NEW PHARMACOLOGICAL TARGETS FOR CYSTIC FIBROSIS TREATMENT FROM OMICS PROFILING OF F508del-CFTR EXPRESSING CELLS.

Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, encoding an anion channel expressed on the epithelial cells of a variety of tissues. The deletion of phenylalanine in position 508 (F508del) is the most frequent CF-causing mutation, causing impaired trafficking and activity of the mutant channel. Today, two classes of drugs are available to treat CF: potentiators (molecules that increase the mutant CFTR function on the cell surface) and correctors (molecules that improve the processing and the delivery of mutant CFTR to the cell surface). It has been demonstrated that the combination of molecules exploiting different mechanisms of action is needed to achieve a therapeutically relevant rescue of CFTR. The aim of this project is to apply mass spectrometry (MS)-based omics techniques to understand what is associated to CFTR rescue and thus finding new potential targets for CF pharmacological treatment. Several strategies were applied for the functional rescue of CFTR at the plasma membrane (both pharmacological and genetic rescue). Proteomic and lipidomic profilings of F508del-CFTR expressing cells were performed after the application of these rescue strategies. The proteomic experiments were performed following the SWATH label-free quantification workflow, after the optimization of the panhuman ion library for CF research. Together with these experiments, Localisation of Organelle Proteins by Isotope Tagging after Differential ultraCentrifugation (LOPIT-DC) workflow was also applied to detect proteins that change their subcellular localization after the treatment with the most used corrector available for CF therapy (VX-809). Several candidate targets were found to be involved in F508del-CFTR rescue. Compounds aiming at the inhibition of these putative targets were tested on both immortalized and primary cells. Further validation studies are needed to confirm these results.