bluuebunny/crossref_metadata_2025_split huggingface dataset:
Staphylococcus aureus
IsdB Is a Hemoglobin Receptor Required for Heme Iron Utilization
Authors: Torres Victor J. , Pishchany Gleb , Humayun Munir , Schneewind Olaf , Skaar Eric P. 
Published: December 2006

ABSTRACT

The pathogenesis of human infections caused by the gram-positive microbe
Staphylococcus aureus
has been previously shown to be reliant on the acquisition of iron from host hemoproteins. The iron-regulated surface determinant system (Isd) encodes a heme transport apparatus containing three cell wall-anchored proteins (IsdA, IsdB, and IsdH) that are exposed on the staphylococcal surface and hence have the potential to interact with human hemoproteins. Here we report that
S. aureus
can utilize the host hemoproteins hemoglobin and myoglobin, but not hemopexin, as iron sources for bacterial growth. We demonstrate that staphylococci capture hemoglobin on the bacterial surface via IsdB and that inactivation of
isdB
, but not
isdA
or
isdH
, significantly decreases hemoglobin binding to the staphylococcal cell wall and impairs the ability of
S. aureus
to utilize hemoglobin as an iron source. Stable-isotope-tracking experiments revealed removal of heme iron from hemoglobin and transport of this compound into staphylococci. Importantly, mutants lacking
isdB
, but not
isdH
, display a reduction in virulence in a murine model of abscess formation. Thus, IsdB-mediated scavenging of iron from hemoglobin represents an important virulence strategy for
S. aureus
replication in host tissues and for the establishment of persistent staphylococcal infections.
Coeliac disease and primary hyperparathyroidism: an association?
Authors: Maida M J , Praveen E , Crimmins S R , Swift G L 
Published: December 2006

Abstract
Primary hyperparathyroidism may present with non-specific symptoms, and this may be one reason why patients with coeliac disease fail to improve despite compliance with a gluten-free diet. Seven case reports of primary hyperparathyroidism due to sporadic adenoma occurring in a series of 310 patients with coeliac disease are presented, highlighting the importance of looking for this condition in this population group. A prevalence of primary hyperparathyroidism of 2.3% in this series suggests a significant association between hyperparathyroidism and coeliac disease; most studies have indicated a prevalence of 3 in 1000 in the general population, although one study found that it may be as high as 21 in 1000 in women aged 55–75 years. The average age of patients in our series was 59 years and all but one were women. Further studies are needed to establish a possible association between primary hyperparathyroidism and coeliac disease.
MUC1/X Protein Immunization Enhances cDNA Immunization in Generating Anti-MUC1 α/β Junction Antibodies that Target Malignant Cells
Authors: Rubinstein Daniel B. , Karmely Maya , Ziv Ravit , Benhar Itai , Leitner Orit , Baron Shoshana , Katz Ben-Zion , Wreschner Daniel H. 
Published: December 2006

AbstractMUC1 has generated considerable interest as a tumor marker and potential target for tumor killing. To date, most antibodies against MUC1 recognize epitopes within the highly immunogenic α chain tandem repeat array. A major shortcoming of such antibodies is that the MUC1 α chain is shed into the peripheral circulation, sequesters circulating antitandem repeat array antibodies, and limits their ability to even reach targeted MUC1-expressing cells. Antibodies recognizing MUC1 epitopes tethered to the cell surface would likely be more effective. MUC1 α subunit binding the membrane-tethered β subunit provides such an epitope. By use of a novel protocol entailing immunization with cDNA encoding full-length MUC1 (MUC1/TM) followed by boosting with the alternatively spliced MUC1/X isoform from which the tandem repeat array has been deleted, we generated monoclonal antibodies, designated DMC209, which specifically bind the MUC1 α/β junction. DMC209 is exquisitely unique for this site; amino acid mutations, which abrogate MUC1 cleavage, also abrogate DMC209 binding. Additionally, DMC209 specifically binds the MUC1 α/β junction on full-length MUC1/TM expressed by breast and ovarian cancer cell lines and on freshly obtained, unmanipulated MUC1-positive malignant plasma cells of multiple myeloma. DMC209 is likely to have clinical application by targeting MUC1-expressing cells directly and as an immunotoxin conjugate. Moreover, the novel immunization procedure used in generating DMC209 can be used to generate additional anti-MUC1 α/β junction antibodies, which may, analogously to Herceptin, have cytotoxic activity. Lastly, sequential immunization with MUC1/TM cDNA acting as a nonspecific adjuvant followed by protein of interest may prove to be a generalizable method to yield high-titer specific antibodies. (Cancer Res 2006; 66(23): 11247-53)
Mesenchymal-to-Epithelial Transition Facilitates Bladder Cancer Metastasis: Role of Fibroblast Growth Factor Receptor-2
Authors: Chaffer Christine L. , Brennan Janelle P. , Slavin John L. , Blick Tony , Thompson Erik W. , Williams Elizabeth D. 
Published: December 2006

Abstract
Epithelial-to-mesenchymal transition (EMT) increases cell migration and invasion, and facilitates metastasis in multiple carcinoma types, but belies epithelial similarities between primary and secondary tumors. This study addresses the importance of mesenchymal-to-epithelial transition (MET) in the formation of clinically significant metastasis. The previously described bladder carcinoma TSU-Pr1 (T24) progression series of cell lines selected in vivo for increasing metastatic ability following systemic seeding was used in this study. It was found that the more metastatic sublines had acquired epithelial characteristics. Epithelial and mesenchymal phenotypes were confirmed in the TSU-Pr1 series by cytoskeletal and morphologic analysis, and by performance in a panel of in vitro assays. Metastatic ability was examined following inoculation at various sites. Epithelial characteristics associated with dramatically increased bone and soft tissue colonization after intracardiac or intratibial injection. In contrast, the more epithelial sublines showed decreased lung metastases following orthotopic inoculation, supporting the concept that EMT is important for the escape of tumor cells from the primary tumor. We confirmed the overexpression of the IIIc subtype of multiple fibroblast growth factor receptors (FGFR) through the TSU-Pr1 series, and targeted abrogation of FGFR2IIIc reversed the MET and associated functionality in this system and increased survival following in vivo inoculation in severe combined immunodeficient mice. This model is the first to specifically model steps of the latter part of the metastatic cascade in isogenic cell lines, and confirms the suspected role of MET in secondary tumor growth. (Cancer Res 2006; 66(23): 11271-8)
Cell Adhesion Molecule L1 Disrupts E-Cadherin-Containing Adherens Junctions and Increases Scattering and Motility of MCF7 Breast Carcinoma Cells
Authors: Shtutman Michael , Levina Elina , Ohouo Patrice , Baig Mirza , Roninson Igor B. 
Published: December 2006

AbstractThe first steps of invasion and metastasis include the dissociation of adherens junctions and the induction of migratory phenotype, through a program that resembles epithelial-mesenchymal transition (EMT). The L1 cell adhesion molecule, which is normally found primarily in the brain, was recently shown to be expressed in different types of cancer and to have tumor-promoting activity. We now find that L1 mediates EMT-like events in MCF7 breast carcinoma cells. MCF7 predominantly expresses the nonneuronal isoform of L1, as do 16 of 17 other cell lines derived from different types of cancer. L1 protein expression in MCF7 cells, which form E-cadherin-containing adherens junctions, is inversely related to cell density. Analysis of MCF7 cells with overexpression or knockdown of nonneuronal L1 isoform revealed that L1 expression leads to the disruption of adherens junctions and increases β-catenin transcriptional activity. As a result, L1 expression promotes the scattering of epithelial cells from compact colonies. Expression of the full-length L1 protein, but not of its soluble extracellular moiety, increases the motility of the MCF7 epithelial monolayer in a wound-healing assay, in which L1 expression is preferentially observed and required in cells leading the movement of the monolayer. Based on these results, we propose a model for the role of L1 as a trigger of EMT-like events in transformed epithelial cells. (Cancer Res 2006; 66(23): 11370-80)
Cyclooxygenase-2 and Colorectal Cancer Chemoprevention: The β-Catenin Connection
Authors: Castellone Maria Domenica , Teramoto Hidemi , Gutkind J. Silvio 
Published: December 2006

Abstract
Colorectal cancer poses a major clinical challenge in the developed world where this disease is common. Recent findings suggest that the prostaglandin E2, the proinflammatory product of elevated cyclooxygenase-2 activity in colon cancer, stimulates cancer cell growth through a G protein–dependent signaling pathway coupling the prostaglandin EP2 receptor to β-catenin control. These findings provide new insights into the molecular framework needed to evaluate chemopreventive strategies for colorectal cancer. (Cancer Res 2006; 66(23): 11085-8)
Transcriptional Profiling Identifies Cyclin D1 as a Critical Downstream Effector of Mutant Epidermal Growth Factor Receptor Signaling
Authors: Kobayashi Susumu , Shimamura Takeshi , Monti Stefano , Steidl Ulrich , Hetherington Christopher J. , Lowell April M. , Golub Todd , Meyerson Matthew , Tenen Daniel G. , Shapiro Geoffrey I. , Halmos Balázs 
Published: December 2006

AbstractActivating mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain determine responsiveness to EGFR tyrosine kinase inhibitors in patients with advanced non–small cell lung cancer (NSCLC). The modulation of transcriptional pathways by mutant EGFR signaling is not fully understood. Previously, we and others identified a single base pair change leading to a threonine to methionine (T790M) amino acid alteration in the ATP-binding pocket of the EGFR as a common mechanism of acquired resistance. The gefitinib-resistant, T790M-mutant H1975 NSCLC cell line undergoes prominent growth arrest and apoptosis when treated with the irreversible EGFR inhibitor, CL-387,785. We did a transcriptional profiling study of mutant EGFR target genes that are differentially expressed in the “resistant” gefitinib-treated and the “sensitive” CL387,785-treated H1975 cells to identify the pivotal transcriptional changes in NSCLC with EGFR-activating mutations. We identified a small subset of early gene changes, including significant reduction of cyclin D1 as a result of EGFR inhibition by CL-387,785 but not by gefitinib. The reduction in cyclin D1 transcription was associated with subsequent suppression of E2F-responsive genes, consistent with proliferation arrest. Furthermore, cyclin D1 expression was higher in EGFR-mutant lung cancer cells compared with cells with wild-type EGFR. EGFR-mutant cells were routinely sensitive to the cyclin-dependent kinase inhibitor flavopiridol, confirming the functional relevance of the cyclin D axis. These studies suggest that cyclin D1 may contribute to the emergence of EGFR-driven tumorigenesis and can be an alternative target of therapy. (Cancer Res 2006; 66(23): 11389-98)
Isolation of Germ Cells from Leukemia and Lymphoma Cells in a Human In vitro Model: Potential Clinical Application for Restoring Human Fertility after Anticancer Therapy
Authors: Fujita Kazutoshi , Tsujimura Akira , Miyagawa Yasushi , Kiuchi Hiroshi , Matsuoka Yasuhiro , Takao Tetsuya , Takada Shingo , Nonomura Norio , Okuyama Akihiko 
Published: December 2006

Abstract
More than 70% of patients survive childhood cancer, but chemotherapy and radiation therapy may cause irreversible impairment of spermatogenesis. To treat infertility secondary to anticancer treatment for childhood cancer, we have developed a procedure to isolate germ cells from leukemic mice by fluorescence-activated cell sorting with two surface markers, and transplantation of isolated germ cells successfully restored fertility without inducing leukemia. In the present study, we analyzed human germ cells and human malignant cells, including five leukemia cell lines and three lymphoma cell lines, by fluorescence-activated cell sorting with antibodies against MHC class I and CD45. Testicular specimens were obtained from a patient who underwent surgery for testicular rupture. In the high forward scatter and low side scatter region, no malignant cells were found in the MHC class I-negative and CD45-negative fraction (the germ cell fraction), with the exception of K562 cells. A total of 39.2% of the germ cells were found in the germ cell fraction. A total of 1.45% of K562 cells were found in the germ cell fraction. Treatment with IFNγ induced the expression of MHC class I on K562 cells but not on germ cells and made it possible to isolate germ cells from K562 cells. In conclusion, we isolated human germ cells from malignant cells with two surface markers after treatment with IFNγ. Immunophenotyping for each patient will be necessary before isolation and induction of surface marker will be clinically applicable. (Cancer Res 2006; 66(23): 11166-71)
Protein Kinase C β Enhances Growth and Expression of Cyclin D1 in Human Breast Cancer Cells
Authors: Li Haiyang , Weinstein I. Bernard 
Published: December 2006

Abstract
Although alterations in the expressions of protein kinase C (PKC) have been implicated in breast carcinogenesis, the roles of specific isoforms in this process remain elusive. In the present study, we examined the specific roles of PKCβ1 and β2 in growth control in human breast cancer cell lines. The PKCβ-specific inhibitor LY379196 significantly inhibited growth of the breast cancer cell lines MCF-7, MDA-MB-231, and BT474, but not the normal mammary epithelial cell line MCF-10F. Treatment of MCF-7 cells with LY379196 caused an increase in the fraction of cells in the G1 phase of the cell cycle. To explore the roles of PKCβ1 and β2, we used cDNA expression vectors that encode wild-type and constitutively activated or dominant negative mutants of these two proteins. When compared with vector controls, derivatives of MCF-7 cells that stably overexpress wild-type PKCβ1 or PKCβ2 displayed a slight increase in growth rate; derivatives that stably express the constitutively active mutants of PKCβ1 or PKCβ2 displayed a marked increase in growth rate; and derivatives that stably express a dominant negative mutant of PKCβ1 or β2 displayed inhibition of growth. The derivatives of MCF-7 cells that stably express the constitutively activated mutants of PKCβ1 or β2 were more resistant to growth inhibition by LY379196 than the vector control MCF-7 cells. Immunoblot analysis indicated that MCF-7 cells that stably overexpress wild-type or constitutively activated mutants of PKCβ1 or β2 had higher cellular levels of cyclin D1 than vector control cells, whereas cells that express a dominant negative mutant had decreased levels of cyclin D1. The derivatives that stably express the constitutively activated mutants of PKCβ1 or β2 also displayed increased cyclin D1 promoter activity in transient transfection luciferase reporter assays, and this induction of activity requires activator protein 1. Constitutively activated PKCβ1 and β2 also enhanced the transcription of c-fos in transient transfection luciferase reporter assays. Thus, PKCβ1 and β2 may play important positive roles in the growth of at least a subset of human breast cancers. Therefore, inhibitors of these isoforms may be useful in breast cancer chemoprevention or therapy. (Cancer Res 2006; 66(23): 11399-408)
Preparing the “Soil”: The Premetastatic Niche
Authors: Kaplan Rosandra N. , Rafii Shahin , Lyden David 
Published: December 2006

Abstract
Current focus on cancer metastasis has centered on the intrinsic factors regulating the cell autonomous homing of the tumor cells to the metastatic site. Specific up-regulation of fibronectin and clustering of bone marrow–derived cellular infiltrates coexpressing matrix metalloproteinases in distant tissue sites before tumor cell arrival are proving to be indispensable for the initial stages of metastasis. These bone marrow–derived hematopoietic progenitors that express vascular endothelial growth factor receptor 1 mobilize in response to the unique array of growth factors produced by the primary tumor. Their arrival in distant sites represents early changes in the local microenvironment, termed the “premetastatic niche,” which dictate the pattern of metastatic spread. Focus on the early cellular and molecular events in cancer dissemination and selectivity will likely lead to new approaches to detect and prevent metastasis at its earliest inception. (Cancer Res 2006; 66(23): 11089-93)
Cellular FLICE-Inhibitory Protein Down-regulation Contributes to Celecoxib-Induced Apoptosis in Human Lung Cancer Cells
Authors: Liu Xiangguo , Yue Ping , Schönthal Axel H. , Khuri Fadlo R. , Sun Shi-Yong 
Published: December 2006

Abstract
The cyclooxygenase-2 (COX-2) inhibitor celecoxib is an approved drug in the clinic for colon cancer chemoprevention and has been tested for its chemopreventive and therapeutic efficacy in various clinical trials. Celecoxib induces apoptosis in a variety of human cancer cells including lung cancer cells. Our previous work has shown that celecoxib induces death receptor 5 expression, resulting in induction of apoptosis and enhancement of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)–induced apoptosis in human lung cancer cells. In the current study, we further show that celecoxib down-regulated the expression of cellular FLICE-inhibitory protein (c-FLIP), a major negative regulator of the death receptor–mediated extrinsic apoptotic pathway, through a ubiquitin/proteasome–dependent mechanism independent of COX-2 in human lung cancer cells. Overexpression of c-FLIP, particularly FLIPL, inhibited not only celecoxib-induced apoptosis but also apoptosis induced by the combination of celecoxib and TRAIL. These results thus indicate that c-FLIP down-regulation also contributes to celecoxib-induced apoptosis and enhancement of TRAIL-induced apoptosis, which complements our previous finding that the extrinsic apoptotic pathway plays a critical role in celecoxib-induced apoptosis in human lung cancer cells. Collectively, we conclude that celecoxib induces apoptosis in human lung cancer cells through activation of the extrinsic apoptotic pathway, primarily by induction of death receptor 5 and down-regulation of c-FLIP. (Cancer Res 2006; 66(23): 11115-9)
Tumor Necrosis Factor-α Increases Reactive Oxygen Species by Inducing Spermine Oxidase in Human Lung Epithelial Cells: A Potential Mechanism for Inflammation-Induced Carcinogenesis
Authors: Babbar Naveen , Casero Robert A. 
Published: December 2006

Abstract
Inflammation has been implicated in the development of many human epithelial cancers, including those of the stomach, lung, colon, and prostate. Tumor necrosis factor-α (TNF-α) is a potent pleiotropic, proinflammatory cytokine produced by many cells in response to injury and inflammation. Here, we show that TNF-α exposure results in increased production of reactive oxygen species (ROS), with a concomitant increase in the production of 8-oxo-deoxyguanosine, a marker for oxidative DNA damage, in human lung bronchial epithelial cells. The source of the ROS in TNF-α–treated cells was determined by both pharmacologic and small interfering RNA (siRNA) strategies to be spermine oxidase (SMO/PAOh1). SMO/PAOh1 oxidizes spermine into spermidine, 3-aminopropanal, and H2O2. Inhibition of TNF-α–induced SMO/PAOh1 activity with MDL 72,527 or with a targeted siRNA prevented ROS production and oxidative DNA damage. Further, similar induction in SMO/PAOh1 is observed with treatment of another inflammatory cytokine, interleukin-6. The data are consistent with a model that directly links inflammation and DNA damage through the production of H2O2 by SMO/PAOh1. Further, these results suggest a common mechanism by which inflammation from multiple sources can lead to the mutagenic changes necessary for the development and progression of epithelial cancers. (Cancer Res 2006; 66(23): 11125-30)
A Phase I Study of Pemetrexed (ALIMTA) and Cyclophosphamide in Patients with Locally Advanced or Metastatic Breast Cancer
Authors: Dittrich Christian , Petruzelka Lubos , Vodvarka Pavel , Gneist Margit , Janku Filip , Kysela Tamara , Melemed Allen , Latz Jane , Simms Lorinda , Krejcy Kurt 
Published: December 2006

Abstract
Purpose: Determine the maximum tolerated dose (MTD) of pemetrexed and cyclophosphamide combination therapy for patients with locally advanced or metastatic breast cancer.
Experimental Design: Patients with locally advanced or metastatic breast cancer and WHO performance status 0 to 2 were eligible. Pemetrexed (range, 400-2,400 mg/m2) was administered on day 1 of a 21-day schedule followed by cyclophosphamide (range, 400-800 mg/m2). Folic acid and vitamin B12 supplementation began 1 to 2 weeks before the first pemetrexed dose.
Results: Fifty-seven pretreated patients were enrolled and received 342 cycles (median, 4 cycles; range, 1-26) through 14 dose levels. The MTD of pemetrexed was 2,400 mg/m2 (combined with cyclophosphamide, 600 mg/m2) with dose-limiting toxicities of grade 4 neutropenia with grade 4 infection and grade 3 diarrhea. Other grade 3 or 4 toxicities included (febrile) neutropenia, thrombocytopenia, anemia, elevated alanine aminotransferase/aspartate aminotransferase, and diarrhea. Pharmacokinetic analysis indicated that pemetrexed clearance and central volume of distribution were 40% lower than single-agent reference data, yielding a 68% increase in total systemic exposure and a 56% increase in maximal plasma concentration. Among the 50 patients evaluable for efficacy, 13 (26%) patients had a partial response and 17 (34%) patients had stable disease.
Conclusions: Pemetrexed was generally well tolerated. The observed toxicities were consistent with the known toxicity profiles of pemetrexed and cyclophosphamide. Considering the MTD and the toxicity and efficacy results in this and prior studies, a low (600 mg/m2) and a high (1,800 mg/m2) dose of pemetrexed with cyclophosphamide (600 mg/m2) will be evaluated in the consecutive prospective randomized phase II study.