Analysis of mRNA translation in endothelial cells exposed to tumour microenvironmental conditions.

Angiogenesis, the process in which new blood vessels arise from pre-existing ones, is one of the hallmarks of cancer. Angiogenesis is indispensable for the transition from a contained tumour to an invasive, metastatic disease. Tumour microenvironment (TME), defined as the tissue context in which the tumour arises, plays a fundamental role in promoting angiogenesis, since many of its cellular components and biochemical features stimulate the production and the release in the extracellular matrix (ECM) of pro-angiogenic factors that deeply influence endothelial cells (ECs) behaviour, stimulating their transition from a quiescent, non-proliferative state, to an activated, proliferating one. During this switch ECs (the cell type constituting the lining of the blood vessels) undergo significative metabolic rearrangements that deeply affect, among others, also their protein biosynthesis apparatus, which is redirected towards the production of proteins essential to sustain cells’ proliferation, migration and reorganization in microvascular structures. The present thesis will focus on how, in Human Umbilical Vein Endothelial Cells (HUVECs), mRNA translation (the key molecular event in which a protein-coding mRNA is converted into a functional polypeptide) is affected by the typical biochemical conditions of the TME, namely hypoxia, low glucose levels, general nutrient starvation, high lactate concentration, pronounced oxidative stress and ECM stiffness. To assess it, useful techniques to investigate translation, among which puromycin pulse labelling and polysome profile, will be presented.