bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of the late sodium current slows t-tubule disruption during the progression of hypertensive heart disease in the rat
Authors: Aistrup Gary L. , Gupta Deepak K. , Kelly James E. , O'Toole Matthew J. , Nahhas Amanda , Chirayil Nimi , Misener Sol , Beussink Lauren , Singh Neha , Ng Jason , Reddy Mahendra , Mongkolrattanothai Thitipong , El-Bizri Nesrine , Rajamani Sridharan , Shryock John C. , Belardinelli Luiz , Shah Sanjiv J. , Wasserstrom J. Andrew
Published: July 2013

The treatment of heart failure (HF) is challenging and morbidity and mortality are high. The goal of this study was to determine if inhibition of the late Na+ current with ranolazine during early hypertensive heart disease might slow or stop disease progression. Spontaneously hypertensive rats (aged 7 mo) were subjected to echocardiographic study and then fed either control chow (CON) or chow containing 0.5% ranolazine (RAN) for 3 mo. Animals were then restudied, and each heart was removed for measurements of t-tubule organization and Ca2+ transients using confocal microscopy of the intact heart. RAN halted left ventricular hypertrophy as determined from both echocardiographic and cell dimension (length but not width) measurements. RAN reduced the number of myocytes with t-tubule disruption and the proportion of myocytes with defects in intracellular Ca2+ cycling. RAN also prevented the slowing of the rate of restitution of Ca2+ release and the increased vulnerability to rate-induced Ca2+ alternans. Differences between CON- and RAN-treated animals were not a result of different expression levels of voltage-dependent Ca2+ channel 1.2, sarco(endo)plasmic reticulum Ca2+-ATPase 2a, ryanodine receptor type 2, Na+/Ca2+ exchanger-1, or voltage-gated Na+ channel 1.5. Furthermore, myocytes with defective Ca2+ transients in CON rats showed improved Ca2+ cycling immediately upon acute exposure to RAN. Increased late Na+ current likely plays a role in the progression of cardiac hypertrophy, a key pathological step in the development of HF. Early, chronic inhibition of this current slows both hypertrophy and development of ultrastructural and physiological defects associated with the progression to HF.
Activation of angiotensin-converting enzyme 2/angiotensin-(1–7)/Mas axis attenuates the cardiac reactivity to acute emotional stress
Authors: Lima Augusto Martins , Xavier Carlos Henrique , Ferreira Anderson José , Raizada Mohan K. , Wallukat Gerd , Velloso Elizabeth Portugal Pimenta , Santos Robson Augusto Sousa dos , Fontes Marco Antônio Peliky
Published: July 2013

Recent data indicate the brain angiotensin-converting enzyme/ANG II/AT1 receptor axis enhances emotional stress responses. In this study, we investigated whether its counterregulatory axis, the angiotensin-converting enzyme 2 (ACE2)/ANG-(1–7)/Mas axis, attenuate the cardiovascular responses to acute emotional stress. In conscious male Wistar rats, the tachycardia induced by acute stress (air jet 10 l/min) was attenuated by intravenous injection of ANG-(1–7) [Δ heart rate (HR): saline 136 ± 22 vs. ANG-(1–7) 61 ± 25 beats/min; P < 0.05]. Peripheral injection of the ACE2 activator compound, XNT, abolished the tachycardia induced by acute stress. We found a similar effect after intracerebroventricular injections of either ANG-(1–7) or XNT. Under urethane anesthesia, the tachycardia evoked by the beta-adrenergic agonist was markedly reduced by ANG-(1–7) [ΔHR: saline 100 ± 16 vs. ANG-(1–7) 18 ± 15 beats/min; P < 0.05]. The increase in renal sympathetic nerve activity (RSNA) evoked by isoproterenol was also abolished after the treatment with ANG-(1–7) [ΔRSNA: saline 39% vs. ANG-(1–7) −23%; P < 0.05]. The tachycardia evoked by disinhibition of dorsomedial hypothalamus neurons, a key nucleus for the cardiovascular response to emotional stress, was reduced by ∼45% after intravenous injection of ANG-(1–7). In cardiomyocyte, the incubation with ANG-(1–7) (1 μM) markedly attenuated the increases in beating rate induced by isoproterenol. Our data show that activation of the ACE2/ANG-(1–7)/Mas axis attenuates stress-induced tachycardia. This effect might be either via the central nervous system reducing anxiety level and/or interfering with the positive chronotropy mediated by activation of cardiac β adrenergic receptors. Therefore, ANG-(1–7) might contribute to reduce the sympathetic load to the heart during situations of emotional stress, reducing the cardiovascular risk.
Serial measurement of hFABP and high-sensitivity troponin I post-PCI in STEMI: how fast and accurate can myocardial infarct size and no-reflow be predicted?
Authors: Uitterdijk André , Sneep Stefan , van Duin Richard W. B. , Krabbendam-Peters Ilona , Gorsse-Bakker Charlotte , Duncker Dirk J. , van der Giessen Willem J. , van Beusekom Heleen M. M.
Published: July 2013

The objective of this study was to compare heart-specific fatty acid binding protein (hFABP) and high-sensitivity troponin I (hsTnI) via serial measurements to identify early time points to accurately quantify infarct size and no-reflow in a preclinical swine model of ST-elevated myocardial infarction (STEMI). Myocardial necrosis, usually confirmed by hsTnI or TnT, takes several hours of ischemia before plasma levels rise in the absence of reperfusion. We evaluated the fast marker hFABP compared with hsTnI to estimate infarct size and no-reflow upon reperfused (2 h occlusion) and nonreperfused (8 h occlusion) STEMI in swine. In STEMI ( n = 4) and STEMI + reperfusion ( n = 8) induced in swine, serial blood samples were taken for hFABP and hsTnI and compared with triphenyl tetrazolium chloride and thioflavin-S staining for infarct size and no-reflow at the time of euthanasia. hFABP increased faster than hsTnI upon occlusion (82 ± 29 vs. 180 ± 73 min, P < 0.05) and increased immediately upon reperfusion while hsTnI release was delayed 16 ± 3 min ( P < 0.05). Peak hFABP and hsTnI reperfusion values were reached at 30 ± 5 and 139 ± 21 min, respectively ( P < 0.05). Infarct size (containing 84 ± 0.6% no-reflow) correlated well with area under the curve for hFABP ( r2 = 0.92) but less for hsTnI ( r2 = 0.53). At 50 and 60 min reperfusion, hFABP correlated best with infarct size ( r2 = 0.94 and 0.93) and no-reflow ( r2 = 0.96 and 0.94) and showed high sensitivity for myocardial necrosis (2.3 ± 0.6 and 0.4 ± 0.6 g). hFABP rises faster and correlates better with infarct size and no-reflow than hsTnI in STEMI + reperfusion when measured early after reperfusion. The highest sensitivity detecting myocardial necrosis, 0.4 ± 0.6 g at 60 min postreperfusion, provides an accurate and early measurement of infarct size and no-reflow.
Quercetin acutely relaxes airway smooth muscle and potentiates β-agonist-induced relaxation via dual phosphodiesterase inhibition of PLCβ and PDE4
Authors: Townsend Elizabeth A. , Emala Charles W.
Published: July 2013

Asthma is a disease of the airways with symptoms including exaggerated airway narrowing and airway inflammation. Early asthma therapies used methylxanthines to relieve symptoms, in part, by inhibiting cyclic nucleotide phosphodiesterases (PDEs), the enzyme responsible for degrading cAMP. The classification of tissue-specific PDE subtypes and the clinical introduction of PDE-selective inhibitors for chronic obstructive pulmonary disease (i.e., roflumilast) have reopened the possibility of using PDE inhibition in the treatment of asthma. Quercetin is a naturally derived PDE4-selective inhibitor found in fruits, vegetables, and tea. We hypothesized that quercetin relaxes airway smooth muscle via cAMP-mediated pathways and augments β-agonist relaxation. Tracheal rings from male A/J mice were mounted in myographs and contracted with acetylcholine (ACh). Addition of quercetin (100 nM-1 mM) acutely and concentration-dependently relaxed airway rings precontracted with ACh. In separate studies, pretreatment with quercetin (100 μM) prevented force generation upon exposure to ACh. In additional studies, quercetin (50 μM) significantly potentiated isoproterenol-induced relaxations. In in vitro assays, quercetin directly attenuated phospholipase C activity, decreased inositol phosphate synthesis, and decreased intracellular calcium responses to Gq-coupled agonists (histamine or bradykinin). Finally, nebulization of quercetin (100 μM) in an in vivo model of airway responsiveness significantly attenuated methacholine-induced increases in airway resistance. These novel data show that the natural PDE4-selective inhibitor quercetin may provide therapeutic relief of asthma symptoms and decrease reliance on short-acting β-agonists.
Effect of unilateral diaphragmatic paralysis on postpneumonectomy lung growth
Authors: Ysasi Alexandra B. , Belle Janeil M. , Gibney Barry C. , Fedulov A. V. , Wagner Willi , AkiraTsuda  , Konerding Moritz A. , Mentzer Steven J.
Published: July 2013

Respiratory muscle-associated stretch has been implicated in normal lung development (fetal breathing movements) and postpneumonectomy lung growth. To test the hypothesis that mechanical stretch from diaphragmatic contraction contributes to lung growth, we performed left phrenic nerve transections (PNT) in mice with and without ipsilateral pneumonectomy. PNT was demonstrated by asymmetric costal margin excursion and confirmed at autopsy. In mice with two lungs, PNT was associated with a decrease in ipsilateral lung volume ( P < 0.05) and lung weight ( P < 0.05). After pneumonectomy, PNT was not associated with a change in activity level, measureable hypoxemia, or altered minute ventilation; however, microCT scanning demonstrated altered displacement and underinflation of the cardiac lobe within the first week after pneumonectomy. Coincident with the altered structural realignment, lung impedance measurements, fitted to the constant-phase model, demonstrated elevated airway resistance ( P < 0.05), but normal peripheral tissue resistance ( P > 0.05). Most important, PNT appeared to abrogate compensatory lung growth after pneumonectomy; the weight of the lobes of the right lung was significantly less than pneumonectomy alone ( P < 0.001) and indistinguishable from nonsurgical controls ( P > 0.05). We conclude that the cyclic stretch associated with diaphragmatic muscle contraction is a controlling factor in postpneumonectomy compensatory lung growth.
Sustained inflation at birth did not protect preterm fetal sheep from lung injury
Authors: Hillman Noah H. , Kemp Matthew W. , Noble Peter B. , Kallapur Suhas G. , Jobe Alan H.
Published: July 2013

Sustained lung inflations (SI) at birth may recruit functional residual capacity (FRC). Clinically, SI increase oxygenation and decrease need for intubation in preterm infants. We tested whether a SI to recruit FRC would decrease lung injury from subsequent ventilation of fetal, preterm lambs. The preterm fetus (128 ± 1 day gestation) was exteriorized from the uterus, a tracheostomy was performed, and fetal lung fluid was removed. While maintaining placental circulation, fetuses were randomized to one of four 15-min interventions: 1) positive end-expiratory pressure (PEEP) 8 cmH2O ( n = 4), 2) 20 s SI to 50 cmH2O then PEEP 8 cmH2O ( n = 10), 3) mechanical ventilation at tidal volume (VT) 7 ml/kg ( n = 13), or 4) 20 s SI then ventilation at VT7 ml/kg ( n = 13). Lambs were ventilated with 95% N2/5% CO2and PEEP 8 cmH2O. Volume recruitment was measured during SI, and fetal tissues were collected after an additional 30 min on placental support. SI achieved a mean FRC recruitment of 15 ml/kg (range 8–27). Fifty percent of final FRC was achieved by 2 s, 65% by 5 s, and 90% by 15 s, demonstrating prolonged SI times are needed to recruit FRC. SI alone released acute-phase proteins into the fetal lung fluid and increased mRNA expression of proinflammatory cytokines and acute-phase response genes in the lung. Mechanical ventilation further increased all markers of lung injury. SI before ventilation, regardless of the volume of FRC recruited, did not alter the acute-phase and proinflammatory responses to mechanical ventilation at birth.
Reduced microtubule acetylation in cystic fibrosis epithelial cells
Authors: Rymut Sharon M. , Harker Alyssa , Corey Deborah A. , Burgess James D. , Sun Hongtao , Clancy John P. , Kelley Thomas J.
Published: July 2013

Dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) leads to many cellular consequences, including perinuclear accumulation of free cholesterol due to impaired endosomal transport. The hypothesis being tested is that CF-related perinuclear cholesterol accumulation due to disrupted endocytic trafficking occurs as a result of reduced microtubule (MT) acetylation. Here, it is identified that acetylated-α-tubulin (Ac-tub) content is reduced by ∼40% compared with respective wild-type controls in both cultured CF cell models (IB3) and primary Cftr−/− mouse nasal epithelial tissue. Histone deacetylase 6 (HDAC6) has been shown to regulate MT acetylation, which provides reasonable grounds to test its impact on reduced Ac-tub content on CF cellular phenotypes. Inhibition of HDAC6, either through tubastatin treatment or HDAC6 knockdown in CF cells, increases Ac-tub content and results in redistributed free cholesterol and reduced stimulation of NF-κB activity. Mechanistically, endoplasmic reticulum stress, which is widely reported in CF and leads to aggresome formation, is identified as a regulator of MT acetylation. F508del CFTR correction with C18 in primary airway epithelial cells restores MT acetylation and cholesterol transport. A significant role for phosphatidyl inositol-3 kinase p110α is also identified as a regulator of MT acetylation.
Sildenafil (Viagra) Protective Effects on Neuroinflammation: The Role of iNOS/NO System in an Inflammatory Demyelination Model
Authors: Raposo Catarina , Nunes Ana Karolina de Santana , Luna Rayana Leal de Almeida , Araújo Shyrlene Meiry da Rocha , da Cruz-Höfling Maria Alice , Peixoto Christina Alves
Published: July 2013

We recently demonstrated that sildenafil reduces the expression of cytokines, COX-2, and GFAP in a demyelinating model induced in wild-type (WT) mice. Herein, the understandings of the neuroprotective effect of sildenafil and the mediation of iNOS/NO system on inflammatory demyelination induced by cuprizone were investigated. The cerebella of iNOS−/−mice were examined after four weeks of treatment with cuprizone alone or combined with sildenafil. Cuprizone increased GFAP, Iba-1, TNF-α, COX-2, IL-1β, and IFN-γexpression, decreased expression of glutathione S-transferase pi (GSTpi), and damaged myelin in iNOS−/−mice. Sildenafil reduced Iba-1, IFN-γ, and IL-1βlevels but had no effect on the expression of GFAP, TNF-α, and COX-2 compared to the cuprizone group. Sildenafil elevated GSTpi levels and improved the myelin structure/ultrastructure. iNOS−/−mice suffered from severe inflammation following treatment with cuprizone, while WT mice had milder inflammation, as found in the previous study. It is possible that inflammatory regulation through iNOS-feedback is absent in iNOS−/−mice, making them more susceptible to inflammation. Sildenafil has at least a partial anti-inflammatory effect through iNOS inhibition, as its effect on iNOS−/−mice was limited. Further studies are required to explain the underlying mechanism of the sildenafil effects.
CFSO3: A New Supervised Swarm-Based Optimization Algorithm
Authors: Laudani Antonino , Riganti Fulginei Francesco , Salvini Alessandro , Schmid Maurizio , Conforto Silvia
Published: July 2013

We present CFSO3, an optimization heuristic within the class of the swarm intelligence, based on a synergy among three different features of the Continuous Flock-of-Starlings Optimization. One of the main novelties is that this optimizer is no more a classical numerical algorithm since it now can be seen as a continuous dynamic system, which can be treated by using all the mathematical instruments available for managing state equations. In addition, CFSO3allows passing from stochastic approaches to supervised deterministic ones since the random updating of parameters, a typical feature for numerical swam-based optimization algorithms, is now fully substituted by a supervised strategy: in CFSO3the tuning of parameters isa prioridesigned for obtaining both exploration and exploitation. Indeed the exploration, that is, the escaping from a local minimum, as well as the convergence and the refinement to a solution can be designed simply by managing the eigenvalues of the CFSO state equations. Virtually in CFSO3, just the initial values of positions and velocities of the swarm members have to be randomly assigned. Both standard and parallel versions of CFSO3together with validations on classical benchmarks are presented.
Norm-Constrained Least-Squares Solutions to the Matrix EquationAXB=C
Authors: Xu An-bao , Peng Zhenyun
Published: July 2013

An iterative method to compute the least-squares solutions of the matrixAXB=Cover the norm inequality constraint is proposed. For this method, without the error of calculation, a desired solution can be obtained with finitely iterative step. Numerical experiments are performed to illustrate the efficiency and real application of the algorithm.
Erlotinib Resistance in Lung Cancer Cells Mediated by Integrin β1/Src/Akt-Driven Bypass Signaling
Authors: Kanda Rina , Kawahara Akihiko , Watari Kosuke , Murakami Yuichi , Sonoda Kahori , Maeda Masashi , Fujita Hideaki , Kage Masayoshi , Uramoto Hidetaka , Costa Carlota , Kuwano Michihiko , Ono Mayumi
Published: July 2013

EGF receptor (EGFR) kinase inhibitors, including gefitinib and erlotinib, exert potent therapeutic efficacy in non–small cell lung cancers harboring EGFR-activating mutations. However, most patients ultimately develop resistance to these drugs. Here, we report a novel mechanism of acquired resistance to EGFR tyrosine kinase inhibitors and the reversal of which could improve clinical outcomes. In erlotinib-resistant lung cancer cells harboring activating EGFR mutations that we established, there was increased expression of Src, integrin β1, α2, and α5 along with enhanced cell adhesion activity. Interestingly, RNAi-mediated silencing of integrin β1 restored erlotinib sensitivity and reduced activation of Src and Akt after erlotinib treatment. Furthermore, Src silencing inhibited Akt phosphorylation and cell growth, with this inhibitory effect further augmented by erlotinib treatment. Increased expression of integrin β1, α5, and/or α2 was also observed in refractory tumor samples from patients with lung cancer treated with erlotinib and/or gefitinib. Together, our findings identify the integrin β1/Src/Akt signaling pathway as a key mediator of acquired resistance to EGFR-targeted anticancer drugs. Cancer Res; 73(20); 6243–53. ©2013 AACR.
A Synthetic Lethality–Based Strategy to Treat Cancers Harboring a Genetic Deficiency in the Chromatin Remodeling Factor BRG1
Authors: Oike Takahiro , Ogiwara Hideaki , Tominaga Yuichi , Ito Kentaro , Ando Osamu , Tsuta Koji , Mizukami Tatsuji , Shimada Yoko , Isomura Hisanori , Komachi Mayumi , Furuta Koh , Watanabe Shun-Ichi , Nakano Takashi , Yokota Jun , Kohno Takashi
Published: July 2013

The occurrence of inactivating mutations in SWI/SNF chromatin-remodeling genes in common cancers has attracted a great deal of interest. However, mechanistic strategies to target tumor cells carrying such mutations are yet to be developed. This study proposes a synthetic-lethality therapy for treating cancers deficient in the SWI/SNF catalytic (ATPase) subunit, BRG1/SMARCA4. The strategy relies upon inhibition of BRM/SMARCA2, another catalytic SWI/SNF subunit with a BRG1-related activity. Immunohistochemical analysis of a cohort of non–small-cell lung carcinomas (NSCLC) indicated that 15.5% (16 of 103) of the cohort, corresponding to preferentially undifferentiated tumors, was deficient in BRG1 expression. All BRG1-deficient cases were negative for alterations in known therapeutic target genes, for example, EGFR and DDR2 gene mutations, ALK gene fusions, or FGFR1 gene amplifications. RNA interference (RNAi)–mediated silencing of BRM suppressed the growth of BRG1-deficient cancer cells relative to BRG1-proficient cancer cells, inducing senescence via activation of p21/CDKN1A. This growth suppression was reversed by transduction of wild-type but not ATPase-deficient BRG1. In support of these in vitro results, a conditional RNAi study conducted in vivo revealed that BRM depletion suppressed the growth of BRG1-deficient tumor xenografts. Our results offer a rationale to develop BRM-ATPase inhibitors as a strategy to treat BRG1/SMARCA4–deficient cancers, including NSCLCs that lack mutations in presently known therapeutic target genes. Cancer Res; 73(17); 5508–18. ©2013 AACR.
Racial Differences in the Incidence and Clearance of Human Papilloma Virus (HPV): The HPV in Men (HIM) Study
Authors: Schabath Matthew B. , Villa Luisa L. , Lin Hui-Yi , Fulp William J. , Akogbe Gabriel O. , Abrahamsen Martha E. , Papenfuss Mary R. , Lazcano-Ponce Eduardo , Salmerón Jorge , Quiterio Manuel , Giuliano Anna R.
Published: July 2013

Background: This analysis assessed the acquisition (incidence) and persistence (clearance) of human papilloma virus (HPV) infection by self-reported race among men in The HPV in Men (HIM) Study, a multinational prospective study of the natural history of genital HPV infections.

Methods: Self-reported race was categorized as White, Black, Asian/Pacific Islander (PI), or multiple and mixed race. Genital samples were combined for HPV DNA testing and categorized by any, oncogenic, and non-oncogenic HPV infections.

Results: Asian/PI race had significantly the lowest incidence of any, oncogenic, and non-oncogenic HPV infection (P < 0.001). In multivariable analyses, Asian/PI race was associated with a lower probability of acquiring any [HR = 0.63; 95% confidence interval (CI), 0.42–0.95] and non-oncogenic HPV infection (HR = 0.61; 95% CI, 0.40–0.93) when compared to Whites. No significant associations were evident for Asian/PI race for clearance. Multiple and mixed race was significantly associated with lower probability of acquiring non-oncogenic HPV infection (HR = 0.83; 95% CI, 0.69–0.99) and borderline significant associations were observed for any HPV (HR = 0.91) and oncogenic infections (HR = 0.92). Multiple and mixed race was associated with a lower probability of clearing any (HR = 0.92; 95% CI, 0.84–1.00) and oncogenic HPV infections (HR = 0.85; 95% CI, 0.75–0.95).

Conclusion: Asian/PI race had the lowest incidence of HPV and exhibited a lower probability of acquiring new HPV infections. Multiple and mixed race had the second lowest incidence of infection and was associated with a lower probability of acquiring and clearing an HPV infection.

Impact: Race-specific differences in HPV infection could be due to behavior, innate genetic differences, or circulating intratypic HPV variants. Cancer Epidemiol Biomarkers Prev; 22(10); 1762–70. ©2013 AACR.
Multiple Myeloma Patients Have a Specific Serum Metabolomic Profile That Changes after Achieving Complete Remission
Authors: Puchades-Carrasco Leonor , Lecumberri Ramón , Martínez-López Joaquín , Lahuerta Juan-José , Mateos María-Victoria , Prósper Felipe , San-Miguel Jesús F. , Pineda-Lucena Antonio
Published: July 2013

Purpose: Multiple myeloma remains an incurable disease. New approaches to develop better tools for improving patient prognostication and monitoring treatment efficacy are very much needed. In this study, we aimed to evaluate the potential of metabolomics by 1H-NMR to provide information on metabolic profiles that could be useful in the management of multiple myeloma.

Experimental Design: Serum samples were collected from multiple myeloma patients at the time of diagnosis and after achieving complete remission. A matched control set of samples was also included in the study. The 1H-NMR measurements used to obtain the metabolic profile for each patient were followed by the application of univariate and multivariate statistical analyses to determine significant differences.

Results: Metabolic profiles of multiple myeloma patients at diagnosis exhibited higher levels of isoleucine, arginine, acetate, phenylalanine, and tyrosine, and decreased levels of 3-hydroxybutyrate, lysine, glutamine, and some lipids compared with the control set. A similar analysis conducted in multiple myeloma patients after achieving complete remission indicated that some of the metabolic changes (i.e., glutamine, cholesterol, lysine) observed at diagnosis displayed a variation in the opposite direction upon responding to treatment, thus contributing to multiple myeloma patients having a closer metabolic profile to those of healthy individuals after the disappearance of major disease manifestations.

Conclusions: The results highlight the potential of metabolic profiles obtained by 1H-NMR in identifying multiple myeloma biomarkers that may be useful to objectively discriminate individuals with and without multiple myeloma, and monitor response to treatment. Clin Cancer Res; 19(17); 4770–9. ©2013 AACR.
Downregulation of Hematopoietic MUC1 during Experimental Colitis Increases Tumor-Promoting Myeloid-Derived Suppressor Cells
Authors: Poh Tze Wei , Madsen Cathy S. , Gorman Jessica E. , Marler Ronald J. , Leighton Jonathan A. , Cohen Peter A. , Gendler Sandra J.
Published: July 2013

Purpose: MUC1 is a tumor-associated antigen that is aberrantly expressed in cancer and inflammatory bowel disease (IBD). Even though immune cells express low MUC1 levels, their modulations of MUC1 are important in tumor progression. Consistent with previous clinical data that show increased myeloid-derived suppressor cells (MDSCs) in IBD, we now show that downregulation of MUC1 on hematopoietic cells increases MDSCs in IBD, similar to our data in tumor-bearing mice. We hypothesize that MDSC expansion in IBD is critical for tumor progression.

Experimental Design: To mechanistically confirm the linkage between Muc1 downregulation and MDSC expansion, we generated chimeric mice that did not express Muc1 in the hematopoietic compartment (KO→WT). These mice were used in two models of colitis and colitis-associated cancer (CAC) and their responses were compared with wild-type (WT) chimeras (WT→WT).

Results: KO→WT mice show increased levels of MDSCs during colitis and increased protumorigenic signaling in the colon during CAC, resulting in larger colon tumors. RNA and protein analysis show increased upregulation of metalloproteinases, collagenases, defensins, complements, growth factors, cytokines, and chemokines in KO→WT mice as compared with WT→WT mice. Antibody-mediated depletion of MDSCs in mice during colitis reduced colon tumor formation during CAC.

Conclusion: Development of CAC is a serious complication of colitis and our data highlight MDSCs as a targetable link between inflammation and cancer. In addition, the lack of MUC1 expression on MDSCs can be a novel marker for MDSCs, given that MDSCs are still not well characterized in human cancers. Clin Cancer Res; 19(18); 5039–52. ©2013 AACR.
Anti-PD-1 Antibody Therapy Potently Enhances the Eradication of Established Tumors By Gene-Modified T Cells
Authors: John Liza B. , Devaud Christel , Duong Connie P.M. , Yong Carmen S. , Beavis Paul A. , Haynes Nicole M. , Chow Melvyn T. , Smyth Mark J. , Kershaw Michael H. , Darcy Phillip K.
Published: July 2013

Purpose: To determine the antitumor efficacy and toxicity of a novel combination approach involving adoptive T-cell immunotherapy using chimeric antigen receptor (CAR) T cells with an immunomodulatory reagent for blocking immunosuppression.

Experimental Design: We examined whether administration of a PD-1 blocking antibody could increase the therapeutic activity of CAR T cells against two different Her-2+ tumors. The use of a self-antigen mouse model enabled investigation into the efficacy, mechanism, and toxicity of this combination approach.

Results: In this study, we first showed a significant increase in the level of PD-1 expressed on transduced anti-Her-2 CD8+ T cells following antigen-specific stimulation with PD-L1+ tumor cells and that markers of activation and proliferation were increased in anti-Her-2 T cells in the presence of anti-PD-1 antibody. In adoptive transfer studies in Her-2 transgenic recipient mice, we showed a significant improvement in growth inhibition of two different Her-2+ tumors treated with anti-Her-2 T cells in combination with anti-PD-1 antibody. The therapeutic effects observed correlated with increased function of anti-Her-2 T cells following PD-1 blockade. Strikingly, a significant decrease in the percentage of Gr1+ CD11b+ myeloid-derived suppressor cells (MDSC) was observed in the tumor microenvironment of mice treated with the combination therapy. Importantly, increased antitumor effects were not associated with any autoimmune pathology in normal tissue expressing Her-2 antigen.

Conclusion: This study shows that specifically blocking PD-1 immunosuppression can potently enhance CAR T-cell therapy that has significant implications for potentially improving therapeutic outcomes of this approach in patients with cancer. Clin Cancer Res; 19(20); 5636–46. ©2013 AACR.
Phase I Study of BIIB028, a Selective Heat Shock Protein 90 Inhibitor, in Patients with Refractory Metastatic or Locally Advanced Solid Tumors
Authors: Hong David , Said Rabih , Falchook Gerald , Naing Aung , Moulder Stacy , Tsimberidou Apostolia-Maria , Galluppi Gerald , Dakappagari Naveen , Storgard Chris , Kurzrock Razelle , Rosen Lee S.
Published: July 2013

Purpose: Heat shot protein 90 (Hsp90) is a ubiquitous molecular chaperone involved in protein folding, activation, and assembly, including key mediators of signal transduction, cell-cycle control, and transcriptional regulation. We conducted a phase I dose-finding and pharmacokinetic/pharmacodynamic study of BIIB028, a prodrug designed to inhibit Hsp90 activity.

Experimental Design: Patients with advanced solid tumors were enrolled and received escalating doses of BIIB028 intravenously twice a week in 21-day cycles (3 + 3 design). Response was evaluated after two cycles.

Results: Forty-one patients received doses of 6 to 192 mg/m2. The maximum tolerated dose was 144 mg/m2. Dose-limiting toxicities were syncope (n = 1) and fatigue (n = 1). Common toxicities at least possibly related to drug were grades 1 to 2, including fatigue (46%), diarrhea (44%), nausea (44%), vomiting (29%), hot flushes (29%), and abnormal dreams (17%). The concentration–time curves for day 1 and day 18 for both prodrug and active metabolite (CF2772) showed a negligible difference. There was a dose-dependent increase in plasma exposure for BIIB028 (CF3647) and CF2772 with plasma half-life of 0.5 and 2.1 hours, respectively. Pharmacodynamic analyses showed significant increases in Hsp70 in peripheral blood mononuclear cells and significantly decreased circulating human EGF receptor-2 extracellular domain in all patients who received BIIB028 at dose levels of 48 mg/m2 or more. Stable disease for at least eight cycles (24 weeks) was achieved in 5 (12%) patients (for durations of 6, 6, 8, 12.5, and 19 months).

Conclusion: BIIB028 is a well-tolerated molecule that showed target impact and was associated with prolonged stable disease in two patients. Clin Cancer Res; 19(17); 4824–31. ©2013 AACR.
The IL-18 Antagonist IL-18–Binding Protein Is Produced in the Human Ovarian Cancer Microenvironment
Authors: Carbotti Grazia , Barisione Gaia , Orengo Anna Maria , Brizzolara Antonella , Airoldi Irma , Bagnoli Marina , Pinciroli Patrizia , Mezzanzanica Delia , Centurioni Maria Grazia , Fabbi Marina , Ferrini Silvano
Published: July 2013

Purpose: Interleukin (IL)-18 is an immune-enhancing cytokine, which induces IFN-γ production, T-helper 1 responses, and antitumor effects. In turn, IFN-γ stimulates IL-18–binding protein production, which blocks IL-18 activity. In view of the potential use of IL-18 in epithelial ovarian cancer (EOC) immunotherapy, here, we studied IL-18BP expression and its regulation by cytokines in EOC cells in vitro and in vivo.

Experimental Design: Expression and production of IL-18BP in EOC cell lines, primary ovarian carcinomas, and the corresponding normal tissues, patients' serum, and ascites were investigated by immunochemistry, ELISA, screening of gene expression profiles, and reverse-transcription PCR.

Results: Analysis of gene expression profiles revealed that IL18BP mRNA is increased in EOC tumors compared with normal ovary cells. Release of IL-18BP was detectable in EOC sera and to a greater extent in the ascites, indicating production at the tumor site. Indeed, immunochemical analyses on cells isolated from the ascites and on tumor sections indicated that IL-18BP is expressed in both tumor cells and tumor-associated leukocytes, which displayed a CD3−CD20−NKp46−CD13+CD14low phenotype. EOC cell lines do not constitutively express IL-18BP. However, its release is inducible both by IFN-γ stimulation in vitro and by xenotransplantation of EOC cells in immune-deficient mice, suggesting a role for the microenvironment. In vitro experiments and immunochemistry indicated that IL-27 is also involved in IL-18BP upregulation in EOC cell lines and primary cells through STAT1 activation. Together, these data indicate that IL-18BP, which is produced in EOC in response to microenvironmental factors, may inhibit endogenous or exogenous IL-18 activity. Clin Cancer Res; 19(17); 4611–20. ©2013 AACR.
Novel Role of MDA-9/Syntenin in Regulating Urothelial Cell Proliferation by Modulating EGFR Signaling
Authors: Dasgupta Santanu , Menezes Mitchell E. , Das Swadesh K. , Emdad Luni , Janjic Aleksandar , Bhatia Shilpa , Mukhopadhyay Nitai D. , Shao Chunbo , Sarkar Devanand , Fisher Paul B.
Published: July 2013

Purpose: Urothelial cell carcinoma (UCC) rapidly progresses from superficial to muscle-invasive tumors. The key molecules involved in metastatic progression and its early detection require clarification. The present study defines a seminal role of the metastasis-associated gene MDA-9/Syntenin in UCC progression.

Experimental Design: Expression pattern of MDA-9/Syntenin was examined in 44 primary UCC and the impact of its overexpression and knockdown was examined in multiple cells lines and key findings were validated in primary tumors.

Results: Significantly higher (P = 0.002–0.003) expression of MDA-9/Syntenin was observed in 64% (28 of 44) of primary tumors and an association was evident with stage (P = 0.01), grade (P = 0.03), and invasion status (P = 0.02). MDA-9/Syntenin overexpression in nontumorigenic HUC-1 cells increased proliferation (P = 0.0012), invasion (P = 0.0001), and EGF receptor (EGFR), AKT, phosphoinositide 3-kinase (PI3K), and c-Src expression. Alteration of β-catenin, E-cadherin, vimentin, claudin-1, ZO-1, and T-cell factor-4 (TCF4) expression was also observed. MDA-9/Syntenin knockdown in three UCC cell lines reversed phenotypic and molecular changes observed in the HUC-1 cells and reduced in vivo metastasis. Key molecular changes observed in the cell lines were confirmed in primary tumors. A physical interaction and colocalization of MDA-9/Syntenin and EGFR was evident in UCC cell lines and primary tumors. A logistic regression model analysis revealed a significant correlation between MDA-9/Syntenin:EGFR and MDA-9/Syntenin:AKT expressions with stage (P = 0.04, EGFR; P = 0.01, AKT). A correlation between MDA-9/Syntenin:β-catenin coexpression with stage (P = 0.03) and invasion (P = 0.04) was also evident.

Conclusions: Our findings indicate that MDA-9/Syntenin might provide an attractive target for developing detection, monitoring, and therapeutic strategies for managing UCC. Clin Cancer Res; 19(17); 4621–33. ©2013 AACR.
Preclinical Activity of the Type II CD20 Antibody GA101 (Obinutuzumab) Compared with Rituximab and Ofatumumab In Vitro and in Xenograft Models
Authors: Herter Sylvia , Herting Frank , Mundigl Olaf , Waldhauer Inja , Weinzierl Tina , Fauti Tanja , Muth Gunter , Ziegler-Landesberger Doris , Van Puijenbroek Erwin , Lang Sabine , Duong Minh Ngoc , Reslan Lina , Gerdes Christian A. , Friess Thomas , Baer Ute , Burtscher Helmut , Weidner Michael , Dumontet Charles , Umana Pablo , Niederfellner Gerhard , Bacac Marina , Klein Christian
Published: July 2013

We report the first preclinical in vitro and in vivo comparison of GA101 (obinutuzumab), a novel glycoengineered type II CD20 monoclonal antibody, with rituximab and ofatumumab, the two currently approved type I CD20 antibodies. The three antibodies were compared in assays measuring direct cell death (AnnexinV/PI staining and time-lapse microscopy), complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cell-mediated phagocytosis (ADCP), and internalization. The models used for the comparison of their activity in vivo were SU-DHL4 and RL xenografts. GA101 was found to be superior to rituximab and ofatumumab in the induction of direct cell death (independent of mechanical manipulation required for cell aggregate disruption formed by antibody treatment), whereas it was 10 to 1,000 times less potent in mediating CDC. GA101 showed superior activity to rituximab and ofatumumab in ADCC and whole-blood B-cell depletion assays, and was comparable with these two in ADCP. GA101 also showed slower internalization rate upon binding to CD20 than rituximab and ofatumumab. In vivo, GA101 induced a strong antitumor effect, including complete tumor remission in the SU-DHL4 model and overall superior efficacy compared with both rituximab and ofatumumab. When rituximab-pretreated animals were used, second-line treatment with GA101 was still able to control tumor progression, whereas tumors escaped rituximab treatment. Taken together, the preclinical data show that the glyoengineered type II CD20 antibody GA101 is differentiated from the two approved type I CD20 antibodies rituximab and ofatumumab by its overall preclinical activity, further supporting its clinical investigation. Mol Cancer Ther; 12(10); 2031–42. ©2013 AACR.
Combination Drug Scheduling Defines a “Window of Opportunity” for Chemopotentiation of Gemcitabine by an Orally Bioavailable, Selective ChK1 Inhibitor, GNE-900
Authors: Blackwood Elizabeth , Epler Jennifer , Yen Ivana , Flagella Michael , O'Brien Tom , Evangelista Marie , Schmidt Stephen , Xiao Yang , Choi Jonathan , Kowanetz Kaska , Ramiscal Judi , Wong Kenton , Jakubiak Diana , Yee Sharon , Cain Gary , Gazzard Lewis , Williams Karen , Halladay Jason , Jackson Peter K. , Malek Shiva
Published: July 2013

Checkpoint kinase 1 (ChK1) is a serine/threonine kinase that functions as a central mediator of the intra-S and G2–M cell-cycle checkpoints. Following DNA damage or replication stress, ChK1-mediated phosphorylation of downstream effectors delays cell-cycle progression so that the damaged genome can be repaired. As a therapeutic strategy, inhibition of ChK1 should potentiate the antitumor effect of chemotherapeutic agents by inactivating the postreplication checkpoint, causing premature entry into mitosis with damaged DNA resulting in mitotic catastrophe. Here, we describe the characterization of GNE-900, an ATP-competitive, selective, and orally bioavailable ChK1 inhibitor. In combination with chemotherapeutic agents, GNE-900 sustains ATR/ATM signaling, enhances DNA damage, and induces apoptotic cell death. The kinetics of checkpoint abrogation seems to be more rapid in p53-mutant cells, resulting in premature mitotic entry and/or accelerated cell death. Importantly, we show that GNE-900 has little single-agent activity in the absence of chemotherapy and does not grossly potentiate the cytotoxicity of gemcitabine in normal bone marrow cells. In vivo scheduling studies show that optimal administration of the ChK1 inhibitor requires a defined lag between gemcitabine and GNE-900 administration. On the refined combination treatment schedule, gemcitabine's antitumor activity against chemotolerant xenografts is significantly enhanced and dose-dependent exacerbation of DNA damage correlates with extent of tumor growth inhibition. In summary, we show that in vivo potentiation of gemcitabine activity is mechanism based, with optimal efficacy observed when S-phase arrest and release is followed by checkpoint abrogation with a ChK1 inhibitor. Mol Cancer Ther; 12(10); 1968–80. ©2013 AACR.
Targeting Aberrant DNA Double-Strand Break Repair in Triple-Negative Breast Cancer with Alpha-Particle Emitter Radiolabeled Anti-EGFR Antibody
Authors: Song Hong , Hedayati Mohammad , Hobbs Robert F. , Shao Chunbo , Bruchertseifer Frank , Morgenstern Alfred , DeWeese Theodore L. , Sgouros George
Published: July 2013

The higher potential efficacy of alpha-particle radiopharmaceutical therapy lies in the 3- to 8-fold greater relative biological effectiveness (RBE) of alpha particles relative to photon or beta-particle radiation. This greater RBE, however, also applies to normal tissue, thereby reducing the potential advantage of high RBE. As alpha particles typically cause DNA double-strand breaks (DSB), targeting tumors that are defective in DSB repair effectively increases the RBE, yielding a secondary, RBE-based differentiation between tumor and normal tissue that is complementary to conventional, receptor-mediated tumor targeting. In some triple-negative breast cancers (TNBC; ER−/PR−/HER-2−), germline mutation in BRCA-1, a key gene in homologous recombination DSB repair, predisposes patients to early onset of breast cancer. These patients have few treatment options once the cancer has metastasized. In this study, we investigated the efficacy of alpha-particle emitter, 213Bi-labeled anti-EGF receptor antibody, cetuximab, in BRCA-1–defective TNBC. 213Bi-cetuximab was found to be significantly more effective in the BRCA-1–mutated TNBC cell line HCC1937 than BRCA-1–competent TNBC cell MDA-MB-231. siRNA knockdown of BRCA-1 or DNA-dependent protein kinase, catalytic subunit (DNA-PKcs), a key gene in non–homologous end-joining DSB repair pathway, also sensitized TNBC cells to 213Bi-cetuximab. Furthermore, the small-molecule inhibitor of DNA-PKcs, NU7441, sensitized BRCA-1–competent TNBC cells to alpha-particle radiation. Immunofluorescent staining of γ-H2AX foci and comet assay confirmed that enhanced RBE is caused by impaired DSB repair. These data offer a novel strategy for enhancing conventional receptor-mediated targeting with an additional, potentially synergistic radiobiological targeting that could be applied to TNBC. Mol Cancer Ther; 12(10); 2043–54. ©2013 AACR.
Uracil–DNA Glycosylase Expression Determines Human Lung Cancer Cell Sensitivity to Pemetrexed
Authors: Weeks Lachelle D. , Fu Pingfu , Gerson Stanton L.
Published: July 2013

Uracil misincorporation into DNA is a consequence of pemetrexed inhibition of thymidylate synthase. The base excision repair (BER) enzyme uracil–DNA glycosylase (UNG) is the major glycosylase responsible for removal of misincorporated uracil. We previously illustrated hypersensitivity to pemetrexed in UNG−/− human colon cancer cells. Here, we examined the relationship between UNG expression and pemetrexed sensitivity in human lung cancer. We observed a spectrum of UNG expression in human lung cancer cells. Higher levels of UNG are associated with pemetrexed resistance and are present in cell lines derived from pemetrexed-resistant histologic subtypes (small cell and squamous cell carcinoma). Acute pemetrexed exposure induces UNG protein and mRNA, consistent with upregulation of uracil–DNA repair machinery. Chronic exposure of H1299 adenocarcinoma cells to increasing pemetrexed concentrations established drug-resistant sublines. Significant induction of UNG protein confirmed upregulation of BER as a feature of acquired pemetrexed resistance. Cotreatment with the BER inhibitor methoxyamine overrides pemetrexed resistance in chronically exposed cells, underscoring the use of BER-directed therapeutics to offset acquired drug resistance. Expression of UNG-directed siRNA and shRNA enhanced sensitivity in A549 and H1975 cells, and in drug-resistant sublines, confirming that UNG upregulation is protective. In human lung cancer, UNG deficiency is associated with pemetrexed-induced retention of uracil in DNA that destabilizes DNA replication forks resulting in DNA double-strand breaks and cell death. Thus, in experimental models, UNG is a critical mediator of pemetrexed sensitivity that warrants evaluation to determine clinical value. Mol Cancer Ther; 12(10); 2248–60. ©2013 AACR.
The Dual Pathway Inhibitor Rigosertib Is Effective in Direct Patient Tumor Xenografts of Head and Neck Squamous Cell Carcinomas
Authors: Anderson Ryan T. , Keysar Stephen B. , Bowles Daniel W. , Glogowska Magdalena J. , Astling David P. , Morton J. Jason , Le Phuong , Umpierrez Adrian , Eagles-Soukup Justin , Gan Gregory N. , Vogler Brian W. , Sehrt Daniel , Takimoto Sarah M. , Aisner Dara L. , Wilhelm Francois , Frederick Barbara A. , Varella-Garcia Marileila , Tan Aik-Choon , Jimeno Antonio
Published: July 2013

The dual pathway inhibitor rigosertib inhibits phosphoinositide 3-kinase (PI3K) pathway activation as well as polo-like kinase 1 (PLK1) activity across a broad spectrum of cancer cell lines. The importance of PIK3CA alterations in squamous cell carcinoma of the head and neck (HNSCC) has raised interest in exploring agents targeting PI3K, the product of PIK3CA. The genetic and molecular basis of rigosertib treatment response was investigated in a panel of 16 HNSCC cell lines, and direct patient tumor xenografts from eight patients with HNSCC [four HPV-serotype16 (HPV16)–positive]. HNSCC cell lines and xenografts were characterized by pathway enrichment gene expression analysis, exon sequencing, gene copy number, Western blotting, and immunohistochemistry (IHC). Rigosertib had potent antiproliferative effects on 11 of 16 HPV− HNSCC cell lines. Treatment sensitivity was confirmed in two cell lines using an orthotopic in vivo xenograft model. Growth reduction after rigosertib treatment was observed in three of eight HNSCC direct patient tumor lines. The responsive tumor lines carried a combination of a PI3KCA-activating event (amplification or mutation) and a p53-inactivating event (either HPV16- or mutation-mediated TP53 inactivation). In this study, we evaluated the in vitro and in vivo efficacy of rigosertib in both HPV+ and HPV− HNSCCs, focusing on inhibition of the PI3K pathway. Although consistent inhibition of the PI3K pathway was not evident in HNSCC, we identified a combination of PI3K/TP53 events necessary, but not sufficient, for rigosertib sensitivity. Mol Cancer Ther; 12(10); 1994–2005. ©2013 AACR.
Plasma Adiponectin and Soluble Leptin Receptor and Risk of Colorectal Cancer: A Prospective Study
Authors: Song Mingyang , Zhang Xuehong , Wu Kana , Ogino Shuji , Fuchs Charles S. , Giovannucci Edward L. , Chan Andrew T.
Published: July 2013

Adipokines are adipocyte-secreted hormones that may mediate the etiologic link between obesity and colorectal cancer; however, the evidence from large prospective studies is limited. We prospectively evaluated the association of plasma adiponectin and soluble leptin receptor (sOB-R) with colorectal cancer risk within the Nurses' Health Study (1990–2008) and the Health Professionals Follow-up Study (1994–2008) among 616 incident colorectal cancer cases and 1,205 controls selected using risk-set sampling and matched on age and date of blood draw. In unconditional logistic regression with adjustment for matching factors and multiple risk factors, plasma adiponectin was significantly associated with reduced risk of colorectal cancer among men, but not among women. Compared with men in the lowest quartile of adiponectin, men in the highest quartile had a relative risk (RR) for colorectal cancer of 0.55 [95% confidence interval (CI), 0.35–0.86; Ptrend = 0.02]. The corresponding RR in women was 0.96 (95% CI, 0.67–1.39; Ptrend = 0.74). Plasma sOB-R was not associated with overall colorectal cancer risk in either men or women. A significant heterogeneity was noted in the association between sOB-R and colorectal cancer by subsite in women (Pheterogeneity = 0.004); sOB-R was significantly associated with increased risk of rectal cancer but not colon cancer. These findings support a role for adiponectin in colorectal carcinogenesis in men. Further studies are warranted to confirm these associations and elucidate potential underlying mechanisms. Cancer Prev Res; 6(9); 875–85. ©2013 AACR.