The strength of the PPTI is its use of genetically engineered mouse models to study the effect of drugs on particular kinds of cancer. In the past, cancer models used mice with weakened or missing immune systems that added in cancer cells to watch their growth (xenografts). This method has yielded many great results but we know that cancer interacts heavily with the immune system interact so this is a major drawback of the model to consider. Another concern is the location of the tumors that grow – the cancer cells are added in places that are easy to get to and are not necessarily the natural site of development.
Both of these issues are addressed in the PPTI models of cancer in that the mice have normal immune systems and are genetically modified so that their tumors begin and expand in the places that are found in patients. Combined with other changes that allow us to “see” these tumors as they develop we believe that we have a unique opportunity to find effective treatments faster than ever before.
