Despite major advances in breast cancer diagnostics and treatment over the years, the disease is still a leading cause of death in women worldwide. Primary breast tumors can be treated relatively... Show moreDespite major advances in breast cancer diagnostics and treatment over the years, the disease is still a leading cause of death in women worldwide. Primary breast tumors can be treated relatively well with radiation, surgery, chemotherapy or a combination of these treatments. The occurrence of distant metastases derived from the primary tumor however, results in a considerable decrease in disease prognosis. Metastasis formation occurs through a series of distinct cell biological steps (outlined above). Understanding the molecular mechanisms that underlie each of these steps will help in the development of more successful anti-metastasis treatments. In this thesis, both in vitro and in vivo studies are described that aim at unraveling some of the processes involved in metastasis formation: signaling by components of the focal adhesions and cell migration. Show less
Tumor cell migration and invasion are essential steps in cancer metastasis. Better understanding of the molecular mechanisms and function of the individual proteins affecting this behaviour is... Show moreTumor cell migration and invasion are essential steps in cancer metastasis. Better understanding of the molecular mechanisms and function of the individual proteins affecting this behaviour is essential to define potential novel drug targets to combat cancer. In general, cells in a normal tissue environment are attached to the extra-cellular matrix (ECM) and to each others. The interactions with the ECM are mediated through integrin adhesion receptors. Matrix adhesions are the physical link between the ECM and the actin cytoskeleton and are important for survival, proliferation, differentiation and migration. These cytoplasmic structures are composed of various signaling (phosphatases and kinases) and structural proteins that form the so-called __integrin-adhesome__. The spatial and temporal regulations of these components determine the type of matrix adhesion, their behaviour and finally the fate of the cell. For instance, resting cells such as renal epithelial cells show enlarged and stable focal adhesions as well as tight cell-cell contacts. In contrast, tumor cells which are able to invade and metastasize, lose their interactions with adjacent cells and show fast, small and highly dynamic matrix adhesions. In this thesis, we set up technologies and investigated the molecular mechanisms of the matrix adhesions dynamics in relation to tumor cell behaviour both in vitro and in vivo situation. Show less
