In vitro mouse model validation

will be performed as follows: First, we will analyze the status of the network model in the individual cell lines carrying specific genetic alterations in the PI3K and MAPK pathway components. Next, we will perform perturbation experiments in mouse and human tumor cell lines by gene over-expression or silencing using RNA interference, or by pharmacological inhibition using clinical inhibitors of PI3K and MAPK pathway components.

In vivo mouse model testing:

In this step, we will evaluate the capacity of our model to predict responses of real tumors in vivo to specific treatments. For this, we will use (combinations of) selective inhibitors of PI3K and MAPK pathway components, as well as shRNA vectors for inducible target gene inactivation in established tumors in our genetically engineered mouse models of TNBC and ILC and our human-in-mouse models of breast cancer. We will record cellular phenotypes by immunohistochemistry and (phospho)protein expression of the candidate genes and correlate these data with tumor response.