Metabolic adaptation is necessary for malignant tumor cells to survive the extreme conditions to which they are exposed within the mass of the primary tumor as well as throughout the metastatic process. In recent years it has been described that, despite having all the biosynthetic pathways intact, cancer cells of different origins are dependent on extracellular non-essential amino acids to support fundamental processes such as proliferation and survival. Here I will present data showing the centrality of amino acid metabolism, in particular of one-carbon metabolism, in the survival and metastatic ability of lung cancer cells. We studied serine hydroxymethyl transferases (SHMT), proteins fundamental in serine/glycine metabolism and revealed peculiar new properties such as their RNA binding ability. Taking advantage of these results, we are developing new approaches based on small RNA molecules to inhibit SHMTs, an enzyme for which effective small molecule inhibitors do not yet exist. We are also studying how the availability of selected amino acids (serine/glycine/glutamate) affect the ability of highly metastatic lung and breast cancer cells to select the brain as a target organ for metastasis formation. We clarified that these cells exploit extracellular amino acids to increase their extravasation ability, and that interfering with the import of these amino acids, which are abundant in the brain parenchyma, limits the formation of metastases in this organ, suggesting a novel therapeutic strategy to limit brain metastasis formation, a major cause of death in cancer patients.
25/03/2022 Dott. Alessio Paone (Dept Biochemical Sciences, Sapienza University of Rome)