bluuebunny/crossref_metadata_2025_split huggingface dataset:
HCMOGT-1 Is a Novel Fusion Partner to
PDGFRB
in Juvenile Myelomonocytic Leukemia with t(5;17)(q33;p11.2)
Authors: Morerio Cristina , Acquila Maura , Rosanda Cristina , Rapella Annamaria , Dufour Carlo , Locatelli Franco , Maserati Emanuela , Pasquali Francesco , Panarello Claudio 
Published: September 2005

Abstract
PDGFRB, a transmembrane tyrosine kinase receptor for plateletderived growth factor, is constitutively activated by gene fusion with different partners in myeloproliferative/myelodysplastic disorders with peculiar clinical characteristics. Six alternative partner genes have been described thus far. In this study, we report the molecular cloning of a novel translocation t(5;17)(q33;p11.2) in a case of juvenile myelomonocytic leukemia. The novel partner gene was identified as HCMOGT-1 using 5′-rapid amplification of cDNA ends; fluorescence in situ hybridization and reverse transcriptase-PCR analyses confirmed that the translocation resulted in PDGFRB/HCMOGT-1 fusion. We show that the breakpoint of PDGFRB occurred at the same site of all previously reported PDGFRB translocations.
Chemoprevention of Cancer of the Upper Respiratory Tract of the Syrian Golden Hamster by Aerosol Administration of Difluoromethylornithine and 5-Fluorouracil
Authors: Wattenberg Lee W. , Wiedmann Timothy S. , Estensen Richard D. 
Published: September 2005

Abstract
Research aimed at identifying effective chemopreventive compounds active against carcinogenesis of the upper respiratory tract (URT) has been largely unsuccessful. We are addressing this problem by efforts at agent identification and by using aerosol delivery. Two compounds, difluoromethylornithine (DFMO) and 5-fluorouracil (5-FU) were investigated. DFMO is an irreversible inhibitor of ornithine decarboxylase, an enzyme important in cell proliferation. It has been used widely by oral administration for chemoprevention. 5-FU is a pyrimidine analog used extensively as a chemotherapeutic agent. It is generally administered i.v. and can cause considerable toxicity. However, aerosol administration for therapy of lung cancer in humans has been reported to be without adverse effects (Tatsumura et al., Br J Cancer 1993;68:1146–9). The experimental model used herein entailed six intratracheal administrations of methylnitrosourea (MNU) to hamsters. Each of the test agents was started about 1 week after MNU and was continued for 29 weeks with DFMO. Infiltrating squamous cell carcinomas of the URT occurred in 92% of the controls and were reduced by 50% in animals receiving DFMO (P = 0.0001). The experiment with 5-FU was of shorter duration being terminated 20 weeks after MNU. Thirty percent of the controls had infiltrating carcinomas and were reduced by 60% in animals receiving 5-FU (P = 0.0274). Both compounds resulted in a significant increase in the percent of cancer-free animals. These two agents may have selected use in subjects at high risk of cancer of the URT.
Alternative Lengthening of Telomeres Is Characterized by High Rates of Telomeric Exchange
Authors: Londoño-Vallejo J. Arturo , Der-Sarkissian Héra , Cazes Lucien , Bacchetti Silvia , Reddel Roger R. 
Published: September 2005

Abstract
Telomere maintenance activity is a hallmark of cancer. In some telomerase-negative tumors, telomeres become lengthened by alternative lengthening of telomeres (ALT), a recombination-mediated DNA replication process in which telomeres use other telomeric DNA as a copy template. Using chromosome orientation fluorescence in situ hybridization, we found that postreplicative exchange events involving a telomere and another TTAGGG-repeat tract occur at remarkably high frequencies in ALT cells (range 28–280/100 metaphases) and rarely or never in non-ALT cells, including cell lines with very long telomeres. Like the ALT phenotype itself, the telomeric exchanges were not suppressed when telomerase was activated in ALT cells. These exchanges are telomere specific because there was no correlation with sister chromatid exchange rates at interstitial locations, and they were not observed in non-ALT Bloom syndrome cells with very high sister chromatid exchange rates.
Tumor-Microenvironment Interactions
Authors: Zipin Adi , Israeli-Amit Mira , Meshel Tsipi , Sagi-Assif Orit , Yron Ilana , Lifshitz Veronica , Bacharach Eran , Smorodinsky Nechama I. , Many Ariel , Czernilofsky Peter A. , Morton Donald L. , Witz Isaac P. 
Published: September 2005

Abstract
Extravasation of tumor cells is a pivotal step in metastasis formation. This step is initiated by an interaction of extravasating tumor cells with endothelial cells. Among the molecules mediating tumor-endothelium interactions are selectins and their fucosylated ligands. In a previous study, we demonstrated that the fucose-generating FX enzyme regulates the expression of selectin ligands by B and T lymphocytes and by head and neck squamous cell carcinoma cells. It was also shown that the FX enzyme regulated important interaction parameters between these cancer cells and endothelial cells. The present study was aimed to determine whether the FX enzyme controls adhesive interactions between colorectal cancer cells and endothelial cells. The results clearly indicate that this is indeed the case. Overexpressing the FX enzyme by the transfer of FX cDNA to low FX-expressing colorectal cancer cells resulted in an increased adhesive capacity of the transfectants to activated endothelial cells and to recombinant E-selectin. Down-regulating FX levels in colorectal cancer cells expressing high levels of endogenous FX by transfection with small-interfering RNA resulted in a down-regulated expression of the selectin ligand sialyl Lewis-a and a decrease in the adhesive capacity of the transfectants to activated endothelial cells and to recombinant E-selectin. These transfection experiments also indicated that manipulating the levels of the FX enzyme affected global cellular fucosylation and altered the interaction of colorectal cancer cells with some extracellular matrix components such as fibronectin. We also found that highly metastatic colorectal cancer variants express higher levels of FX and of sialyl Lewis-a than low metastatic variants originating in the same tumors. These results lead us to hypothesize that the FX enzyme controls the capacity of colorectal cancer to extravasate and form metastasis. If this hypothesis will be confirmed the FX enzyme could become a target molecule for metastasis prevention.
A Transcriptional Profiling Study of CCAAT/Enhancer Binding Protein Targets Identifies Hepatocyte Nuclear Factor 3β as a Novel Tumor Suppressor in Lung Cancer
Authors: Halmos Balazs , Bassères Daniela S. , Monti Stefano , D‘Aló Francesco , Dayaram Tajhal , Ferenczi Katalin , Wouters Bas J. , Huettner Claudia S. , Golub Todd R. , Tenen Daniel G. 
Published: September 2005

Abstract
We showed previously that CCAAT/enhancer binding protein α (C/EBPα), a tissue-specific transcription factor, is a candidate tumor suppressor in lung cancer. In the present study, we have performed a transcriptional profiling study of C/EBPα target genes using an inducible cell line system. This study led to the identification of hepatocyte nuclear factor 3β (HNF3β), a transcription factor known to play a role in airway differentiation, as a downstream target of C/EBPα. We found down-regulation of HNF3β expression in a large proportion of lung cancer cell lines examined and identified two novel mutants of HNF3β, as well as hypermethylation of the HNF3β promoter. We also developed a tetracycline-inducible cell line model to study the cellular consequences of HNF3β expression. Conditional expression of HNF3β led to significant growth reduction, proliferation arrest, apoptosis, and loss of clonogenic ability, suggesting additionally that HNF3β is a novel tumor suppressor in lung cancer. This is the first study to show genetic abnormalities of lung-specific differentiation pathways in the development of lung cancer.
DNA Microarrays Reveal Relationship of Ewing Family Tumors to Both Endothelial and Fetal Neural Crest-Derived Cells and Define Novel Targets
Authors: Staege Martin S. , Hutter Christoph , Neumann Ingo , Foja Sabine , Hattenhorst Uwe E. , Hansen Gesine , Afar Danny , Burdach Stefan E. G. 
Published: September 2005

Abstract
Ewing family tumors (EFTs) are small round blue cell tumors that show features of neuroectodermal differentiation. However, the histogenetic origin of EFTs is still a matter of debate. We used high-density DNA microarrays for the identification of EFT-specific gene expression profiles in comparison with normal tissues of diverse origin. We identified 37 genes that are up-regulated in EFTs compared with normal tissues and validated expression of these genes in EFTs by both conventional and quantitative reverse transcription-polymerase chain reaction. The expression pattern of EFT-associated genes in normal tissues indicated a high similarity between EFTs and fetal and neuronal as well as endothelial tissues and supports the concept that a primitive neural crest-derived progenitor at the transition to mesenchymal and endothelial differentiation is transformed in EFTs. EFT-associated genes could be used for molecular discrimination between EFTs and other small round blue cell tumors and clearly identified a cell line (SK-N-MC) that was initially established as neuroblastoma as being an EFT. Ectopic expression of the EFT-specific EWS-FLI1 fusion protein in human embryonic kidney (HEK293) cells was not sufficient to induce the complete EFT-specific gene expression signature, suggesting that the EFT-specific gene expression profile is not just a consequence of EWS-FLI1 expression but depends on the histogenetic background of the EFT stem cell.
Enhancement of the Efficacy of Chemotherapy for Lung Cancer by Simultaneous Suppression of Multidrug Resistance and Antiapoptotic Cellular Defense
Authors: Pakunlu Refika I. , Wang Yang , Tsao William , Pozharov Vitaly , Cook Thomas J. , Minko Tamara 
Published: September 2005

Abstract
The efficacy of chemotherapy of lung cancer is limited by the development of resistance in cancer cells during treatment. In most lung cancers, this resistance is associated with the overexpression of (a) multidrug resistance-associated protein (MRP) responsible for drug efflux from the cancer cells (pump resistance) and (b) BCL2 protein that activates antiapoptotic cellular defense (nonpump resistance). A novel liposomal proapoptotic anticancer drug delivery system was developed to enhance anticancer efficacy of the well-established drug doxorubicin (DOX). This multicomponent drug delivery system was tested on multidrug-sensitive and -resistant human small-cell lung cancer cells. The drug delivery system includes four components: (a) liposome as a carrier, (b) DOX as an inductor of apoptosis, (c) antisense oligonucleotides (ASOs) targeted to MRP1 mRNA as a suppressor of pump resistance, and (d) ASOs targeted to BCL2 mRNA as a suppressor of nonpump resistance. Intracellular internalization of ASOs and DOX; the influence of the proposed system on the expression of genes and proteins involved in the multidrug resistance, cytotoxicity, and apoptosis induction and antiapoptotic defense; and the activity of caspases were studied. It was found that the proposed liposomal delivery system successfully delivered ASOs and DOX to cell nuclei, inhibited MRP1 and BCL2 protein synthesis, and substantially increased the anticancer action of DOX by stimulating the caspase-dependent pathway of apoptosis in multidrug-resistant human lung cancer cells.
Excellent
In vivo
Bystander Activity of Fludarabine Phosphate against Human Glioma Xenografts that Express the
Escherichia coli
Purine Nucleoside Phosphorylase Gene
Authors: Hong Jeong S. , Waud William R. , Levasseur Dana N. , Townes Tim M. , Wen Hui , McPherson Sylvia A. , Moore Bryan A. , Bebok Zsuzsa , Allan Paula W. , Secrist John A. , Parker William B. , Sorscher Eric J. 
Published: September 2005

Abstract
Escherichia coli purine nucleoside phosphorylase (PNP) expressed in tumors converts relatively nontoxic prodrugs into membrane-permeant cytotoxic compounds with high bystander activity. In the present study, we examined tumor regressions resulting from treatment with E. coli PNP and fludarabine phosphate (F-araAMP), a clinically approved compound used in the treatment of hematologic malignancies. We tested bystander killing with an adenoviral construct expressing E. coli PNP and then more formally examined thresholds for the bystander effect, using both MuLv and lentiviral vectoring. Because of the importance of understanding the mechanism of bystander action and the limits to this anticancer strategy, we also evaluated in vivo variables related to the expression of E. coli PNP (level of E. coli PNP activity in tumors, ectopic expression in liver, percentage of tumor cells transduced in situ, and accumulation of active metabolites in tumors). Our results indicate that F-araAMP confers excellent in vivo dose-dependent inhibition of bystander tumor cells, including strong responses in subcutaneous human glioma xenografts when 95 to 97.5% of the tumor mass is composed of bystander cells. These findings define levels of E. coli PNP expression necessary for antitumor activity with F-araAMP and demonstrate new potential for a clinically approved compound in solid tumor therapy.
Mek1 Alters Epidermal Growth and Differentiation
Authors: Scholl Florence A. , Dumesic Phillip A. , Khavari Paul A. 
Published: September 2005

Abstract
The highly homologous kinases, Mek1 and Mek2, act downstream of Ras and Raf to activate extracellular signal-regulated kinase (ERK) mitogen-activated protein kinases. In epidermis, Ras and Raf promote hyperplasia; however, they act on multiple Mek-independent effectors, and the extent to which Meks can mediate these effects is unknown. To address this, we expressed inducible Meks in transgenic murine and human epidermis. Both Mek1 and Mek2 triggered ERK phosphorylation. Only Mek1, however, recapitulated Ras/Raf effects in increasing proliferation and integrin expression while suppressing differentiation, which are impacts characteristic of epidermal neoplasia. Furthermore, a kinase-dead Mek1 mutant incapable of phosphorylating ERK proteins retained ability to mediate Mek1-driven epidermal proliferation. Mek1 is thus sufficient to promote the proliferative epithelial phenotype in a manner independent of intact kinase function.
Depletion of Methionine Aminopeptidase 2 Does Not Alter Cell Response to Fumagillin or Bengamides
Authors: Kim Sunkyu , LaMontagne Kenneth , Sabio Michael , Sharma Sushil , Versace Richard W. , Yusuff Naeem , Phillips Penny E. 
Published: September 2005

Abstract
Inhibition of endothelial cell growth by fumagillin has been assumed to be mediated by inhibition of the molecular target methionine aminopeptidase 2 (MetAp2). New data show that depletion of MetAp2 by siRNA does not inhibit endothelial cell growth. Moreover, MetAp2-depleted endothelial cells remain responsive to inhibition by either fumagillin or a newly identified MetAp2 enzyme inhibitor. These data suggest that MetAp2 function is not required for endothelial cell proliferation.
Lysophosphatidic Acid Stimulates Ovarian Cancer Cell Migration via a Ras-MEK Kinase 1 Pathway
Authors: Bian Dafang , Su Shibing , Mahanivong Chitladda , Cheng Robert K. , Han Qiwei , Pan Zhixing K. , Sun Peiqing , Huang Shuang 
Published: September 2005

Abstract
Lysophosphatidic acid (LPA) is present at high concentrations in ascites and plasma of ovarian cancer patients. Studies conducted in experimental models demonstrate that LPA promotes ovarian cancer invasion/metastasis by up-regulating protease expression, elevating protease activity, and enhancing angiogenic factor expression. In this study, we investigated the effect of LPA on ovarian cancer migration, an essential component of cancer cell invasion. LPA stimulates both chemotaxis and chemokinesis of ovarian cancer cells and LPA-stimulated cell migration is GI dependent. Moreover, constitutively active H-Ras enhances ovarian cancer cell migration, whereas dominant negative H-Ras blocks LPA-stimulated cell migration, suggesting that Ras works downstream of Gi to mediate LPA-stimulated cell migration. Interestingly, H-Ras mutants that specifically activate Raf-1, Ral-GDS, or phosphatidylinositol 3′-kinase are unable to significantly enhance ovarian cancer cell migration, suggesting that a Ras downstream effector distinct from Raf-1, Ral-GDS, and phosphatidylinositol 3′-kinase is responsible for LPA-stimulated cell migration. In this article, we demonstrate that LPA activates mitogen-activated protein kinase kinase 1 (MEKK1) in a Gi-Ras-dependent manner and that MEKK1 activity is essential for LPA-stimulated ovarian cancer cell migration. Inhibitors that block MEKK1 downstream pathways, including MEK1/2, MKK4/7, and nuclear factor-κB pathways, do not significantly alter LPA-stimulated cell migration. Instead, LPA induces the redistribution of focal adhesion kinase to focal contact regions of the cytoplasm membrane, and this event is abolished by pertussis toxin, dominant negative H-Ras, or dominant negative MEKK1. Our studies thus suggest that the Gi-Ras-MEKK1 signaling pathway mediates LPA-stimulated ovarian cancer cell migration by facilitating focal adhesion kinase redistribution to focal contacts.
Infectivity-Enhanced Cyclooxygenase-2-Based Conditionally Replicative Adenoviruses for Esophageal Adenocarcinoma Treatment
Authors: Davydova Julia , Le Long P. , Gavrikova Tatyana , Wang Minghui , Krasnykh Victor , Yamamoto Masato 
Published: September 2005

Abstract
The employment of conditionally replicative adenoviruses (CRAd) constitutes a promising alternative for cancer treatment; however, in the case of esophageal adenocarcinoma (EAC) the lack of an appropriate tumor-specific promoter and relative resistance to adenovirus infection have hampered the construction of CRAds with clinically applicable specificity and efficacy. By combining transcriptional targeting with infectivity enhancement for CRAds, we generated novel cyclooxygenase-2 (Cox-2) promoter-controlled replicative viral agents for the treatment of EAC. We used infectivity enhancement based on incorporation of an RGD-4C motif into the HI loop of the adenoviral (Ad) fiber knob domain as well as replacement of the Ad5 knob with the Ad3 knob. The Cox-2 promoter was highly active in EAC, whereas showing no significant activity in Cox-2-negative cell lines and primary cells isolated from normal mouse esophagus and stomach. Evaluation of infectivity-enhanced vectors revealed that the transduction and virus-cell binding ability of Ad5/Ad3-chimera were significantly more efficient than that of unmodified and Arg-Gly-Asp (RGD)-modified vectors. All of the Cox-2 CRAds demonstrated replication and subsequent oncolysis in EAC cells but not in Cox-2-negative cells in vitro, thus confirming the dependence of their replication on the Cox-2 promoter activity. Ad5/Ad3 CRAds exhibited significantly improved oncolysis and progeny production compared with unmodified and RGD-modified vectors without sacrificing tumor selectivity. Whereas unmodified and RGD-modified CRAds showed insignificant therapeutic effect in vivo, Ad5/Ad3 CRAds remarkably suppressed tumor growth of established xenografts in mice. Thus, our studies have demonstrated that Ad5/Ad3-chimeric Cox-2 promoter-driven CRAds are selective and potent agents for the treatment of EAC.
The Matrix Metalloproteinase Inhibitor Prinomastat Enhances Photodynamic Therapy Responsiveness in a Mouse Tumor Model
Authors: Ferrario Angela , Chantrain Christophe F. , von Tiehl Karl , Buckley Sue , Rucker Natalie , Shalinsky David R. , Shimada Hiroyuki , DeClerck Yves A. , Gomer Charles J. 
Published: September 2005

Abstract
Photodynamic therapy (PDT) clinical results are promising; however, tumor recurrences can occur and, therefore, methods for improving treatment efficacy are needed. PDT elicits direct tumor cell death and microvascular injury as well as expression of angiogenic, inflammatory, and prosurvival molecules. Preclinical studies combining antiangiogenic drugs or cyclooxygenase-2 inhibitors with PDT show improved treatment responsiveness (A. Ferrario et al., Cancer Res 2000;60:4066–9; A. Ferrario et al., Cancer Res 2002;62:3956–61). In the present study, we evaluated the role of Photofrin-mediated PDT in eliciting expression of matrix metalloproteinases (MMPs) and modulators of MMP activity. We also examined the efficacy of a synthetic MMP inhibitor, Prinomastat, to enhance tumoricidal activity after PDT, using a mouse mammary tumor model. Immunoblot analysis of extracts from PDT-treated tumors demonstrated strong expression of MMPs and extracellular MMP inducer along with a concomitant decrease in expression of tissue inhibitor of metalloproteinase-1. Gelatin zymography and enzyme activity assays performed on protein extracts from treated tumors confirmed the induction of both latent and enzymatically active forms of MMP-9. Immunohistochemical analysis indicated that infiltrating inflammatory cells and endothelial cells were primary sources of MMP-9 expression after PDT, whereas negligible expression was observed in tumor cells. Administration of Prinomastat significantly improved PDT-mediated tumor response (P = 0.02) without affecting normal skin photosensitization. Our results indicate that PDT induces MMPs and that the adjunctive use of an MMP inhibitor can improve PDT tumor responsiveness.
External Beam Radiation of Tumors Alters Phenotype of Tumor Cells to Render Them Susceptible to Vaccine-Mediated T-Cell Killing
Authors: Chakraborty Mala , Abrams Scott I. , Coleman C. Norman , Camphausen Kevin , Schlom Jeffrey , Hodge James W. 
Published: September 2005

AbstractLocal radiation is an established therapy for human tumors. Radiation also has been shown to alter the phenotype of target tissue, including gene products that may make tumor cells more susceptible to T-cell-mediated immune attack. We demonstrate a biological synergy between local radiation of tumor and active vaccine therapy. The model used consisted of mice transgenic for human carcinoembryonic antigen (CEA) and a murine carcinoma cell line transfected with CEA. The vaccine regimen consisted of a prime and boost strategy using vaccinia and avipox recombinants expressing CEA and three T-cell costimulatory molecules. One dose of 8-Gy radiation to tumor induced up-regulation of the death receptor Fas in situ for up to 11 days. However, neither radiation at this dose nor vaccine therapy was capable of inhibiting growth of 8-day established tumor. When vaccine therapy and local radiation of tumor were used in combination, dramatic and significant cures were achieved. This was mediated by the engagement of the Fas/Fas ligand pathway because Ag-bearing tumor cells expressing dominant-negative Fas were not susceptible to this combination therapy. Following the combination of vaccine and local radiation, tumors demonstrated a massive infiltration of T cells not seen with either modality alone. Mice cured of tumors demonstrated CD4+ and CD8+ T-cell responses specific for CEA but also revealed the induction of high levels of T-cell responses to two other antigens (gp70 and p53) overexpressed in tumor, indicating the presence of a consequential antigen cascade. Thus, these studies demonstrate a new paradigm for the use of local tumor irradiation in combination with active specific vaccine therapy to elicit durable antitumor responses of established tumors.