Refine
Year of publication
Document Type
Way of publication
- Open Access (2)
Keywords
- Graphene (2)
- Transistor (2)
- Carboxylate (1)
- Ethyleneglycol (1)
- Flexible electronics (1)
- Inkjet printing (1)
- Minimum width (1)
- Polytope (1)
- Reducedness (1)
- Silver (1)
Institute
- FG Medizinische Informationssysteme (8)
- FG Molekulare Zellbiologie (4)
- Institut für Medizintechnologie (3)
- FG Anorganische Chemie (2)
- FG Halbleitermaterialien (2)
- FG Management regionaler Energieversorgungsstrukturen (2)
- FG Gewässerökologie (1)
- FG Optimale Steuerung (1)
- Forschungszentrum Landschaftsentwicklung und Bergbaulandschaften (FZLB) (1)
Mechanical interaction between cells - specifically distortion of tensional homeostasis-emerged as an important aspect of breast cancer genesis and progression. We investigated the biophysical characteristics of mechanosensitive ion channels (MSCs) in the malignant MCF-7 breast cancer cell line. MSCs turned out to be the most abundant ion channel species and could be activated by negative pressure at the outer side of the cell membrane in a saturable manner. Assessing single channel conductance (GΛ) for different monovalent cations revealed an increase in the succession: Li⁺ < Na⁺ < K⁺ ≈Rb⁺ ≈ Cs⁺. Divalent cations permeated also with the order: Ca²⁺ < Ba²⁺. Comparison of biophysical properties enabled us to identify MSCs in MCF-7 as ion channels formed by the Piezo1 protein. Using patch clamp technique no functional MSCs were observed in the benign MCF-10A mammary epithelial cell line. Blocking of MSCs by GsMTx-4 resulted in decreased motility of MCF-7, but not of MCF-10A cells, underscoring a possible role of Piezo1 in invasion and metastatic propagation. The role of Piezo1 in biology and progression of breast cancer is further substantiated by markedly reduced overall survival in patients with increased Piezo1 mRNA levels in the primary tumor.
Background Overexpression the KCNJ3, a gene that encodes subunit 1 of G-protein activated inwardly rectifying K+ channel (GIRK1) in the primary tumor has been found to be associated with reduced survival times and increased lymph node metastasis in breast cancer patients. Methods In order to survey possible tumorigenic properties of GIRK1 overexpression, a range of malignant mammary epithelial cells, based on the MCF-7 cell line that permanently overexpress different splice variants of the KCNJ3 gene (GIRK1a, GIRK1c, GIRK1d and as a control, eYFP) were produced. Subsequently, selected cardinal neoplasia associated cellular parameters were assessed and compared. ResultsAdhesion to fibronectin coated surface as well as cell proliferation remained unaffected. Other vital parameters intimately linked to malignancy, i.e. wound healing, chemoinvasion, cellular velocities / motilities and angiogenesis were massively affected by GIRK1 overexpression. Overexpression of different GIRK1 splice variants exerted differential actions. While GIRK1a and GIRK1c overexpression reinforced the affected parameters towards malignancy, overexpression of GIRK1d resulted in the opposite. Single channel recording using the patch clamp technique revealed functional GIRK channels in the plasma membrane of MCF-7 cells albeit at very low frequency. DiscussionWe conclude that GIRK1d acts as a dominant negative constituent of functional GIRK complexes present in the plasma membrane of MCF-7 cells, while overexpression of GIRK1a and GIRK1c augmented their activity. The core component responsible for the cancerogenic action of GIRK1 is apparently presented by a segment comprising aminoacids 235–402, that is present exclusively in GIRK1a and GIRK1c, but not GIRK1d (positions according to GIRK1a primary structure). Conclusions The current study provides insight into the cellular and molecular consequences of KCNJ3 overexpression in breast cancer cells and the mechanism upon clinical outcome in patients suffering from breast cancer.
The chemical and physical properties of [AgO2C(CH2OCH2)3H] (3) and its use as an aqueous, ligand-free MOD ink (MOD = metal−organic decomposition) for piezo inkjet printing is discussed. The printed, thermal, or photochemical sintered silver features are electrically conductive on glass (2.7 × 107 S m−1) and PET (PET = polyethylene terephthalate) substrates (1.1 × 107 S m−1) corresponding to 43% and 18% of the bulk silver conductivity. Conducted tape tests show the suitability of the ink for particularly polymer substrates. TG-MS studies demonstrate a two-step decomposition for the conversion of 3 to elemental silver. The structure of 3 in the solid state was determined by single X-ray structure determination.
The use of silver(I)-2-[2-(2-methoxyethoxy)ethoxy]acetate, [AgO2C(CH2OCH2)3H], and its application as an aqueous metal-organic decomposition (MOD) inkjet ink is reported. The chemical and physical properties of the silver carboxylate and the ink formulated thereof are discussed. The ink meets all requirements of piezo driven inkjet printing. The printed features were converted into electrically conducting silver patterns by thermal or photo-thermal treatment. The conversion of [AgO2C(CH2OCH2)3H] to elemental silver follows a two-step decomposition as demonstrated by thermogravimetry–mass spectrometry (TG–MS) measurements. The measured conductivities of the printed features on glass and polyethylene-terephthalate (PET) are 2.7 × 107 S m−1 and 1.1 × 107 S m−1, respectively, which correspond to 43% (glass) and 18% (PET) of the bulk silver conductivity.
Der Klimawandel hat Auswirkungen auf die Umwelt, die Menschen und ihre Lebensbedingungen, aber auch auf ihre Gestaltungsmöglichkeiten für die Zukunft. Die Bundesregierung hat deshalb klare und weit reichende Ziele für den Klimaschutz vorgegeben. Die Forschung mit ihren naturwissenschaftlich-technischen Lösungen und ihren gesellschaftswissenschaftlichen Erkenntnissen trägt zur Umsetzung dieser Ziele bei. Eine kohlenstofffreie Energiegewinnung und -nutzung zu fördern und weiterzuentwickeln sowie die vorhandenen Potenziale von energieeffizienten Techniken zu erschließen, kann einen entscheidenden Beitrag zur Senkung von Treibhausgasemissionen leisten. Verdeutlicht man sich jedoch die Herausforderungen, die mit dem Ziel einer Begrenzung des Temperaturanstiegs auf maximal zwei Grad verbunden sind, so ist unabweisbar, dass durch technologische Innovationen allein die Probleme des Klimawandels nicht gelöst werden können.
Die Broschüre "Klimaschutz erfordert Handeln" des Bundesministeriums für Bildung und Forschung zeigt Ergebnisse aus Forschungsvorhaben des Förderschwerpunktes "Sozial-ökologische Forschung", die eine lösungsorientierte Wissensbasis der dynamischen Wechselwirkungen zwischen Gesellschaften und ihrer natürlichen Umwelt geschaffen haben.