Single molecule tracking based drug screening.

Area of Science:

• Cell biology
• Pharmacology
• Biophysics

Background:

• Single-molecule tracking (SMT) reveals insights into transmembrane receptor signaling, including mobility and clustering dynamics.
• These dynamics are crucial for receptor activation/inactivation and present a potential avenue for drug discovery screening.
• Conventional screening methods may miss compounds targeting subtle receptor functions.

Purpose of the Study:

• To demonstrate the utility of SMT-based screening for identifying novel therapeutics targeting disease-related receptors.
• To screen FDA-approved drugs for compounds affecting epidermal growth factor receptor (EGFR) signaling using SMT.
• To explore previously untargeted mechanisms of therapeutic intervention for EGFR-dependent diseases.

Main Methods:

• Development and application of an automated, high-throughput single-molecule analysis system.
• Screening of 1134 FDA-approved drugs for their effects on EGFR mobility and clustering in living cells.
• Analysis of drug-induced changes in EGFR phosphorylation-dependent mobility shifts and EGF-induced signaling.

Main Results:

• The screen identified 18 hit compounds, including all known EGFR-targeted tyrosine kinase inhibitors (TKIs) that altered EGFR mobility.
• Novel non-TKI compounds were discovered that affected EGFR mobility and/or clustering independently of EGF stimulation.
• These non-TKI compounds induced EGFR internalization and impeded EGFR-dependent cell growth.

Conclusions:

• SMT-based screening is a powerful approach for discovering therapeutics targeting diverse receptor functions, including those missed by conventional methods.
• The study validates SMT as a viable platform for identifying novel drug candidates with previously untargeted mechanisms of action.
• This approach expands the scope of drug discovery for receptors like EGFR, offering new therapeutic strategies.