A multi-omics approach reveals mechanisms of nanomaterial toxicity and structure-activity relationships in alveolar macrophages.

In respect to the high number of released nanomaterials and their highly variable properties, novel grouping approaches are required based on the effects of nanomaterials. Proper grouping calls for a combination of an experimental setup with a higher number of structurally similar nanomaterials and for employing integrated omics approaches to identify the mode of action. Here, we analyzed the effects of seven well-characterized NMs comprising different chemical compositions, sizes and chemical surface modifications on the rat alveolar macrophage cell line NR8383.

An in-depth multi-omics analysis in RLE-6TN rat alveolar epithelial cells allows for nanomaterial categorization.

Background: Nanomaterials (NMs) can be fine-tuned in their properties resulting in a high number of variants, each requiring a thorough safety assessment. Grouping and categorization approaches that would reduce the amount of testing are in principle existing for NMs but are still mostly conceptual. One drawback is the limited mechanistic understanding of NM toxicity.

Analyzing expression and phosphorylation of the EGF receptor in HNSCC.

Overexpression of the epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinomas (HNSCC) is considered to cause increased EGFR activity, which adds to tumorigenicity and therapy resistance. Since it is still unclear, whether EGFR expression is indeed associated with increased activity in HNSCC, we analyzed the relationship between EGFR expression and auto-phosphorylation as a surrogate marker for activity. We used a tissue micro array, fresh frozen HNSCC tumor and corresponding normal tissue samples and a large panel of HNSCC cell lines.

Immature O-glycans recognized by the macrophage glycoreceptor CLEC10A (MGL) are induced by 4-hydroxy-tamoxifen, oxidative stress and DNA-damage in breast cancer cells.

Background: Ligands of the C-type lectin CLEC10A such as Tn and sialyl-Tn representing early intermediates of O-glycosylation are hallmarks of many human malignancies. A variety of regulatory mechanisms underlying their expression are being discussed.

Methods: CLEC10A ligands were detected in various tissues and cells using the recombinant glycan-binding domain of CLEC10A.

SH2 Domain Histochemistry.

Among posttranslational modifications, the phosphorylation of tyrosine residues is a key modification in cell signaling. Because of its biological importance, characterization of the cellular state of tyrosine phosphorylation is of great interest. Based on the unique properties of endogenously expressed SH2 domains recognizing tyrosine phosphorylated signaling proteins with high specificity we have developed an alternative approach, coined SH2 profiling, enabling us to decipher complex patterns of tyrosine phosphorylation in various normal and cancerous tissues.

Identification of Tyrosine Phosphorylated Proteins by SH2 Domain Affinity Purification and Mass Spectrometry.

Phosphotyrosine signaling plays a major role in the control of many important biological functions such as cell proliferation and apoptosis. Deciphering of phosphotyrosine-dependent signaling is therefore of great interest paving the way for the understanding of physiological and pathological processes of signal transduction. On the basis of the specific binding of SH2 domains to phosphotyrosine residues, we here present an experimental workflow for affinity purification and subsequent identification of tyrosine phosphorylated proteins by mass spectrometry.

The Protein Tyrosine Phosphatase Rptpζ Suppresses Osteosarcoma Development in Trp53-Heterozygous Mice.

Osteosarcoma (OS), a highly aggressive primary bone tumor, belongs to the most common solid tumors in growing children. Since specific molecular targets for OS treatment remain to be identified, surgical resection combined with multimodal (neo-)adjuvant chemotherapy is still the only way to help respective individuals. We have previously identified the protein tyrosine phosphatase Rptpζ as a marker of terminally differentiated osteoblasts, which negatively regulates their proliferation in vitro.

Deciphering of ADP-induced, phosphotyrosine-dependent signaling networks in human platelets by Src-homology 2 region (SH2)-profiling.

Tyrosine phosphorylation plays a central role in signal transduction controlling many important biological processes. In platelets, the activity of several signaling proteins is controlled by tyrosine phosphorylation ensuring proper platelet activation and aggregation essential for regulation of the delicate balance between bleeding and hemostasis. Here, we applied Src-homology 2 region (SH2)-profiling for deciphering of the phosphotyrosine state of human platelets activated by adenosine diphosphate (ADP).