Ricerc@Sapienza

Task#1. The results coming from this task will allow to better characterize the anatomy and physiology of HPC and PBG stem cell niches and their involvement in biliary disease, clarifying the pathways involved in biliary regeneration. Moreover, data obtained from this part of the project will be useful to clarify the fibrogenetic pathways in cholangiopathies and relevant clinical correlations.
In PBC, the activation of HPC niche due to cholangiocyte loss in PBC patients will be examined in human. HPC activation and DR will be put in the context of a deep clinical characterization of our PBC patient cohort to individuate novel histological features useful for risk stratification and to predict response to first-line therapy. This study will look at the mechanisms leading to the extension of DR due to cholestasis, with particular regard to its role in re-establish the ductular-canalicular junctions.
This objective of the project will further characterize pathogenetic mechanisms underlying fibrogenetic strictures of the large intrahepatic and extrahepatic bile ducts observed in patients affected by PSC and NAS. Moreover, differences in PBG activation and participation to damage will be individuated, thus defining the exact mechanism of fibrosis. In keeping, Biliary complications after liver transplantation, including non-anastomotic strictures (NAS), represent a major cause for re-transplantation, with a reported incidence varying between 5% and 30%; therefore, their pathogenesis would be crucial to individuate prognostic and clinical target. The correlation of histological study with clinical, radiological, and surgical parameters will unravel whether a proper activation of PBG niche both in terms of degree and mature fate commitment would be necessary for regenerating surface epithelium defects due to transplantation procedure.
Task#2. The spatially-resolved transcriptomic dataset will be used to build a data repository for the present study and to perform other future projects on the specific molecular targets and pathways identified in the discovery phase. Transcriptomic data of tumors with different anatomical and histological features will be integrated with clinical information to define tumor heterogeneity at molecular level and its association with a specific cell of origin. This will impact on developing novel tumor classification based on cell of origin, adding valuable contribution in patient stratification and prognosis, and in individuating possible risk factors for a specific tumor subtype. Currently, molecular characterization of tumors at diagnosis is not routinely performed; by individuating histological features associated with specific targetable molecular alterations, our study will allow to individuate patients that would benefit from specific therapeutic approaches, second-line treatments of further diagnostic workup. Obtained results will also represent the basis of unravelling the histological and molecular intra-tumoral heterogeneity of CCA. Most important and uniquely with respect to single cell transcriptomic approaches, the in situ molecular analysis of stromal and inflammatory cells (tumor microenvironment) will allow to clarify the interactions between tumor stroma and tumor epithelial cell growth and invasion. The impact of such study resides in the possibility of defining cell subpopulations or molecular features associated with tumor progression, with the potential individuation of tissue biomarkers and novel therapeutic targets. From a therapeutic point of view, the individuation of multiple targets in heterogenous tumor areas is an utmost need for defining personalized treatment approaches based on cellular compositions and tumor subgroup in every single patient.
Task#3. The results obtained from this task will furnish a comprehensive depict of immuno-oncology of CCA developed in patients affected by PSC. This task will clarify interactions between immune and epithelial cells within the biliary tree. The possibility to study cells at different step of carcinogenesis (hyperplasia, dysplasia, neoplasia) will identify relevant molecular events in this process. The comparison with sporadic CCA will allow to define whether biliary carcinogenesis in PSC is a unique process or it shares molecular events with other CCAs. Moreover, obtained results will clarify whether LPS-mediated TLR4 activation could have a role in PSC carcinogenesis, thus individuating the role of gut microbiota as a potential therapeutic target in these patients for CCA prevention. This task would also allow to individuate potential tissue/clinical biomarkers for PSC-CCA with a significant impact in the clinical management of these patients.