality, and no effective targeted therapy exists at present. CLBC is thought to originate from mammary stem cells, but little is known on how or why these tumors express a stable epithelial-to-mesenchymal transition phenotype, or what are the driving forces of this disease. Here, we report that Manic Fringe (Mfng), which encodes an O-fucosylpeptide 3-β-N-acetylglucosaminyltransferase known to modify EGF repeats in the Notch extracellular domain, is highly expressed in CLBC and functions as an oncogene in this context. We show that Mfng modulates Notch activation in human and mouse CLBC cell lines, as well as in mouse mammary gland. Mfng silencing in CLBC cell lines reduced cell migration, tumorsphere formation, and in vivo tumorigenicity associated with a decrease in the stem-like cell population. Mfng deletion in the Lfngflox/flox;MMTV-Cre mouse model, in which one-third of mammary tumors resemble human CLBC, caused a tumor subtype shift away from CLBC. We identified the phosphoinositide kinase Pik3cg as a direct transcriptional target of Mfng-facilitated RBPJκ-dependent Notch signaling. Indeed, pharmacologic inhibition of PI3Kγ in CLBC cell lines blocked migration and tumorsphere formation. Taken together, our results define Mfng as an oncogene acting through Notch-mediated induction of Pik3cg. Furthermore, they suggest that targeting PI3Kγ may prove beneficial for the treatment of CLBC subtype. Cancer Res; 75(10); 1936–43. ©2015 AACR.
Replication and Heritability of Prostate Cancer Risk Variants: Impact of Population-Specific Factors
Authors: Virlogeux Victor , Graff Rebecca E. , Hoffmann Thomas J. , Witte John S.
Published: March 2015

Background: Prostate cancer incidence and mortality rates vary across populations, with African American men exhibiting the highest rates. To date, genome-wide association studies have identified 104 SNPs independently associated with prostate cancer in men of European ancestry.

Methods: We investigated whether the ability to replicate findings for these 104 SNPs in African American, Asian, and Latino populations depends on variation in risk allele frequencies (RAF), strength of associations, and/or patterns of linkage disequilibrium (LD) at the associated loci. We extracted estimates of effect from the literature, and determined RAF and LD information across the populations from the 1000 Genomes Project.

Results: Risk variants were largely replicated across populations. Relative to Europeans, 83% had smaller effect sizes among African Americans and 73% demonstrated smaller effect sizes among Latinos. Among Asians, however, 56% showed larger effect sizes than among Europeans. The largest difference in RAFs was observed between European and African ancestry populations, but this difference did not impact our ability to replicate. The extent of LD within 250 kb of risk loci in Asian ancestry populations was suggestively lower for variants that did not replicate (P = 0.013).

Conclusions: Despite substantial overlap in prostate cancer risk SNPs across populations, the variation in prostate cancer incidence among different populations may still in part reflect unique underlying genetic architectures.

Impact: Studying different ancestral populations is crucial for deciphering the genetic basis of prostate cancer. Cancer Epidemiol Biomarkers Prev; 24(6); 938–43. ©2015 AACR.
Oral Human Papillomavirus Is Common in Individuals with Fanconi Anemia
Authors: Sauter Sharon L. , Wells Susanne I. , Zhang Xue , Hoskins Elizabeth E. , Davies Stella M. , Myers Kasiani C. , Mueller Robin , Panicker Gitika , Unger Elizabeth R. , Sivaprasad Umasundari , Brown Darron R. , Mehta Parinda A. , Butsch Kovacic Melinda
Published: March 2015

Background: Fanconi anemia is a rare genetic disorder resulting in a loss of function of the Fanconi anemia–related DNA repair pathway. Individuals with Fanconi anemia are predisposed to some cancers, including oropharyngeal and gynecologic cancers, with known associations with human papillomavirus (HPV) in the general population. As individuals with Fanconi anemia respond poorly to chemotherapy and radiation, prevention of cancer is critical.

Methods: To determine whether individuals with Fanconi anemia are particularly susceptible to oral HPV infection, we analyzed survey-based risk factor data and tested DNA isolated from oral rinses from 126 individuals with Fanconi anemia and 162 unaffected first-degree family members for 37 HPV types.

Results: Fourteen individuals (11.1%) with Fanconi anemia tested positive, significantly more (P = 0.003) than family members (2.5%). While HPV prevalence was even higher for sexually active individuals with Fanconi anemia (17.7% vs. 2.4% in family; P = 0.003), HPV positivity also tended to be higher in the sexually inactive (8.7% in Fanconi anemia vs. 2.9% in siblings). Indeed, having Fanconi anemia increased HPV positivity 4.9-fold (95% CI, 1.6–15.4) considering age and sexual experience, but did not differ by other potential risk factors.

Conclusion: Our studies suggest that oral HPV is more common in individuals with Fanconi anemia. It will be essential to continue to explore associations between risk factors and immune dysfunction on HPV incidence and persistence over time.

Impact: HPV vaccination should be emphasized in those with Fanconi anemia as a first step to prevent oropharyngeal cancers, although additional studies are needed to determine whether the level of protection it offers in this population is adequate. Cancer Epidemiol Biomarkers Prev; 24(5); 864–72. ©2015 AACR.
Genome-wide siRNA Screen Identifies the Radiosensitizing Effect of Downregulation of MASTL and FOXM1 in NSCLC
Authors: Nagel Remco , Stigter-van Walsum Marijke , Buijze Marijke , van den Berg Jaap , van der Meulen Ida H. , Hodzic Jasmina , Piersma Sander R. , Pham Thang V. , Jiménez Connie R. , van Beusechem Victor W. , Brakenhoff Ruud H.
Published: March 2015

Lung cancer is the most common cancer worldwide and on top of that has a very poor prognosis, which is reflected by a 5-year survival rate of 5% to 15%. Radiotherapy is an integral part of most treatment regimens for this type of tumor, often combined with radiosensitizing cytotoxic drugs. In this study, we identified many genes that could potentially be exploited for targeted radiosensitization using a genome-wide siRNA screen in non–small cell lung cancer (NSCLC) cells. The screen identified 433 siRNAs that potentially sensitize lung cancer cells to radiation. Validation experiments showed that knockdown of expression of Forkhead box M1 (FOXM1) or microtubule-associated serine/threonine kinase-like (MASTL) indeed causes radiosensitization in a panel of NSCLC cells. Strikingly, this effect was not observed in primary human fibroblasts, suggesting that the observed radiosensitization is specific for cancer cells. Phosphoproteomics analyses with and without irradiation showed that a number of cell-cycle–related proteins were significantly less phosphorylated after MASTL knockdown in comparison to the control, while there were no changes in the levels of phosphorylation of DNA damage response proteins. Subsequent analyses showed that MASTL knockdown cells respond differently to radiation, with a significantly shortened G2–M phase arrest and defects in cytokinesis, which are followed by a cell-cycle arrest. In summary, we have identified many potential therapeutic targets that could be used for radiosensitization of NSCLC cells, with MASTL being a very promising and druggable target to combine with radiotherapy. Mol Cancer Ther; 14(6); 1434–44. ©2015 AACR.
Hemidiaphragm Paralysis after Robotic Prostatectomy: Medical Malpractice or Unforeseeable Event?
Authors: Focardi Martina , Bonelli Aurelio , Pinchi Vilma , Vittori Gianni , De Luca Federica , Norelli Gian-Aristide
Published: March 2015

The authors present a case of suspected malpractice linked to the onset of hemidiaphragm paralysis after robot-assisted radical prostatectomy (RARP). The approach to the case is shown from a medico-legal point of view. It is demonstrated how, after a thorough review of the literature, this was not a case of medical malpractice but an unforeseeable event. This paper aims at contributing to the very few reports dealing with the onset of hemidiaphragm paralysis after RARP, thus fostering clinical knowledge of these rare events and meanwhile providing useful data for the medico-legal handling in case of alleged negligence of surgeons.
Diffuse Brain Abnormalities in Myotonic Dystrophy Type 1 Detected by 3.0 T Proton Magnetic Resonance Spectroscopy
Authors: Takado Yuhei , Terajima Kenshi , Ohkubo Masaki , Okamoto Kouichirou , Shimohata Takayoshi , Nishizawa Masatoyo , Igarashi Hironaka , Nakada Tsutomu
Published: March 2015

Patients with myotonic dystrophy type 1 (DM1) (n = 14) were compared with healthy controls (n = 13) using 3.0 T proton magnetic resonance spectroscopy (1H-MRS) to investigate brain pathophysiology. 1H-MRS imaging revealed reduced N-acetylaspartate to creatine ratio (NAA/Cr) in multiple brain regions (average 24%), suggesting diffuse brain abnormalities among patients with DM1. Single-voxel 1H-MRS among patients with DM1 showed (1) reduced NAA in both the frontal cortex (23%) and frontal white matter (31%) and unaltered myo-inositol, suggesting neuronal abnormalities without significant gliosis; and (2) elevated glutamine in the frontal cortex (36%) and reduced glutamate in the frontal white matter (20%) among patients with DM1, suggesting abnormalities in the glutamatergic system in the brain of patients with DM1. We consider that these results reflect brain abnormalities that cannot be detected by neuropathological assessment in patients with DM1.
Micro-RNAs and Their Roles in Eye Disorders
Authors: Raghunath Azhwar , Perumal Ekambaram
Published: March 2015

Micro-RNAs (miRNAs) are members of the family of noncoding RNA molecules that regulate gene expression by translational repression and mRNA degradation. Initial identification of miRNAs revealed them only as developmental regulators; later, their radiated roles in various cellular processes have been established. They regulate several pathways, including developmental timing, hematopoiesis, organogenesis, apoptosis, cell differentiation and proliferation. Their roles in eye disorders are being explored by biologists around the world. Eye physiology requires the perfect orchestration of all the regulatory networks; any defect in any of the networks leads to eye disorders. The dysregulation of miRNA expression has been reported in many eye disorders, which paves the way for new therapeutics. This review summarizes the biogenesis of miRNAs and their role in eye disorders. miRNA studies also have implications for the understanding of various complex metabolic pathways leading to disorders of the eye. The ultimate understanding leads to potential opportunities in evaluating miRNAs as molecular biomarkers, prognostic tools, diagnostic tools and therapeutic agents for eye disorders.