bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Cytomegalovirus Protein pp71 Displaces the Chromatin-Associated Factor ATRX from Nuclear Domain 10 at Early Stages of Infection
Authors: Lukashchuk Vera , McFarlane Steven , Everett Roger D. , Preston Chris M. 
Published: October 2008

ABSTRACT
The human cytomegalovirus (HCMV) tegument protein pp71, encoded by gene UL82, stimulates viral immediate-early (IE) transcription. pp71 interacts with the cellular protein hDaxx at nuclear domain 10 (ND10) sites, resulting in the reversal of hDaxx-mediated repression of viral transcription. We demonstrate that pp71 displaces an hDaxx-binding protein, ATRX, from ND10 prior to any detectable effects on hDaxx itself and that this event contributes to the role of pp71 in alleviating repression. Introduction of pp71 into cells by transfection, infection with a pp71-expressing herpes simplex virus type 1 vector, or by generation of transformed cell lines promoted the rapid relocation of ATRX from ND10 to the nucleoplasm without alteration of hDaxx levels or localization. A pp71 mutant protein unable to interact with hDaxx did not affect the intranuclear distribution of ATRX. Infection with HCMV at a high multiplicity of infection resulted in rapid displacement of ATRX from ND10, the effect being observed maximally by 2 h after adsorption, whereas infection with the UL82-null HCMV mutant ADsubUL82 did not affect ATRX localization even at 7 h postinfection. Cell lines depleted of ATRX by transduction with shRNA-expressing lentiviruses supported increased IE gene expression and virus replication after infection with ADsubUL82, demonstrating that ATRX has a role in repressing IE transcription. The results show that ATRX, in addition to hDaxx, is a component of cellular intrinsic defenses that limit HCMV IE transcription and that displacement of ATRX from ND10 by pp71 is important for the efficient initiation of viral gene expression.
Measles Virus V Protein Is a Decoy Substrate for IκB Kinase α and Prevents Toll-Like Receptor 7/9-Mediated Interferon Induction
Authors: Pfaller Christian K. , Conzelmann Karl-Klaus 
Published: October 2008

ABSTRACT

The central role of plasmacytoid dendritic cells (pDC) in activating host immune responses stems from their high capacity to express alpha interferon (IFN-α) after stimulation of Toll-like receptors 7 and 9 (TLR7 and -9). This involves the adapter MyD88 and the kinases interleukin-1 receptor-associated kinase 1 (IRAK1), IRAK4, and IκB kinase α (IKKα), which activates IFN regulatory factor 7 (IRF7) and is independent of the canonical kinases TBK1 and IKKε. We have recently shown that the immunosuppressive measles virus (MV) abolishes TLR7/9/MyD88-dependent IFN induction in human pDC (Schlender et al., J. Virol.
79:
5507-5515, 2005), but the molecular mechanisms remained elusive. Here, we have reconstituted the pathway in cell lines and identified IKKα and IRF7 as specific targets of the MV V protein (MV-V). Binding of MV-V to IKKα resulted in phosphorylation of V on the expense of IRF7 phosphorylation by IKKα in vitro and in living cells. This corroborates the role of IKKα as the kinase phosphorylating IRF7. MV-V in addition bound to IRF7 and to phosphomimetic IRF7 and inhibited IRF7 transcriptional activity. Binding to both IKKα and IRF7 required the 68-amino-acid unique C-terminal domain of V. Inhibition of TLR/MyD88-dependent IFN induction by MV-V is unique among paramyxovirus V proteins and should contribute to the unique immunosuppressive phenotype of measles. The mechanisms employed by MV-V inspire strategies to interfere with immunopathological TLR/MyD88 signaling.
Simian Virus 40 Large T Antigen Disrupts Genome Integrity and Activates a DNA Damage Response via Bub1 Binding
Authors: Hein Jennifer , Boichuk Sergei , Wu Jiaping , Cheng Yuan , Freire Raimundo , Jat Parmjit S. , Roberts Thomas M. , Gjoerup Ole V. 
Published: October 2008

ABSTRACT
Simian virus 40 (SV40) large T antigen (LT) is a multifunctional protein that is important for viral replication and oncogenic transformation. Previously, infection of monkey or human cells with SV40 was shown to lead to the induction of DNA damage response signaling, which is required for efficient viral replication. However, it was not clear if LT is sufficient to induce the damage response and, if so, what the genetic requirements and functional consequences might be. Here, we show that the expression of LT alone, without a replication origin, can induce key DNA damage response markers including the accumulation of γ-H2AX and 53BP1 in nuclear foci. Other DNA damage-signaling components downstream of ATM/ATR kinases were induced, including chk1 and chk2. LT also bound the Claspin mediator protein, which normally facilitates the ATR activation of chk1 and monitors cellular replication origins. Stimulation of the damage response by LT depends mainly on binding to Bub1 rather than to the retinoblastoma protein. LT has long been known to stabilize p53 despite functionally inactivating it. We show that the activation of a DNA damage response by LT via Bub1 appears to play a major role in p53 stabilization by promoting the phosphorylation of p53 at Ser15. Accompanying the DNA damage response, LT induces tetraploidy, which is also dependent on Bub1 binding. Taken together, our data suggest that LT, via Bub1 binding, breaches genome integrity mechanisms, leading to DNA damage responses, p53 stabilization, and tetraploidy.
Antiviral Activity of the Zinc Ionophores Pyrithione and Hinokitiol against Picornavirus Infections
Authors: Krenn B. M. , Gaudernak E. , Holzer B. , Lanke K. , Van Kuppeveld F. J. M. , Seipelt J. 
Published: October 2008

ABSTRACTWe have discovered two metal ion binding compounds, pyrithione (PT) and hinokitiol (HK), that efficiently inhibit human rhinovirus, coxsackievirus, and mengovirus multiplication. Early stages of virus infection are unaffected by these compounds. However, the cleavage of the cellular eukaryotic translation initiation factor eIF4GI by the rhinoviral 2A protease was abolished in the presence of PT and HK. We further show that these compounds inhibit picornavirus replication by interfering with proper processing of the viral polyprotein. In addition, we provide evidence that these structurally unrelated compounds lead to a rapid import of extracellular zinc ions into cells. Imported Zn2+was found to be localized in punctate structures, as well as in mitochondria. The observed elevated level of zinc ions was reversible when the compounds were removed. As the antiviral activity of these compounds requires the continuous presence of the zinc ionophore PT, HK, or pyrrolidine-dithiocarbamate, the requirement for zinc ions for the antiviral activity is further substantiated. Therefore, an increase in intracellular zinc levels provides the basis for a new antipicornavirus mechanism.
IL12RB2 and ABCA1 Genes Are Associated with Susceptibility to Radiation Dermatitis
Authors: Isomura Minoru , Oya Natsuo , Tachiiri Seiji , Kaneyasu Yuko , Nishimura Yasumasa , Akimoto Tetsuo , Hareyama Masato , Sugita Tadasi , Mitsuhashi Norio , Yamashita Takashi , Aoki Masahiko , Sai Heitetsu , Hirokawa Yutaka , Sakata Koh-ichi , Karasawa Kumiko , Tomida Akihiro , Tsuruo Takashi , Miki Yoshio , Noda Tetsuo , Hiraoka Masahiro 
Published: October 2008

Abstract
Purpose: Severe acute radiation dermatitis is observed in approximately 5% to 10% of patients who receive whole-breast radiotherapy. Several factors, including treatment-related and patient-oriented factors, are involved in susceptibility to severe dermatitis. Genetic factors are also thought to be related to a patient's susceptibility to severe dermatitis. To elucidate genetic polymorphisms associated with a susceptibility to radiation-induced dermatitis, a large-scale single-nucleotide polymorphism (SNP) analysis using DNA samples from 156 patients with breast cancer was conducted.
Experimental Design: Patients were selected from more than 3,000 female patients with early breast cancer who received radiotherapy after undergoing breast-conserving surgery. The dermatitis group was defined as patients who developed dermatitis at a National Cancer Institute Common Toxicity Criteria grade of ≥2. For the SNP analysis, DNA samples from each patient were subjected to the genotyping of 3,144 SNPs covering 494 genes.
Results: SNPs that mapped to two genes, ABCA1 and IL12RB2, were associated with radiation-induced dermatitis. In the ABCA1 gene, one of these SNPs was a nonsynonymous coding SNP causing R219K (P = 0.0065). As for the IL12RB2 gene, the strongest association was observed at SNP-K (rs3790568; P = 0.0013). Using polymorphisms of both genes, the probability of severe dermatitis was estimated for each combination of genotypes. These analyses showed that individuals carrying a combination of genotypes accounting for 14.7% of the Japanese population have the highest probability of developing radiation-induced dermatitis.
Conclusion: Our results shed light on the mechanisms responsible for radiation-induced dermatitis. These results may also contribute to the individualization of radiotherapy.
Activation of the RAF/Mitogen-Activated Protein/Extracellular Signal-Regulated Kinase Kinase/Extracellular Signal-Regulated Kinase Pathway Mediates Apoptosis Induced by Chelerythrine in Osteosarcoma
Authors: Yang Rui , Piperdi Sajida , Gorlick Richard 
Published: October 2008

Abstract
Purpose: Chelerythrine, a widely used broad-range protein kinase C inhibitor, induces apoptosis in many cell types. In this study, the mechanism of chelerythrine-induced apoptosis in osteosarcoma was investigated.
Experimental Design: Signaling pathways activated by chelerythrine in osteosarcoma were detected by Western blots. Impacts of RAF/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK MAPK on apoptosis and cell survival were studied using genetic approaches and pharmacologic pathway–specific inhibitors.
Results: Osteosarcoma cells underwent apoptosis rapidly after treatment with chelerythrine. Three parallel MAPKs pathways, including the ERKs, c-Jun NH2 kinases, and p38, were activated by chelerythrine in a dose-dependent and time-dependent fashion. For the ERKs, the activation was evident at the earliest time point tested (2 minutes) and sustained for &gt;4 hours. Introduction of a dominant-negative H-RAS mutant (17N) partially attenuated ERK activation and delayed the onset of apoptosis induced by chelerythrine. The ERK activation and apoptotic effects of chelerythrine were greatly abrogated by the pharmaceutical inhibitors of MEK, but not by those of c-Jun NH2 kinase or p38. Moreover, osteosarcoma cells were sensitized to chelerythrine by transient transfection with wild-type MEK1 or constitutively active MEK1 and became resistant with dominant-negative MEK1. Other protein kinase C inhibitors, including GF109203X or Gö6976, did not cause ERK activation or apoptosis in the same timeframe tested.
Conclusion: In osteosarcoma, chelerythrine-induced apoptosis is mediated through activation of the RAF/MEK/ERK pathway. These findings suggest that activating the ERK MAPK, as opposed to inhibiting it, may be a therapeutic strategy in osteosarcoma.
DNA Double-Strand Break Repair of Blood Lymphocytes and Normal Tissues Analysed in a Preclinical Mouse Model: Implications for Radiosensitivity Testing
Authors: Rübe Claudia E. , Grudzenski Saskia , Kühne Martin , Dong Xiaorong , Rief Nicole , Löbrich Markus , Rübe Christian 
Published: October 2008

Abstract
Purpose: Radiotherapy is an effective cancer treatment, but a few patients suffer severe radiation toxicities in neighboring normal tissues. There is increasing evidence that the variable susceptibility to radiation toxicities is caused by the individual genetic predisposition, by subtle mutations, or polymorphisms in genes involved in cellular responses to ionizing radiation. Double-strand breaks (DSB) are the most deleterious form of radiation-induced DNA damage, and DSB repair deficiencies lead to pronounced radiosensitivity. Using a preclinical mouse model, the highly sensitive γH2AX-foci approach was tested to verify even subtle, genetically determined DSB repair deficiencies known to be associated with increased normal tissue radiosensitivity.
Experimental Design: By enumerating γH2AX-foci in blood lymphocytes and normal tissues (brain, lung, heart, and intestine), the induction and repair of DSBs after irradiation with therapeutic doses (0.1-2 Gy) was investigated in repair-proficient and repair-deficient mouse strains in vivo and blood samples irradiated ex vivo.
Results: γH2AX-foci analysis allowed to verify the different DSB repair deficiencies; even slight impairments caused by single polymorphisms were detected similarly in both blood lymphocytes and solid tissues, indicating that DSB repair measured in lymphocytes is valid for different and complex organs. Moreover, γH2AX-foci analysis of blood samples irradiated ex vivo was found to reflect repair kinetics measured in vivo and, thus, give reliable information about the individual DSB repair capacity.
Conclusions: γH2AX analysis of blood and tissue samples allows to detect even minor genetically defined DSB repair deficiencies, affecting normal tissue radiosensitivity. Future studies will have to evaluate the clinical potential to identify patients more susceptible to radiation toxicities before radiotherapy.
Establishment of Patient-Derived Non–Small Cell Lung Cancer Xenografts as Models for the Identification of Predictive Biomarkers
Authors: Fichtner Iduna , Rolff Jana , Soong Richie , Hoffmann Jens , Hammer Stefanie , Sommer Anette , Becker Michael , Merk Johannes 
Published: October 2008

AbstractPurpose: It was the aim of our study to establish an extensive panel of non-small cell lung cancer (NSCLC) xenograft models useful for the testing of novel compounds and for the identification of biomarkers.Experimental Design: Starting from 102 surgical NSCLC specimens, which were obtained from primarily diagnosed patients with early-stage tumors (T2/T3), 25 transplantable xenografts were established and used for further investigations.Results: Early passages of the NSCLC xenografts revealed a high degree of similarity with the original clinical tumor sample with regard to histology, immunohistochemistry, as well as mutation status. The chemotherapeutic responsiveness of the xenografts resembled the clinical situation in NSCLC with tumor shrinkage obtained with paclitaxel (4 of 25), gemcitabine (3 of 25), and carboplatin (3 of 25) and lower effectiveness of etoposide (1 of 25) and vinorelbine (0 of 11). Twelve of 25 NSCLC xenografts were &gt;50% growth inhibited by the anti-epidermal growth factor receptor (EGFR) antibody cetuximab and 6 of 25 by the EGFR tyrosine kinase inhibitor erlotinib. The response to the anti-EGFR therapies did not correlate with mutations in the EGFR or p53, but there was a correlation of K-ras mutations and erlotinib resistance. Protein analysis revealed a heterogeneous pattern of expression. After treatment with cetuximab, we observed a down-regulation of EGFR in 2 of 6 sensitive xenograft models investigated but never in resistant models.Conclusion: An extensive panel of patient-derived NSCLC xenografts has been established. It provides appropriate models for testing marketed as well as novel drug candidates. Additional expression studies allow the identification of stratification biomarkers for targeted therapies.
Phase I Combination Study of Trabectedin and Doxorubicin in Patients with Soft-Tissue Sarcoma
Authors: Blay Jean-Yves , von Mehren Margaret , Samuels Brian L. , Fanucchi Michael P. , Ray-Coquard Isabelle , Buckley Brigid , Gilles Leen , Lebedinsky Claudia , Elsayed Yusri A. , Le Cesne Axel 
Published: October 2008

Abstract
Purpose: To determine the dose of trabectedin plus doxorubicin with granulocyte colony-stimulating factor support associated with manageable neutropenia and acceptable dose-limiting toxicities (DLT) in patients with recurrent or persistent soft-tissue sarcoma.
Methods: In this phase I, open-label, multicenter trial, patients previously treated with 0-1 prior chemotherapy regimens excluding doxorubicin, an Eastern Cooperative Oncology Group performance status 0-1, and adequate organ function received a 10- to 15-min i.v. infusion of doxorubicin 60 mg/m2 immediately followed by a 3-h i.v. infusion of trabectedin 0.9 to 1.3 mg/m2 on day 1 of a 3-week cycle. Because four of the first six patients experienced DLT-defining neutropenia during cycle 1, all subsequent patients received primary prophylactic granulocyte colony-stimulating factor. The maximum tolerated dose was the highest dose level with six or more patients in which less than one-third of the patients experienced severe neutropenia or DLT. Blood was collected during cycle 1 for pharmacokinetic analyses. Adverse events, tumor response, and survival were assessed.
Results: Patients (N = 41) received a median of six cycles of treatment (range, 2-13). The maximum tolerated dose was trabectedin 1.1 mg/m2 and doxorubicin 60 mg/m2. Common grade 3/4 treatment-emergent adverse events were neutropenia (71%), alanine aminotransferase increase (46%), and thrombocytopenia (37%). Overall, 5 (12%) patients achieved a partial response and 34 (83%) maintained stable disease. Median progression-free survival was 9.2 months. Doxorubicin and trabectedin pharmacokinetics were not altered substantially with concomitant administration.
Conclusion: The combination of doxorubicin 60 mg/m2 followed by trabectedin 1.1 mg/m2 every 21 days is safe and active in patients with soft-tissue sarcoma.
Clinical Determinants of Response to Irinotecan-Based Therapy Derived from Cell Line Models
Authors: Allen Wendy L. , Coyle Vicky M. , Jithesh Puthen V. , Proutski Irina , Stevenson Leanne , Fenning Cathy , Longley Daniel B. , Wilson Richard H. , Gordon Michael , Lenz Heinz-Josef , Johnston Patrick G. 
Published: October 2008

AbstractPurpose: In an attempt to identify genes that are involved in resistance to SN38, the active metabolite of irinotecan (also known as CPT-11), we carried out DNA microarray profiling of matched HCT116 human colon cancer parental cell lines and SN38-resistant cell lines following treatment with SN38 over time.Experimental Design: Data analysis identified a list of genes that were acutely altered in the parental cells following SN38 treatment as well as constitutively altered in the SN38-resistant cells.Results: Independent validation of 20% of these genes by quantitative reverse transcription-PCR revealed a strong correlation with the microarray results: Pearson's correlation was 0.781 (r2 = 0.61, P &lt; 0.000001) for those genes that were acutely altered in the parental setting following SN38 treatment and 0.795 (r2 = 0.63, P &lt; 0.000002) for those genes that were constitutively altered in the SN38-resistant cells. We then assessed the ability of our in vitro-derived gene list to predict clinical response to 5-fluorouracil/irinotecan using pretreatment metastatic biopsies from responding and nonresponding colorectal cancer patients using both unsupervised and supervised approaches. When principal components analysis was used with our in vitro classifier gene list, a good separation between responding and nonresponding patients was obtained, with only one nonresponding and two responding patients separating with the incorrect groups. Supervised class prediction using support vector machines algorithm identified a 16-gene classifier with 75% overall accuracy, 81.8% sensitivity, and 66.6% specificity.Conclusions: These results suggest that in vitro-derived gene lists can be used to predict clinical response to chemotherapy in colorectal cancer.
Von Hippel-Lindau–Coupled and Transcription-Coupled Nucleotide Excision Repair–Dependent Degradation of RNA Polymerase II in Response to Trabectedin
Authors: Aune Gregory J. , Takagi Kazutaka , Sordet Olivier , Guirouilh-Barbat Josée , Antony Smitha , Bohr Vilhelm A. , Pommier Yves 
Published: October 2008

Abstract
Purpose: Ecteinascidin 743 (Et743; trabectedin, Yondelis) has recently been approved in Europe for the treatment of soft tissue sarcomas and is undergoing clinical trials for other solid tumors. Et743 selectively targets cells proficient for TC-NER, which sets it apart from other DNA alkylating agents. In the present study, we examined the effects of Et743 on RNA Pol II.
Experimental Design and Results: We report that Et743 induces the rapid and massive degradation of transcribing Pol II in various cancer cell lines and normal fibroblasts. Pol II degradation was abrogated by the proteasome inhibitor MG132 and was dependent on TC-NER. Cockayne syndrome (CS) cells and xeroderma pigmentosum (XP) cells (XPD, XPA, XPG, and XPF) were defective in Pol II degradation, whereas XPC cells whose defect is limited to global genome NER in nontranscribing regions were proficient for Pol II degradation. Complementation of the CSB and XPD cells restored Pol II degradation. We also show that cells defective for the VHL complex were defective in Pol II degradation and that complementation of those cells restores Pol II degradation. Moreover, VHL deficiency rendered cells resistant to Et743-induced cell death, a similar effect to that of TC-NER deficiency.
Conclusion: These results suggest that both TC-NER–induced and VHL-mediated Pol II degradation play a role in cell killing by Et743.
Cyclin D1–Specific Cytotoxic T Lymphocytes Are Present in the Repertoire of Cancer Patients: Implications for Cancer Immunotherapy
Authors: Kondo Eisei , Maecker Britta , Weihrauch Martin R. , Wickenhauser Claudia , Zeng WanYong , Nadler Lee M. , Schultze Joachim L. , von Bergwelt-Baildon Michael S. 
Published: October 2008

AbstractPurpose: Cyclin D1, a key cell cycle regulator, is overexpressed in multiple types of cancer. Such tumor-associated genes may be useful targets for cancer immunotherapy. Nevertheless, it had previously been suggested that efficient T cells recognizing cyclin D1-derived epitopes are absent from the repertoire because of thymic deletion. We attempted to induce autologous CTL from healthy donors and patients with cyclin D1-overexpressing tumors using a highly efficient T-cell expansion system based on CD40-activated B cells as antigen-presenting cells.Experimental Design: Cyclin D1-derived, HLA-A*0201–restricted epitopes were predicted by multiple computer algorithms, screened in HLA-A2-binding assays, and used for T-cell stimulation. The generated CTL lines and clones were analyzed by IFN-γ enzyme-linked immunosorbent spot assay or cytolysis assay.Results: After screening, at least two naturally processed and presented HLA-A*0201–binding cyclin D1 epitopes were identified. CTL specific for these epitopes could be successfully generated from HLA-A2+ donors. T cells efficiently recognized target cells pulsed with the cognate peptide and cyclin D1-expressing tumor cell lines in an HLA-A*0201–restricted manner. More importantly, HLA-A*0201–matched, primary cyclin D1+ tumor cells were efficiently recognized by cyclin D1-specific CTL. These CTL could be generated from patients with mantle cell lymphoma and cyclin D1+ colon cancer.Conclusions: These results underscore that cyclin D1 needs to be considered as a target for broad-based antitumor immunotherapy.