In the process of metastasis, cancer cells may transmigrate through the endothelium barrier of the vascular walls and into the circulatory blood system. During this process, the cancer cells...Show moreIn the process of metastasis, cancer cells may transmigrate through the endothelium barrier of the vascular walls and into the circulatory blood system. During this process, the cancer cells interact with the endothelial cells, resulting in the alternation of their mechanical properties. Although this interaction has been broadly studied from the perspective of cancer cells, no thorough investigation of the endothelial mechanical properties has been performed. In this thesis, by using a micro-rheology AFM-based approach, we show that the properties of endothelial cells change when cultured in cancer cell conditioned medium, as well as when in contact with cancer cells. We found that the stiffness of endothelial cells increased when cultured in a low-dilution cancer cell medium, while it decreased in high-dilution medium. This change was also evident on the viscoelasticity of the cells, with the endothelial cells cultured in high dilution medium showing lower viscoelastic properties. Furthermore, endothelial cells in direct contact with a cancer cell showed an increased height, as a result of the cancer cell's transmigration through the monolayer. Our findings demonstrate that the properties of endothelial cells change indirectly due to cancer cell secreted substances, and directly during the cancer cells' physical transmigration. This indicates that the endothelium is actively responding to the presence of cancer cells, rather than being a passive barrier as once believed.Show less
