Identifying and Inhibiting Cholesterol-Protein Interactions for Therapeutic Development

Constitutive activation of key proteins in cancer and autoimmune diseases is typically attributed to mutations in cell signaling axes or increased external stimuli. Accumulating evidence implicates perturbation of lipid levels caused by reprogrammed lipid metabolism in a variety of human diseases. In particular, elevated cellular cholesterol has been associated with the pathogenesis of cancer, neurodegenerative diseases and autoimmune diseases. However, the exact spatiotemporal cellular mechanisms by which cholesterol enrichment may regulate disease progression in a spatiotemporally specific manner are poorly defined. Here, we aim to elucidate how cholesterol enriched in the inner leaflet of the plasma membrane modulates protein signaling axes in breast cancer and inflammatory bowel disease and develop new therapeutics designed to target specific cholesterol-protein interactions. First, we introduce a new method using Turbo ID proximity labeling paired with site-specific modulation of the cholesterol concentration to identify new cholesterol-protein interactions in the inner plasma membrane in live cells. Surface plasmon resonance is employed to further characterize specific cholesterol-protein interactions for the identified proteins. Then, we describe the discovery and characterization of cholesterol-protein interaction inhibitors for two selected proteins, STAT3 and AKT. These results provide new insight into how locally elevated cholesterol in breast cancer and inflammatory bowel disease acts as a specific signaling molecule that drives cell-intrinsic signaling pathways by specific interaction with protein molecules, leading to the pathogenesis of these diseases. Additionally, we show that cholesterol-activated signaling proteins, such as STAT3 and AKT, can be specifically blocked by small molecule inhibitors that disrupt cholesterol-protein interaction. These cholesterol-protein-interaction inhibitors specifically and effectively target diseased cells with abnormally high levels of inner plasma membrane cholesterol, allowing for high potency and safety in in vitro and in vivo drug testing. As a whole, this dissertation aims to demonstrate that cholesterol-protein interaction inhibitors represent a viable new platform technology for design and development of new small molecule-based targeted therapy.

Author dc:creator

• Kyli Berkley (23292169)

• Cholesterol-protein interactions

Statement dc:rights

• In Copyright
• Open Access after 2028-01-01

DOI dc:identifier

https://doi.org/10.25417/uic.31451932.v1

OAI identifier oai:identifier

oai:figshare.com:article/31451932