bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECTIVENESS OF THE COMPONENT IMPACT TEST METHOD FOR THE SIDE IMPACT INJURY ASSESSMENT OF THE DOOR TRIM
Authors: YOUN YOUNGHAN , KOO JEONG-SEO
Published: June 2008

The complete evaluation of the side vehicle structure and the occupant protection is only possible by means of the full scale side impact crash test. But, auto part manufacturers such as door trim makers can not conduct the test especially when the vehicle is under the developing process. The main objective of this study is to obtain the design guidelines by a simple component level impact test. The relationship between the target absorption energy and impactor speed were examined using the energy absorbed by the door trim. Since each different vehicle type required different energy levels on the door trim. A simple impact test method was developed to estimate abdominal injury by measuring reaction force of the impactor. The reaction force will be converted to a certain level of the energy by the proposed formula. The target of absorption energy for door trim only and the impact speed of simple impactor are derived theoretically based on the conservation of energy. With calculated speed of dummy and the effective mass of abdomen, the energy allocated in the abdomen area of door trim was calculated. The impactor speed can be calculated based on the equivalent energy of door trim absorbed during the full crash test. With the proposed design procedure for the door trim by a simple impact test method was demonstrated to evaluate the abdominal injury. This paper describes a study that was conducted to determine sensitivity of several design factors for reducing abdominal injury values using the matrix of orthogonal array method.

In conclusion, with theoretical considerations and empirical test data, the main objective, standardization of door trim design using the simple impact test method was established.
A STUDY ON PERFORMANCE ASSESSMENT OF DAMAGED BEAM BASED ON STATIC APPROACH
Authors: LEE EUN-TAIK , KIM GON , LEE MIN-SU , BAE CHUNG-YEOL , EUN HEE-CHANG
Published: June 2008

Starting from the derivation of an analytical method to expand measured static displacement data to full degrees of freedom, this study proposes a damage detection method to detect the damage of damaged beam by introducing displacement curvature and damage factor (DF). The validity of the proposed method is evaluated in damaged beam system that two simple beams are perpendicularly interconnected at a point.
STRENGTH DEGRADATIONS FROM HERTZIAN CONTACT DAMAGES IN NITRIDED PRESSURELESS SINTERED SILICON NITRIDE CERAMICS
Authors: GUAHK KIL HO , HAN IN SUB , LEE KEE SUNG
Published: June 2008

Strength degradations in silicon nitride ceramics subject to damage from contact with hard spheres are investigated. Strengths against indentation load, number of cycles in contact, or stress-rate parameter are reported and compared with theoretical models. Silicon nitride ceramics are prepared by nitride pressureless sintering (NPS) process, which process is the continuous process of nitridation reaction of Si metal combined with subsequent pressureless sintering. Microstructure characterizations reveal silicon nitride fabricated by NPS process exhibits a quasi-plastic mode, with continuous strength loss beyond a load above the onset of yield, and falloff at high number of cycles, > 105 at contact load, P = 950 N , using WC sphere r = 1.98 mm . The strength degradation is substantially faster by dynamic fatigue. Failures originated from contact damages, quasi-plastic microcrack zones, with developing radial cracks during strength test. The implication is that quasi-plastic damage of NPS silicon nitride itself can preserve benefits from the inherent higher damage tolerance at lower number of cycles of contacts, but fatigue susceptibility at multicycle contacts and lower stressing rate.
APPLICATION AND PERFORMANCE EVALUATION FOR THE DMS SYSTEM IN THE SLS PROCESS
Authors: KIM DONG SOO , BAE SUNG WOO , CHOI KYUNG HYUN
Published: June 2008

A Solid Freeform Fabrication (SFF) system using Selective Laser Sintering (SLS) is currently recognized as a leading process and SLS extends the applications to machinery and automobiles due to the various materials employed. Especially, accuracy and processing time are very important factors when the desired shape is fabricated with Selective Laser Sintering (SLS), one of Solid Freeform Fabrication (SFF) system. In the convectional SLS process, laser spot size is fixed during laser exposing on the sliced figure. Therefore, it is difficult to accuracy and rapidly fabricates the desired shape. In this paper, to deal with those problems a SFF system having ability of changing spot size is developed. The system provides high accuracy and optimal processing time. Specifically, a variable beam expander is employed to adjust spot size for different figures on a sliced shape. Therefore, design and performance estimation of the SFF system employing a variable beam expander are achieved and the mechanism will be addressed to measure the real spot size generated from the variable beam expander. Also, the reduction of total processing time is an important issue in SFF system. A digital mirror system (DMS) is a system which scans the laser beam with different spot size. The spot size is selected based on the slicing section to decrease and accuracy of the process time and improve the processing efficiency. In this study, the optimal scan path generation for DMS will be addressed, and this development will improve the whole processing efficiency and accuracy through the scan efficiency by considering the existing scan path algorithm and heat energy distribution.
EXPERIMENTAL AND THEORETICAL STUDY ON FREEZE-THAWING DAMAGE PROPAGATION OF SATURATED ROCKS
Authors: LIU QUANSHENG , XU GUANGMIAO , LIU XIAOYAN
Published: June 2008

The freezing and thawing cycles tests were conducted on red sandstone and shale. In this paper, freezing-thawing damage propagation processes are analyzed, and two deterioration modes, i.e. scaling mode for red sandstone and fracturing mode for shale, are suggested. The uniaxial compression tests are also conducted on the two types of rock subjected to different freeze-thaw cycles at room temperature. It is shown that the uniaxial compression strength and the elastic modulus of rocks at low-temperature depended on the number of freeze-thaw cycles. The mechanism and influence factors of rock deterioration due to freeze-thaw are analyzed, and the damage process of rock should be divided into two coupled parts: rocks damage due to freeze-thaw cycle as well as the damage propagation caused by stress erosion. The damage evolvement equations for the two rocks are established, and the constitutive equations for the two types of rock subjected to freeze-thaw are deduced, accordingly. It is approved that the constitutive model considering the freeze-thaw damage is credible and can be used for the following theory analysis.
HIGH EFFICIENCY MICROMACHINING SYSTEM APPLIED IN NANOLITHOGRAPHY
Authors: CHEN XING , LEE DONG WEON , CHOI YOUNG SOO
Published: June 2008

Scanning probe lithography such as direct–writing lithographic processes and nanoscratching techniques based on scanning probe microscopy have presented new micromachining methods for microelectromechanical system (MEMS). In this paper, a micromachining system for thermal scanning probe lithography is introduced, which consists of the cantilever arrays and a big stroke micro XY–stage. A large machining area and high machining speed can be realized by combining arrays of cantilevers possessing sharp tips at their top with the novel micro XY–stage which can obtain big displacements under relatively low driving voltage and in a small size. According to the above configuration, this micromachining system is provided with high throughputs and suitable for industrialization due to its MEMS–based simple fabrication process. The novel micro XY–stage applied in this system is presented in detail including the unique structure and principles, which shows an obvious improvement and distinct advantages in comparison with traditional structures. It is analyzed by mathematical model and then simulated using finite element method (FEM), it is proved to be able to practically serve the micromachining system with high capability.
INTEGRATED DRIVE FOR CONTACT-FREE FULL ROTATION AND ITS NOVEL POSITIONING METHODOLOGY
Authors: JUNG KWANG SUK , LEE SANG HEON
Published: June 2008

To expand an inevitably limited rotating range of the existing planar precision stage, we suggest a revolving stage driven by three-separate axial type of transverse flux induction motors spaced 120° apart. It is a non-contact integrated rotating system that uses three-axial vector forces such as normal and thrust force of each motor. In this paper, the primary principles capable of realizing such a contact-less revolving stage are reviewed and compared, with results that seem to confirm the main principles of the suggested system. And then, the positioning method with only the air-gap measurements covering full degree of freedom is presented, compared with that of existing stages.
A NOTE ON QUASI-PERIODIC FACTORIZATIONS
Authors: SANDS A. D.
Published: June 2008

A question was raised in [3] concerning a hereditary property for quasi-periodic factorizations. In this note a result is proved which leads to a negative answer to this question.
SURFACE SUBGROUPS OF RIGHT-ANGLED ARTIN GROUPS
Authors: CRISP JOHN , SAGEEV MICHAH , SAPIR MARK
Published: June 2008

We consider the question of which right-angled Artin groups contain closed hyperbolic surface subgroups. It is known that a right-angled Artin group A(K) has such a subgroup if its defining graph K contains an n-hole (i.e. an induced cycle of length n) with n ≥ 5. We construct another eight "forbidden" graphs and show that every graph K on ≤ 8 vertices either contains one of our examples, or contains a hole of length ≥ 5, or has the property that A(K) does not contain hyperbolic closed surface subgroups. We also provide several sufficient conditions for a right-angled Artin group to contain no hyperbolic surface subgroups.

We prove that for one of these "forbidden" subgraphs P2(6), the right-angled Artin group A(P2(6)) is a subgroup of a (right-angled Artin) diagram group. Thus we show that a diagram group can contain a non-free hyperbolic subgroup answering a question of Guba and Sapir. We also show that fundamental groups of non-orientable surfaces can be subgroups of diagram groups. Thus the first integral homology of a subgroup of a diagram group can have torsion (all homology groups of all diagram groups are free Abelian by a result of Guba and Sapir).
DETERMINANTS RELATED TO DIRICHLET CHARACTERS MODULO 2, 4 AND 8 OF BINOMIAL COEFFICIENTS AND THE ALGEBRA OF RECURRENCE MATRICES
Authors: BACHER ROLAND
Published: June 2008

Using recurrence matrices, defined and described with some details, we study a few determinants related to evaluations of binomial coefficients on Dirichlet characters modulo 2,4 and 8.
THERMODYNAMICAL PROPERTIES OF HALL SYSTEMS
Authors: JELLAL AHMED , KHEDIF YOUSSEF
Published: June 2008

We study quantum Hall effect within the framework of a newly proposed approach, which captures the principal results of some proposals. This can be established by considering a system of particles living on the noncommutative plane in the presence of an electromagnetic field and quantum statistical mechanically investigate its basic features. Solving the eigenvalue equation, we analytically derive the energy levels and the corresponding wavefunctions. These will be used, at low temperature and weak electric field, to determine the thermodynamical potential Ω nc and related physical quantities. Varying Ω nc with respect to the noncommutativity parameter θ, we define a new function that can be interpreted as a Ω nc density. Evaluating the particle number, we show that the Hall conductivity of the system is θ-dependent. This allows us to make contact with the quantum Hall effect by offering different interpretations. We study the high temperature regime and discuss the magnetism of the system. We finally show that at [Formula: see text], the system is sharing some common features with the Laughlin theory.
AN OPTIMAL CONTROL PROBLEM ON THE LIE GROUP SO(4)
Authors: ARON ANANIA , MOŞ IONEL , CSAKY ANIKO , PUTA MIRCEA
Published: June 2008

An optimal control problem for a drift-free controllable system on the Lie group SO(4) is discussed and some of its dynamical and geometrical properties are pointed out.
GEOMETRIC STRUCTURE OF THE HILBERT–YANG–MILLS FUNCTIONAL
Authors: PATÁK A. , KRUPKA D.
Published: June 2008

The global variational functional, defined by the Hilbert–Yang–Mills Lagrangian over a smooth manifold, is investigated within the framework of prolongation theory of principal fiber bundles, and global variational theory on fibered manifolds. The principal Lepage equivalent of this Lagrangian is constructed, and the corresponding infinitesimal first variation formula is obtained. It is shown, in particular, that the Noether currents, associated with isomorphisms of the underlying geometric structures, split naturally into several terms, one of which is the exterior derivative of the Komar–Yang–Mills superpotential. Consequences of invariance of the Hilbert–Yang–Mills Lagrangian under isomorphisms of underlying geometric structures such as Noether's conservation laws for global currents are then established. As an example, a general formula for the Komar–Yang–Mills superpotential of the Reissner–Nordström solution of the Einstein equations is found.
HEAT KERNEL ON HOMOGENEOUS BUNDLES
Authors: AVRAMIDI IVAN G.
Published: June 2008

We consider Laplacians acting on sections of homogeneous vector bundles over symmetric spaces. By using an integral representation of the heat semi-group we find a formal solution for the heat kernel diagonal that gives a generating function for the whole sequence of heat invariants. We argue that the obtained formal solution correctly reproduces the exact heat kernel diagonal after a suitable regularization and analytical continuation.
FUNCTIONALLY GRADED MEDIA
Authors: CAMPOS CÉDRIC M. , EPSTEIN MARCELO , DE LEÓN MANUEL
Published: June 2008

The notions of uniformity and homogeneity of elastic materials are reviewed in terms of Lie groupoids and frame bundles. This framework is also extended to consider the case of Functionally Graded Media, which allows us to obtain some homogeneity conditions.
GEOMETRICAL ASPECTS OF INTEGRABLE SYSTEMS
Authors: FIORANI EMANUELE
Published: June 2008

We review some basic theorems on integrability of Hamiltonian systems, namely the Liouville–Arnold theorem on complete integrability, the Nekhoroshev theorem on partial integrability and the Mishchenko–Fomenko theorem on noncommutative integrability, and for each of them we give a version suitable for the noncompact case. We give a possible global version of the previous local results, under certain topological hypotheses on the base space. It turns out that locally affine structures arise naturally in this setting.
Osteoglossomorpha: phylogeny, biogeography, and fossil record and the significance of key African and Chinese fossil taxa
Authors: Wilson M. V. H. , Murray A. M.
Published: June 2008

The Osteoglossomorpha are a clade of primitive teleostean fishes with modern representatives in five biogeogeographic regions and fossil representatives on six continents. The centre of modern diversity is in Africa but the centre of fossil diversity is in E Asia. Key fossil taxa include: †
Phareodus
, †
Joffrichthys
, and †
Ostariostoma
in N America; †
Lycoptera
, †
Paralycoptera
, and †
Huashia
among others in E Asia; †
Brychaetus
and possibly †
Thaumaturus
in Europe; †
Palaeonotopterus
, †
Singida
, and †
Chauliopareion
in Africa; †
Tavernichthys
in India; and †
Musperia
in SE Asia.

Morphological phylogenies to date have disagreed on three main points: the relationships of †
Lycoptera
, of
Pantodon
, and of Notopterids and Mormyrids. Molecular phylogenies have similarly differed on the last two points. In this study a combined set of morphological data was generated from previous studies, including data from three recently described or redescribed taxa (the African †
Singida
and †
Chauliopareion
and the Chinese †
Xixiaichthys
) and maximum parsimony was used to generate a revised hypothesis of relationships. Our analysis recovered †
Lycoptera
, †
Paralycoptera
+ †
Tanolepis
, and †
Xixiaichthys
as stem-group osteoglossomorphs, †
Singida
as sister to
Pantodon
within Osteoglossidae, †
Chauliopareion
as a stem osteoglossid, †
Ostariostoma
as a stem osteoglossiform, and Notopteridae as sister to Mormyroidea and †
Palaeonotopterus
.

These results do not lend themselves to easy explanations of osteoglossomorph biogeography involving either dispersal from a centre of origin or vicariant division of a widely distributed ancestor. Recent suggestions of an ancient (Palaeozoic) origin for osteoglossomorphs are flawed. The evidence, instead, is consistent with an origin within the Mesozoic and the biogeographic explanation involves extensive extinction of clades from continents where they occurred in the past.
Fishes and the Break-up of Pangaea: an introduction
Authors: Cavin Lionel , Longbottom Alison , Richter Martha
Published: June 2008

There is general agreement that a tight relationship exists between evolutionary histories of living lineages and the shifting geography of the Earth during the Phanerozoic, but how to depict that link has been much disputed in recent decades. The issue is fundamental, as it involves two supposedly-irreconcilable paradigms for how we interpret past and present distributions: the Darwin–Wallace biogeographic paradigm that involves dispersal from centres of origin, and the vicariance paradigm. When dealing with extinct organisms, for which we have only sparse and fragmentary fossil remains, the limit between the two paradigms becomes blurred. Here, all available data about time (stratigraphy) and space (palaeogeography) need to be gathered in order to detect biogeographical signals.

Because of the incompleteness of the fossil record, the analyses may lead to storytelling style descriptions of biogeographic scenarios (phylogenies are often weakly supported, datings are frequently vague and occurrences are sparse). But these scenarios are always open to refutation if new fossils are found and, accordingly, are genuine scientific hypotheses. The Darwin–Wallace biogeographic paradigm and the vicariance paradigm have been described as the extreme points of a pendulum; in this book, examples of relationships between the evolutionary history of fish clades and the break-up of Pangaea are described using approaches that lie between these extreme points of the pendulum.
New eugeneodontid sharks from the Lower Triassic Sulphur Mountain Formation of Western Canada
Authors: Mutter Raoul J. , Neuman Andrew G.
Published: June 2008

Eugeneodontid sharks, previously believed to have become virtually extinct during the great end-Permian extinction event, are here shown to be diverse in the Early Triassic of western Canada. Although the specimens are probably predominantly Olenekian in age, they show an abundance similar to that of the Late Permian of East Greenland. Similar in size and morphology to their Palaeozoic predecessors, this diverse assemblage is seen to have a short duration within the Early Triassic. A number of identifiable dentitions and postcranial skeletal remains suggest the presence of at least two caseodontid species (
Caseodus varidentis
sp. nov. and
Fadenia uroclasmato
sp. nov.) and an edestoid (
Paredestus bricircum
gen. et sp. nov.) Many other specimens recovered from the Lower Triassic Vega-Phroso Siltstone Member (Sulphur Mountain Formation) at Wapiti Lake are too poorly preserved for identification but help demonstrate the major taxonomic problems in eugeneodontid systematics. We discuss the survival of this highly specialized group of ‘sharks’ and comment on their biogeographical distribution across the Permo-Triassic boundary.
Mel-18 Negatively Regulates INK4a/ARF-Independent Cell Cycle Progression via Akt Inactivation in Breast Cancer
Authors: Lee Jeong-Yeon , Jang Ki-Seok , Shin Dong-Hui , Oh Mi-Yun , Kim Hyun-Jun , Kim Yongseok , Kong Gu
Published: June 2008

Mel-18, a polycomb group (PcG) protein, has been suggested as a tumor suppressor in human breast cancer. Previously, we reported that Mel-18 has antiproliferative activity in breast cancer cells. However, its functional mechanism has not been fully elucidated. Here, we investigated the role of Mel-18 in human breast cancer. We saw an inverse correlation between Mel-18 and phospho-Akt, which were expressed at low and high levels, respectively, in primary breast tumor tissues from 40 breast cancer patients. The effect of Mel-18 on cell growth was examined in two breast cancer cell lines, SK-BR-3 and T-47D, which express relatively low and high levels of endogenous Mel-18, respectively. On Mel-18 overexpression in SK-BR-3 cells, cell growth was attenuated and G1 arrest was observed. Likewise, suppression of Mel-18 by antisense expression in T-47D cells led to enhanced cell growth and accelerated G1-S phase transition. In these cells, cyclin-dependent kinase (Cdk)-4 and Cdk2 activities were affected by Mel-18, which were mediated by changes in cyclin D1 expression and p27Kip1 phosphorylation at Thr157, but not by INK4a/ARF genes. The changes were both dependent on the phosphatidylinositol 3-kinase/Akt signaling pathway. Akt phosphorylation at Ser473 was reduced by Mel-18 overexpression in SK-BR-3 cells and enhanced by Mel-18 suppression in T-47D cells. Akt-mediated cytoplasmic localization of p27Kip1 was inhibited by Mel-18 in SK-BR-3 cells. Moreover, Mel-18 overexpression showed reduced glycogen synthase kinase-3β phosphorylation, β-catenin nuclear localization, T-cell factor/lymphoid enhancer factor promoter activity, and cyclin D1 mRNA level. Taken together, we established a linear relationship between Mel-18→Akt→G1 phase regulators. [Cancer Res 2008;68(11):4201–9]
Functional and Clinical Evidence for NDRG2 as a Candidate Suppressor of Liver Cancer Metastasis
Authors: Lee Dong Chul , Kang Yun Kyung , Kim Woo Ho , Jang Ye Jin , Kim Dong Joon , Park In Young , Sohn Bo Hwa , Sohn Hyun Ahm , Lee Hee Gu , Lim Jong Seok , Kim Jae Wha , Song Eun Young , Kim Dong Min , Lee Mi-Ni , Oh Goo Taeg , Kim Soo Jung , Park Kyung Chan , Yoo Hyang Sook , Choi Jong Young , Yeom Young Il
Published: June 2008

We searched for potential suppressors of tumor metastasis by identifying the genes that are frequently down-regulated in hepatocellular carcinomas (HCC) while being negatively correlated with clinical parameters relevant to tumor metastasis, and we report here on the identification of N-myc downstream regulated gene 2 (NDRG2) as a promising candidate. NDRG2 expression was significantly reduced in HCC compared with nontumor or normal liver tissues [87.5% (35 of 40) and 62% (62 of 100) at RNA and protein levels, respectively]. Reduction of NDRG2 expression was intimately associated with promoter hypermethylation because its promoter region was found to carry extensively methylated CpG sites in HCC cell lines and primary tumors. Immunohistochemical analysis of NDRG2 protein in 100 HCC patient tissues indicated that NDRG2 expression loss is significantly correlated with aggressive tumor behaviors such as late tumor-node-metastasis (TNM) stage (P = 0.012), differentiation grade (P = 0.024), portal vein thrombi (P = 0.011), infiltrative growth pattern (P = 0.015), nodal/distant metastasis (P = 0.027), and recurrent tumor (P = 0.021), as well as shorter patient survival rates. Ectopically expressed NDRG2 suppressed invasion and migration of a highly invasive cell line, SK-Hep-1, and experimental tumor metastasis in vivo, whereas small interfering RNA–mediated knockdown resulted in increased invasion and migration of a weakly invasive cell line, PLC/PRF/5. In addition, NDRG2 could antagonize transforming growth factor β1–mediated tumor cell invasion by specifically down-regulating the expression of matrix metalloproteinase 2 and laminin 332 pathway components, with concomitant suppression of Rho GTPase activity. These results suggest that NDRG2 can inhibit extracellular matrix–based, Rho-driven tumor cell invasion and migration and thereby play important roles in suppressing tumor metastasis in HCC. [Cancer Res 2008;68(11):4210–20]
ASAP1, a Gene at 8q24, Is Associated with Prostate Cancer Metastasis
Authors: Lin Dong , Watahiki Akira , Bayani Jane , Zhang Fang , Liu Lin , Ling Victor , Sadar Marianne D. , English John , Fazli Ladan , So Alan , Gout Peter W. , Gleave Martin , Squire Jeremy A. , Wang Yu-Zhuo
Published: June 2008

Metastatic prostate cancer is a terminal disease, and the development of reliable prognostic tools and more effective therapy is critically important for improved disease survival and management. This study was aimed at identifying genes that are differentially expressed in metastatic and nonmetastatic prostate cancer cells and, as such, could be critical in the development of metastasis. Long-SAGE analysis was used to compare a transplantable human metastatic prostate cancer subline, PCa1-met, with a nonmetastatic counterpart, PCa2. Both sublines were developed from a patient's prostate cancer specimen via subrenal capsule grafting and subsequent orthotopic implantation into SCID mice. Among various differentially expressed genes identified, ASAP1, an 8q24 gene encoding an ADP-ribosylation factor GTPase-activating protein not previously associated with prostate cancer, was up-regulated in the metastatic subline as confirmed by quantitative real-time PCR. Immunohistochemistry of xenograft sections showed that cytoplasmic ASAP1 protein staining was absent or weak in benign tissue, significantly stronger in nonmetastatic PCa2 tissue, and strongest in PCa1-met tissue. In clinical specimens, ASAP1 protein staining was elevated in 80% of primary prostate cancers and substantially higher in metastatic lesions compared with benign prostate tissue. Moreover, additional ASAP1 gene copies were detected in 58% of the primary prostate cancer specimens. Small interfering RNA–induced reduction of ASAP1 protein expression markedly suppressed in vitro PC-3 cell migration (∼50%) and Matrigel invasion (∼67%). This study suggests that the ASAP1 gene plays a role in prostate cancer metastasis and may represent a therapeutic target and/or biomarker for metastatic disease. [Cancer Res 2008;68(11):4352–9]
Interleukin-21 Augments the Efficacy of T-Cell Therapy by Eliciting Concurrent Cellular and Humoral Responses
Authors: Iuchi Takekazu , Teitz-Tennenbaum Seagal , Huang Jianhua , Redman Bruce G. , Hughes Steven D. , Li Mu , Jiang Guihua , Chang Alfred E. , Li Qiao
Published: June 2008

Interleukin (IL)-21 modulates T-cell–associated, B-cell–associated, and natural killer cell–associated immunity. However, the potential of IL-21 to simultaneously stimulate cellular and humoral antitumor responses and the mechanisms involved have not yet been adequately explored. In this report, we examined the immune-modulating effect of IL-21 when used in vitro and its adjuvant effects when administrated concomitantly with T-cell transfer for cancer therapy. Use of IL-21 in concert with IL-2 in culture up-regulated both type 1 and type 2 cytokine production of activated tumor-draining lymph node cells and enhanced their therapeutic efficacy. Administration of IL-21 and IL-2 as an adjuvant to T-cell transfer resulted in simultaneously elicited cellular and humoral responses. This concurrent response has led to effective regression of established pulmonary metastatic tumors and s.c. tumors. T-cell transfer plus IL-21/IL-2 administration conferred systemic immunity to the treated hosts. This was evident by the induction of protective immunity against tumor rechallenge, expansion of memory T cells, and significantly elevated serum levels of IFNγ and IL-10. Furthermore, we observed significantly enhanced tumor-associated antibody response after T-cell + IL-2 + IL-21 therapy. Cytotoxic antibody subclass IgG2b increased strikingly in the sera of treated animals; they bound specifically to MCA205 tumor cells, and such immune sera mediated tumor cell lysis in the presence of complement. Use of B-cell–deficient mice provided direct evidence that humoral responses contribute to T-cell + IL-2 + IL-21–elicited antitumor immunity. Collectively, these findings provide a rationale to evaluate the use of IL-21 in T-cell therapy of human cancers. [Cancer Res 2008;68(11):4431–41]
Pediatric Malignant Germ Cell Tumors Show Characteristic Transcriptome Profiles
Authors: Palmer Roger D. , Barbosa-Morais Nuno L. , Gooding Emma L. , Muralidhar Balaji , Thornton Claire M. , Pett Mark R. , Roberts Ian , Schneider Dominik T. , Thorne Natalie , Tavaré Simon , Nicholson James C. , Coleman Nicholas ,   on behalf of Children's Cancer and Leukaemia Group
Published: June 2008

Malignant germ cell tumors (GCT) of childhood are rare and heterogeneous neoplasms thought to arise from primordial germ cells. They vary substantially in their natural history and show important clinical differences from their adult counterparts. To address the biological basis for these observations, we have undertaken a comprehensive analysis of global gene expression patterns in pediatric malignant GCTs and compared these findings with published data on adult testicular GCTs (TGCT). Our study included 27 primary tumors and assessed the principal malignant histologic types of pediatric GCT, yolk sac tumor (YST; n = 18), and seminoma (n = 9). Analysis of Affymetrix U133A GeneChip data was performed using the statistical software environment R, including gene set enrichment analysis, with cross-validation at the RNA and protein level. Unsupervised analysis showed complete separation of YSTs and seminomas by global gene expression profiles and identified a robust set of 657 discriminatory transcripts. There was no segregation of tumors of the same histology arising at different sites or at different ages within the pediatric range. In contrast, there was segregation of pediatric malignant GCTs and adult malignant TGCTs, most notably for the YSTs. The pediatric seminomas were significantly enriched for genes associated with the self-renewing pluripotent phenotype, whereas the pediatric YSTs were significantly enriched for genes associated with a differentiation and proliferation phenotype. We conclude that histologic type is the key discriminator in pediatric malignant GCTs and that the observed clinical differences between malignant GCTs of children and adults are mirrored by significant differences in global gene expression. [Cancer Res 2008;68(11):4239–47]
Immunoglobulin Allotypes Influence Antibody Responses to Mucin 1 in Patients with Gastric Cancer
Authors: Pandey Janardan P. , Nietert Paul J. , von Mensdorff-Pouilly Silvia , Klaamas Kersti , Kurtenkov Oleg
Published: June 2008

There are significant interindividual differences in naturally occurring antibody responses to the tumor-associated antigen mucin 1 (MUC1), but the host genetic factors that might contribute to these differences have not been identified. The aim of the present investigation was to determine whether the variation in naturally occurring antibody levels to MUC1 in patients with gastric cancer is associated with GM and KM allotypes, genetic markers of IgG heavy chains and κ-type light chains, respectively. A total of 169 Caucasian subjects with gastric cancer were allotyped for several GM and KM markers. These subjects were also characterized for IgG and IgM antibodies to MUC1. GM 3 23 5,13 phenotype was highly significantly associated with MUC1 IgG levels; subjects with this phenotype had lower antibody levels compared with those lacking this phenotype (median IgG level 65.5 relative units versus 91.0 relative units, P = 0.0058). In addition, this phenotype had an interactive effect with KM phenotypes on the levels of IgG antibodies to this antigen (P = 0.0081). Levels of MUC1 IgM antibodies were not associated with these genetic markers. These results show, for the first time, that GM and KM allotypes contribute to the interindividual differences in humoral immunity to MUC1. [Cancer Res 2008;68(11):4442–6]
Defective Claudin-7 Regulation by Tcf-4 and Sox-9 Disrupts the Polarity and Increases the Tumorigenicity of Colorectal Cancer Cells
Authors: Darido Charbel , Buchert Michael , Pannequin Julie , Bastide Pauline , Zalzali Hassan , Mantamadiotis Theo , Bourgaux Jean-François , Garambois Véronique , Jay Philippe , Blache Philippe , Joubert Dominique , Hollande Frédéric
Published: June 2008

Tight junctions have recently emerged as essential signaling regulators of proliferation and differentiation in epithelial tissues. Here, we aimed to identify the factors regulating claudin-7 expression in the colon, and analyzed the consequences of claudin-7 overexpression in colorectal carcinoma (CRC). In healthy human colonic crypts, claudin-7 expression was found to be low in the stem/progenitor cell compartment, where Tcf-4 activity is high, but strong in differentiated and postmitotic cells, where Tcf-4 is inactive. In contrast, claudin-7 was overexpressed in areas with high Tcf-4 target gene levels in CRC samples. In vitro, Tcf-4 was able to repress claudin-7 expression, and the high mobility group–box transcription factor Sox-9 was identified as an essential mediator of this effect. Claudin-7 was strongly expressed in the intestine of Sox-9–deficient mice and in CRC cells with low Sox transcriptional activity. Sox-9 overexpression in these cells reinstated claudin-7 repression, and residual claudin-7 was no longer localized along the basolateral membrane, but was instead restricted to tight junctions. Using HT-29Cl.16E CRC cell spheroids, we found that Sox-9–induced polarization was completely reversed after virus-mediated claudin-7 overexpression. Claudin-7 overexpression in this context increased Tcf-4 target gene expression, proliferation, and tumorigenicity after injection in nude mice. Our results indicate that Tcf-4 maintains low levels of claudin-7 at the bottom of colonic crypts, acting via Sox-9. This negative regulation seems to be defective in CRC, possibly due to decreased Sox-9 activity, and the resulting claudin-7 overexpression promotes a loss of tumor cell polarization and contributes to tumorigenesis. [Cancer Res 2008;68(11):4258–68]
Human Melanoma Cytolysis by Combined Inhibition of Mammalian Target of Rapamycin and Vascular Endothelial Growth Factor/Vascular Endothelial Growth Factor Receptor-2
Authors: Molhoek Kerrington R. , Griesemann Heinrich , Shu Jianfen , Gershenwald Jeffrey E. , Brautigan David L. , Slingluff Craig L.
Published: June 2008

Vascular endothelial growth factor (VEGF) plays a vital role in tumor angiogenesis. VEGF is produced by human melanomas, and the VEGF receptor 2 (VEGFR-2) is expressed by most advanced stage melanomas, suggesting the possibility of an autocrine loop. Here, we show that bevacizumab, an anti-VEGF antibody, inhibits proliferation of VEGFR-2+ melanoma cell lines by an average of 41%; however, it failed to inhibit proliferation of VEGFR-2neg melanoma cell lines. The growth inhibitory effect of bevacizumab was eliminated by VEGFR-2 knockdown with small interfering RNA, showing that VEGF autocrine growth in melanoma is mediated through VEGFR-2. However, bevacizumab inhibition of autocrine signals did not completely inhibit cell proliferation nor cause cell death. Cell survival is mediated partially through mammalian target of rapamycin (mTOR), which is inhibited by rapamycin. Combination of bevacizumab with rapamycin caused loss of half of the VEGFR-2+ melanoma cells, but no reduction in the number of VEGFR-2neg melanoma cells. The results show (a) an autocrine growth loop active in VEGFR-2+ melanoma, (b) a nonangiogenic mechanism for inhibition of melanoma by blocking autocrine VEGFR-2 activation, and (c) a possible therapeutic role for combination of inhibitors of mTOR plus VEGF in selected melanomas. [Cancer Res 2008;68(11):4392–7]
RAP80 Responds to DNA Damage Induced by Both Ionizing Radiation and UV Irradiation and Is Phosphorylated at Ser205
Authors: Yan Jun , Yang Xiao-Ping , Kim Yong-Sik , Jetten Anton M.
Published: June 2008

Receptor-associated protein (RAP80), a nuclear protein containing two ubiquitin-interacting motifs (UIM), was recently found to be associated with breast cancer-1 (BRCA1) and to translocate to ionizing radiation–induced foci (IRIF). In this study, we show that the BRCT mutant of BRCA1, R1699W, which is associated with increased risk of breast cancer, is unable to interact with RAP80. Previously, we showed that ataxia-telangiectasia mutated protein kinase (ATM) can phosphorylate RAP80 in vitro at Ser205, but whether this site is a target of ATM in whole cells was not established. To address this question, we generated an anti-RAP80Ser205P antibody that specifically recognizes RAP80 phosphorylated at Ser205. Our data show that RAP80 becomes phosphorylated at Ser205 in cells exposed to ionizing irradiation and that RAP80Ser205P translocates to IRIF. We show that this phosphorylation is mediated by ATM and does not require a functional BRCA1. The phosphorylation occurs within 5 minutes after irradiation, long before the translocation of RAP80 to IRIF. In addition, we show that UV irradiation induces translocation of RAP80 to DNA damage foci that colocalize with γ-H2AX. We further show that this translocation is also dependent on the UIMs of RAP80 and that the UV-induced phosphorylation of RAP80 at Ser205 is mediated by ATM- and RAD3-related kinase, not ATM. These findings suggest that RAP80 has a more general role in different types of DNA damage responses. [Cancer Res 2008;68(11):4269–76]
Is Tumor Growth Sustained by Rare Cancer Stem Cells or Dominant Clones?
Authors: Adams Jerry M. , Strasser Andreas
Published: June 2008

A key issue for cancer biology and therapy is whether the relentless growth of a tumor is driven by a substantial proportion of its cells or exclusively by a rare subpopulation, commonly termed “cancer stem cells.” Support for the cancer stem cell model has been stimulated by experiments in which human tumor cells were transplanted into immunodeficient mice. Most notably, in human acute myeloid leukemia, only a minute proportion of the cells, displaying a defined phenotype, could seed leukemia in mice. Xenotransplantation, however, may fail to reveal many tumor growth–sustaining cells because the foreign microenvironment precludes essential interactions with support cells. In studies that instead have transplanted mouse leukemias and lymphomas into syngeneic animals, most of the tumors seem to be maintained by the dominant cell population, and only a few types of mouse leukemia seem to be sustained by a minor tumor growth–sustaining subpopulation. The collective evidence suggests that various tumors may span the spectrum between the extremes represented by the two models. If tumor growth can indeed be sustained either by rare cancer stem cells or dominant clones or both, as current evidence suggests, curative therapy for many types of tumors will most likely require targeting all the tumor cell populations. [Cancer Res 2008;68(11):4018–21]
β1 Integrin Inhibition Dramatically Enhances Radiotherapy Efficacy in Human Breast Cancer Xenografts
Authors: Park Catherine C. , Zhang Hui J. , Yao Evelyn S. , Park Chong J. , Bissell Mina J.
Published: June 2008

β1 Integrin signaling has been shown to mediate cellular resistance to apoptosis after exposure to ionizing radiation (IR). Other signaling molecules that increase resistance include Akt, which promotes cell survival downstream of β1 integrin signaling. We previously showed that β1 integrin inhibitory antibodies (e.g., AIIB2) enhance apoptosis and decrease growth in human breast cancer cells in three-dimensional laminin-rich extracellular matrix (lrECM) cultures and in vivo. Here, we asked whether AIIB2 could synergize with IR to modify Akt-mediated IR resistance. We used three-dimensional lrECM cultures to test the optimal combination of AIIB2 with IR treatment of two breast cancer cell lines, MCF-7 and HMT3522-T4-2, as well as T4-2 myr-Akt breast cancer colonies or HMT3522-S-1, which form normal organotypic structures in three-dimensional lrECM. Colonies were assayed for apoptosis and β1 integrin/Akt signaling pathways were evaluated using Western blot. In addition, mice bearing MCF-7 xenografts were used to validate the findings in three-dimensional lrECM. We report that AIIB2 increased apoptosis optimally post-IR by down-regulating Akt in breast cancer colonies in three-dimensional lrECM. In vivo, addition of AIIB2 after IR significantly enhanced tumor growth inhibition and apoptosis compared with either treatment alone. Remarkably, the degree of tumor growth inhibition using AIIB2 plus 2 Gy radiation was similar to that of 8 Gy alone. We previously showed that AIIB2 had no discernible toxicity in mice; here, its addition allowed for a significant reduction in the IR dose that was necessary to achieve comparable growth inhibition and apoptosis in breast cancer xenografts in vivo. [Cancer Res 2008;68(11):4398–405]
Molecular Signature of MT1-MMP: Transactivation of the Downstream Universal Gene Network in Cancer
Authors: Rozanov Dmitri V. , Savinov Alexei Y. , Williams Roy , Liu Kang , Golubkov Vladislav S. , Krajewski Stan , Strongin Alex Y.
Published: June 2008

Invasion-promoting MT1-MMP is directly linked to tumorigenesis and metastasis. Our studies led us to identify those genes, the expression of which is universally linked to MT1-MMP in multiple tumor types. Genome-wide expression profiling of MT1-MMP–overexpressing versus MT1-MMP–silenced cancer cells and a further data mining analysis of the preexisting expression database of 190 human tumors of 14 cancer types led us to identify 11 genes, the expression of which correlated firmly and universally with that of MT1-MMP (P < 0.00001). These genes included regulators of energy metabolism (NNT), trafficking and membrane fusion (SLCO2A1 and ANXA7), signaling and transcription (NR3C1, JAG1, PI3Kδ, and CK2α), chromatin rearrangement (SMARCA1), cell division (STK38/NDR1), apoptosis (DAPK1), and mRNA splicing (SNRPB2). Our subsequent extensive analysis of cultured cells, tumor xenografts, and cancer patient biopsies supported our data mining. Our results suggest that transcriptional reprogramming of the specific downstream genes, which themselves are associated with tumorigenesis, represents a distinctive “molecular signature” of the proteolytically active MT1-MMP. We suggest that the transactivation activity of MT1-MMP contributes to the promigratory cell phenotype, which is induced by this tumorigenic proteinase. The activated downstream gene network then begins functioning in unison with MT1-MMP to rework the signaling, transport, cell division, energy metabolism, and other critical cell functions and to commit the cell to migration, invasion, and, consequently, tumorigenesis. [Cancer Res 2008;68(11):4086–96]
Inhibition of Gastric Cancer Invasion and Metastasis by PLA2G2A, a Novel β-Catenin/TCF Target Gene
Authors: Ganesan Kumaresan , Ivanova Tatiana , Wu Yonghui , Rajasegaran Vikneswari , Wu Jeanie , Lee Ming Hui , Yu Kun , Rha Sun Young , Chung Hyun Cheol , Ylstra Bauke , Meijer Gerrit , Lian Kon Oi , Grabsch Heike , Tan Patrick
Published: June 2008

Elevated expression of the PLA2G2A phospholipase in gastric cancer (GC) is associated with improved patient survival. To elucidate function and regulation of PLA2G2A in GC, we analyzed a panel of GC cell lines. PLA2G2A was specifically expressed in lines with constitutive Wnt activity, implicating β-catenin–dependent Wnt signaling as a major upstream regulator of PLA2G2A expression. The invasive ability of PLA2G2A-expressing AGS cells was enhanced by PLA2G2A silencing, whereas cellular migration in non–PLA2G2A-expressing N87 cells was inhibited by enforced PLA2G2A expression, indicating that PLA2G2A is both necessary and sufficient to function as an inhibitor of GC invasion in vitro. We provide evidence that antiinvasive effect of PLA2G2A occurs, at least in part, through its ability to inhibit the S100A4 metastasis mediator gene. Consistent with its invasion inhibitor role, PLA2G2A expression was elevated in primary gastric, colon, and prostrate early-stage tumors, but was decreased in metastatic and late-stage tumors. There was a strong association between PLA2G2A promoter methylation status and PLA2G2A expression, suggesting that the loss of PLA2G2A expression in late-stage cancers may be due to epigenetic silencing. Supporting this, among the non–PLA2G2A-expressing lines, pharmacologic inhibition of epigenetic silencing reactivated PLA2G2A in Wnt-active lines, but in non–Wnt-active lines, a combination of Wnt hyperactivation and inhibition of epigenetic silencing were both required for PLA2G2A reactivation. Our results highlight the complexity of PLA2G2A regulation and provide functional evidence for PLA2G2A as an important regulator of invasion and metastasis in GC. [Cancer Res 2008;68(11):4277–86]
Advanced Transmission Raman Spectroscopy: A Promising Tool for Breast Disease Diagnosis
Authors: Stone Nicholas , Matousek Pavel
Published: June 2008

A novel approach to noninvasively probe the composition of endogenous materials concealed deeply within mammalian tissue is presented. The method relies upon transmission Raman spectroscopy and permits the detailed characterization of the chemical composition of the probed volume. The technique has been enhanced by the deployment of chemometric methods and the use of a dielectric optical element at the surface to force escaping photons back into the tissue and, thus, enhance the relatively weak signals from the deeper tissue and its components. This permitted reaching both the clinically relevant depth and sufficient sensitivity in phantoms for the noninvasive identification of the calcification types associated with benign or malignant breast disease. Both calcium hydroxyapatite and calcium oxalate monohydrate have been chemically identified from depths of up to 2.7 cm within a breast phantom made up of porcine tissues. The technique has shown significant potential for probing human breasts to provide complementary data in the early diagnosis of breast cancer. [Cancer Res 2008;68(11):4424–30]
Novel Role of Thromboxane Receptors β Isoform in Bladder Cancer Pathogenesis
Authors: Moussa Omar , Ashton Anthony W. , Fraig Mostafa , Garrett-Mayer Elizabeth , Ghoneim Mohamed A. , Halushka Perry V. , Watson Dennis K.
Published: June 2008

These studies were undertaken to determine the potential role of thromboxane receptors (TP) in bladder cancer. The data reported herein show that expression of the TP-β receptor protein is increased in tissue obtained from patients with bladder cancer and associated with a significantly poorer prognosis (P < 0.005). Bladder cancer cell lines express the TP-β isoform, unlike immortalized nontransformed urothelial cells (SV-HUC) that express only the TP-α isoform. TP-β receptor expression, but not TP-α, promoted cell proliferation, migration, and invasion in vitro, and also resulted in malignant transformation of SV-HUC cells in vivo. Agonist-mediated phosphorylation of extracellular signal-regulated kinase and FAK was dependent on the expression of TP-β. Furthermore, TP-β mediated multiple biological effects by signaling through either G-protein α subunit 12 or β-arrestin 2. Treatment of mice with the TP receptor antagonist GR32191, alone or in combination with cisplatin, significantly delayed tumor onset and prolonged survival of mice transplanted with TCC-SUP bladder cancer cells compared with vehicle or cisplatin alone. These results support the model that the TP-β receptor isoform plays a unique role in bladder cancer progression and its expression may have predictive value and provide a novel therapeutic target. [Cancer Res 2008;68(11):4097–104]