SP 2

In vitro and in vivo testing of phenotypic model predictions

Mathematical modeling (WP3) employing quantitative proteomic data (WP1) will result in predictions on molecular and phenotypic effects caused by drug treatment. The resulting hypothesis will be challenged by in vitro and in vivo experimentation. This workpackage provides an experimental platform for phenotypic in vitro and in vivo testing employing cell line models and xenograft mice, respectively. A panel of established and specifically engineered cell lines will be utilized as test systems. Since no ERBB3-expressing TNBCa cell line is available (attempts to generate such a cell line from tumors have failed thus far), the isogenic cell line technology available at DKFZ will be employed to generate MDA-MB-231 cells inducibly overexpressing ErbB3 protein. Parallel to this, RG7116 resistant cell lines will be produced by increasing drug concentrations for the ER+ background (MCF-7, T47D, ZR-75) as previously described for TrasR BT474 cells. Engineered as well as newly established cell lines will be employed in phenotypic assays to test effects of drugs as well as of targeted gene perturbations (RNAi, overexpression) to refine mathematical models. Testing will initially been done in vitro (2D, 3D cell culture), and ultimately in xenograft mouse models in order to quantitatively assess tumor growth and also metastasis formation in vivo. This workpackage thus complements the proteomic analyses of WP1 and predictions made by WP3 towards the validation and refinement of mathematical models.