Thesis title: Identification of molecules able to interfere with the interaction between Aurora-A and N-Myc in Neuroblastoma
Neuroblastoma is a severe childhood disease accounting for the 10% of all infant cancers. The MYCN gene amplification, coding for the N-Myc transcriptional factor, is an essential marker correlated with prognosis and progression. In these cells, another protein frequently implicated and overexpressed in cancer, the mitotic kinase Aurora-A, offers stabilization to N-Myc by binding directly to the highly conserved region called Myc Box I. As a result, the correct turnover of N-Myc does not occur properly, explaining the elevated levels of this oncoprotein that is required for the growth of MYCN amplified cells.
During the years, it has been demonstrated that certain competitive inhibitors of Aurora-A, like CD532 and Alisertib, previously designed to target the kinase activity of the protein, are also able to impair the formation of the undesired Aurora-A/N-Myc complex in Neuroblastoma. Indeed, due to essential conformational changes in the structure of the kinase caused by the binding of such inhibitors, it has been noticed in vitro and in vivo that N-Myc finds difficulty to associate at the complex.
Here we present the identification of conformation disrupting compounds, starting from an in silico screening on the PDB among all the crystal structures of Aurora-A in complex with known inhibitors, where as a next step each one of them was superposed with that of the kinase bound to CD532 using the molecular modeling software PyMOL. Subsequently, the best candidates were initially tested with a kinase activity assay for their inhibitory ability against Aurora-A. Within a series of competition assays, conducted by Surface Plasmon Resonance means, we demonstrated for the first time in vitro that in presence of the previously identified compounds, N-Myc is not able to bind to Aurora-A. Last, through virtual screening and docking means, we obtained novel compounds to be tested for the exact same properties. Finally, we have identified promising compounds that could function as potential anti-cancer drugs that prevent the interaction between Aurora-A and N-Myc in Neuroblastoma.