Cell Cycle Synchronization for the Study of DNA Wrapped Single Walled Carbon Nanotube Influence on Neural Stem Cells

Abstract

as epithelial-mesenchymal transition (EMT), allows cells to facilitate cell migration, extracellular matrix assembly, and tissue patterning. The role of mechanical properties in EMT behavior is not well understood. Cellular mechanical properties affect cell migration, proliferation, signaling, and differentiation. Despite wide recognition of the importance of mechanobiology in cellular behavior, shortcomings in techniques to measure cellular forces generated by epithelial cells are difficult to accurately measure due to the low magnitude of cell forces and the lack of cytoskeletal rigidity in these cells. Additionally, EMT is regulated by two distinct sets of mechanical forces: forces between cells and the underlying matrix, and forces between neighboring cells. We have developed a system that can quantify both of these values, and determine how their interactions drive EMT. Our data shows that cell-matrix forces increase as the distance from the cell centroid increases, as has previously been modeled computationally by our lab. We also observe that epithelial cell colonies distribute forces as a single large aggregate, instead of as individual cells. This suggests that cellular forces are linked between cells via cell-cell adhesions, resulting in all force summing towards a collective cell centroid. Most notably, EMT stimuli such as TGF-beta produce significant increases in cellular traction forces, as well as a loss of this collective force pattern. This finding supports the hypothesis that mesenchymal cells are able to apply greater local cell-matrix forces. Together, these results promote a greater connection between the process of EMT and cellular forces which could provide future insight into understanding and treating diseases. Pancreatic cancer is the fifth most common cancer in the United States. Despite the advancements in modern medicine, five-year survival rate of such cancer is generally less than 10%. To better understand the underlying cause, mechanobiology of the PANC-1 cell line is ought to be investigated. Mechanical cellular interactions heavily influence major cellular processes such as metastasis, embryogenesis, angiogenesis, etc. Most of these physiological processes are in direct relations to cell migration. Such biological function is responsible for positive responses in one's body in aid of healing of wounds, or infamously, invasion of cancer cells through the connective tissues. To better understand these major physiological phenomena, it's critical to understand how these contractile motions are generated and quantification of traction forces is necessary. To measure these forces, resent studies showed that fluorescent beads were embedded in the substrate as markers to tract the forces being applied, named Traction Force Microscopy (TFM). However, such setup has no control over marker positions and often introduce background noise, e.g. loss of spatial resolution. In addition, beads usually have no direct contact with the cells, meaning traction force has higher degree of estimation as...