Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Abstract: Radiotherapy is a cornerstone of cancer therapy. The recently established particle therapy with raster-scanning protons and carbon ions landmarks a new era in the field of high-precision cancer medicine. However, molecular mechanisms governing radiation induced intracellular signaling remain elusive. Here, we present the first comprehensive proteomic and phosphoproteomic study applying stable isotope labeling by amino acids in cell culture (SILAC) in combination with high-resolution mass spectrometry to decipher cellular response to irradiation with X-rays, protons and carbon ions. At protein expression level limited alterations were observed 2 h post irradiation of human lung adenocarcinoma cells. In contrast, 181 phosphorylation sites were found to be differentially regulated out of which 151 sites were not hitherto attributed to radiation response as revealed by crosscheck with the PhosphoSitePlus database.Radiation-induced phosphorylation of the p(S/T)Q motif was the prevailing regulation pattern affecting proteins involved in DNA damage response signaling. Because radiation doses were selected to produce same level of cell kill and DNA double-strand breakage for each radiation quality, DNA damage responsive phosphorylation sites were regulated to same extent. However, differential phosphorylation between radiation qualities was observed for 55 phosphorylation sites indicating the existence of distinct signaling circuitries induced by X-ray versus particle (proton/carbon) irradiation beyond the canonical DNA damage response. This unexpected finding was confirmed in targeted spike-in experiments using synthetic isotope labeled phosphopeptides. Herewith, we successfully validated uniform DNA damage response signaling coexisting with altered signaling involved in apoptosis and metabolic processes induced by X-ray and particle based treatments.In summary, the comprehensive insight into the radiation-induced phosphoproteome landscape is instructive for the design of functional studies aiming to decipher cellular signaling processes in response to radiotherapy, space radiation or ionizing radiation per se Further, our data will have a significant impact on the ongoing debate about patient treatment modalities.
    Type of Publication: Journal article published
    PubMed ID: 28302921
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
  • 3
    Keywords: CANCER ; tumor ; CELL ; Germany ; human ; SYSTEM ; SYSTEMS ; DISEASE ; liver ; PROTEIN ; PROTEINS ; SAMPLE ; SAMPLES ; MOLECULES ; TISSUE ; TISSUES ; BIOLOGY ; MOLECULE ; IDENTIFICATION ; MEMBRANE ; INSTABILITY ; ELECTROPHORESIS ; pancreatic cancer ; SECTIONS ; molecular biology ; pancreas ; PANCREATIC-CANCER ; EXTRACTION ; SEPARATION ; USA ; protein fractionation ; CELL-CELL ; EFFECTOR MOLECULE ; ISLETS ; protein extraction
    Abstract: Proteins are the major class of effector molecules in cellular systems. For the identification of functional differences between normal and diseased tissues, a reliable analysis of their protein content is essential. Reproducible isolation and fractionation of intact proteins are important in this respect, but their complexity in structure and concentration, their close interaction, and their instability represent major challenges. For protein isolation in tissues, the breakdown of cell-cell and cell-matrix connections within a tissue without affecting protein quality is a critical factor. We compared different processes for a compartmental protein preparation from pancreatic tissue, one of the most challenging tissues for protein isolation because of its high protease content. Success of the different procedures varied greatly. Based on a scheme of tissue-slicing and subsequent cell isolation, we established a reliable workflow for the fractional extraction of cytosolic proteins, membrane and organelle proteins, nuclear proteins, and cytoskeletal filaments. The tissue slices also allow for a representative confirmation of individual samples' cellular status by histochemical processes, and a proper separation or mixing of cellular material from across a tumor if required
    Type of Publication: Journal article published
    PubMed ID: 19450236
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: brain ; COMBINATION ; Germany ; GENERATION ; SYSTEM ; liver ; PROTEIN ; PROTEINS ; HEART ; COMPLEX ; COMPLEXES ; MECHANISM ; RAT ; PHOSPHORYLATION ; TARGET ; RAT-LIVER ; SUBUNIT ; MEMBRANE ; STRESS ; MODULATION ; MITOCHONDRIA ; OXYGEN ; antioxidants ; PROTEOMICS ; reactive oxygen species ; glutathione-S-transferase ; GENE-EXPRESSION PROFILE ; ageing ; GEL-ELECTROPHORESIS ; assembly ; proteome ; REACTIVE OXYGEN ; ROS ; CALORIE RESTRICTION ; SHORT-TERM ; COMPLEX-I ; MEMBRANE-PROTEINS ; CYTOCHROME-C-OXIDASE ; DIGE ; Species ; ROS PRODUCTION ; SHIFT ; RESPIRATORY-CHAIN
    Abstract: Mitochondria being the major source and target of reactive oxygen species (ROS) play a crucial role during ageing. We analyzed ageing and calorie restriction (CR)-induced changes in abundance of rat liver mitochondrial proteins to understand key aspects behind the age-retarding mechanism of CR. The combination of blue-native (BN) gel system with fluorescence Difference Gel Electrophoresis (DIGE) facilitated an efficient analysis of soluble and membrane proteins, existing as monomers or multi-protein assemblies. Changes in abundance of specific key subunits of respiratory chain complexes I, IV and V, critical for activity and/or assembly of the complexes were identified. CR lowered complex I assembly and complex IV activity, which is discussed as a molecular mechanism to minimize ROS production at mitochondria. Notably, the antioxidant system was found to be least affected. The GSH:GSSG couple could be depicted as a rapid mean to handle the fluctuations in ROS levels led by reversible metabolic shifts. We evaluated the relative significance of ROS generation against quenching. We also observed parallel and unidirectional changes as effect of ageing and CR, in subunits of ATP synthase, cytochrome P450 and glutathione S-transferase. This is the first report on such 'putatively hormetic' ageing-analogous effects of CR, besides the age-retarding ones
    Type of Publication: Journal article published
    PubMed ID: 19894137
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: brain ; CANCER ; CELLS ; ENDOTHELIAL-CELLS ; EXPRESSION ; tumor ; CELL ; Germany ; LUNG-CANCER ; SYSTEM ; DISEASE ; PROTEIN ; TISSUE ; MICE ; PATIENT ; ANTIGEN ; T-CELL ; T-CELLS ; BONE-MARROW ; MEMORY ; RECOGNITION ; MOUSE ; IDENTIFICATION ; LYMPHOMA ; EFFICACY ; MELANOMA ; MASS-SPECTROMETRY ; HEAD ; NECK ; EPITOPE ; IMMUNOTHERAPY ; IMMUNOGENICITY ; CANCER PATIENTS ; CALCIUM-BINDING PROTEINS ; TUMOR-ASSOCIATED ANTIGENS ; NECK-CANCER ; brain tumor ; head and neck cancer ; endothelial cells ; proteome ; EGFR ; SEPARATION ; EXPRESSION PROFILES ; Type ; HEAD-AND-NECK
    Abstract: Identifying the antigens that have the potential to trigger endogenous antitumor responses in an individual cancer patient is likely to enhance the efficacy of cancer immunotherapy, but current methodologies do not efficiently identify such antigens. This study describes what we believe to be a new method of comprehensively identifying candidate tissue antigens that spontaneously cause T cell responses in disease situations. We used the newly developed automated, two-dimensional chromatography system PF2D to fractionate the proteome of human tumor tissues and tested protein fractions for recognition by preexisting tumor-specific CD4(+) Th cells and CTLs. Applying this method using mice transgenic for a TCR that recognizes an OVA peptide presented by MHC class I, we demonstrated efficient separation, processing, and cross-presentation to CD8(+) T cells by DCs of OVA expressed by the OVA-transfected mouse lymphoma RMA-OVA. Applying this method to human tumor tissues, we identified MUC1 and EGFR as tumor-associated antigens selectively recognized by T cells in patients with head and neck cancer. Finally, in an exemplary patient with a malignant brain tumor, we detected CD4(+) and CD8(+) T cell responses against two novel antigens, transthyretin and calgranulin B/S100A9, which were expressed in tumor and endothelial cells. The immunogenicity of these antigens was confirmed in 4 of 10 other brain tumor patients. This fast and inexpensive method therefore appears suitable for identifying candidate T cell antigens in various disease situations, such as autoimmune and malignant diseases, without being restricted to expression by a certain cell type or HLA allele
    Type of Publication: Journal article published
    PubMed ID: 20458140
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: CANCER ; EXPRESSION ; QUANTIFICATION ; IDENTIFICATION ; AMINO-ACIDS ; POSTTRANSCRIPTIONAL REGULATION ; MESSENGER-RNAS ; BIOGENESIS ; TRANSLATION INITIATION ; CELL-CULTURE ; MICRORNA-BINDING-SITES
    Abstract: Background: MicroRNAs are 22 nucleotides long non-coding RNAs and exert their function either by transcriptional or translational inhibition. Although many microRNA profiles in different tissues and disease states have already been discovered, only little is known about their target proteins. The microRNA miR-155 is deregulated in many diseases, including cancer, where it might function as an oncoMir. Methodology/Principal Findings: We employed a proteomics technique called "stable isotope labelling by amino acids in cell culture" (SILAC) allowing relative quantification to reliably identify target proteins of miR-155. Using SILAC, we identified 46 putative miR-155 target proteins, some of which were previously reported. With luciferase reporter assays, CKAP5 was confirmed as a new target of miR-155. Functional annotation of miR-155 target proteins pointed to a role in cell cycle regulation. Conclusions/Significance: To the best of our knowledge we have investigated for the first time miR-155 target proteins in the HEK293T cell line in large scale. In addition, by comparing our results to previously identified miR-155 target proteins in other cell lines, we provided further evidence for the cell line specificity of microRNAs
    Type of Publication: Journal article published
    PubMed ID: 21799781
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: EXPRESSION ; TOLERANCE ; CAENORHABDITIS-ELEGANS ; ARABIDOPSIS-THALIANA ; SUPEROXIDE-DISMUTASE ; RICHTERSIUS-CORONIFER ; LIFE-SPAN REGULATION ; VITELLOGENIN GENES ; YOLK PROTEINS ; WATER-STRESS
    Abstract: Tardigrades have fascinated researchers for more than 300 years because of their extraordinary capability to undergo cryptobiosis and survive extreme environmental conditions. However, the survival mechanisms of tardigrades are still poorly understood mainly due to the absence of detailed knowledge about the proteome and genome of these organisms. Our study was intended to provide a basis for the functional characterization of expressed proteins in different states of tardigrades. High-throughput, high-accuracy proteomics in combination with a newly developed tardigrade specific protein database resulted in the identification of more than 3000 proteins in three different states: early embryonic state and adult animals in active and anhydrobiotic state. This comprehensive proteome resource includes protein families such as chaperones, antioxidants, ribosomal proteins, cytoskeletal proteins, transporters, protein channels, nutrient reservoirs, and developmental proteins. A comparative analysis of protein families in the different states was performed by calculating the exponentially modified protein abundance index which classifies proteins in major and minor components. This is the first step to analyzing the proteins involved in early embryonic development, and furthermore proteins which might play an important role in the transition into the anhydrobiotic state.
    Type of Publication: Journal article published
    PubMed ID: 23029181
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Keywords: PROTEINS ; EYE ; LARGE GENE LISTS ; POLYACRYLAMIDE GEL-ELECTROPHORESIS ; PROLIFERATIVE DIABETIC-RETINOPATHY ; AQUEOUS-HUMOR ; PANTHER
    Abstract: Mapping of proteins involved in normal eye functions is a prerequisite to identify pathological changes during eye disease processes. We therefore analysed the proteome of human vitreous by applying in-depth proteomic screening technologies. For ethical reasons human vitreous samples were obtained by vitrectomy from "surrogate normal patients" with epiretinal gliosis that is considered to constitute only negligible pathological vitreoretinal changes. We applied different protein prefractionation strategies including liquid phase isoelectric focussing, 1D SDS gel electrophoresis and a combination of both and compared the number of identified proteins obtained by the respective method. Liquid phase isoelectric focussing followed by SDS gel electrophoresis increased the number of identified proteins by a factor of five compared to the analysis of crude unseparated human vitreous. Depending on the prefractionation method proteins were subjected to trypsin digestion either in-gel or in solution and the resulting peptides were analysed on a UPLC system coupled online to an LTQ Orbitrap XL mass spectrometer. The obtained mass spectra were searched against the SwissProt database using the Mascot search engine. Bioinformatics tools were used to annotate known biological functions to the detected proteins. Following this strategy we examined the vitreous proteomes of three individuals and identified 1111 unique proteins. Besides structural, transport and binding proteins, we detected 261 proteins with known enzymatic activity, 51 proteases, 35 protease inhibitors, 35 members of complement and coagulation cascades, 15 peptide hormones, 5 growth factors, 11 cytokines, 47 receptors, 30 proteins of visual perception, 91 proteins involved in apoptosis regulation and 265 proteins with signalling activity. This highly complex mixture strikingly differs from the human plasma proteome. Thus human vitreous fluid seems to be a unique body fluid. 262 unique proteins were detected which are present in all three patient samples indicating that these might represent the constitutive protein pattern of human vitreous. The presented catalogue of human vitreous proteins will enhance our understanding of physiological processes in the eye and provides the groundwork for future studies on pathological vitreous proteome changes.
    Type of Publication: Journal article published
    PubMed ID: 23688336
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: inactivation ; DIVERSITY ; glycosylation ; inflammation ; BETA RECEPTOR ; ROLES
    Abstract: Protein-linked glycans play key roles in cell differentiation, cell-cell interactions, cell growth, adhesion and immune response. Aberrant glycosylation is a characteristic feature of tumor cells and is involved in tumor growth, escape from apoptosis, metastasis formation, and resistance to therapy. It can serve as cancer biomarker and treatment target. To enable comprehensive screening for the impact of tumor driving mutations in colorectal cancer cells we present a method for specific analysis of tumor driver-induced glycome changes. The strategy is based on a combination of three technologies, that is recombinase-mediated cassette exchange (RMCE), Click-It chemistry and mass spectrometry. The new method is exemplified by the analysis of the impact of inactivating mutations of the TGF-ss-receptor type II (TGFBR2) on sialic acid incorporation into protein-linked glycans of the colon cancer cell line HCT116. Overall, 70 proteins were found to show de novo sialic acid incorporation exclusively upon TGFBR2 expression whereas 7 proteins lost sialylation upon TGFBR2 reconstitution. Validation of detected candidate glycoproteins is demonstrated with the cell surface glycoprotein nectin-3 known to be involved in metastasis, invasion and prognosis of various cancers. Altogether, our new approach can help to systematically puzzle out the influence of tumor-specific mutations in a major signaling pathway, as exemplified by the TGFBR2 tumor suppressor, on the tumor glycome. It facilitates the identification of glycan-based tumor markers that could be used for diagnostic and therapeutic applications. In principle the outlined strategy can be adapted to any cancer cell line, tumor driver mutation and several glycan-building blocks.
    Type of Publication: Journal article published
    PubMed ID: 26177744
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...