SP 6

In vivo characterization of oncogenically rewired signaling networks in lung cancer

Lung cancer is the most common cause of cancer deaths in the Western world. Here, we are generating novel genetically-engineered mouse models of lung cancer that mimic not only the genetic events leading to tumor development, but also provide a time resolved order of these genetic alterations through the use of dual and triple recombination strategies. We will use these models to directly investigate the characteristics of the rewired signaling networks that are driven by these genetic alterations. We will further probe the rewired signaling networks for actionable molecular liabilities that might prove to represent valid drug for cancer therapy. Cancer patients typically succumb not to their primary tumors. Instead, metastatic disease is usually the cause of death in these patients. Thus, we will use our novel mouse models as a platform to molecularly dissect the events leading to metastatic spread. We specifically aim to identify pathways that are critical modulators of this process with the ultimate goal to pharmacologically intercept this process. It is the declared goal of this project to identify actionable drug targets for the treatment of primary tumors, as well as metastatic disease.

A dual recombinase strategy to induce KRAS-driven non-small cell lung cancer (NSCLC).
(A) H/E stained tissue section of a tumor-bearing lung. NSCLC was induced in this KRASFrt.STOP.Frt;ROSA26::Frt.STOP.Frt.CreERT2;ROSA26::Lox.STOP.Lox.GFP animal via intratracheal AdenoFlp inhalation. (B) Depicted are µCT images of KRASFrt.STOP.Frt;ROSA26::Frt.STOP.Frt.CreERT2;ROSA26::Lox.STOP.Lox.GFP animals that were intratracheally inhaled with an empty Adeno vector (top) or AdenoFlp (bottom). Lungs were imaged 3 months after inhalation. (C) Graphic representation of the different alleles used in this proposal. (D) The animals depicted in (B) were treated with a one-week course of intraperitoneal 4OH-tamoxifen 4 weeks after inhalation to activate Cre-recombinase. In this system, Cre activity can only be induced in tumor cells, as only these cells have been previously exposed to AdenoFlp, which is necessary to remove the ROSA26::Frt.STOP.Frt cassette. Cre-mediated deletion of the ROSA26::Lox.STOP.Lox cassette allows for GFP expression, which was detected by flow cytometry of isolated tumor cells. Tumors were harvested 12 weeks after AdenoFlp.