Abstract

Complex Cell- and Tissue Based Models for Phenotypic High Content Screening, Target Validation, and Lead Development

Matthias Nees, Principal Scientist, VTT Technical Research Centre

The lecture will describe the development of a miniaturized platform for phenotypic screening of small-molecule inhibitors or biosimilars, using organotypic tissue cultures and co-cultures in vitro. The readout described mainly relies on morphometric, real-time and live cell assays, based on automated confocal microscopy & subsequent image analyses. The purpose is to more faithfully recapitulate cell-cell-interactions in a genuine (tumor-) microenvironment (TME) and a spectrum of biologically relevant extracellular matrices (ECM). Our tissue culture models are initiated by seeding small numbers of single cells between two layers of ECM, supporting the formation of genuine tissue-like and often functional structures. Ideally, this clonal approach recapitulates the intrinsic differentiation potential of normal, and reflects defective differentiation capacity of tumor cells. This can be further supported by co-culture with relevant stromal components (fibroblasts, smooth muscle, immune, mesenchymal stem or endothelial cells), which typically have a strong impact on epithelial differentiation patterns. Automated image analysis is then used to categorize, classify and cluster the structures formed in vitro. Here, we use a combined approach that utilizes size, shape and texture features to quantitate morphologic information into numerical values. Statistical post-processing, machine learning and non-supervised methods are then used to correlate phenotypic features with biological parameters, such as response to small molecule inhibitors, siRNAs, or altered experimental conditions. Furthermore, we are aiming to capture the heterogeneity of such in vitro cultures as well as dynamic changes (such as cell motility and invasion) over time. This intrinsic heterogeneity is particularly relevant and informative in primary, patient-derived cultures e.g. for personalized medicine settings. In summary, our tissue-culture platform provides a broadly applicable enabling technology