Cell contractility drives mechanical memory of oral squamous cell carcinoma

To study if non-invasive oral squamous cell carcinoma (OSCC) cells can acquire mechanical memory from stiff matrix and investigate the role of cell contractility in that process, Cal27 were conditioned (for 5 days) either by matrix stiffness or by direct modulation of cell contractility and then replated to a new niche lack of sources for the cells to learn. Cal27 with different types of conditioning were categorized either "Learn" or "Don't Lean/Forget" based on the existence of mechanical memory. Comparative gene expression profiling was done between "Learn" vs. "Don't Learn/Forget" Cal27 groups by RNA sequencing Every group underwent 5 days of conditioning followed by a day of replating phase. "Learn" group were prepared either by treating Cal27 with lisophosphatidic acid (LPA) or seeding cells on stiff (20 kPa polyacrylamide gel) during conditioning phase. "Don't Learn/Forget" group was prepared by seeding cells on soft gel without any treatment during conditioning phase or by inhibiting FAK signaling pathway during replating phase. Transcriptomic difference between Cal27 groups with ("Learn") and without ("Don't Learn/Forget") memory was analyzed by identifying differentially expressed genes from comparing RNA sequencing data.