Imparing proliferation, survival and invasiveness of Intrahepatic Cholangiocarcinoma through a novel natural Hedgehog pathway inhibitor

Background and aims: Intrahepatic cholangiocarcinoma (iCCA) represents a rare and aggressive cancer that originate from the biliary tree bearing a fatal prognosis (5-years relative survival rate). Nowadays, it is a worldwide health issue that need an imperative resolution. Depending on its molecular, histological, and clinical various features, its subcategorization into small and large bile duct iCCA has been approved by World Health Organization (ICD-O-3.2). From a molecular perspective, there are several signaling pathways entailed in the genesis, promotion and aggressiveness, and diagnosis and prognosis of iCCA. Among them, Hedgehog (Hh) pathway plays a decisive function in tumor proliferation, survival and epithelial-mesenchymal transition. The main purpose of this study is to shed a light on a new Hh inhibitor, a natural product named Glabrescione B (GlaB), in vitro in iCCA established and primary cell lines. Method: Trypan Blue Exclusion test have been used to assess the dose-response of free GlaB and hyaluronic acid (HA)-encapsulated GlaB, an inhibitor of Gli1 (a transcription factor and the final effector of Hh pathway). Western blot has been used to evaluate the target protein levels. Wound healing assay has been established to evaluate the migratory activity. Flow cytometry analyses has been used to assess cell death after treatments. All experiments have been conducted in n.3 experimental replicates. Results: Our research reports a mitigation in iCCA cell rate proliferation, migration, and decrease of Gli1 levels in a dose- and time-dependent manner after both free GlaB and HA-GlaB (for better deliver the drug in the site of injury) treatments (p <0.05), leading to a significant reduction of invasiveness and aggressiveness in cancer cells. Further, flow cytometry preliminary data indicates an induction of cell death after drug administration compared to controls. Conclusion: These data provide the basis for additional in vitro investigations and in vivo pre-clinical studies for the management of iCCA.