FBS Colloquia No.417Laboratory of Single Molecule Biology

High-Throughput In-Cell Single-Molecule Imaging: Applications in Drug Screening and Extension through AI?Robotics Integration

High-throughput single-molecule imaging, which enables the visualization of individual fluorescence-labeled molecules in living cells, was achieved using an automated imaging system developed in our laboratory. We applied this system to drug screening targeting the epidermal growth factor receptor (EGFR), a clinically important molecular target in cancer therapy, by evaluating changes in molecular mobility and oligomer formation as quantitative screening indices. Using a library of approved drugs, this method successfully identified approved EGFR kinase inhibitors, as expected, while also demonstrating the potential to detect compounds with mechanisms of action that are not readily accessible using conventional methods. To investigate the molecular processes underlying these screening indices, we performed large-scale measurements of EGFR mutants with structural deletions as well as drug-resistant mutations. By analyzing the spatiotemporal dynamics of EGFR molecules using machine learning-based approaches, we clarified how molecular structure and the plasma membrane environment contribute to EGFR function and signal transduction. Based on these findings, we are extending this strategy to drug screening of oncogenic EGFR mutants associated with non-small cell lung cancer. However, further enhancement of throughput will be indispensable for future screening using larger compound libraries. In this colloquium, ongoing efforts to automate processes beyond imaging, such as cell culture, through the integration of AI and robotics will also be presented.