bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein Kinase C δ Overexpressing Transgenic Mice Are Resistant to Chemically but not to UV Radiation–Induced Development of Squamous Cell Carcinomas: A Possible Link to Specific Cytokines and Cyclooxygenase-2
Authors: Aziz Moammir H. , Wheeler Deric L. , Bhamb Bhushan , Verma Ajit K. 
Published: January 2006

Abstract
Protein kinase C δ (PKCδ), a Ca2+-independent, phospholipid-dependent serine/threonine kinase, is among the novel PKCs (δ, ε, and η) expressed in mouse epidermis. We reported that FVB/N transgenic mice that overexpress (∼8-fold) PKCδ protein in basal epidermal cells and cells of the hair follicle are resistant to the development of both skin papillomas and squamous cell carcinoma (SCC) elicited by 7,12-dimethylbenz(a)anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion protocol. We now present that PKCδ overexpression in transgenic mice failed to suppress the induction of SCC developed by repeated exposures to UV radiation (UVR), the environmental carcinogen linked to the development of human SCC. Both TPA and UVR treatment of wild-type mice (a) increased the expression of proliferating cell nuclear antigen (PCNA) and apoptosis; (b) stimulated the expression of cytokines tumor necrosis factor-α (TNF-α), granulocyte macrophage colony-stimulating factor (GM-CSF), and granulocyte CSF (G-CSF); and (c) increased cyclooxygenase-2 (COX-2) expression and expression of phosphorylated Akt (p-Akt), p38, extracellular signal-regulated kinase-1 (ERK1), and ERK2. PKCδ overexpression in transgenic mice enhanced TPA-induced but not UVR-induced apoptosis and suppressed TPA-stimulated but not UVR-stimulated levels of cell PCNA, cytokines (TNF-α, G-CSF, and GM-CSF), and the expression of COX-2, p-Akt, and p38. The results indicate that UVR-mediated signal transduction pathway to the induction of SCC does not seem to be sensitive to PKCδ overexpression. The proapoptotic activity of PKCδ coupled with its ability to suppress TPA-induced expression of proinflammatory cytokines, COX-2 expression, and the phosphorylation of Akt and p38 may play roles in the suppression of TPA-promoted development of SCC. (Cancer Res 2006; 66(2): 713-22)
Oncogenic BRAF Is Required for Tumor Growth and Maintenance in Melanoma Models
Authors: Hoeflich Klaus P. , Gray Daniel C. , Eby Michael T. , Tien Janet Y. , Wong Leo , Bower Janeko , Gogineni Alvin , Zha Jiping , Cole Mary J. , Stern Howard M. , Murray Lesley J. , Davis David P. , Seshagiri Somasekar 
Published: January 2006

Abstract
The usual paradigm for developing kinase inhibitors in oncology is to use a high-affinity proof-of-concept inhibitor with acceptable metabolic properties for key target validation experiments. This approach requires substantial medicinal chemistry and can be confounded by drug toxicity and off-target activities of the test molecule. As a better alternative, we have developed inducible short-hairpin RNA xenograft models to examine the in vivo efficacy of inhibiting oncogenic BRAF. Our results show that tumor regression resulting from BRAF suppression is inducible, reversible, and tightly regulated in these models. Analysis of regressing tumors showed the primary mechanism of action for BRAF to be increased tumor cell proliferation and survival. In a metastatic melanoma model, conditional BRAF suppression slowed systemic tumor growth as determined by in vivo bioluminescence imaging. Taken together, gain-of-function BRAF signaling is strongly associated with in vivo tumorigenicity, confirming BRAF as an important target for small-molecule and RNA interference–based therapeutics. (Cancer Res 2006; 66(2): 999-1006)
Differential Gene Expression Analysis Reveals Generation of an Autocrine Loop by a Mutant Epidermal Growth Factor Receptor in Glioma Cells
Authors: Ramnarain Deepti B. , Park Seongmi , Lee Diana Y. , Hatanpaa Kimmo J. , Scoggin Shane O. , Otu Hasan , Libermann Towia A. , Raisanen Jack M. , Ashfaq Raheela , Wong Eric T. , Wu Julian , Elliott Robert , Habib Amyn A. 
Published: January 2006

Abstract
The epidermal growth factor receptor (EGFR) gene is commonly amplified and rearranged in glioblastoma multiforme leading to overexpression of wild-type and mutant EGFRs. Expression of wild-type EGFR ligands, such as transforming growth factor-α (TGF-α) or heparin-binding EGF (HB-EGF), is also often increased in gliomas resulting in an autocrine loop that contributes to the growth autonomy of glioma cells. Glioblastoma multiformes express a characteristic EGFR mutant (EGFRvIII, de 2-7) that does not bind ligand, signals constitutively, and is more tumorigenic than the wild-type receptor. However, the downstream signals that mediate this increased tumorigenicity are not well understood. We hypothesized that signals induced specifically by EGFRvIII and not the wild-type receptor are more likely to mediate its increased tumorigenic activity and examined the gene expression profiles resulting from inducible expression of comparable levels of either wild-type EGFR or EGFRvIII in a U251-MG glioma cell line. Expression of EGFRvIII resulted in specific up-regulation of a small group of genes. Remarkably, all these genes, which include TGFA, HB-EGF, EPHA2, IL8, MAP4K4, FOSL1, EMP1, and DUSP6, influence signaling pathways known to play a key role in oncogenesis and function in interconnected networks. Increased expression of EGFRvIII-induced genes was validated by real-time PCR. The mutant receptor does not bind ligand, and EGFRvIII-induced expression of TGF-α and HB-EGF suggests that EGFRvIII plays a role in generating an autocrine loop using the wild-type EGFR in glioma. It also raises the possibility that EGFRvIII may signal, at least in part, through the wild-type receptor. Indeed, we show that inhibiting the activity of HB-EGF, a potent mitogen, with neutralizing antibodies reduces cell proliferation induced by expression of EGFRvIII. This suggests that the EGFRvIII-HB-EGF-wild-type EGFR autocrine loop plays an important role in signal transduction by EGFRvIII in glioma cells. We also show by immunohistochemistry that HB-EGF expression correlates with the presence of EGFRvIII in glioblastoma multiforme. Thus, our study provides a new insight into oncogenic signaling by EGFRvIII and improves our understanding of how autocrine loops are generated in glioma. (Cancer Res 2006; 66(2): 867-74)
Vaccine with β-Defensin 2–Transduced Leukemic Cells Activates Innate and Adaptive Immunity to Elicit Potent Antileukemia Responses
Authors: Ma Xiao-Tong , Xu Bin , An Li-Li , Dong Cheng-Ya , Lin Yong-Min , Shi Yang , Wu Ke-Fu 
Published: January 2006

AbstractMurine β-defensin 2 (MBD2) is a small antimicrobial peptide of the innate immune system. Recent study showed that MBD2 could not only recruit immature dendritic cells but also activate them by Toll-like receptor 4 and thus may provide a critical link between the innate immune system and the adaptive immune response. In this report, we examined the antileukemia activity of MBD2 in a murine model of acute lymphoid leukemia (ALL) L1210. L1210 cells were engineered to secrete biologically functional MBD2. MBD2-modified L1210 (L1210-MBD2) showed significantly reduced leukemogenecity, resulting in a 80% rate of complete leukemia rejection. Inoculation of mice with L1210-MBD2 induced enhanced CTL and natural killer (NK) activity and augmented interleukin-12 and IFN-γ production. All the recovered mice from the inoculation showed a protective immunity to the following challenge with parental L1210 cells and generate leukemia-specific memory CTL. Vaccines with irradiated L1210-MBD2 cells could cure 50% leukemia-bearing mice. Depletion of CD8+ T cells but not CD4+ T cells completely abrogated the antileukemia activity of MBD2. Interestingly, NK cells were also required for the MBD2-mediated antileukemia response, although ALL generally display a high degree of resistance to NK-mediated lysis. Our results suggest that MBD2 can activate both innate and adaptive immunity to generate potent antileukemia response, and MBD2 immunotherapy warrants further evaluation as a potential treatment for ALL. (Cancer Res 2006; 66(2): 1169-76)
Expression of a Fibroblast Growth Factor–Binding Protein during the Development of Adenocarcinoma of the Pancreas and Colon
Authors: Tassi Elena , Henke Ralf T. , Bowden Emma T. , Swift Matthew R. , Kodack David P. , Kuo Angera H. , Maitra Anirban , Wellstein Anton 
Published: January 2006

Abstract
The activity of growth factors is crucial for tumor progression. We previously characterized a secreted fibroblast growth factor–binding protein (FGF-BP1) as a chaperone molecule, which enhances the biological functions of FGFs by releasing FGFs from the extracellular matrix. Here, we characterize the frequency and pattern of FGF-BP1 expression during the malignant progression of pancreas and colorectal carcinoma. For this, we generated monoclonal antibodies that detect FGF-BP1 protein in formalin-fixed, paraffin-embedded tissues and applied in situ hybridization to detect FGF-BP1 mRNA in adjacent tissue sections. FGF-BP1 protein and mRNA were found up-regulated (&gt;70% positive) in parallel (r = 0.70, P &lt; 0.0001) in colon adenoma (n = 9) as well as primary (n = 46) and metastatic (n = 71) colorectal cancers relative to normal colon epithelia (all P &lt; 0.0001, versus normal). Similarly, pancreatitis (n = 17), pancreatic intraepithelial neoplasia (n = 80), and pancreatic adenocarcinoma (n = 67) showed a significant up-regulation of FGF-BP1 compared with normal pancreas (n = 42; all P &lt; 0.0001, relative to normal). Furthermore, the biological activity of FGF-BP1 is neutralized by one of the antibodies, suggesting the potential for antibody-based therapeutic targeting. We propose that the up-regulation of the secreted FGF-BP1 protein during initiation of pancreas and colon neoplasia could make this protein a possible serum marker indicating the presence of high-risk premalignant lesions. (Cancer Res 2006; 66(2): 1191-8)
TC1 (C8orf4) Enhances the Wnt/β-Catenin Pathway by Relieving Antagonistic Activity of Chibby
Authors: Jung Yusun , Bang Seunghyun , Choi Kyungho , Kim Eunsoon , Kim Youngmi , Kim Jungtae , Park Juhee , Koo Hyunlyoung , Moon Randall T. , Song Kyuyoung , Lee Inchul 
Published: January 2006

Abstract
The Wnt/β-catenin pathway has been implicated in human cancers. Here, we show that TC1 (C8orf4), a small protein present in vertebrates, functions as a positive regulator of the pathway. TC1 interacts with Chibby (Cby) and thereby enhances the signaling pathway by relieving the antagonistic function of Cby on the β-catenin–mediated transcription. Upon coexpression in mammalian cells, TC1 redistributes from nucleolus to nuclear speckles, where it colocalizes with Cby. TC1 up-regulates the expression of β-catenin target genes that are implicated in invasiveness and aggressive behavior of cancers, such as metalloproteinases, laminin γ2, and others. Our data indicate that TC1 is a novel upstream regulator of the Wnt/β-catenin pathway that enhances aggressive behavior of cancers. (Cancer Res 2006; 66(2): 723-8)
HIV-1 Vpr Induces DNA Double-Strand Breaks
Authors: Tachiwana Hiroaki , Shimura Mari , Nakai-Murakami Chikako , Tokunaga Kenzo , Takizawa Yoshimasa , Sata Tetsutaro , Kurumizaka Hitoshi , Ishizaka Yukihito 
Published: January 2006

Abstract
Recent observations imply that HIV-1 infection induces chromosomal DNA damage responses. However, the precise molecular mechanism and biological relevance are not fully understood. Here, we report that HIV-1 infection causes double-strand breaks in chromosomal DNA. We further found that Vpr, an accessory gene product of HIV-1, is a major factor responsible for HIV-1–induced double-strand breaks. The purified Vpr protein promotes double-strand breaks when incubated with isolated nuclei, although it does not exhibit endonuclease activity in vitro. A carboxyl-terminally truncated Vpr mutant that is defective in DNA-binding activity is less capable of Vpr-dependent double-strand break formation in isolated nuclei. The data suggest that double-strand breaks induced by Vpr depend on its DNA-binding activity and that Vpr may recruit unknown nuclear factor(s) with positive endonuclease activity to chromosomal DNA. This is the first direct evidence that Vpr induces double-strand breaks in HIV-1–infected cells. We discuss the possible roles of Vpr-induced DNA damage in HIV-1 infection and the involvement of Vpr in further acquired immunodeficiency syndrome–related tumor development. (Cancer Res 2006; 66(2): 627-31)
Comparison of Metabolic Pathways between Cancer Cells and Stromal Cells in Colorectal Carcinomas: a Metabolic Survival Role for Tumor-Associated Stroma
Authors: Koukourakis Michael I. , Giatromanolaki Alexandra , Harris Adrian L. , Sivridis Efthimios 
Published: January 2006

Abstract
Understanding tumor metabolism is important for the development of anticancer therapies. Immunohistochemical evaluation of colorectal adenocarcinomas showed that cancer cells share common enzyme/transporter activities suggestive of an anaerobic metabolism [high lactate dehydrogenase 5 (LDH5)/hypoxia-inducible factor αs (HIFαs)] with high ability for glucose absorption and lactate extrusion [high glucose transporter 1 (GLUT1)/monocarboxylate transporter (MCT1)]. The tumor-associated fibroblasts expressed proteins involved in lactate absorption (high MCT1/MCT2), lactate oxidation (high LDH1 and low HIFαs/LDH5), and reduced glucose absorption (low GLUT1). The expression profile of the tumor-associated endothelium indicated aerobic metabolism (high LDH1 and low HIFαs/LDH5), high glucose absorption (high GLUT1), and resistance to lactate intake (lack of MCT1). It is suggested that the newly formed stroma and vasculature express complementary metabolic pathways, buffering and recycling products of anaerobic metabolism to sustain cancer cell survival. Tumors survive and grow because they are capable of organizing the regional fibroblasts and endothelial cells into a harmoniously collaborating metabolic domain. (Cancer Res 2006; 66(2): 632-7)
Radiation-Induced Changes in Gene Expression Involve Recruitment of Existing Messenger RNAs to and away from Polysomes
Authors: Lü Xing , de la Peña Lorena , Barker Christopher , Camphausen Kevin , Tofilon Philip J. 
Published: January 2006

Abstract
Although ionizing radiation has been shown to influence gene transcription, little is known about the effects of radiation on gene translational efficiency. To obtain a genome-wide perspective of the effects of radiation on gene translation, microarray analysis was done on polysome-bound RNA isolated from irradiated human brain tumor cells; to allow for a comparison with the effects of radiation on transcription, microarray analysis was also done using total RNA. The number of genes whose translational activity was modified by radiation was ∼10-fold greater than those whose transcription was affected. The radiation-induced change in a gene's translational activity was shown to involve the recruitment of existing mRNAs to and away from polysomes. Moreover, the change in a gene's translational activity after irradiation correlated with changes in the level of its corresponding protein. These data suggest that radiation modifies gene expression primarily at the level of translation. In contrast to transcriptional changes, there was considerable overlap in the genes affected at the translational level among brain tumor cell lines and normal astrocytes. Thus, the radiation-induced translational control of a subset of mRNAs seems to be a fundamental component of cellular radioresponse. (Cancer Res 2006; 66(2): 1052-61)
CpG Island Methylation and Expression of the Secreted Frizzled-Related Protein Gene Family in Chronic Lymphocytic Leukemia
Authors: Liu Te-Hui , Raval Aparna , Chen Shih-Shih , Matkovic Jennifer J. , Byrd John C. , Plass Christoph 
Published: January 2006

Abstract
B-cell chronic lymphocytic leukemia (CLL) is characterized by a clonal accumulation of mature neoplastic B cells indicating disruption of apoptosis. Restriction Landmark Genome Scanning was done to identify novel target genes silenced by CpG island methylation in CLL. Secreted frizzled-related protein 4 (SFRP4), a negative regulator of the Wnt signaling pathway, was found to be frequently methylated in CLL samples. Wnt signaling has been shown to control normal apoptotic behavior and is required for normal B-cell development whereas aberrant activation of this pathway has been observed in CLL. We show aberrant DNA methylation and silencing of SFRP4, as well as of additional SFRP family members, in primary CLL samples. Induction of their expression in a dose-dependent manner following treatment with a demethylating agent, 5-aza-2′-deoxycytidine, was shown. Of the five SFRP family members studied in detail, SFRP1 was hypermethylated and down-regulated in all CLL patient samples studied, suggesting that this epigenetic event is a critical step during leukemogenesis. Our results suggest that silencing of SFRPs by CpG island methylation is one possible mechanism contributing to aberrant activation of Wnt signaling pathway in CLL. (Cancer Res 2006; (66)2: 653-8)
Neutrophils modulate post-thrombotic vein wall remodeling but not thrombus neovascularization
Authors: Varma Manu , Deatrick K. , Dewyer Nicholas , Lynch Erin , Moore Andrea , Dubay Derek , Sukheepod Pasu , Pearce Charles , Upchurch Gilbert , Kunkel Steven , Franz Michael , Wakefield Thomas , Henke Peter 
Published: January 2006

SummaryEarly deep venous thrombosis (DVT) resolution is associated with neutrophil (PMN) influx. This study examined the role of PMNs in thrombus neovascularization and vein wall injury after DVT. A rat model of DVT by inferior vena cava (IVC) ligation was performed with control serum or rabbit anti-rat PMN serum administered perioperatively with sacrifice at 2 and 7 days. At 2 days, neutropenic rats had 1.6-fold larger thrombi (P = .04) and 1.4-fold higher femoral venous pressures by water manometry (P = .008) but no difference in thrombus neovascularization was observed. By7 days, DVT sizes were similar, but vein wall injury persisted in the neutropenic rats with a 2.0-fold increase in vein wall stiffness by microtensiometry (P< .05), as well asa 1.2-fold increased thickness (P = .04). Collagen and profibrotic growth factors were significantly increased in neutropenic IVC at7 days (all P< .05).Vein wall and intrathrombus uPA by Western immunoblotting, and intrathrombus MMP-9 gelatinase activity were significantly less in neutropenic rats than controls (P < .001). Conversely, MMP-2 was significantly elevated in neutropenic IVC at 2 days after DVT. However, neutropenia induced 24 hours after DVT formation resulted in no significant increase in vein wall stiffness or collagen levels at 7 days, despite 1.4-fold larger thrombi (P < .05). These data suggest a critical early role for PMN in post DVT vein wall remodeling.
A role for immunoglobulin G in donor-specific Streptococcus sanguis-induced platelet aggregation
Authors: Zhu Raymond , Pesun Robert , Pampolina Caroline , Jackson Elke , Bowden George , Zelinski Teresa , McNicol Archibald 
Published: January 2006

SummaryThere is increasing evidence fora relationship between bacterial infections and several cardiovascular disorders. Although the precise mechanism(s) underlying this association is unknown, the direct activation of platelets by bacteria is one possibility. Individual strains of S. sanguis activate platelets in a non-uniform, donor-dependent manner. In the current study, platelet aggregation profiles were obtained for fourteen donors in response to four strains of S. sanguis (2017–78, 133–79, SK112, SK108a) and one of S. gordonii (SK8). The platelets from all donors responded to strains 2017–78 and 133–79,whereas strains SK112, SK8 and SK108a caused aggregation in one, five and twelve donors, respectively. Immunoglobulin G (IgG) binding to strains 2017–78, 133–79 and SK108a were significantly greater than to strains SK112 and SK8. Absorption of IgG by strain 2017–78 caused significant decreases in IgG binding, and platelet aggregation in response, to all strains. Single-strand conformational polymorphisms were observed in the FcγRIIA gene from four donors. Sequencing revealed two known and two novel point mutations, none of which correlated with the aggregation profile. Thus, platelet activation to the various strains depends ona common IgG and, while in most cases the level of IgG binding to S. sanguis determines platelet responsiveness, neither the levels of IgG nor FcγRIIA polymorphisms can fully account for donor variability.
No added value of the methionine loading test in assessment for venous thrombosis and cardiovascular disease risk
Authors: Keijzer Miranda , Verhoef Petra , Borm George , Blom Henk , den Heijer Martin 
Published: January 2006

SummaryHomocysteine isa risk factor for cardiovascular disease and venous thrombosis. Clinical guidelines differ in their recommendation whether or not to measure homocysteine after methionine loading. In this study, we investigated the added value of the methionine loading test next to fasting homocysteine levels for identifying subjects at risk for venous thrombosis or cardiovascular disease, using Receiver Operating Characteristic (ROC) curves.The analysis was performed in 185 patients with recurrent venous thrombosis, 130 patients with cardiovascular disease and 601 controls.The discriminatory power of the fasting homocysteine measurement alone for identifying subjects at risk of venous thrombosis expressed as the area under the ROC curve (AUC) was 0.61 (95%CI 0.56-0.66). Using both a fasting homocysteine measurement and a methionine loading test together yielded a similar AUC of 0.65 (95%CI 0.60-0.69), indicating no added value of methionine loading next to fasting homocysteine measurement in identifying subjects at risk for thrombosis. Similar results where found for cardiovascular disease, with anAUC of 0.62 (95%CI 0.57-0.67) for the fasting homocysteine measurement alone and an AUC of 0.62 (95%CI 0.57-0.67) for the combination of both the fasting and the postload homocysteine measurement. The methionine loading test has no added value next to measuring fasting homocysteine levels for identifying subjects at risk for venous thrombosis or cardiovascular disease and for that reason should not be used in clinical practice.
Relation between ADAMTS13 activity and ADAMTS13 antigen levels in healthy donors and patients with thrombotic microangiopathies (TMA)
Authors: Hovinga Johanna A. , Konetschny Christian , Herzog Andrea , Koller Letizia , Weber Alfred , Remuzzi Giuseppe , Dockal Michael , Plaimauer Barbara , Rieger Manfred , Ferrari Silvia , Scheiflinger Friedrich 
Published: January 2006

SummaryWe have established a new, enzyme-linked immunosorbent assay (ELISA) for the detection of ADAMTS13 antigen using purified polyclonal rabbit anti-human ADAMTS13 IgG. Normal plasma ADAMTS13 antigen levels span a concentration of 740 –1420ng/ml (median 1080ng/ml) resulting in an ADAMTS13 activity to antigen ratio of 0.48 to 1.68 U/µg. In a cohort of HUS patients, ADAMTS13 antigen was in the normal range, whereas in hereditary TTP patients antigen levels were low to undetectable, in concordance with severe deficient ADAMTS13 activity. Plasma of acquired TTP patients was found to contain free as well as autoantibody-bound ADAMTS13. We also present evidence for circulating anti-ADAMTS13 antibody/ADAMTS13 antigen immune complexes not only in acutely ill or actively treated patients but also in patients who have already achieved clinical remission. This new developed ADAMTS13 antigen ELISA assay allows rapid determination of ADAMTS13 antigen levels in human plasma but is of limited predictive value for the diagnosis or treatment of acquired TTP due to the detection of ADAMTS13 in antibody complexes.