Targeting Cancer at the Protein-Membrane Interface - Project Summary Significant progress in human cancer therapy in the last decade has been driven by conceptionally new approaches to treating cancer, including cancer immunotherapy, cancer nanotherapy (e.g. liposomal doxorubicin or mRNA vaccines), or new types of biologics and small molecules. I propose to develop new approaches to targeting protein-membrane interactions that could yield unprecedented methods to modulate cancer signaling and generate useful paradigms for pharmacology at large. The role of protein-membrane and drug-membrane interactions will be explored and targeted on various levels, each highly relevant to cancer pharmacology: 1. Cancer signaling, a hallmark of cancer, is largely dependent on the recruitment of kinases (e.g. PI3K or PKC) and GTPases (e.g. RAS) to hotspots localized at the inner plasma membrane leaflet. I aim to develop bifunctional inhibitors with the capacity to modulate these interactions as a new approach to target cancer signaling. 2a. Membrane-integrated receptors are also key players in cellular signaling (e.g. enzyme-linked receptors or GPCRs). Recently, a number of pharmacophores have been discovered that target these proteins directly from the intramembrane space. These `Intramembrane pharmacophores' first partition into the membrane and then engage their target through lateral diffusion and entry. I aim to systematically modulate membrane exposed pharmacophore sites to explore principles governing the action of these pharmacophores which in turn will aid in the discoveries of new intramembrane pharmacophores. 2b. The majority of bioactive molecules acts on membrane proteins or intracellular targets and therefore needs to partition into or cross biological membranes. I propose to use combinatorial chemistry to discover new principles and chemical structures that modulate and privilege pharmacophores for cellular uptake. These will be tested in live cells using high throughput assays as a holistic approach to covering all possible uptake mechanisms on the first level of screening (e.g. endocytosis, transporters, passive diffusion). Combined, the proposed research will provide important insights into the functional role of protein- membrane interactions in cancer signaling and their vulnerability to small molecule-based modulation. Each of the proposed directions has the potential to yield fundamentally new and unprecedented approaches to targeting cancer and other diseases. My mentor and collaborators have extensive experience in cancer pharmacology, drug discovery, and the biophysical characterization of protein-membrane interfaces and will provide the training needed to conduct the proposed research. They will also provide the mentorship needed to acquire all skills and preliminary data needed for a successful transition to an independent career in cancer research.
