Identification of novel drug targets in the Notch pathway that are relevant to tumor formation
Worldwide Cancer Research
University of Milan
Recent work in Drosophila melanogaster has revealed a central role of the endo-lysosomal compartment in Notch signaling activation. However, endo-lysosomal Notch signaling is ill-understood in mammals and strategies to counteract it have not emerged yet, limiting our ability to act on tumors arising from Notch signaling alterations.   We postulate that endo-lysosomal Notch signaling might play a yet unrecognized important role in Notch-dependent tumorigenesis that awaits experimental exploration.   In Task 1, we aim to study 30+ new drug targets that we have identified in a recent screen for trafficking regulators of Notch in human cells. For this, we have established a pipeline for quantitative assessment Notch trafficking and activation. New genes that are found to act in the endo-lysosomal activation process will be modulated in specific Notch-dependent cancer cell lines, upon depletion or by pharmacologic treatment. In Task 2, the Drosophila homologs of the most promising ones will be analyzed to determine their effect on Notch-dependent tumorigenesis using genetic assays in vivo. For such effort, we will generate mutants by CRISPR/Cas9 gene editing and will study them using Notch and endocytic assays that recapitulate features of tumorigenesis in vivo. In task 3, based on the indications of task 2, we will use Drosophila as a host for tumor transplantation and drug testing.   In summary, we will identify new regulators of endo-lysosomal Notch signaling, understand their role in tumorigenesis, and characterize their potential pharmacologic modulators. At a time in which clinical therapies based on targeting Notch signaling are still an unfulfilled promise, detailed understanding of Notch events associated to the endo-lysosomal system will be key to devise more effective and less toxic pharmacologic options.
2.1 Biological and endogenous factors