Acting on membrane protein-protein interactions: Mammalian Membrane Two Hybrid (MaMTH) as an Innovative Technology for Drug Discovery Against Protein- Protein Interactions

Challenge: Membrane proteins, representing approximately one-third of all proteins in a cell, interact with each other and are responsible for a variety of processes, making them attractive therapeutic targets for many diseases such as hypertension, diabetes, neurological disorders and various cancers. In fact, membrane proteins represent 60% of all clinical drug targets, however, they are still extremely difficult to study because of their biochemical complexity.

Solution: The researcher has developed a novel platform called Mammalian Membrane Two Hybrid (MaMTH) which is a live cell-based assay to study the interactions of any mammalian membrane protein in vivo, as well as understand how such protein interactions respond to various therapeutic compounds in their natural cellular context. MaMTH was designed to overcome the difficulties faced when using traditional biochemical methods, which do not work in the complex biochemical environment of the mammalian cell membrane. The two-hybrid screen is based on disrupting protein-protein interactions (PPI) between a “bait” and a “prey” of therapeutic importance. This project aimed to adapt and validate MaMTH as a drug screening assay for small molecule compounds that can modulate membrane PPIs.

Achievements/Impact: The team used MaMTH to screen a library of 2,960 compounds to isolate small molecule inhibitors targeting the interaction of SHC1 with EGFR triple mutant responsible for drug resistance in lung cancer patients. Using the same methodology, the team eliminated any hits that also reacted against wild type EGFR, thus selecting three molecules (Midostaurin, Gilteritinib and Chembridge compound X that inhibited the growth of lung cancer cells expressing the triple EGFR mutant. Based on these results, Gilteritinib was selected for clinical trials. This unique technology also allowed the creation of Protein Network Therapeutix Inc., a biotechnology start-up that will exploit the MaMTH assay, and elicited high interest from biotech and pharma industry.