Christoph Krüll, Beckman Coulter

Library screening can be a daunting task. Between all the samples, keeping track of your cells, and the heaps of data, it’s not unusual to get a bit overwhelmed. The good news is that screening can be straightforward and data friendly, but it takes a little forethought and planning. This talk will deal with five questions that can help prepare you for the realities of secondary screening, keeping you on track for meaningful data. 

Sakshi Garg, Merck, Darmstadt

Over the last decades, data has emerged highlighting that conventional 2D cell culture tumor models fail to capture important aspects of tumor physiology such as the delicate microenvironment, cell-cell communication, diffusion and availability of nutrients etc. The predictive value of phenotypic screening, especially in the field of tumor biology, is directly correlated to how closely the chosen assay represents the in vivo conditions. With that in mind, we at Merck aim to develop an in vitro model that closely mimics the cell physiology and biological characteristics of tumors for drug screening.

Axel Johann, Promega, Mannheim

The physical nature and size of 3D cell culture models can be much different than cells grown as a monolayer on a plastic surface. Applying off the shelf commercial assay reagents that were originally designed for use with monolayers of cells can lead to artifacts if incomplete cell lysis or incomplete reagent penetration occurs in the larger 3D structures. We have designed modified cell health assay formulations and protocols to overcome some of the problems encountered with assaying 3D culture models.

Benjamin Simona, Ectica Technologies AG, Zurich, Switzerland
Vincent Milleret, Greta Thompson-Steckel, Laboratory of Biosensors and Bioelectronics, ETH Zurich, Zurich, Switzerland

Hydrogels are widely used as an artificial extracellular matrix to grow neural cells in a three-dimensional (3D) environment. 3D cultures have the advantage of closely recapitulating aspects of the human tissues including the architecture and organization among cells (cell-cell and cell-matrix interactions) and more physiologically relevant diffusion characteristics. In 2014, Kim and co-workers reported in Nature a human neuronal cell culture 3D model in Matrigel [1]. The authors demonstrated that the 3D cell culture conditions promoted neural maturation compared to 2D and observed a dramatic increase in the levels of 4-repeat adult Tau isorforms, which are essential for reconstituting tauopathy in vitro. Finally, the authors demonstrated the presence of insoluble extracellular amyloid β deposits, an aspect of the disease that is not recapitulated in conventional 2D cultures because secreted Aβ freely diffuses in a large volume of media and is not confined in a matrix surrounding the cells. Overall, adopting 3D neuronal cultures to establish Alzheimer’s disease in vitro models is a promising strategy to recapitulate the biological relevance of in vivo model with the advantage of using cells of human origin.

Nicole Merten, University of Bonn, Institute for Pharmaceutical Biology, Molecular-, Cellular- and Pharmacobiology Section, Bonn

It is now well accepted that G protein-coupled receptors (GPCRs) simultaneously engage distinct G proteins leading to the activation of multiple downstream effectors, potentially with different potencies, efficacies and in vivo relevance. While traditional second messenger assays are intended to portray precisely the activation of defined signaling cascades, label-free technology platforms capture complex phenotypic cell responses in a G protein-unbiased manner and are therefore ideally suited for investigations of orphan receptors. We took advantage of label-free assays, based on dynamic mass redistribution (DMR) of cellular constituents, to investigate the signaling of GPR17, initially in recombinant cells.