Differential response of MDA‑MB‑231 breast cancer and MCF10A normal breast cells to cytoskeletal disruption

Metastasis remains a major clinical problem in cancer diagnosis and treatment. Metastasis is the leading cause of cancer-related mortality but is still poorly understood. Cytoskeletal proteins are considered potential therapeutic targets for metastatic cancer cells because the cytoskeleton serves a key role in the migration and invasion of these cells. Vimentin and F-actin exhibit several functional similarities and undergo quantitative and structural changes during carcinogenesis. The present study investigated the effects of vimentin and F-actin deficiency on the survival and motility of breast cancer cells. In metastatic breast cancer cells (MDA-MB-231) and breast epithelial cells (MCF10A), vimentin was knocked down by small interfering RNA and F-actin was depolymerized by latrunculin A, respectively. The effect of reduced vimentin and F-actin content on cell viability was analyzed using the MTT assay and the proliferative capacity was compared by analyzing the recovery rate. The effect on motility was analyzed based on two processes: The distance traveled by tracking the cell nucleus and the movement of the protrusions. The effects on cell elasticity were measured using atomic force microscopy. Separately reducing vimentin or F-actin did not effectively inhibit the growth and motility of MDA-MB-231 cells; however, when both vimentin and F-actin were simultaneously deficient, MDA-MB-231 cells growth and migration were severely impaired. Vimentin deficiency in MDA-MB-231 cells was compensated by an increase in F-actin polymerization, but no complementary action of vimentin on the decrease in F-actin was observed. In MCF10A cells, no complementary interaction was observed for both vimentin and F-actin.