Cytoskeletal Perturbing Drugs and Their Effect on Cell Elasticity

The cytoskeleton is primarily responsible for providing structural support, localization and transport of organelles, and intracellular trafficking. The structural support is supplied by actin filaments, microtubules, and intermediate filaments, which contribute to overall cell elasticity to varying degrees. We evaluate cell elasticity in five different cell types with drug-induced cytoskeletal derangements to probe how actin filaments and microtubules contribute to cell elasticity and whether it is conserved across cell type. Specifically, we measure elastic stiffness in chondrocytes, fibroblasts, endothelial cells, hepatocellular carcinoma, and fibrosarcoma using atomic force microscopy. We subject all five cell lines to two cytoskeletal destabilizers: cytochalasin D and nocodazole, which disrupt actin and microtubule polymerization, respectively. Non-cancer cells treated with cytochalasin D show a decrease of 60-80 % in moduli values compared to untreated cells of the same origin, whereas the nocodazole-treated cells show no change. Alternatively, cancer cells exhibit increased stiffness as well as stiffness variability when subjected to nocodazole. Overall, we demonstrate actin filaments contribute more to elastic stiffness than microtubules but this result is cell type dependent. Lastly, we show that disruption of microtubule dynamics affects cancer cell elasticity, suggesting therapeutic drugs targeting microtubules be monitored for significant elastic changes.