bluuebunny/crossref_metadata_2025 huggingface dataset:
Sum-frequency-generation spectroscopy of DNA films in air and aqueous environments
Authors: Howell Caitlin , Schmidt Ronny , Kurz Volker , Koelsch Patrick
Published: January 2009

Understanding the organization and orientation of surface-immobilized single stranded DNA (ssDNA) in aqueous environments is essential for optimizing and further developing the technology based on oligonucleotide binding. Here the authors demonstrate how sum-frequency-generation (SFG) spectroscopy can be used to compare the structure and orientation of model monolayers of ssDNA on gold in air, D2O, and phosphate buffered saline (PBS) solution. Films of adenine and thymine homo-oligonucleotides showed significant conformational changes in air versus aqueous environments in the CH stretching region. The thymine films showed changes between D2O and PBS solution, whereas the SFG spectra of adenine films under these conditions were largely similar, suggesting that the thymine films undergo greater conformational changes than the adenine films. Examination of thymine films in the amide I vibrational region revealed that molecules in films of nonthiolated DNA were lying down on the gold surface whereas molecules in films of thiol-linked DNA were arranged in a brushlike structure. Comparison of SFG spectra in the amide I region for thiol-linked DNA films in air and D2O also revealed substantial conformational changes.
In Vitro Activity and Preclinical Profile of TMC435350, a Potent Hepatitis C Virus Protease Inhibitor
Authors: Lin Tse-I , Lenz Oliver , Fanning Gregory , Verbinnen Thierry , Delouvroy Frédéric , Scholliers Annick , Vermeiren Katrien , Rosenquist Åsa , Edlund Michael , Samuelsson Bertil , Vrang Lotta , de Kock Herman , Wigerinck Piet , Raboisson Pierre , Simmen Kenneth
Published: January 2009

The hepatitis C virus (HCV) NS3/4A serine protease has been explored as a target for the inhibition of viral replication in preclinical models and in HCV-infected patients. TMC435350 is a highly specific and potent inhibitor of NS3/4A protease selected from a series of novel macrocyclic inhibitors. In biochemical assays using NS3/4A proteases of genotypes 1a and 1b, inhibition constants of 0.5 and 0.4 nM, respectively, were determined. TMC435350 inhibited HCV replication in a cellular assay (subgenomic 1b replicon) with a half-maximal effective concentration (EC50) of 8 nM and a selectivity index of 5,875. The compound was synergistic with alpha interferon and an NS5B inhibitor in the replicon model and additive with ribavirin. In rats, TMC435350 was extensively distributed to the liver and intestinal tract (tissue/plasma area under the concentration-time curve ratios of >35), and the absolute bioavailability was 44% after a single oral administration. Compound concentrations detected in both plasma and liver at 8 h postdosing were above the EC99value measured in the replicon. In conclusion, given the selective and potent in vitro anti-HCV activity, the potential for combination with other anti-HCV agents, and the favorable pharmacokinetic profile, TMC435350 has been selected for clinical development.
Using a Field Quantitative Real-Time PCR Test To Rapidly Identify Highly Viremic Rift Valley Fever Cases
Authors: Njenga M. Kariuki , Paweska Janusz , Wanjala Rose , Rao Carol Y. , Weiner Matthew , Omballa Victor , Luman Elizabeth T. , Mutonga David , Sharif Shanaaz , Panning Marcus , Drosten Christian , Feikin Daniel R. , Breiman Robert F.
Published: January 2009

Approximately 8% of Rift Valley fever (RVF) cases develop severe disease, leading to hemorrhage, hepatitis, and/or encephalitis and resulting in up to 50% of deaths. A major obstacle in the management of RVF and other viral hemorrhagic fever cases in outbreaks that occur in rural settings is the inability to rapidly identify such cases, with poor prognosis early enough to allow for more-aggressive therapies. During an RVF outbreak in Kenya in 2006 to 2007, we evaluated whether quantitative real-time reverse transcription-PCR (qRT-PCR) could be used in the field to rapidly identify viremic RVF cases with risk of death. In 52 of 430 RVF cases analyzed by qRT-PCR and virus culture, 18 died (case fatality rate [CFR] = 34.6%). Levels of viremia in fatal cases were significantly higher than those in nonfatal cases (mean of 10
5.2
versus 10
2.9
per ml;
P
< 0.005). A negative correlation between the levels of infectious virus particles and the qRT-PCR crossover threshold (
C

T

) values allowed the use of qRT-PCR to assess prognosis. The CFR was 50.0% among cases with
C

T

values of <27.0 (corresponding to 2.1 × 10
4
viral RNA particles/ml of serum) and 4.5% among cases with
C

T

values of ≥27.0. This cutoff yielded 93.8% sensitivity and a 95.5% negative predictive value; the specificity and positive predictive value were 58% and 50%, respectively. This study shows a correlation between high viremia and fatality and indicates that qRT-PCR testing can identify nearly all fatal RVF cases.
Human-to-Human Transmission of Tuberculosis Caused by
Mycobacterium bovis
in Immunocompetent Patients
Authors: Sunder S. , Lanotte P. , Godreuil S. , Martin C. , Boschiroli M. L. , Besnier J. M.
Published: January 2009

Human-to-human transmission
of Mycobacterium bovis in
two immunocompetent patients from the same family was confirmed by spoligotyping (pattern F35, which was only observed in cattle from the same area in France). A single allelic difference between animal and human isolates was observed with mycobacterial interspersed repetitive units containing variable-number tandem repeats, suggesting a jump across the species barrier.
Visualising vitreous through modified trans-scleral illumination by maximising the Tyndall effect
Authors: Veckeneer M , Wong D
Published: January 2009

Background:

A new technique for visualisation of the vitreous base is described. It uses a standard lightpipe for scleral indentation and transillumination. Visualisation of the vitreous using low light levels can be achieved by enhancing the Tyndall effect.

Discussion:

Perfluorocarbon liquid (PFCL) is used to confine the aqueous environment to the anterior vitreous cavity and triamcinolone is added to increase light scatter. The technique clearly differentiates vitreous from PFCL and infusion fluid, and facilitates trimming of the vitreous base, draining of subretinal fluid and air/fluid exchange.
Central aponeurosis tears of the rectus femoris: practical sonographic prognosis
Authors: Balius R , Maestro A , Pedret C , Estruch A , Mota J , Rodríguez L , García P , Mauri E
Published: January 2009

Objective:

This study is a statistical analysis to establish whether a correlation exists between the level and degree of rectus femoris (RF) central tendon injury and the amount of time that an athlete is unable to participate subsequently, referred to as “sports participation absence” (SPA).

Design:

Causal–comparative study.

Patients:

35 players from two high-level Spanish soccer teams with an injury to the central tendon of the RF based on clinical and ultrasound criteria.

Main Outcome Measure:

Ultrasound examination was performed with an 8–2 MHz linear multifrequency transducer. All studies included both longitudinal and transverse RF sections.

Results:

At the proximal level the SPA time is 45.1 days when the injury length is 4.0 cm. This value increases by 5.3 days with each 1 cm increase in the length of injury. In the case of distal level injury, SPA time is 32.9 days when the injury length is 3.9 cm. This value increases by 3.4 days with each 1 cm increase. In the total representative sample, SPA time when the injury length is 4.2 cm corresponds to 39.1 days. This value increases by 4.2 days per length unit.

Conclusions:

RF central tendon injury at the proximal level is associated with a greater SPA time than at the distal level. Patients with a grade II injury have an SPA time longer than those with a grade I injury whether the injury is located proximal or distal.
A prospective cohort study of hamstring injuries in competitive sprinters: preseason muscle imbalance as a possible risk factor
Authors: Yeung S S , Suen A M Y , Yeung E W
Published: January 2009

Background:

Hamstring injuries are common in sprinters. Identifying preseason risk factors is essential to target injury-prone athletes and develop injury preventive measures.

Objective:

To investigate the incidence of hamstring muscle injury in sprinters over an athletic season and to explore the preseason predictor of this injury.

Design:

Prospective cohort study.

Participants:

44 sprinters from the Hong Kong Sports Institute, the Hong Kong Amateur Athletic Association and intercollegiate athletic teams were recruited.

Methods:

Preseason assessment of hamstring flexibility, concentric and eccentric isokinetic peak torque and peak torque angle were obtained at the beginning of an athletic season. The athletes were followed over 12 months and were asked to report all injuries resulting from training and competition.

Results:

Eight athletes sustained hamstring injuries over the season. The injury rate was 0.87 per 1000 h of exposure. The incidence of injuries was higher at the beginning of the season, with 58.3% injuries occurring in the first 100 h of exposure. Cox regression analysis revealed that athletes with a decrease in the hamstring : quadriceps peak torque ratio of less than 0.60 at an angular velocity of 180°/s have a 17-fold increased risk of hamstring injury.

Conclusion:

Performing preseason hamstring : quadriceps peak torque ratio assessments may be useful to identify sprinters susceptible to hamstring injury.
Berberine improves lipid dysregulation in obesity by controlling central and peripheral AMPK activity
Authors: Kim Woo Sik , Lee Yun Sok , Cha Seung Hun , Jeong Hyun Woo , Choe Sung Sik , Lee Mi-Ran , Oh Goo Taeg , Park Hye-Sun , Lee Ki-Up , Lane M. Daniel , Kim Jae Bum
Published: January 2009

AMP-activated protein kinase (AMPK) plays an important role in regulating whole body energy homeostasis. Recently, it has been demonstrated that berberine (BBR) exerts antiobesity and antidiabetic effects in obese and diabetic rodent models through the activation of AMPK in peripheral tissues. Here we show that BBR improves lipid dysregulation and fatty liver in obese mice through central and peripheral actions. In obese db/db and ob/ob mice, BBR treatment reduced liver weight, hepatic and plasma triglyceride, and cholesterol contents. In the liver and muscle of db/db mice, BBR promoted AMPK activity and fatty acid oxidation and changed expression of genes involved in lipid metabolism. Additionally, intracerebroventricular administration of BBR decreased the level of malonyl-CoA and stimulated the expression of fatty acid oxidation genes in skeletal muscle. Together, these data suggest that BBR would improve fatty liver in obese subjects, which is probably mediated not only by peripheral AMPK activation but also by neural signaling from the central nervous system.
Human apolipoprotein D overexpression in transgenic mice induces insulin resistance and alters lipid metabolism
Authors: Carmo Sonia Do , Fournier David , Mounier Catherine , Rassart Eric
Published: January 2009

Apolipoprotein D (apoD), a widely expressed lipocalin, has the capacity to transport small hydrophobic molecules. Although it has been proposed that apoD may have multiple tissue-specific, physiological ligands and functions, these have yet to be identified. To gain insight in some of its functions, we generated transgenic mice overexpressing human apoD (H-apoD) under the control of neuron-specific promoters. In Thy-1/apoD and NSE/apoD mice, expression of H-apoD was strong in the nervous system although weakly detected in peripheral organs such as the liver and blood cells. These mice displayed not entirely anticipated metabolic defects. Although they are not obese and have normal lipid concentration in circulation, Thy-1/apoD and NSE/apoD mice are glucose intolerant, insulin resistant, and develop hepatic steatosis. The steatosis and its associated insulin resistance are correlated with impairments in hepatic lipogenesis. However, they are not strongly related with inflammation. This impaired insulin response is not caused by a decrease in circulating leptin or a modulation of adiponectin and resistin levels. These results suggest that variations in the levels and/or sites of apoD expression influence the lipid and glucose metabolism, consolidating apoD as a target for insulin-resistance-related disorders.
Adaptation to Visuomotor Rotation and Force Field Perturbation Is Correlated to Different Brain Areas in Patients With Cerebellar Degeneration
Authors: Rabe K. , Livne O. , Gizewski E. R. , Aurich V. , Beck A. , Timmann D. , Donchin O.
Published: January 2009

Although it is widely agreed that the cerebellum is necessary for learning and consolidation of new motor tasks, it is not known whether adaptation to kinematic and dynamic errors is processed by the same cerebellar areas or whether different parts play a decisive role. We investigated arm movements in a visuomotor (VM) rotation and a force field (FF) perturbation task in 14 participants with cerebellar degeneration and 14 age- and gender-matched controls. Magnetic resonance images were used to calculate the volume of cerebellar areas (medial, intermediate, and lateral zones of the anterior and posterior lobes) and to identify cerebellar structure important for the two tasks. Corroborating previous studies, cerebellar participants showed deficits in adaptation to both tasks compared with controls ( P < 0.001). However, it was not possible to draw conclusions from the performance in one task on the performance in the other task because an individual participant could show severe impairment in one task and perform relatively well in the other (ρ = 0.1; P = 0.73). We found that atrophy of distinct cerebellar areas correlated with impairment in different tasks. Whereas atrophy of the intermediate and lateral zone of the anterior lobe correlated with impairment in the FF task (ρ = 0.72, 0.70; P = 0.003, 0.005, respectively), atrophy of the intermediate zone of the posterior lobe correlated with adaptation deficits in the VM task (ρ = 0.64; P = 0.015). Our results suggest that adaptation to the different tasks is processed independently and relies on different cerebellar structures.
Discovery of the gene signature for acute lung injury in patients with sepsis
Authors: Howrylak Judie A. , Dolinay Tamas , Lucht Lorrie , Wang Zhaoxi , Christiani David C. , Sethi Jigme M. , Xing Eric P. , Donahoe Michael P. , Choi Augustine M. K.
Published: January 2009

The acute respiratory distress syndrome (ARDS)/acute lung injury (ALI) was described 30 yr ago, yet making a definitive diagnosis remains difficult. The identification of biomarkers obtained from peripheral blood could provide additional noninvasive means for diagnosis. To identify gene expression profiles that may be used to classify patients with ALI, 13 patients with ALI + sepsis and 20 patients with sepsis alone were recruited from the Medical Intensive Care Unit of the University of Pittsburgh Medical Center, and microarrays were performed on peripheral blood samples. Several classification algorithms were used to develop a gene signature for ALI from gene expression profiles. This signature was validated in an independently obtained set of patients with ALI + sepsis ( n = 8) and sepsis alone ( n = 1). An eight-gene expression profile was found to be associated with ALI. Internal validation found that the gene signature was able to distinguish patients with ALI + sepsis from patients with sepsis alone with 100% accuracy, corresponding to a sensitivity of 100%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 100%. In the independently obtained external validation set, the gene signature was able to distinguish patients with ALI + sepsis from patients with sepsis alone with 88.9% accuracy. The use of classification models to develop a gene signature from gene expression profiles provides a novel and accurate approach for classifying patients with ALI.
Velocity Induced by a Plane Uniform Vortex Having the Schwarz Function of Its Boundary with Two Simple Poles
Authors: Riccardi G. , Durante D.
Published: January 2009

The velocity induced by a plane, uniform vortex is investigated through the use of an integral relation between Schwarz function of the vortex boundary and conjugate of the velocity. The analysis is restricted to a certain class of vortices, the boundaries of which are described through conformal maps onto the unit circle and the corresponding Schwarz functions possess two poles in the plane of the circle. The dependence of the velocity field on the vortex shape is investigated by comparing velocity and streamfunction with the ones of the equivalent Rankine vortex (which has the same vorticity, area, and center of vorticity). By changing the parameters of the Schwarz function (poles and corresponding residues), rather complicated vortex shapes can be easily analyzed, some of them mimicing an incipient filamentation of the vortex boundary.
Adhesion Dynamics in Probing Micro‐ and Nanoscale Thin Solid Films
Authors: He Xiaoling
Published: January 2009

This study focuses on modeling the probe dynamics in scratching and indenting thin solid films at micro‐ and nanoscales. The model identifies bifurcation conditions that define the stick‐slip oscillation patterns of the tip. It is found that the local energy fluctuations as a function of the inelastic deformation, defect formation, material properties, and contact parameters determine the oscillation behavior. The transient variation of the localized function makes the response nonlinear at the adhesion junction. By quantifying the relation between the bifurcation parameters and the oscillation behavior, this model gives a realistic representation of the complex adhesion dynamics. Specifically, the model establishes the link between the stick‐slip behavior and the inelastic deformation and the local potentials. This model justifies the experimental observations and the molecular dynamics simulation of the adhesion and friction dynamics in both the micro‐ and nanoscale contact.
Effect of Sm Substitution on Structural, Dielectric, and Transport Properties of PZT Ceramics
Authors: Ranjan Rajiv , Kumar Rajiv , Choudhary R. N. P.
Published: January 2009

The polycrystalline samples of Pb1−xSmx (Zr0.45Ti0.55)1−x/4O3 (PSZT) (where x  =  0.00,  0.03,  0.06, and 0.09) were prepared by a high-temperature solid-state reaction technique. Preliminary X-ray structural analysis of the materials at room temperature has confirmed their formation in single-phase with tetragonal crystal structure. The temperature dependence of dielectric response of the samples at selected frequencies has exhibited their phase transition well above the room temperature. The variation of ac conductivity with temperature and the value of activation energy reveal that their conduction process is of mixed type (i.e., singly ionized in ferroelectric region and doubly ionized in paraelectric phase).
Targeting Heat Shock Protein 90 Overrides the Resistance of Lung Cancer Cells by Blocking Radiation-Induced Stabilization of Hypoxia-Inducible Factor-1α
Authors: Kim Woo-Young , Oh Seung Hyun , Woo Jong-Kyu , Hong Waun Ki , Lee Ho-Young
Published: January 2009

Hypoxia-inducible factor-1 (HIF-1) has been suggested to play a major role in tumor radioresistance. However, the mechanisms through which irradiation regulates HIF-1α expression remain unclear. The purpose of this study was to investigate the mechanisms that mediate HIF-1 activation and thus radioresistance. Here, we show that irradiation induces survival and angiogenic activity in a subset of radioresistant lung cancer cell lines by elevating HIF-1α protein expression. Radiation induced HIF-1α protein expression mainly through two distinct pathways, including an increase in de novo protein synthesis via activation of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and stabilization of HIF-1α protein via augmenting the interaction between heat shock protein 90 (Hsp90) and HIF-1α protein. Whereas the PI3K/Akt/mTOR pathway was activated by irradiation in all the lung cancer cells examined, the Hsp90-HIF-1α interaction was enhanced in the resistant cells only. Inhibition of Hsp90 function by 17-allylamino-17-demethoxygeldanamycin or deguelin, a novel natural inhibitor of Hsp90, suppressed increases in HIF-1α/Hsp90 interaction and HIF-1α expression in radioresistant cells. Furthermore, combined treatment of radiation with deguelin significantly decreased the survival and angiogenic potential of radioresistant lung cancer cells in vitro. We finally determined in vivo that systemic administration of deguelin resulted in profound inhibition of tumor growth and angiogenesis when combined with radiation. These results provide a strong rationale to target Hsp90 as a means to block radiation-induced HIF-1α and thus to circumvent radioresistance in lung cancer cells. [Cancer Res 2009;69(4):1624–32]
Expression and Functions of Transmembrane Mucin MUC13 in Ovarian Cancer
Authors: Chauhan Subhash C. , Vannatta Kelley , Ebeling Mara C. , Vinayek Namita , Watanabe Akira , Pandey Krishan K. , Bell Maria C. , Koch Michael D. , Aburatani Hiroyuki , Lio Yuhlong , Jaggi Meena
Published: January 2009

MUC13, a transmembrane mucin, is normally expressed in gastrointestinal and airway epithelium. Its aberrant expression has been correlated with gastric colon and cancer. However, the expression and functions of MUC13 in ovarian cancer are unknown. In the present study, the expression profile and functions of MUC13 were analyzed to elucidate its potential role in ovarian cancer diagnosis and pathogenesis. A recently generated monoclonal antibody (clone PPZ0020) was used to determine the expression profile of MUC13 by immunohistochemistry using ovarian cancer tissue microarrays and 56 additional epithelial ovarian cancer (EOC) samples. The expression of MUC13 was significantly (P < 0.005) higher in cancer samples compared with the normal ovary/benign tissues. Among all ovarian cancer types, MUC13 expression was specifically present in EOC. For the functional analyses, a full-length MUC13 gene cloned in pcDNA3.1 was expressed in a MUC13 null ovarian cancer cell line, SKOV-3. Here, we show that the exogenous MUC13 expression induced morphologic changes, including scattering of cells. These changes were abrogated through c-Jun NH2 kinase (JNK) chemical inhibitor (SP600125) or JNK2 siRNA. Additionally, a marked reduction in cell-cell adhesion and significant (P < 0.05) increases in cell motility, proliferation, and tumorigenesis in a xenograft mouse model system were observed upon exogenous MUC13 expression. These cellular characteristics were correlated with up-regulation of HER2, p21-activated kinase 1, and p38 protein expression. Our findings show the aberrant expression of MUC13 in ovarian cancer and that its expression alters the cellular characteristics of SKOV-3 cells. This implies a significant role of MUC13 in ovarian cancer. [Cancer Res 2009;69(3):765–74]
The Hypoxia-Activated ProDrug AQ4N Penetrates Deeply in Tumor Tissues and Complements the Limited Distribution of Mitoxantrone
Authors: Trédan Olivier , Garbens Alaina B. , Lalani Alshad S. , Tannock Ian F.
Published: January 2009

Hypoxic tumor cells are likely to be resistant to conventional chemotherapy, in large part because many anticancer drugs are unable to penetrate into poorly oxygenated tumor tissue. Here, we used quantitative immunofluorescence to study the distribution of mitoxantrone and AQ4N in tumor tissue. AQ4N is a prodrug activated under hypoxic conditions to AQ4, which is structurally similar to mitoxantrone and inhibits topoisomerase II. We characterized the penetration of mitoxantrone and AQ4N/AQ4 through multilayered cell cultures (MCC) and in relation to blood vessels and hypoxic regions in human tumor xenografts. We also studied tumor growth delay after treatment with each agent alone and with the combination. In both MCC and xenografts, mitoxantrone is taken up by proximal cells and penetrates slowly to distant regions. In contrast, AQ4N rapidly penetrates MCC and tumor tissue in vivo, and AQ4N (or its reduced form AQ4) is detected at high concentration within hypoxic regions. The targeting of mitoxantrone to oxygenated regions and AQ4N/AQ4 to hypoxic tumor regions results in effective drug exposure over the entire tumor after combined treatment and increases tumor growth delay compared with either drug alone. The combination of a clinically used anticancer drug with limited tissue penetration and a structurally related drug activated in regions of tumor hypoxia is an effective strategy to overcome chemoresistance due to the tumor microenvironment. This study supports clinical evaluation of AQ4N in combination with conventional anticancer agents, such as mitoxantrone. [Cancer Res 2009;69(3):940–7]
A Multiscale Mathematical Model for Oncolytic Virotherapy
Authors: Paiva Leticia R. , Binny Christopher , Ferreira Silvio C. , Martins Marcelo L.
Published: January 2009

One of the most promising strategies to treat cancer is attacking it with viruses. Oncolytic viruses can kill tumor cells specifically or induce anticancer immune response. A multiscale model for virotherapy of cancer is investigated through simulations. It was found that, for intratumoral virus administration, a solid tumor can be completely eradicated or keep growing after a transient remission. Furthermore, the model reveals undamped oscillatory dynamics of tumor cells and virus populations, which demands new in vivo and in vitro quantitative experiments aiming to detect this oscillatory response. The conditions for which each one of the different tumor responses dominates, as well as the occurrence probabilities for the other nondominant therapeutic outcomes, were determined. From a clinical point of view, our findings indicate that a successful, single agent virotherapy requires a strong inhibition of the host immune response and the use of potent virus species with a high intratumoral mobility. Moreover, due to the discrete and stochastic nature of cells and their responses, an optimal range for viral cytotoxicity is predicted because the virotherapy fails if the oncolytic virus demands either a too short or a very large time to kill the tumor cell. This result suggests that the search for viruses able to destroy tumor cells very fast does not necessarily lead to a more effective control of tumor growth. [Cancer Res 2009;69(3):1205–11]
Curcumin Disrupts the Mammalian Target of Rapamycin-Raptor Complex
Authors: Beevers Christopher S. , Chen Long , Liu Lei , Luo Yan , Webster Nicholas J.G. , Huang Shile
Published: January 2009

Curcumin (diferuloylmethane), a polyphenol natural product of the plant Curcuma longa, is undergoing early clinical trials as a novel anticancer agent. However, the anticancer mechanism of curcumin remains to be elucidated. Recently, we have shown that curcumin inhibits phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4E-BP1), two downstream effector molecules of the mammalian target of rapamycin complex 1 (mTORC1) in numerous cancer cell lines. This study was designed to elucidate the underlying mechanism. We observed that curcumin inhibited mTORC1 signaling not by inhibition of the upstream kinases, such as insulin-like growth factor 1 receptor (IGF-IR) and phosphoinositide-dependent kinase 1 (PDK1). Further, we found that curcumin inhibited mTORC1 signaling independently of protein phosphatase 2A (PP2A) or AMP-activated protein kinase AMPK-tuberous sclerosis complex (TSC). This is evidenced by the findings that curcumin was able to inhibit phosphorylation of S6K1 and 4E-BP1 in the cells pretreated with PP2A inhibitor (okadaic acid) or AMPK inhibitor (compound C), or in the cells expressing dominant-negative (dn) PP2A, shRNA to PP2A-A subunit, or dn-AMPKα. Curcumin did not alter the TSC1/2 interaction. Knockout of TSC2 did not affect curcumin inhibition of mTOR signaling. Finally, we identified that curcumin was able to dissociate raptor from mTOR, leading to inhibition of mTORC1 activity. Therefore, our data indicate that curcumin may represent a new class of mTOR inhibitor. [Cancer Res 2009;69(3):1000–8]
GGAP2/PIKE-A Directly Activates Both the Akt and Nuclear Factor-κB Pathways and Promotes Prostate Cancer Progression
Authors: Cai Yi , Wang Jianghua , Li Rile , Ayala Gustavo , Ittmann Michael , Liu Mingyao
Published: January 2009

GGAP2/PIKE-A is a GTP-binding protein that can enhance Akt activity. Increased activation of the AKT and nuclear factor-κB (NF-κB) pathways have been identified as critical steps in cancer initiation and progression in a variety of human cancers. We have found significantly increased expression GGAP2 in the majority of human prostate cancers and GGAP2 expression increases Akt activation in prostate cancer cells. Thus, increased GGAP2 expression is a common mechanism for enhancing the activity of the Akt pathway in prostate cancers. In addition, we have found that activated Akt can bind and phosphorylate GGAP2 at serine 629, which enhances GTP binding by GGAP2. Phosphorylated GGAP2 can bind the p50 subunit of NF-κB and enhances NF-κB transcriptional activity. When expressed in prostate cancer cells, GGAP2 enhances proliferation, foci formation, and tumor progression in vivo. Thus, increased GGAP2 expression, which is present in three quarters of human prostate cancers, can activate two critical pathways that have been linked to prostate cancer initiation and progression. [Cancer Res 2009;69(3):819–27]
Prostaglandin E2 Stimulates Human Lung Carcinoma Cell Growth through Induction of Integrin-Linked Kinase: The Involvement of EP4 and Sp1
Authors: Zheng Ying , Ritzenthaler Jeffrey D. , Sun XiaoJuan , Roman Jesse , Han ShouWei
Published: January 2009

Cyclooxygenase-2–derived prostaglandin E2 (PGE2) stimulates tumor cell growth and progression. However, the mechanisms by which PGE2 increases tumor growth remain incompletely understood. In studies performed in non–small cell lung carcinoma (NSCLC) cells, we found that PGE2 stimulates the expression of integrin-linked kinase (ILK). ILK small interfering RNA (siRNA) inhibited the mitogenic effects of PGE2. In view of its perceived importance, we turned our attention to the mechanisms involved in PGE2-induced ILK expression and found that this effect was blocked by an antagonist of the PGE2 receptor subtype EP4 and by EP4 siRNA. Furthermore, we showed that PGE2 induction of ILK was associated with phosphorylation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/Akt, which were abrogated by ILK siRNA. Transient transfection, gel mobility shift assays, and chromatin immunoprecipitation experiments showed that PGE2 induced ILK promoter activity and increased Sp1, although it had no effect on nuclear factor-κB and AP-2 DNA-binding activity. Blockade of Sp1 abrogated the effect of PGE2 on expression of ILK and promoter activity and on cell growth. In summary, our observations show that PGE2 increases NSCLC cell growth through increased ILK expression, which is dependent on EP4 signaling and on induction of Sp1 protein and Sp1 DNA-binding activity in the ILK promoter. These studies suggest a novel molecular mechanism by which PGE2 stimulates NSCLC cell growth and unveils a new molecular target for the development of therapies against NSCLC. [Cancer Res 2009;69(3):896–904]
Achaete-Scute Complex Homologue 1 Regulates Tumor-Initiating Capacity in Human Small Cell Lung Cancer
Authors: Jiang Tianyun , Collins Brendan J. , Jin Ning , Watkins David N. , Brock Malcolm V. , Matsui William , Nelkin Barry D. , Ball Douglas W.
Published: January 2009

The basic helix-loop-helix transcription factor achaete-scute complex homologue 1 (ASCL1) is essential for the development of normal lung neuroendocrine cells as well as other endocrine and neural tissues. Small cell lung cancer (SCLC) and non-SCLC with neuroendocrine features express ASCL1, where the factor may play a role in the virulence and primitive neuroendocrine phenotype of these tumors. In this study, RNA interference knockdown of ASCL1 in cultured SCLC resulted in inhibition of soft agar clonogenic capacity and induction of apoptosis. cDNA microarray analyses bolstered by expression studies, flow cytometry, and chromatin immunoprecipitation identified two candidate stem cell marker genes, CD133 and aldehyde dehydrogenase 1A1 (ALDH1A1), to be directly regulated by ASCL1 in SCLC. In SCLC direct xenograft tumors, we detected a relatively abundant CD133high-ASCL1high-ALDH1high subpopulation with markedly enhanced tumorigenicity compared with cells with weak CD133 expression. Tumorigenicity in the CD133high subpopulation depended on continued ASCL1 expression. Whereas CD133high cells readily reconstituted the range of CD133 expression seen in the original xenograft tumor, CD133low cells could not. Our findings suggest that a broad range of SCLC cells has tumorigenic capacity rather than a small discrete population. Intrinsic tumor cell heterogeneity, including variation in key regulatory factors such as ASCL1, can modulate tumorigenicity in SCLC. [Cancer Res 2009;69(3):845–54]
Suppression of cFLIP by Lupeol, a Dietary Triterpene, Is Sufficient to Overcome Resistance to TRAIL-Mediated Apoptosis in Chemoresistant Human Pancreatic Cancer Cells
Authors: Murtaza Imtiyaz , Saleem Mohammad , Adhami Vaqar Mustafa , Hafeez Bilal Bin , Mukhtar Hasan
Published: January 2009

Overexpression of cellular FLICE-like inhibitory protein (cFLIP) is reported to confer chemoresistance in pancreatic cancer (PaC) cells. This study was designed to investigate the effect of lupeol, a dietary triterpene, on (a) apoptosis of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) therapy–resistant PaC cells overexpressing cFLIP and (b) growth of human pancreatic tumor xenografts in vivo. The effect of lupeol treatment on proliferation and TRAIL/caspase-8/cFLIP machinery in PaC cells was investigated. Next, cFLIP-overexpressing and cFLIP-suppressed cells were tested for sensitivity to recombinant TRAIL therapy in the presence of lupeol. Further, athymic nude mice implanted with AsPC-1 cells were treated with lupeol (40 mg/kg) thrice a week and surrogate biomarkers were evaluated in tumors. Lupeol alone treatment of cells caused (a) decrease in proliferation, (b) induction of caspase-8 and poly(ADP-ribose) polymerase cleavage, and (c) down-regulation of transcriptional activation and expression of cFLIP. Lupeol was observed to increase the TRAIL protein level in cells. Lupeol significantly decreased the viability of AsPC-1 cells both in cFLIP-suppressed cells and in cFLIP-overexpressing cells. Lupeol significantly sensitized chemoresistant PaC cells to undergo apoptosis by recombinant TRAIL. Finally, lupeol significantly reduced the growth of human PaC tumors propagated in athymic nude mice and caused modulation of cFLIP and TRAIL protein levels in tumors. Our findings showed the anticancer efficacy of lupeol with mechanistic rationale against highly chemoresistant human PaC cells. We suggest that lupeol, alone or as an adjuvant to current therapies, could be useful for the management of human PaC. [Cancer Res 2009;69(3):1156–65]
A Long, Naturally Presented Immunodominant Epitope from NY-ESO-1 Tumor Antigen: Implications for Cancer Vaccine Design
Authors: Ebert Lisa M. , Liu Yu Chih , Clements Craig S. , Robson Neil C. , Jackson Heather M. , Markby Jessica L. , Dimopoulos Nektaria , Tan Bee Shin , Luescher Immanuel F. , Davis Ian D. , Rossjohn Jamie , Cebon Jonathan , Purcell Anthony W. , Chen Weisan
Published: January 2009

The tumor antigen NY-ESO-1 is a promising cancer vaccine target. We describe here a novel HLA-B7–restricted NY-ESO-1 epitope, encompassing amino acids 60-72 (APRGPHGGAASGL), which is naturally presented by melanoma cells. The tumor epitope bound to HLA-B7 by bulging outward from the peptide-binding cleft. This bulged epitope was not an impediment to T-cell recognition, however, because four of six HLA-B7+ melanoma patients vaccinated with NY-ESO-1 ISCOMATRIX vaccine generated a potent T-cell response to this determinant. Moreover, the response to this epitope was immunodominant in three of these patients and, unlike the T-cell responses to bulged HLA class I viral epitopes, the responding T cells possessed a remarkably broad TCR repertoire. Interestingly, HLA-B7+ melanoma patients who did not receive the NY-ESO-1 ISCOMATRIX vaccine rarely generated a spontaneous T-cell response to this cryptic epitope, suggesting a lack of priming of such T cells in the natural anti–NY-ESO-1 response, which may be corrected by vaccination. Together, our results reveal several surprising aspects of antitumor immunity and have implications for cancer vaccine design. [Cancer Res 2009;69(3):1046–54]
The Plexin-A1 Receptor Activates Vascular Endothelial Growth Factor-Receptor 2 and Nuclear Factor-κB to Mediate Survival and Anchorage-Independent Growth of Malignant Mesothelioma Cells
Authors: Catalano Alfonso , Lazzarini Raffaella , Di Nuzzo Silvia , Orciari Silvia , Procopio Antonio
Published: January 2009

The semaphorins and their receptors, the neuropilins and the plexins, are constituents of a complex regulatory system that controls axonal guidance. Moreover, many types of tumor cells express various members of semaphorins and receptors, but the biological activities within tumor mass and the signal transduction mechanism(s) they use are largely unknown. Here, we show that in asbestos-related malignant pleural mesothelioma (MPM), Semaphorin-6D (Sema6D) and its receptor plexin-A1 are frequently expressed and trigger a prosurvival program that promotes anchorage-independent growth of MPM cells. Interestingly, the same response is also controlled by the tyrosine kinase receptors of vascular endothelial growth factor (VEGF) through a nuclear factor-κB (NF-κB)–dependent pathway. We found that in MPM cells, plexin-A1 and VEGF-receptor 2 (VEGF-R2) are associated in a complex. Moreover, the presence of Sema6D promotes the tyrosine phosphorylation of VEGF-R2 in a plexin-A1–dependent manner. This is necessary for basal and Sema6D-induced NF-κB transcriptional activity, and NF-κB mediates tumor cell survival. Expression of Sema6D and plexin-A1 is induced by asbestos fibers and overexpression of plexin-A1 in nonmalignant mesothelial cells inhibits cell death after asbestos exposure. This work identifies a new biological function of semaphorins in cancer cells and suggests the involvement of an undescribed survival pathway during MPM tumorigenesis. [Cancer Res 2009;69(4):1485–93]
Osteopontin Levels in an Asbestos-Exposed Population
Authors: Park Eun-Kee , Thomas Paul S. , Johnson Anthony R. , Yates Deborah H.
Published: January 2009

Purpose: Serum osteopontin levels in patients with malignant mesothelioma have been reported to be higher than in healthy subjects. This study assessed serum osteopontin levels in an asbestos-exposed population to test whether nonmalignant asbestos-related disorders could influence osteopontin levels.

Experimental Design: This cross-sectional study evaluated serum osteopontin levels in 525 male subjects. Subjects were classified into six different diagnostic groups, including asbestosis (n = 23), silicosis (n = 20), diffuse pleural thickening (n = 110), asbestosis and diffuse pleural thickening (n = 13), pleural plaques (n = 142), and healthy subjects with a history of asbestos exposure (n = 217).

Results: Mean serum osteopontin levels differed among the six groups (P < 0.0001). Mean osteopontin values of the healthy individuals exposed to asbestos were significantly different from that of subjects with asbestosis (P < 0.001) and diffuse pleural thickening (P < 0.001). There was a significant difference in mean serum levels of osteopontin in healthy individuals exposed to asbestos (n = 217) compared with the group mean of all subjects with asbestos-related disorders (n = 288; P < 0.0001).

Conclusions: Our results suggest that osteopontin levels are elevated in subjects with asbestos-related disorders without malignant mesothelioma. These data indicate that osteopontin, although reported to be useful for detecting malignant mesothelioma in asbestos-exposed individuals, may be influenced by nonmalignant processes.
Inhibition of cervical cancer cell growth by human papillomavirus virus–like particles packaged with human papillomavirus oncoprotein short hairpin RNAs
Authors: Bousarghin Latifa , Touze Antoine , Gaud Guillaume , Iochmann Sophie , Alvarez Eva , Reverdiau Pascale , Gaitan Julien , Jourdan Marie-Lise , Sizaret Pierre-Yves , Coursaget Pierre L.
Published: January 2009

Overexpression of human papillomavirus (HPV E6 and HPV E7) oncogenes in human cervical cells results in the development of cancer, and E6 and E7 proteins are therefore targets for preventing cervical cancer progression. Here, we describe the silencing of E6 and E7 expression in cervical carcinoma cells by RNA interference. In order to increase the efficacy of the RNA interference, HPV pseudovirions coding for a short hairpin RNA (shRNA) sequence were produced. The results indicated the degradation of E6 and E7 mRNAs when shRNA against E6 or E7 were delivered by pseudovirions in HPV-positive cells (CaSki and TC1 cells). E6 silencing resulted in the accumulation of cellular p53 and reduced cell viability. More significant cell death was observed when E7 expression was suppressed. Silencing E6 and E7 and the consequences for cancer cell growth were also investigated in vivo in mice using the capacity of murine TC1 cells expressing HPV-16 E6 and E7 oncogenes to induce fast-growing tumors. Treatment with lentiviruses and HPV virus-like particle vectors coding for an E7 shRNA sequence both resulted in dramatic inhibition of tumor growth. These results show the ability of pseudovirion-delivered shRNA to produce specific gene suppression and provide an effective means of reducing HPV-positive tumor growth. [Mol Cancer Ther 2009;8(2):357–65]
Effective sensitization of temozolomide by ABT-888 is lost with development of temozolomide resistance in glioblastoma xenograft lines
Authors: Clarke Michelle J. , Mulligan Evan A. , Grogan Patrick T. , Mladek Ann C. , Carlson Brett L. , Schroeder Mark A. , Curtin Nicola J. , Lou Zhenkun , Decker Paul A. , Wu Wenting , Plummer E. Ruth , Sarkaria Jann N.
Published: January 2009

Resistance to temozolomide and radiotherapy is a major problem for patients with glioblastoma but may be overcome using the poly(ADP-ribose) polymerase inhibitor ABT-888. Using two primary glioblastoma xenografts, the efficacy of ABT-888 combined with radiotherapy and/or temozolomide was evaluated. Treatment with ABT-888 combined with temozolomide resulted in significant survival prolongation (GBM12: 55.1%, P = 0.005; GBM22: 54.4%, P = 0.043). ABT-888 had no effect with radiotherapy alone but significantly enhanced survival in GBM12 when combined with concurrent radiotherapy/temozolomide. With multicycle therapy, ABT-888 further extended the survival benefit of temozolomide in the inherently sensitive GBM12 and GBM22 xenograft lines. However, after in vivo selection for temozolomide resistance, the derivative GBM12TMZ and GBM22TMZ lines were no longer sensitized by ABT-888 in combination with temozolomide, and a similar lack of efficacy was observed in two other temozolomide-resistant tumor lines. Thus, the sensitizing effects of ABT-888 were limited to tumor lines that have not been previously exposed to temozolomide, and these results suggest that patients with newly diagnosed glioblastoma may be more likely to respond to combined temozolomide/poly(ADP-ribose) polymerase inhibitor therapy than patients with recurrent disease. [Mol Cancer Ther 2009;8(2):OF407–8]
Biological characterization of AT7519, a small-molecule inhibitor of cyclin-dependent kinases, in human tumor cell lines
Authors: Squires Matthew S. , Feltell Ruth E. , Wallis Nicola G. , Lewis E. Jonathan , Smith Donna-Michelle , Cross David M. , Lyons John F. , Thompson Neil T.
Published: January 2009

Cyclin-dependent kinases (CDK), and their regulatory cyclin partners, play a central role in eukaryotic cell growth, division, and death. This key role in cell cycle progression, as well as their deregulation in several human cancers, makes them attractive therapeutic targets in oncology. A series of CDK inhibitors was developed using Astex's fragment-based medicinal chemistry approach, linked to high-throughput X-ray crystallography. A compound from this series, designated AT7519, is currently in early-phase clinical development. We describe here the biological characterization of AT7519, a potent inhibitor of several CDK family members. AT7519 showed potent antiproliferative activity (40-940 nmol/L) in a panel of human tumor cell lines, and the mechanism of action was shown here to be consistent with the inhibition of CDK1 and CDK2 in solid tumor cell lines. AT7519 caused cell cycle arrest followed by apoptosis in human tumor cells and inhibited tumor growth in human tumor xenograft models. Tumor regression was observed following twice daily dosing of AT7519 in the HCT116 and HT29 colon cancer xenograft models. We show that these biological effects are linked to inhibition of CDKs in vivo and that AT7519 induces tumor cell apoptosis in these xenograft models. AT7519 has an attractive biological profile for development as a clinical candidate, and the tolerability and efficacy in animal models compare favorably with other CDK inhibitors in clinical development. Studies described here formed the biological rationale for investigating the potential therapeutic benefit of AT7519 in cancer patients. [Mol Cancer Ther 2009;8(2):324–32]
Mapatumumab and lexatumumab induce apoptosis in TRAIL-R1 and TRAIL-R2 antibody-resistant NSCLC cell lines when treated in combination with bortezomib
Authors: Luster Troy A. , Carrell Jeffrey A. , McCormick Kathy , Sun David , Humphreys Robin
Published: January 2009

Mapatumumab and lexatumumab are fully human monoclonal antibodies that bind and activate human tumor necrosis factor-related apoptosis-inducing ligand receptors 1 and 2, respectively. These antibodies induce apoptosis in various tumor cell types, although the degree of sensitivity can vary from highly sensitive to completely resistant. Importantly, tumor cells that are partially or completely resistant to mapatumumab or lexatumumab can often be sensitized when treated in combination with chemotherapeutic drugs. In this regard, the proteasome inhibitor bortezomib has recently shown synergistic activity against established lymphoma cell lines and primary lymphomas when combined with mapatumumab and lexatumumab. Here, we report similar findings using a panel of human non-small cell lung cancer (NSCLC) cell lines. Specifically, we show that bortezomib rapidly induces sensitivity to mapatumumab and lexatumumab in NSCLC cell lines that are completely resistant to antibody alone and that bortezomib concentrations as low as 25 nmol/L sensitize NSCLC cells to the antibodies. Furthermore, bortezomib at the tested concentration has minimal effect on its own, indicating the combination generates synergistic cytotoxicity. Combination treatment induces activation of the caspase cascade and the effect of the combination is caspase dependent. Bortezomib treatment increases the intracellular levels of several important apoptosis regulators that may mediate enhanced sensitivity to mapatumumab and lexatumumab. These results suggest future evaluation of mapatumumab or lexatumumab in combination with bortezomib is warranted in NSCLC patients. [Mol Cancer Ther 2009;8(2):292–302]