Pharmacologically controlling protein-protein interactions through epichaperomes for therapeutic vulnerability in cancer

Cancer cell plasticity due to the dynamic architecture of interactome networks provides a vexing outlet for therapy evasion. Here, through chemical biology approaches for systems level exploration of protein connectivity changes applied to pancreatic cancer cell lines, patient biospecimens, and cell- and patient-derived xenografts in mice, we demonstrate interactomes can be re-engineered for vulnerability. By manipulating epichaperomes pharmacologically, we control and anticipate how thousands of proteins interact in real-time within tumours. Further, we can essentially force tumours into interactome hyperconnectivity and maximal protein-protein interaction capacity, a state whereby no rebound pathways can be deployed and where alternative signalling is supressed. This approach therefore primes interactomes to enhance vulnerability and improve treatment efficacy, enabling therapeutics with traditionally poor performance to become highly efficacious. These findings provide proof-of-principle for a paradigm to overcome drug resistance through pharmacologic manipulation of proteome-wide protein-protein interaction networks. Joshi, Gomes et al. employ a chemical modulation approach of the cellular interactome to a hyperconnectivity state and show association with the increased response of pancreatic cancer cell lines to specific drugs, including those that target the MAPK-pathways and PI3K-mTOR pathway. To achieve this, the authors employ chemical modulation of the interactome via epichaperome inhibition with the small molecule PU-H71.