Via Zoom: https://wse.zoom.us/j/145648770
“Mechanical Regulation of Cell Growth and Proliferation”
Presented by Professor Sean Sun
Department of Mechanical Engineering, Johns Hopkins University
From the point-of-view of engineering, the cell is an extraordinary autonomous system capable of self regulation in a changing environment. One of the critical processes of the cell that require extensive regulation is cell growth and proliferation. Indeed, failure in proper regulation of cell growth is the root cause of many diseases, including cancer. However, studying cell growth control turns out to be difficult, due to measurement problems at the cell single level and inherent noisiness of the growth process. In this talk, I will describe a new AI-based microscopy method to quantitatively measure cell size in real time. Using this method, we can observe single cell growth over multiple rounds of cell division. We find novel signatures of cell growth control and the presence of a cell size checkpoint during the cell cycle. The data clearly shows that cancer cells and normal cells regulate their cell size and growth differently. Moreover, normal cell growth is sensitive to mechanical tension and forces applied to the cell, whereas cancer cells seems to be insensitive to force application. These results suggest that there are redundant control mechanisms of cell growth and cell size regulation in normal cells, and cancer cells can escape normal growth regulation by altering their mechanosensitivity. The implications of these results are important for understanding disease mechanisms, and our method of studying cell growth and proliferation will be useful for further revealing molecular-level control algorithms.
Sean Sun is a faculty member in the Department of Mechanical Engineering and Institute of NanoBioTechnology at JHU. He is interested in the mechanical behavior of the cell and the mechanisms behind cell movement, cell growth and cell size regulation. He uses a combination of microfluidic methods, microscopy, genetic and biophysical techniques, and mathematical modeling to reveal novel mechanisms in cell biomechanics. He is a member of the JHU Physical Sciences in Oncology Center, and a Fellow of the American Physical Society (APS) and the American Institute for Medical and Biological Engineering (AIMBE).