The project

Extracellular vesicles fingerprint to anticipate evolution and metastases organotropism in HER2-positive breast cancer – EV-PRINT

Breast cancer (BC) is the most commonly diagnosed type of cancer globally. Thanks to the implementation of screening programs and the new treatments available, the 5-year relative survival now exceeds 90%. BC can thus be considered a remarkable success in the war against cancer; however, this means that there is an increasing number of BC survivors at high risk of developing secondary metastatic cancer that might need a close follow-up. HER2+ BC patients can indeed develop distant metastasis even after several years from the primary cancer removal, making highly desirable the development of a non-invasive liquid biopsy that can provide accurate monitoring with a low burden for the patients. Extracellular Vesicles (EVs) attracted massive interest as a promising liquid biomarker for BC. Breast tumor-derived EVs can prime the premetastatic niche, promoting tumor progression, and are now considered crucial also in organ-specific metastasis, especially considering their capacity to cross the blood-brain barrier through transcytosis. However, many aspects of EVs’ biological roles remain unexplored. The gaps in our knowledge are largely due to the many challenges associated with working on EVs: nanometric size, the limited understanding of their heterogeneity, the low abundance of cancer-related EVs subpopulations in biofluids, as well as the severe technical limitations affecting current EVs isolation and characterization protocols. EV-PRINT will take advantage of the access to one of the most important oncological biobanks in Italy to merge clinical /hystopathological classifications of metastatic vs non-metastatic BC tumors with advanced digital analytical techniques, namely, able to reach the single-analyte sensitivity. Single-vesicle microarrays will be used to phenotype blood isolated EVs, dissecting the EVs’ co-localization of relevant markers such as HER2, EpCAM, CEMIP, Del-1, Caveolin-1, and ANXA6. This knowledge will be transferred to single-molecule array technology (SiMoA, Quanterix) to develop an accurate, high-throughput and robust screening to be run in minimally processed plasma. Data will be fused with clinical and histological features to generate a fingerprint of HER2+ breast cancer predictive of metastases, especially in the brain, shedding light on the role of EVs in the complex process of metastatic organotropism. EV-PRINT will contribute to developing a new generation of cancer management strategies that will eventually decrease the overall costs of cancer health care and impact the sustainability of national health systems by providing improved tools for timely, accurate, and personalized disease diagnosis and prognosis.