DYRK1B as therapeutic target in Hedgehog/GLI-dependent cancer cells with Smoothened inhibitor resistance
Wolfgang Gruber, Martin Hutzinger, Dominik Patrick Elmer, Thomas Parigger, Christina Sternberg, Lukasz Cegielkowski, Mirko Zaja, Johann Leban, Susanne Michel, Svetlana Hamm, Daniel Vitt and Fritz Aberger
Abstract: A wide range of human malignancies displays aberrant activation of Hedgehog (HH)/GLI signaling, including cancers of the skin, brain, gastrointestinal tract and hematopoietic system. Targeting oncogenic HH/GLI signaling with small molecule inhibitors of the essential pathway effector Smoothened (SMO) has shown remarkable therapeutic effects in patients with advanced and metastatic basal cell carcinoma. However, acquired and de novo resistance to SMO inhibitors poses severe limitations to the use of SMO antagonists and urgently calls for the identification of novel targets and compounds. Here we report on the identification of the Dual-Specificity-Tyrosine-Phosphorylation-Regulated Kinase 1B (DYRK1B) as critical positive regulator of HH/GLI signaling downstream of SMO. Genetic and chemical inhibition of DYRK1B in human and mouse cancer cells resulted in marked repression of HH signaling and GLI1 expression, respectively. Importantly, DYRK1B inhibition profoundly impaired GLI1 expression in both SMO-inhibitor sensitive and resistant settings. We further introduce a novel small molecule DYRK1B inhibitor, DYRKi, with suitable pharmacologic properties to impair SMO-dependent and SMO-independent oncogenic GLI activity. The results support the use of DYRK1B antagonists for the treatment of HH/GLI-associated cancers where SMO inhibitors fail to demonstrate therapeutic efficacy.
The open access article can be found  here
PRIZE: € 250,-

Identification of E-cadherin signature motifs functioning as cleavage sites for Helicobacter pylori HtrA
Thomas P. Schmidt, Anna M. Perna, Tim Fugmann, Manja Böhm, Jan Hiss, Sarah Haller, Camilla Götz, Nicole Tegtmeyer, Benjamin Hoy, Tilman T. Rau, Dario Neri, Steffen Backert, Gisbert Schneider & Silja Wessler
Abstract: The cell adhesion protein and tumour suppressor E-cadherin exhibits important functions in the prevention of gastric cancer. The class-I carcinogen Helicobacter pylori (H. pylori) has developed a unique strategy to interfere with E-cadherin functions. H. pylori secretes the protease high temperature requirement A (HtrA) which cleaves off the E-cadherin ectodomain on epithelial cells. This opens cell-to-cell junctions, allowing bacterial transmigration across the epithelium. Here, we investigated the molecular mechanism of the HtrA-E-cadherin interaction and identified E-cadherin cleavage sites for HtrA.
The open access article can be found  here
PRIZE: € 250,-

Mapping molecular adhesion sites inside SMIL coated capillaries using atomic force microscopy recognition imaging
Michael Leitner¹, Lorenz G. Stock¹, Lukas Traxler, Laurent Leclercq, Klaus Bonazza, Gernot Friedbacher, Hervé Cottet, Hanno Stutz, Andreas Ebner
1 Authors contributed equally
Abstract: Capillary zone electrophoresis (CZE) is a powerful analytical technique for fast and efficient separation of different analytes ranging from small inorganic ions to large proteins. However electrophoretic resolution significantly depends on the coating of the inner capillary surface. High technical efforts like Successive Multiple Ionic Polymer Layer (SMIL) generation have been taken to develop stable coatings with switchable surface charges fulfilling the requirements needed for optimal separation. Although the performance can be easily proven in normalized test runs, characterization of the coating itself remains challenging. Atomic force microscopy (AFM) allows for topographical investigation of biological and analytical relevant surfaces with nanometer resolution and yields information about the surface roughness and homogeneity. Upgrading the scanning tip to a molecular biosensor by adhesive molecules (like partly inverted charged molecules) allows for performing topography and recognition imaging (TREC). As a result, simultaneously acquired sample topography and adhesion maps can be recorded. We optimized this technique for electrophoresis capillaries and investigated the charge distribution of differently composed and treated SMIL coatings. By using the positively charged protein avidin as a single molecule sensor, we compared these SMIL coatings with respect to negative charges, resulting in adhesion maps with nanometer resolution. The capability of TREC as a functional investigation technique at the nanoscale was successfully demonstrated.
The open access article can be found  here
PRIZE: € 250,-

 
Copper oxide nanoparticle toxicity profiling using untargeted metabolomics
Matthew S. P. Boyles, Christina Ranninger, Roland Reischl, Marc Rurik, Richard Tessadri, Oliver Kohlbacher, Albert Duschl and Christian G. Huber
Abstract: Background: The rapidly increasing number of engineered nanoparticles (NPs), and products containing NPs, raises concerns for human exposure and safety. With this increasing, and ever changing, catalogue of NPs it is becoming more difficult to adequately assess the toxic potential of new materials in a timely fashion. It is therefore important to develop methods which can provide high-throughput screening of biological responses. The use of omics technologies, including metabolomics, can play a vital role in this process by providing relatively fast, comprehensive, and cost-effective assessment of cellular responses. These techniques thus provide the opportunity to identify specific toxicity pathways and to generate hypotheses on how to reduce or abolish toxicity. Results: We have used untargeted metabolome analysis to determine differentially expressed metabolites in human lung epithelial cells (A549) exposed to copper oxide nanoparticles (CuO NPs). Toxicity hypotheses were then generated based on the affected pathways, and critically tested using more conventional biochemical and cellular assays. CuO NPs induced regulation of metabolites involved in oxidative stress, hypertonic stress, and apoptosis. The involvement of oxidative stress was clarified more easily than apoptosis, which involved control experiments to confirm specific metabolites that could be used as standard markers for apoptosis; based on this we tentatively propose methylnicotinamide as a generic metabolic marker for apoptosis. Conclusions: Our findings are well aligned with the current literature on CuO NP toxicity. We thus believe that untargeted metabolomics profiling is a suitable tool for NP toxicity screening and hypothesis generation.
The open access article can be found  here
PRIZE: € 250,- each

CONGRATULATIONS!