ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Breast Cancer Special Feature  (19)
  • Surface Chemistry  (14)
  • National Academy of Sciences  (33)
  • Copernicus
  • 2010-2014  (33)
  • 1995-1999
  • 1980-1984
  • 1945-1949
  • 1925-1929
  • 1
    facet.materialart.
    Unbekannt
    Disruption of bone morphogenetic protein receptor 2 (BMPR2) in mammary tumors promotes metastases through cell autonomous and paracrine mediators [Cell Biology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily of signaling molecules. BMPs can elicit a wide range of effects in many cell types and have previously been shown to induce growth inhibition in carcinoma cells as well as normal epithelia. Recently, it has been demonstrated that BMP4 and BMP7 are overexpressed in human breast cancers and may have tumor suppressive and promoting effects. We sought to determine whether disruption of the BMP receptor 2 (BMPR2) would alter mammary tumor progression in mice that express the Polyoma middle T antigen. Mice expressing Polyoma middle T antigen under the mouse mammary tumor virus promoter were combined with mice that have doxycycline-inducible expression of a dominant-negative (DN) BMPR2. We did not observe any differences in tumor latency. However, mice expressing the BMPR2-DN had a fivefold increase in lung metastases. We characterized several cell autonomous changes and found that BMPR2-DN–expressing tumor cells had higher rates of proliferation. We also identified unique changes in inflammatory cells and secreted chemokines/cytokines that accompanied BMPR2-DN–expressing tumors. By immunohistochemistry, it was found that BMPR2-DN primary tumors and metastases had an altered reactive stroma, indicating specific changes in the tumor microenvironment. Among the changes we discovered were increased myeloid derived suppressor cells and the chemokine CCL9. BMP was shown to directly regulate CCL9 expression. We conclude that BMPR2 has tumor-suppressive function in mammary epithelia and microenvironment and that disruption can accelerate mammary carcinoma metastases.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 2
    facet.materialart.
    Unbekannt
    Homeobox B9 induces epithelial-to-mesenchymal transition-associated radioresistance by accelerating DNA damage responses [Cell Biology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Homeobox 9 (HOXB9), a nontransforming transcription factor overexpressed in breast cancer, alters tumor cell fate and promotes tumor progression and metastasis. Here we show that HOXB9 confers resistance to ionizing radiation by promoting DNA damage response. In nonirradiated cells, HOXB9 induces spontaneous DNA damage, phosphorylated histone 2AX and p53 binding protein 1 foci, and increases baseline ataxia telangiectasia mutated (ATM) phosphorylation. Upon ionizing radiation, ATM is hyperactivated in HOXB9-expressing cells during the early stages of the double-stranded DNA break (DSB) response, accelerating accumulation of phosphorylated histone 2AX, mediator of DNA-damage checkpoint 1, and p53 binding protein 1, at DSBs and enhances DSB repair. The effect of HOXB9 on the response to ionizing radiation requires the baseline ATM activity before irradiation and epithelial-to-mesenchymal transition induced by TGF-β, a HOXB9 transcriptional target. Our results reveal the impact of a HOXB9–TGF-β–ATM axis on checkpoint activation and DNA repair, suggesting that TGF-β may be a key factor that links tumor microenvironment, tumor cell fate, DNA damage response, and radioresistance in a subset of HOXB9-overexpressing breast tumors.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 3
    facet.materialart.
    Unbekannt
    Leukocyte composition of human breast cancer [Immunology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Retrospective clinical studies have used immune-based biomarkers, alone or in combination, to predict survival outcomes for women with breast cancer (BC); however, the limitations inherent to immunohistochemical analyses prevent comprehensive descriptions of leukocytic infiltrates, as well as evaluation of the functional state of leukocytes in BC stroma. To more fully evaluate this complexity, and to gain insight into immune responses after chemotherapy (CTX), we prospectively evaluated tumor and nonadjacent normal breast tissue from women with BC, who either had or had not received neoadjuvant CTX before surgery. Tissues were evaluated by polychromatic flow cytometry in combination with confocal immunofluorescence and immunohistochemical analysis of tissue sections. These studies revealed that activated T lymphocytes predominate in tumor tissue, whereas myeloid lineage cells are more prominant in “normal” breast tissue. Notably, residual tumors from an unselected group of BC patients treated with neoadjuvant CTX contained increased percentages of infiltrating myeloid cells, accompanied by an increased CD8/CD4 T-cell ratio and higher numbers of granzyme B-expressing cells, compared with tumors removed from patients treated primarily by surgery alone. These data provide an initial evaluation of differences in the immune microenvironment of BC compared with nonadjacent normal tissue and reveal the degree to which CTX may alter the complexity and presence of selective subsets of immune cells in tumors previously treated in the neoadjuvant setting.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 4
    facet.materialart.
    Unbekannt
    Comparative oncogenomics identifies breast tumors enriched in functional tumor-initiating cells [Genetics] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: The claudin-low subtype is a recently identified rare molecular subtype of human breast cancer that expresses low levels of tight and adherens junction genes and shows high expression of epithelial-to-mesenchymal transition (EMT) genes. These tumors are enriched in gene expression signatures derived from human tumor-initiating cells (TICs) and human mammary stem cells. Through cross-species analysis, we discovered mouse mammary tumors that have similar gene expression characteristics as human claudin-low tumors and were also enriched for the human TIC signature. Such claudin-low tumors were similarly rare but came from a number of distinct mouse models, including the p53 null transplant model. Here we present a molecular characterization of 50 p53 null mammary tumors compared with other mouse models and human breast tumor subtypes. Similar to human tumors, the murine p53 null tumors fell into multiple molecular subtypes, including two basal-like, a luminal, a claudin-low, and a subtype unique to this model. The claudin-low tumors also showed high gene expression of EMT inducers, low expression of the miR-200 family, and low to absent expression of both claudin 3 and E-cadherin. These murine subtypes also contained distinct genomic DNA copy number changes, some of which are similarly altered in their cognate human subtype counterpart. Finally, limiting dilution transplantation revealed that p53 null claudin-low tumors are highly enriched for TICs compared with the more common adenocarcinomas arising in the same model, thus providing a unique preclinical mouse model to investigate the therapeutic response of TICs.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 5
    facet.materialart.
    Unbekannt
    Maintenance of hormone responsiveness in luminal breast cancers by suppression of Notch [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Luminal breast cancers express estrogen (ER) and/or progesterone (PR) receptors and respond to hormone therapies. Basal-like “triple negative” cancers lack steroid receptors but are cytokeratin (CK) 5-positive and require chemotherapy. Here we show that more than half of primary ER+PR+ breast cancers contain an ER−PR−CK5+ “luminobasal” subpopulation exceeding 1% of cells. Starting from ER+PR+ luminal cell lines, we generated lines with varying luminal to luminobasal cell ratios and studied their molecular and biological properties. In luminal disease, luminobasal cells expand in response to antiestrogen or estrogen withdrawal therapies. The phenotype and gene signature of the hormone-resistant cells matches that of clinical triple negative basal-like and claudin-low disease. Luminobasal cell expansion in response to hormone therapies is regulated by Notch1 signaling and can be blocked by γ-secretase inhibitors. Our data establish a previously unrecognized plasticity of ER+PR+ luminal breast cancers that, without genetic manipulation, mobilizes outgrowth of hormone-resistant basal-like disease in response to treatment. This undesirable outcome can be prevented by combining endocrine therapies with Notch inhibition.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 6
    facet.materialart.
    Unbekannt
    The HOXB7 protein renders breast cancer cells resistant to tamoxifen through activation of the EGFR pathway [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Multiple factors including long-term treatment with tamoxifen are involved in the development of selective estrogen receptor (ER) modulator resistance in ERα-positive breast cancer. Many underlying molecular events that confer resistance are known but a unifying theme is yet to be revealed. In this report, we provide evidence that HOXB7 overexpression renders MCF-7 cells resistant to tamoxifen via cross-talk between receptor tyrosine kinases and ERα signaling. HOXB7 is an ERα-responsive gene. Extended treatment of MCF-7 cells with tamoxifen resulted in progressively increasing levels of HOXB7 expression, along with EGFR and EGFR ligands. Up-regulation of EGFR occurs through direct binding of HOXB7 to the EGFR promoter, enhancing transcriptional activity. Finally, higher expression levels of HOXB7 in the tumor significantly correlated with poorer disease-free survival in ERα-positive patients with breast cancer on adjuvant tamoxifen monotherapy. These studies suggest that HOXB7 acts as a key regulator, orchestrating a major group of target molecules in the oncogenic hierarchy. Functional antagonism of HOXB7 could circumvent tamoxifen resistance.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 7
    facet.materialart.
    Unbekannt
    Cyclin-dependent kinase subunit (Cks) 1 or Cks2 overexpression overrides the DNA damage response barrier triggered by activated oncoproteins [Cell Biology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Cyclin-dependent kinase subunit (Cks) proteins are small cyclin-dependent kinase-interacting proteins that are frequently overexpressed in breast cancer, as well as in a broad spectrum of other human malignancies. However, the mechanistic link between Cks protein overexpression and oncogenesis is still unknown. In this work, we show that overexpression of Cks1 or Cks2 in human mammary epithelial and breast cancer-derived cells, as well as in other cell types, leads to override of the intra–S-phase checkpoint that blocks DNA replication in response to replication stress. Specifically, binding of Cks1 or Cks2 to cyclin-dependent kinase 2 confers partial resistance to the effects of inhibitory tyrosine phosphorylation mediated by the intra–S-phase checkpoint, allowing cells to continue replicating DNA even under conditions of replicative stress. Because many activated oncoproteins trigger a DNA damage checkpoint response, which serves as a barrier to proliferation and clonal expansion, Cks protein overexpression likely constitutes one mechanism whereby premalignant cells can circumvent this DNA damage response barrier, conferring a proliferative advantage under stress conditions, and therefore contributing to tumor development.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 8
    facet.materialart.
    Unbekannt
    Mechanistic insight into Myc stabilization in breast cancer involving aberrant Axin1 expression [Cell Biology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: High expression of the oncoprotein Myc has been linked to poor outcome in human tumors. Although MYC gene amplification and translocations have been observed, this can explain Myc overexpression in only a subset of human tumors. Myc expression is in part controlled by its protein stability, which can be regulated by phosphorylation at threonine 58 (T58) and serine 62 (S62). We now report that Myc protein stability is increased in a number of breast cancer cell lines and this correlates with increased phosphorylation at S62 and decreased phosphorylation at T58. Moreover, we find this same shift in phosphorylation in primary breast cancers. The signaling cascade that controls phosphorylation at T58 and S62 is coordinated by the scaffold protein Axin1. We therefore examined Axin1 in breast cancer and report decreased AXIN1 expression and a shift in the ratio of expression of two naturally occurring AXIN1 splice variants. We demonstrate that this contributes to increased Myc protein stability, altered phosphorylation at S62 and T58, and increased oncogenic activity of Myc in breast cancer. Thus, our results reveal an important mode of Myc activation in human breast cancer and a mechanism contributing to Myc deregulation involving unique insight into inactivation of the Axin1 tumor suppressor in breast cancer.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 9
    facet.materialart.
    Unbekannt
    Sensitization of BCL-2-expressing breast tumors to chemotherapy by the BH3 mimetic ABT-737 [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Overexpression of the prosurvival protein BCL-2 is common in breast cancer. Here we have explored its role as a potential therapeutic target in this disease. BCL-2, its anti-apoptotic relatives MCL-1 and BCL-XL, and the proapoptotic BH3-only ligand BIM were found to be coexpressed at relatively high levels in a substantial proportion of heterogeneous breast tumors, including clinically aggressive basal-like cancers. To determine whether the BH3 mimetic ABT-737 that neutralizes BCL-2, BCL-XL, and BCL-W had potential efficacy in targeting BCL-2–expressing basal-like triple-negative tumors, we generated a panel of primary breast tumor xenografts in immunocompromised mice and treated recipients with either ABT-737, docetaxel, or a combination. Tumor response and overall survival were significantly improved by combination therapy, but only for tumor xenografts that expressed elevated levels of BCL-2. Treatment with ABT-737 alone was ineffective, suggesting that ABT-737 sensitizes the tumor cells to docetaxel. Combination therapy was accompanied by a marked increase in apoptosis and dissociation of BIM from BCL-2. Notably, BH3 mimetics also appeared effective in BCL-2–expressing xenograft lines that harbored p53 mutations. Our findings provide in vivo evidence that BH3 mimetics can be used to sensitize primary breast tumors to chemotherapy and further suggest that elevated BCL-2 expression constitutes a predictive response marker in breast cancer.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 10
    facet.materialart.
    Unbekannt
    Integrated molecular profiles of invasive breast tumors and ductal carcinoma in situ (DCIS) reveal differential vascular and interleukin signaling [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: We use an integrated approach to understand breast cancer heterogeneity by modeling mRNA, copy number alterations, microRNAs, and methylation in a pathway context utilizing the pathway recognition algorithm using data integration on genomic models (PARADIGM). We demonstrate that combining mRNA expression and DNA copy number classified the patients in groups that provide the best predictive value with respect to prognosis and identified key molecular and stromal signatures. A chronic inflammatory signature, which promotes the development and/or progression of various epithelial tumors, is uniformly present in all breast cancers. We further demonstrate that within the adaptive immune lineage, the strongest predictor of good outcome is the acquisition of a gene signature that favors a high T-helper 1 (Th1)/cytotoxic T-lymphocyte response at the expense of Th2-driven humoral immunity. Patients who have breast cancer with a basal HER2-negative molecular profile (PDGM2) are characterized by high expression of protumorigenic Th2/humoral-related genes (24–38%) and a low Th1/Th2 ratio. The luminal molecular subtypes are again differentiated by low or high FOXM1 and ERBB4 signaling. We show that the interleukin signaling profiles observed in invasive cancers are absent or weakly expressed in healthy tissue but already prominent in ductal carcinoma in situ, together with ECM and cell-cell adhesion regulating pathways. The most prominent difference between low and high mammographic density in healthy breast tissue by PARADIGM was that of STAT4 signaling. In conclusion, by means of a pathway-based modeling methodology (PARADIGM) integrating different layers of molecular data from whole-tumor samples, we demonstrate that we can stratify immune signatures that predict patient survival.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 11
    facet.materialart.
    Unbekannt
    Mammary epithelial-specific disruption of c-Src impairs cell cycle progression and tumorigenesis [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: The tyrosine kinase c-Src is activated in a large proportion of breast cancers, in which it is thought to play a key role in promoting the malignant phenotype. c-Src activity is also elevated in transgenic mouse models of breast cancer, including the widely used polyomavirus middle-T antigen (PyVmT) model, which provides an opportunity to study the importance of c-Src in mammary tumorigenesis. However, germline c-Src deletion in mammary epithelial and stromal compartments complicates the interpretation of in vivo tumorigenesis studies as a result of severe defects in mammary gland development. We have therefore engineered a mouse strain in which deletion of c-Src can be targeted to the mammary epithelium. We demonstrate that mammary epithelial disruption of c-Src impairs proliferation and tumor progression driven by PyVmT in vivo. Whereas related kinases substitute for c-Src in PyVmT signaling, c-Src ablation impairs cell cycle progression with decreased cyclin expression and elevated expression of cyclin-dependent kinase inhibitors. Our data indicate that c-Src has essential and unique functions in proliferation and tumor progression in this mouse model that may also be important in certain contexts in some human breast cancers.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 12
    facet.materialart.
    Unbekannt
    Subtype and pathway specific responses to anticancer compounds in breast cancer [Systems Biology] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Breast cancers are comprised of molecularly distinct subtypes that may respond differently to pathway-targeted therapies now under development. Collections of breast cancer cell lines mirror many of the molecular subtypes and pathways found in tumors, suggesting that treatment of cell lines with candidate therapeutic compounds can guide identification of associations between molecular subtypes, pathways, and drug response. In a test of 77 therapeutic compounds, nearly all drugs showed differential responses across these cell lines, and approximately one third showed subtype-, pathway-, and/or genomic aberration-specific responses. These observations suggest mechanisms of response and resistance and may inform efforts to develop molecular assays that predict clinical response.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 13
    facet.materialart.
    Unbekannt
    Impact of surface chemistry [Perspective] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 14
    facet.materialart.
    Unbekannt
    Density functional theory in surface chemistry and catalysis [Perspective] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Recent advances in the understanding of reactivity trends for chemistry at transition-metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. The current status of the field is discussed with an emphasis on the role of coupling theory and experiment and future challenges.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 15
    facet.materialart.
    Unbekannt
    Surface chemistry: Key to control and advance myriad technologies [Introductions] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: This special issue on surface chemistry is introduced with a brief history of the field, a summary of the importance of surface chemistry in technological applications, a brief overview of some of the most important recent developments in this field, and a look forward to some of its most exciting future directions. This collection of invited articles is intended to provide a snapshot of current developments in the field, exemplify the state of the art in fundamental research in surface chemistry, and highlight some possibilities in the future. Here, we show how those articles fit together in the bigger picture of this field.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 16
    facet.materialart.
    Unbekannt
    Imprinting self-assembled patterns of lines at a semiconductor surface, using heat, light, or electrons [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: The fabrication of nano devices at surfaces makes conflicting demands of mobility for self-assembly (SA) and immobility for permanence. The solution proposed in earlier work from this laboratory involved pattern formation in physisorbed molecules by SA, followed by localized reaction to chemically imprint the pattern substantially unchanged, a procedure we termed molecular-scale imprinting (MSI). Here, as proof of generality we extended this procedure, previously applied to imprinting circles on Si(111)-7 × 7, to SA lines of 1-chloropentane (CP) on Si(100)-2 × 1. The physisorbed lines consisted of pairs of CP that grew perpendicular to the Si dimer rows, as shown by scanning tunneling microscopy and ab initio theory. Chemical reaction of these lines with the surface was triggered in separate experiments by three different modes of energization: heat, electrons, or light. In all cases the CP molecules underwent MSI with a Si atom beneath so that the physisorbed lines of CP pairs were imprinted as chemisorbed lines of Cl pairs.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 17
    facet.materialart.
    Unbekannt
    Simulation of surface processes [Reviews] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Computer simulations of surface processes can reveal unexpected insight regarding atomic-scale structure and transitions. Here, the strengths and weaknesses of some commonly used approaches are reviewed as well as promising avenues for improvements. The electronic degrees of freedom are usually described by gradient-dependent functionals within Kohn–Sham density functional theory. Although this level of theory has been remarkably successful in numerous studies, several important problems require a more accurate theoretical description. It is important to develop new tools to make it possible to study, for example, localized defect states and band gaps in large and complex systems. Preliminary results presented here show that orbital density-dependent functionals provide a promising avenue, but they require the development of new numerical methods and substantial changes to codes designed for Kohn–Sham density functional theory. The nuclear degrees of freedom can, in most cases, be described by the classical equations of motion; however, they still pose a significant challenge, because the time scale of interesting transitions, which typically involve substantial free energy barriers, is much longer than the time scale of vibrations—often 10 orders of magnitude. Therefore, simulation of diffusion, structural annealing, and chemical reactions cannot be achieved with direct simulation of the classical dynamics. Alternative approaches are needed. One such approach is transition state theory as implemented in the adaptive kinetic Monte Carlo algorithm, which, thus far, has relied on the harmonic approximation but could be extended and made applicable to systems with rougher energy landscape and transitions through quantum mechanical tunneling.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 18
    facet.materialart.
    Unbekannt
    Tuning the reactivity of semiconductor surfaces by functionalization with amines of different basicity [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Surface functionalization of semiconductors has been the backbone of the newest developments in microelectronics, energy conversion, sensing device design, and many other fields of science and technology. Over a decade ago, the notion of viewing the surface itself as a chemical reagent in surface reactions was introduced, and adding a variety of new functionalities to the semiconductor surface has become a target of research for many groups. The electronic effects on the substrate have been considered as an important consequence of chemical modification. In this work, we shift the focus to the electronic properties of the functional groups attached to the surface and their role on subsequent reactivity. We investigate surface functionalization of clean Si(100)-2 × 1 and Ge(100)-2 × 1 surfaces with amines as a way to modify their reactivity and to fine tune this reactivity by considering the basicity of the attached functionality. The reactivity of silicon and germanium surfaces modified with ethylamine (CH3CH2NH2) and aniline (C6H5NH2) is predicted using density functional theory calculations of proton attachment to the nitrogen of the adsorbed amine to differ with respect to a nucleophilic attack of the surface species. These predictions are then tested using a model metalorganic reagent, tetrakis(dimethylamido)titanium (((CH3)2N)4Ti, TDMAT), which undergoes a transamination reaction with sufficiently nucleophilic amines, and the reactivity tests confirm trends consistent with predicted basicities. The identity of the underlying semiconductor surface has a profound effect on the outcome of this reaction, and results comparing silicon and germanium are discussed.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 19
    facet.materialart.
    Unbekannt
    Electronic decoupling of a cyclophane from a metal surface [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Electronic self-decoupling of an organic chromophore from a metal substrate is achieved using a naphtalenediimide cyclophane to spatially separate one chromophore unit of the cyclophane from the substrate. Observations of vibronic excitations in scanning tunneling spectra demonstrate the success of this approach. These excitations contribute a significant part of the tunneling current and give rise to clear structure in scanning tunneling microscope images. We suggest that this approach may be extended to implement molecular functions at metal surfaces.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 20
    facet.materialart.
    Unbekannt
    Planar oxide supported rhodium nanoparticles as model catalysts [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: C2H4/CO/H2 reaction is investigated on Rh/SiO2 model catalyst surfaces. Kinetic reactivity and infrared spectroscopic measurements are investigated as a function of Rh particle size under near atmospheric reaction conditions. Results show that propionaldehyde turnover frequency (TOF) (CO insertion pathway) exhibits a maximum activity near 〈dp〉 = 2.5 nm. Polarization modulation infrared reflection absorption spectroscopy under CO and reaction (C2H4/CO/H2) conditions indicate the presence of Rh carbonyl species (Rh(CO)2, Rh(CO)H) on small Rh particles, whereas larger particles appear resistant to dispersion and carbonyl formation. Combined these observations suggest the observed particle size dependence for propionaldehyde production via CO insertion is driven by two factors: (i) an increase in propionaldehyde formation on undercoordinated Rh sites and (ii) creation of carbonyl hydride species (Rh(CO)H)) on smaller Rh particles, whose presence correlates with the lower activity for propionaldehyde formation for 〈dp〉 
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 21
    facet.materialart.
    Unbekannt
    Artificial atoms on semiconductor surfaces [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Semiconductor nanocrystals are called artificial atoms because of their atom-like discrete electronic structure resulting from quantum confinement. Artificial atoms can also be assembled into artificial molecules or solids, thus, extending the toolbox for material design. We address the interaction of artificial atoms with bulk semiconductor surfaces. These interfaces are model systems for understanding the coupling between localized and delocalized electronic structures. In many perceived applications, such as nanoelectronics, optoelectronics, and solar energy conversion, interfacing semiconductor nanocrystals to bulk materials is a key ingredient. Here, we apply the well established theories of chemisorption and interfacial electron transfer as conceptual frameworks for understanding the adsorption of semiconductor nanocrystals on surfaces, paying particular attention to instances when the nonadiabatic Marcus picture breaks down. We illustrate these issues using recent examples from our laboratory.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 22
    facet.materialart.
    Unbekannt
    Hydrogenation of N over Fe{111} [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Over the past five decades, ultra high vacuum (uhv) techniques applied to well-defined single-crystal samples (the “surface science paradigm”) have transformed our understanding of fundamental surface chemistry. To translate this success to the world of realistic heterogeneous catalysis, however, requires one seriously to address the fact that real heterogeneous catalysts usually operate under near-ambient or higher pressures. Nevertheless, the surface science paradigm can undoubtedly provide crucial insights into catalytic processes, so long as care is exercised in the design of experiments. Forging a secure link between two radically different pressure regimes is the major challenge, which we illustrate here with reference to the vitally important ammonia synthesis reaction, achieved industrially only under extremely high pressure.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 23
    facet.materialart.
    Unbekannt
    Comparative surface dynamics of amorphous and semicrystalline polymer films [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: The surface dynamics of amorphous and semicrystalline polymer films have been measured using helium atom scattering. Time-of-flight data were collected to resolve the elastic and inelastic scattering components in the diffuse scattering of neutral helium atoms from the surface of a thin poly(ethylene terephthalate) film. Debye–Waller attenuation was observed for both the amorphous and semicrystalline phases of the polymer by recording the decay of elastically scattered helium atoms with increasing surface temperature. Thermal attenuation measurements in the specular scattering geometry yielded perpendicular mean-square displacements of 2.7•10-4 Å2 K-1 and 3.1•10-4 Å2 K-1 for the amorphous and semicrystalline surfaces, respectively. The semicrystalline surface was consistently ∼15% softer than the amorphous across a variety of perpendicular momentum transfers. The Debye–Waller factors were also measured at off-specular angles to characterize the parallel mean-square displacements, which were found to increase by an order of magnitude over the perpendicular mean-square displacements for both surfaces. In contrast to the perpendicular motion, the semicrystalline state was ∼25% stiffer than the amorphous phase in the surface plane. These results were uniquely accessed through low-energy neutral helium atom scattering due to the highly surface-sensitive and nonperturbative nature of these interactions. The goal of tailoring the chemical and physical properties of complex advanced materials requires an improved understanding of interfacial dynamics, information that is obtainable through atomic beam scattering methods.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 24
    facet.materialart.
    Unbekannt
    Self-assembly of metal nanostructures on binary alloy surfaces [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Deposition of metals on binary alloy surfaces offers new possibilities for guiding the formation of functional metal nanostructures. This idea is explored with scanning tunneling microscopy studies and atomistic-level analysis and modeling of nonequilibrium island formation. For Au/NiAl(110), complex monolayer structures are found and compared with the simple fcc(110) bilayer structure recently observed for Ag/NiAl(110). We also consider a more complex codeposition system, (Ni + Al)/NiAl(110), which offers the opportunity for fundamental studies of self-growth of alloys including deviations for equilibrium ordering. A general multisite lattice-gas model framework enables analysis of structure selection and morphological evolution in these systems.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 25
    facet.materialart.
    Unbekannt
    Time-dependent electron phenomena at surfaces [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Femtosecond and subfemtosecond time scales typically rule electron dynamics at metal surfaces. Recent advance in experimental techniques permits now remarkable precision in the description of these processes. In particular, shorter time scales, smaller system sizes, and spin-dependent effects are current targets of interest. In this article, we use state-of-the-art theoretical methods to analyze these refined features of electron dynamics. We show that the screening of localized charges at metal surfaces is created locally in the attosecond time scale, while collective excitations transfer the perturbation to larger distances in longer time scales. We predict that the elastic width of the resonance in excited alkali adsorbates on ferromagnetic surfaces can depend on spin orientation in a counterintuitive way. Finally, we quantitatively evaluate the electron–electron and electron–phonon contributions to the electronic excited states widths in ultrathin metal layers. We conclude that confinement and spin effects are key factors in the behavior of electron dynamics at metal surfaces.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 26
    facet.materialart.
    Unbekannt
    Surface functionalization of thin-film diamond for highly stable and selective biological interfaces [Chemistry] (2011)
    National Academy of Sciences
    Details
    Publikationsdatum: 2011-01-19
    Beschreibung: Carbon is an extremely versatile family of materials with a wide range of mechanical, optical, and mechanical properties, but many similarities in surface chemistry. As one of the most chemically stable materials known, carbon provides an outstanding platform for the development of highly tunable molecular and biomolecular interfaces. Photochemical grafting of alkenes has emerged as an attractive method for functionalizing surfaces of diamond, but many aspects of the surface chemistry and impact on biological recognition processes remain unexplored. Here we report investigations of the interaction of functionalized diamond surfaces with proteins and biological cells using X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and fluorescence methods. XPS data show that functionalization of diamond with short ethylene glycol oligomers reduces the nonspecific binding of fibrinogen below the detection limit of XPS, estimated as 〉 97% reduction over H-terminated diamond. Measurements of different forms of diamond with different roughness are used to explore the influence of roughness on nonspecific binding onto H-terminated and ethylene glycol (EG)-terminated surfaces. Finally, we use XPS to characterize the chemical stability of Escherichia coli K12 antibodies on the surfaces of diamond and amine-functionalized glass. Our results show that antibody-modified diamond surfaces exhibit increased stability in XPS and that this is accompanied by retention of biological activity in cell-capture measurements. Our results demonstrate that surface chemistry on diamond and other carbon-based materials provides an excellent platform for biomolecular interfaces with high stability and high selectivity.
    Schlagwort(e): Surface Chemistry
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 27
    facet.materialart.
    Unbekannt
    Progress in breast cancer research [Introductions] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Breast cancer is a heterogeneous disease composed of multiple different subtypes with distinct molecular features and clinical behavior (1). Gene expression profiling studies have identified at least four major subtypes classified as luminal A, luminal B, HER2+, and basal-like (2). Genome-wide expression profiling of breast tumors has not entered routine clinical practice, but molecular classification according to immunohistochemical assessment of estrogen and progesterone receptors and of HER2 is the basis of individualized therapy that has been guiding the clinical management of patients with breast cancer for the past two decades. Indeed, the first molecular target for cancer therapy was the...
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 28
    facet.materialart.
    Unbekannt
    Transducin-like enhancer protein 1 mediates estrogen receptor binding and transcriptional activity in breast cancer cells [Applied Biological Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Estrogen receptor (ER) binds to distal enhancers within the genome and requires additional factors, such as the Forkhead protein FoxA1, for mediating chromatin interactions. We now show that the human Groucho protein, Transducin-like enhancer protein 1 (TLE1), positively assists some ER-chromatin interactions, a role that is distinct from its general role as a transcriptional repressor. We show that specific silencing of TLE1 inhibits the ability of ER to bind to a subset of ER binding sites within the genome, a phenomenon that results in perturbations in phospho-RNA Pol II recruitment. Furthermore, TLE1 is essential for effective ER-mediated cell division. We have discovered a distinct role for TLE1, as a necessary transcriptional component of the ER complex, where it facilitates ER-chromatin interactions.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 29
    facet.materialart.
    Unbekannt
    Feedback upregulation of HER3 (ErbB3) expression and activity attenuates antitumor effect of PI3K inhibitors [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: We examined the effects of an inhibitor of PI3K, XL147, against human breast cancer cell lines with constitutive PI3K activation. Treatment with XL147 resulted in dose-dependent inhibition of cell growth and levels of pAKT and pS6, signal transducers in the PI3K/AKT/TOR pathway. In HER2-overexpressing cells, inhibition of PI3K was followed by up-regulation of expression and phosphorylation of multiple receptor tyrosine kinases, including HER3. Knockdown of FoxO1 and FoxO3a transcription factors suppressed the induction of HER3, InsR, IGF1R, and FGFR2 mRNAs upon inhibition of PI3K. In HER2+ cells, knockdown of HER3 with siRNA or cotreatment with the HER2 inhibitors trastuzumab or lapatinib enhanced XL147-induced cell death and inhibition of pAKT and pS6. Trastuzumab and lapatinib each synergized with XL147 for inhibition of pAKT and growth of established BT474 xenografts. These data suggest that PI3K antagonists will inhibit AKT and relieve suppression of receptor tyrosine kinase expression and their activity. Relief of this feedback limits the sustained inhibition of the PI3K/AKT pathway and attenuates the response to these agents. As a result, PI3K pathway inhibitors may have limited clinical activity overall if used as single agents. In patients with HER2-overexpressing breast cancer, PI3K inhibitors should be used in combination with HER2/HER3 antagonists.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 30
    facet.materialart.
    Unbekannt
    Genome-wide functional screen identifies a compendium of genes affecting sensitivity to tamoxifen [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Therapies that target estrogen signaling have made a very considerable contribution to reducing mortality from breast cancer. However, resistance to tamoxifen remains a major clinical problem. Here we have used a genome-wide functional profiling approach to identify multiple genes that confer resistance or sensitivity to tamoxifen. Combining whole-genome shRNA screening with massively parallel sequencing, we have profiled the impact of more than 56,670 RNA interference reagents targeting 16,487 genes on the cellular response to tamoxifen. This screen, along with subsequent validation experiments, identifies a compendium of genes whose silencing causes tamoxifen resistance (including BAP1, CLPP, GPRC5D, NAE1, NF1, NIPBL, NSD1, RAD21, RARG, SMC3, and UBA3) and also a set of genes whose silencing causes sensitivity to this endocrine agent (C10orf72, C15orf55/NUT, EDF1, ING5, KRAS, NOC3L, PPP1R15B, RRAS2, TMPRSS2, and TPM4). Multiple individual genes, including NF1, a regulator of RAS signaling, also correlate with clinical outcome after tamoxifen treatment.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 31
    facet.materialart.
    Unbekannt
    Antiangiogenic agents increase breast cancer stem cells via the generation of tumor hypoxia [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Antiangiogenic therapy has been thought to hold significant potential for the treatment of cancer. However, the efficacy of such treatments, especially in breast cancer patients, has been called into question, as recent clinical trials reveal only limited effectiveness of antiangiogenic agents in prolonging patient survival. New research using preclinical models further suggests that antiangiogenic agents actually increase invasive and metastatic properties of breast cancer cells. We demonstrate that by generating intratumoral hypoxia in human breast cancer xenografts, the antiangiogenic agents sunitinib and bevacizumab increase the population of cancer stem cells. In vitro studies revealed that hypoxia-driven stem/progenitor cell enrichment is primarily mediated by hypoxia-inducible factor 1α. We further show that the Akt/β-catenin cancer stem cell regulatory pathway is activated in breast cancer cells under hypoxic conditions in vitro and in sunitinib-treated mouse xenografts. These studies demonstrate that hypoxia-driven cancer stem cell stimulation limits the effectiveness of antiangiogenic agents, and suggest that to improve patient outcome, these agents might have to be combined with cancer stem cell-targeting drugs.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 32
    facet.materialart.
    Unbekannt
    Defining the cellular precursors to human breast cancer [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Human breast cancers are broadly classified based on their gene-expression profiles into luminal- and basal-type tumors. These two major tumor subtypes express markers corresponding to the major differentiation states of epithelial cells in the breast: luminal (EpCAM+) and basal/myoepithelial (CD10+). However, there are also rare types of breast cancers, such as metaplastic carcinomas, where tumor cells exhibit features of alternate cell types that no longer resemble breast epithelium. Until now, it has been difficult to identify the cell type(s) in the human breast that gives rise to these various forms of breast cancer. Here we report that transformation of EpCAM+ epithelial cells results in the formation of common forms of human breast cancer, including estrogen receptor-positive and estrogen receptor-negative tumors with luminal and basal-like characteristics, respectively, whereas transformation of CD10+ cells results in the development of rare metaplastic tumors reminiscent of the claudin-low subtype. We also demonstrate the existence of CD10+ breast cells with metaplastic traits that can give rise to skin and epidermal tissues. Furthermore, we show that the development of metaplastic breast cancer is attributable, in part, to the transformation of these metaplastic breast epithelial cells. These findings identify normal cellular precursors to human breast cancers and reveal the existence of a population of cells with epidermal progenitor activity within adult human breast tissues.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 33
    facet.materialart.
    Unbekannt
    Altered antisense-to-sense transcript ratios in breast cancer [Medical Sciences] (2012)
    National Academy of Sciences
    Details
    Publikationsdatum: 2012-02-22
    Beschreibung: Transcriptome profiling studies suggest that a large fraction of the genome is transcribed and many transcripts function independent of their protein coding potential. The relevance of noncoding RNAs (ncRNAs) in normal physiological processes and in tumorigenesis is increasingly recognized. Here, we describe consistent and significant differences in the distribution of sense and antisense transcripts between normal and neoplastic breast tissues. Many of the differentially expressed antisense transcripts likely represent long ncRNAs. A subset of genes that mainly generate antisense transcripts in normal but not cancer cells is involved in essential metabolic processes. These findings suggest fundamental differences in global RNA regulation between normal and cancer cells that might play a role in tumorigenesis.
    Schlagwort(e): Breast Cancer Special Feature
    Print ISSN: 0027-8424
    Digitale ISSN: 1091-6490
    Thema: Biologie , Medizin , Allgemeine Naturwissenschaft
    Publiziert von National Academy of Sciences
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...