bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-time In vivo Dual-color Imaging of Intracapillary Cancer Cell and Nucleus Deformation and Migration
Authors: Yamauchi Kensuke , Yang Meng , Jiang Ping , Yamamoto Norio , Xu Mingxu , Amoh Yasuyuki , Tsuji Kazuhiko , Bouvet Michael , Tsuchiya Hiroyuki , Tomita Katsuro , Moossa A.R. , Hoffman Robert M. 
Published: September 2005

Abstract
The mechanism of cancer cell deformation and migration in narrow vessels is incompletely understood. In order to visualize the cytoplasmic and nuclear dynamics of cells migrating in capillaries, red fluorescent protein was expressed in the cytoplasm, and green fluorescent protein, linked to histone H2B, was expressed in the nucleus of cancer cells. Immediately after the cells were injected in the heart of nude mice, a skin flap on the abdomen was made. With a color CCD camera, we could observe highly elongated cancer cells and nuclei in capillaries in the skin flap in living mice. The migration velocities of the cancer cells in the capillaries were measured by capturing images of the dual-color fluorescent cells over time. The cells and nuclei in the capillaries elongated to fit the width of these vessels. The average length of the major axis of the cancer cells in the capillaries increased to approximately four times their normal length. The nuclei increased their length 1.6 times in the capillaries. Cancer cells in capillaries over 8 μm in diameter could migrate up to 48.3 μm/hour. The data suggests that the minimum diameter of capillaries where cancer cells are able to migrate is approximately 8 μm. The use of the dual-color cancer cells differentially labeled in the cytoplasm and nucleus and associated fluorescent imaging provide a powerful tool to understand the mechanism of cancer cell migration and deformation in small vessels.
A Role for ADAM12 in Breast Tumor Progression and Stromal Cell Apoptosis
Authors: Kveiborg Marie , Fröhlich Camilla , Albrechtsen Reidar , Tischler Verena , Dietrich Nikolaj , Holck Peter , Kronqvist Pauliina , Rank Fritz , Mercurio Arthur M. , Wewer Ulla M. 
Published: September 2005

Abstract
As in developmental and regenerative processes, cell survival is of fundamental importance in cancer. Thus, a tremendous effort has been devoted to dissecting the molecular mechanisms involved in understanding the resistance of tumor cells to programmed cell death. Recently, the importance of stromal fibroblasts in tumor initiation and progression has been elucidated. Here, we show that stromal cell apoptosis occurs in human breast carcinoma but is only rarely seen in nonmalignant breast lesions. Furthermore, we show that ADAM12, a disintegrin and metalloprotease up-regulated in human breast cancer, accelerates tumor progression in a mouse breast cancer model. ADAM12 does not influence tumor cell proliferation but rather confers both decreased tumor cell apoptosis and increased stromal cell apoptosis. This dual role of ADAM12 in governing cell survival is underscored by the finding that ADAM12 increases the apoptotic sensitivity of nonneoplastic cells in vitro while rendering tumor cells more resistant to apoptosis. Together, these results show that the ability of ADAM12 to influence apoptosis may contribute to tumor progression.
Disruption of the Inhibitor of Apoptosis Protein Survivin Sensitizes Bcr-abl–Positive Cells to STI571-Induced Apoptosis
Authors: Wang Zhanxiang , Sampath Janardhan , Fukuda Seiji , Pelus Louis M. 
Published: September 2005

Abstract
The Bcr-abl oncogene induces hematopoietic cell transformation and protects cells from apoptosis; however, the mechanisms whereby Bcr-abl blocks apoptosis are poorly defined. We examined whether the inhibitor of apoptosis protein (IAP) family, in particular survivin, are regulated by Bcr-abl. Overexpression of Bcr-abl in Mo7e or BaF3 hematopoietic cells elevated survivin mRNA and protein concomitant with a 4-fold increase in survivin promoter activity. The region of the survivin promoter responding to Bcr-abl was narrowed down to a 116 bp fragment between nucleotides −1,194 and −1,078. The IAP family member IAP-like protein-2 was also up-regulated by Bcr-abl. Disruption of Bcr-abl in Bcr-abl–transduced BaF3 cells by small interfering RNA resulted in 3- to 4-fold reduction in survivin protein confirming the link between Bcr-abl and survivin. Survivin disruption in Bcr-abl–transduced Mo7e cells, or in K562 cells that endogenously express Bcr-abl, by transfection with dominant-negative or antisense survivin constructs promoted apoptosis induced by the Bcr-abl tyrosine kinase inhibitor STI571, which was accompanied by caspase-dependent cleavage of Bcr-abl, mitochondrial membrane potential disruption, and enhanced mitochondrial cytochrome c release. Although ectopic survivin protected K562 cells from apoptosis induced by STI571, it did not protect cells from apoptosis induced either by tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) or the combination of TRAIL plus Hemin. Our results identify a new signal pathway downstream of Bcr-abl, in addition to the Bcl-2 family involved in the antiapoptotic effects of Bcr-abl, and suggest that anti-survivin therapy may have utility in patients with chronic myelogenous leukemia.
Identification of a Novel c-Myc Protein Interactor, JPO2, with Transforming Activity in Medulloblastoma Cells
Authors: Huang Annie , Ho Cynthia S.W. , Ponzielli Romina , Barsyte-Lovejoy Dalia , Bouffet Eric , Picard Daniel , Hawkins Cynthia E. , Penn Linda Z. 
Published: September 2005

Abstract
c-myc oncogene activation is critical in the pathogenesis of a spectrum of human malignancies. The c-Myc NH2-terminal domain (MycNTD) is essential for cellular transformation, and mediates critical protein interactions that modulate c-Myc oncogenic properties. In medulloblastoma, the most common malignant pediatric brain tumor, deregulated c-myc expression is linked with poorer disease phenotypes and outcomes. The biological basis for these associations is, however, not well understood. To better understand mechanisms underlying Myc-mediated transformation of medulloblastoma, we sought to identify novel MycNTD protein interactors from a medulloblastoma cell line library using a unique two-hybrid system. We identified a novel MycNTD binding protein, JPO2, which shows nuclear colocalization with c-Myc, and interacts with c-Myc both in vitro and in mammalian cells. In Rat1a transformation assays, JPO2 potentiates c-Myc transforming activity, and can complement a transformation-defective Myc mutant. Immunohistochemical studies indicate tumor-specific JPO2 expression in human medulloblastoma, and an association of JPO2 expression with metastatic tumors. Significantly, JPO2 expression induces colony formation in UW228, a medulloblastoma cell line, whereas RNAi-mediated JPO2 knockdown impairs colony formation in UW228, and in Myc-transformed UW228 cells. These data provide evidence for biochemical and functional interaction between c-Myc and JPO2 in medulloblastoma transformation. JPO2 is closely related to JPO1, a Myc transcriptional target with transforming activity. As tumor-specific JPO1 expression in human and murine medulloblastoma has also been reported; these collective observations suggest important functional links between the novel JPO protein family and c-Myc in medulloblastoma transformation.
Plasminogen Kringle 5–Engineered Glioma Cells Block Migration of Tumor-Associated Macrophages and Suppress Tumor Vascularization and Progression
Authors: Perri Sabrina R. , Nalbantoglu Josephine , Annabi Borhane , Koty Zafiro , Lejeune Laurence , François Moïra , Di Falco Marcos R. , Béliveau Richard , Galipeau Jacques 
Published: September 2005

Abstract
Angiostatin, a well-characterized angiostatic agent, is a proteolytic cleavage product of human plasminogen encompassing the first four kringle structures. The fifth kringle domain (K5) of human plasminogen is distinct from angiostatin and has been shown, on its own, to act as a potent endothelial cell inhibitor. We propose that tumor-targeted K5 cDNA expression may act as an effective therapeutic intervention as part of a cancer gene therapy strategy. In this study, we provide evidence that eukaryotically expressed His-tagged human K5 cDNA (hK5His) is exported extracellularly and maintains predicted disulfide bridging conformation in solution. Functionally, hK5His protein produced by retrovirally engineered human U87MG glioma cells suppresses in vitro migration of both human umbilical vein endothelial cells and human macrophages. Subcutaneous implantation of Matrigel-embedded hK5His-producing glioma cells in nonobese diabetic/severe combined immunodeficient mice reveals that hK5His induces a marked reduction in blood vessel formation and significantly suppresses the recruitment of tumor-infiltrating CD45+Mac3+Gr1− macrophages. Therapeutically, we show in a nude mouse orthotopic brain cancer model that tumor-targeted K5 expression is capable of effectively suppressing glioma growth and promotes significant long-term survival (&gt;120 days) of test animals. These data suggest that plasminogen K5 acts as a novel two-pronged anticancer agent, mediating its inhibitory effect via its action on host-derived endothelial cells and tumor-associated macrophages, resulting in a potent, clinically relevant antitumor effect.
Therapeutic EphA2 Gene Targeting In vivo Using Neutral Liposomal Small Interfering RNA Delivery
Authors: Landen Charles N. , Chavez-Reyes Arturo , Bucana Corazon , Schmandt Rosemarie , Deavers Michael T. , Lopez-Berestein Gabriel , Sood Anil K. 
Published: September 2005

Abstract
Inducing destruction of specific mRNA using small interfering RNA (siRNA) is a powerful tool in analysis of protein function, but its use as a therapeutic modality has been limited by inefficient or impractical delivery systems. We have used siRNA incorporated into the neutral liposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) for efficient in vivo siRNA delivery. In nude mice bearing i.p. ovarian tumors, nonsilencing siRNA tagged with the fluorochrome Alexa 555 was encapsulated into DOPC liposomes and shown to be taken up by the tumor as well as many major organs. Furthermore, DOPC-encapsulated siRNA targeting the oncoprotein EphA2 was highly effective in reducing in vivo EphA2 expression 48 hours after a single dose as measured by both Western blot and immunohistochemistry. Therapy experiments in an orthotopic mouse model of ovarian cancer were initiated 1 week after injection of either HeyA8 or SKOV3ip1 cell lines. Three weeks of treatment with EphA2-targeting siRNA-DOPC (150 μg/kg twice weekly) reduced tumor growth when compared with a nonsilencing siRNA (SKOV3ip1: 0.35 versus 0.70 g; P = 0.020; HeyA8: 0.98 versus 1.51 g; P = 0.16). When EphA2-targeting siRNA-DOPC was combined with paclitaxel, tumor growth was dramatically reduced compared with treatment with paclitaxel and a nonsilencing siRNA (SKOV3ip1: 0.04 versus 0.22 g; P &lt; 0.001; HeyA8: 0.21 versus 0.84 g; P = 0.0027). These studies show the feasibility of siRNA as a clinically applicable therapeutic modality.
Protein Kinase Cε Is a Predictive Biomarker of Aggressive Breast Cancer and a Validated Target for RNA Interference Anticancer Therapy
Authors: Pan Quintin , Bao Li Wei , Kleer Celina G. , Sabel Michael S. , Griffith Kent A. , Teknos Theodoros N. , Merajver Sofia D. 
Published: September 2005

Abstract
Tumor metastasis is the major cause of morbidity and mortality in patients with breast cancer. It is critical to identify metastasis enabling genes and understand how they are responsible for inducing specific aspects of the metastatic phenotype to allow for improved clinical detection and management. Protein kinase Cε (PKCε), a member of a family of serine/threonine protein kinases, is a transforming oncogene that has been reported to be involved in cell invasion and motility. In this study, we investigated the role of PKCε in breast cancer development and progression. High-density tissue microarray analysis showed that PKCε protein was detected in 73.6% (106 of 144) of primary tumors from invasive ductal breast cancer patients. Increasing PKCε staining intensity was associated with high histologic grade (P = 0.0206), positive Her2/neu receptor status (P = 0.0419), and negative estrogen (P = 0.0026) and progesterone receptor status (P = 0.0008). Kaplan-Meier analyses showed that PKCε was significantly associated with poorer disease-free and overall survival (log-rank, P = 0.0478 and P = 0.0414, respectively). RNA interference of PKCε in MDA-MB231 cells, an aggressive breast cancer cell line with elevated PKCε levels, resulted in a cell phenotype that was significantly less proliferative, invasive, and motile than the parental or the control RNA interference transfectants. Moreover, in vivo tumor growth of small interfering RNA-PKCε MDA-MB231 clones was retarded by a striking 87% (P &lt; 0.05) and incidence of lung metastases was inhibited by 83% (P &lt; 0.02). PKCε-deficient clones were found to have lower RhoC GTPase protein levels and activation. Taken together, these results revealed that PKCε plays a critical and causative role in promoting an aggressive metastatic breast cancer phenotype and as a target for anticancer therapy.
High Mobility Group A1 Is a Molecular Target for MYCN in Human Neuroblastoma
Authors: Giannini Giuseppe , Cerignoli Fabio , Mellone Massimiliano , Massimi Isabella , Ambrosi Cinzia , Rinaldi Christian , Dominici Carlo , Frati Luigi , Screpanti Isabella , Gulino Alberto 
Published: September 2005

Abstract
High mobility group A1 (HMGA1) is an architectural transcription factor and a putative protoncogene. Deregulation of its expression has been shown in most human cancers. We have previously shown that the expression of the HMGA family members is deregulated in neuroblastoma cell lines and primary tumors. On retinoic acid (RA) treatment of MYCN-amplified neuroblastoma cell lines, HMGA1 decreases with a kinetics that strictly follows MYCN repression. In addition, MYCN constitutive expression abolishes HMGA1 repression by RA. Here we explored the possibility that HMGA1 expression might be sustained by MYCN in amplified cells. Indeed, MYCN transfection induced HMGA1 expression in several neuroblastoma cell lines. HMGA1 expression increased in a transgene dose–dependent fashion in neuroblastoma-like tumors of MYCN transgenic mice. In addition, it was significantly more expressed in MYCN-amplified compared with MYCN single-copy primary human neuroblastomas. MYCN cotransfection activated a promoter/luciferase reporter containing a 1,600 bp region surrounding the first three transcription start sites of the human HMGA1 and eight imperfect E-boxes. By heterodimerizing with its partner MAX, MYCN could bind to multiple DNA fragments within the 1,600 bp. Either 5′ or 3′ deletion variants of the 1,600 bp promoter/luciferase reporter strongly decreased luciferase activity, suggesting that, more than a single site, the cooperative function of multiple cis-acting elements mediates direct HMGA1 transactivation by MYCN. Finally, HMGA1 repression by RNA interference reduced neuroblastoma cell proliferation, indicating that HMGA1 is a novel MYCN target gene relevant for neuroblastoma tumorigenesis.
Tobacco Smoke Stimulates the Transcription of Amphiregulin in Human Oral Epithelial Cells: Evidence of a Cyclic AMP-Responsive Element Binding Protein–Dependent Mechanism
Authors: Du Baoheng , Altorki Nasser K. , Kopelovich Levy , Subbaramaiah Kotha , Dannenberg Andrew J. 
Published: September 2005

AbstractActivation of epidermal growth factor receptor (EGFR)–mediated signaling has been implicated in the pathogenesis of tobacco smoke–induced cancers. Recently, elevated levels of amphiregulin, a ligand of the EGFR, were found in the oral mucosa of smokers. The main objective of this study was to elucidate the mechanism by which tobacco smoke induces amphiregulin. Treatment of a nontumorigenic human oral epithelial cell line (MSK-Leuk1) with a saline extract of tobacco smoke stimulated amphiregulin (AR) transcription resulting in increased amounts of amphiregulin mRNA and protein. Tobacco smoke stimulated the cyclic AMP (cAMP)→protein kinase A (PKA) pathway leading to increased cAMP-responsive element binding protein–dependent activation of AR transcription. These inductive effects of tobacco smoke were dependent on the aryl hydrocarbon receptor (AhR). In fact, α-naphthoflavone, an AhR antagonist, blocked tobacco smoke–mediated induction of binding of cAMP-responsive element binding protein to the AR promoter and thereby suppressed the induction of amphiregulin. Notably, treatment of MSK-Leuk1 cells with tobacco smoke or exogenous amphiregulin stimulated DNA synthesis. An inhibitor of EGFR tyrosine kinase or a neutralizing antibody to amphiregulin abrogated the increase in DNA synthesis mediated by tobacco smoke. Taken together, these findings suggest that tobacco smoke stimulated a signaling pathway comprised of AhR→cAMP→PKA resulting in enhanced AR transcription and increased DNA synthesis. The ability of tobacco smoke to induce amphiregulin and thereby enhance DNA synthesis is likely to contribute to the procarcinogenic effects of tobacco smoke.
Introduction of Sda Carbohydrate Antigen in Gastrointestinal Cancer Cells Eliminates Selectin Ligands and Inhibits Metastasis
Authors: Kawamura Yuki I. , Kawashima Rei , Fukunaga Ryuko , Hirai Kazunari , Toyama-Sorimachi Noriko , Tokuhara Makoto , Shimizu Toshio , Dohi Taeko 
Published: September 2005

Abstract
The Sda blood group carbohydrate structure is expressed in the normal gastrointestinal mucosa. We reported previously that the expression of Sda carbohydrate structures and β1,4-N-acetylgalactosaminyltransferase (β1,4GalNAcT) activity responsible for Sda synthesis were remarkably decreased in cancer lesions of the gastrointestinal tract. In this study, we found that Sda antigen was expressed mainly in chief cells of normal stomach but not in cancer tissue by immunohistologic staining. In separated gastric mucosal cells, the Sda glycolipids and β1,4GalNAcT activity were concentrated in a fraction that contained chief cells as a major population. We cloned the cDNA encoding the glycosyltransferase that catalyzes the synthesis of Sda (Sda-β1,4GalNAcT). Introduction of this cloned cDNA into KATO III gastric or HT29 colonic cancer cell lines, which originally expressed the E-selectin ligands, sialyl Lewisx and sialyl Lewisa, resulted in a marked increase in cell-surface expression of Sda along with the concomitant total loss of both sialyl Lewisx and sialyl Lewisa. Both KATO III and HT29 cells transfected with the Sda-β1,4GalNAcT gene showed significantly decreased adhesion to activated human umbilical vein endothelial cells when compared with mock-transfected cells. Sda determinants showed no direct binding to Siglec-3, -5, -7, and -9. These Sda-β1,4GalNAcT-transfected cells showed strikingly reduced metastatic potential in vivo when compared with mock-transfected cells. In summary, forced expression of Sda carbohydrate determinant caused remarkable elimination of carbohydrate ligands for selectin and reduced metastasis of human gastrointestinal tract cancer cells.
CaSm-Mediated Cellular Transformation Is Associated with Altered Gene Expression and Messenger RNA Stability
Authors: Fraser Melissa M. , Watson Patricia M. , Fraig Mostafa M. , Kelley Joseph R. , Nelson Peter S. , Boylan Alice M. , Cole David J. , Watson Dennis K. 
Published: September 2005

Abstract
CaSm (cancer-associated Sm-like) was originally identified based on elevated expression in pancreatic cancer and in several cancer-derived cell lines. CaSm encodes a 133 amino acid protein that contains two Sm motifs found in the common small nuclear RNA proteins and the LSm (like-Sm) family of proteins. Compared with normal human prostate tissue and primary prostate epithelial cells, some primary prostate tumors and prostate cancer–derived cell lines have elevated CaSm expression. Expression of antisense CaSm RNA in DU145 cells results in reduced CaSm protein levels and less transformed phenotype, measured by anchorage-independent growth in vitro and tumor formation in severe combined immunodeficient mice in vivo. Additional data shows that adenoviral delivery of antisense CaSm inhibits the growth of prostate cancer cell lines by altering cell cycle progression, and is associated with reduced expression of cyclin B1 and CDK1 proteins. Consistent with failure of antisense-treated cells to enter mitosis, microarray analysis identified altered expression of NEK2 and nucleophosmin/B23. Although the mechanisms by which CaSm contributes to neoplastic transformation and cellular proliferation are unknown, it has been shown that the yeast homologue (spb8/LSm1) of CaSm is required for 5′ to 3′ degradation of specific mRNAs. We provide data consistent with a similar role for CaSm in human cells, supporting the hypothesis that elevated CaSm expression observed in cancer leads to destabilization of multiple gene transcripts, contributing to the mutator phenotype of cancer cells.
Expression of a Natural Tumor Antigen by Thymic Epithelial Cells Impairs the Tumor-Protective CD4+ T-Cell Repertoire
Authors: Bos Rinke , van Duikeren Suzanne , van Hall Thorbald , Kaaijk Patricia , Taubert Richard , Kyewski Bruno , Klein Ludger , Melief Cornelis J.M. , Offringa Rienk 
Published: September 2005

Abstract
A variety of antigens that display a highly tissue-specific expression pattern have recently found to be also expressed in medullary thymic epithelial cells (mTEC). This unique feature of mTEC plays an important role in preventing hazardous autoimmune responses through thymic tolerization of T-cell subsets directed against autoantigens but could also limit the possibility of exploiting tumor-associated antigens for immune-mediated targeting of cancers. Our present study shows that expression of carcinoembryonic antigen (CEA) in thymic epithelial cells of CEA-transgenic mice results in tolerization of a major fraction of the CD4+ T-cell repertoire against this antigen, thereby markedly limiting the effect of CEA-specific immunization against CEA-overexpressing tumors. The expression of CEA in mTEC of CEA-transgenic mice is mirrored by its expression in human mTEC, arguing that promiscuous gene expression in these thymic stromal cells needs to be considered as a potential hurdle for immunotherapies of cancer that target tissue-specific autoantigens.