Manuela Gatto

UNLABELLED: Multipotent stem/progenitors are present in peribiliary glands of extrahepatic biliary trees from humans of all ages and in high numbers in hepato-pancreatic common duct, cystic duct, and hilum. They express endodermal transcription factors (e.g., Sox9, SOX17, FOXA2, PDX1, HES1, NGN3, PROX1) intranuclearly, stem/progenitor surface markers (EpCAM, NCAM, CD133, CXCR4), and sometimes weakly adult liver, bile duct, and pancreatic genes (albumin, cystic fibrosis transmembrane conductance regulator [CFTR], and insulin). They clonogenically expand on plastic and in serum-free medium, tailored for endodermal progenitors, remaining phenotypically stable as undifferentiated cells for months with a cell division initially every ≈36 hours and slowing to one every 2-3 days. Transfer into distinct culture conditions, each comprised of a specific mix of hormones and matrix components, yields either cords of hepatocytes (express albumin, CYP3A4, and transferrin), branching ducts of cholangiocytes (expressing anion exchanger-2-AE2 and CFTR), or regulatable C-peptide secreting neoislet-like clusters (expressing glucagon, insulin) and accompanied by changes in gene expression correlating with the adult fate. Transplantation into quiescent livers of immunocompromised mice results in functional human hepatocytes and cholangiocytes, whereas if into fat pads of streptozocin-induced diabetic mice, results in functional islets secreting glucose-regulatable human C-peptide. CONCLUSION: The phenotypes and availability from all age donors suggest that these stem/progenitors have considerable potential for regenerative therapies of liver, bile duct, and pancreatic diseases including diabetes.

Cholangiocarcinoma (CCA) is a devastating cancer arising from the neoplastic transformation of the biliary epithelium. It is characterized by a progressive increase in incidence and prevalence. The only curative therapy is radical surgery or liver transplantation but, unfortunately, the majority of patients present with advanced stage disease, which is not amenable to surgical therapies. Recently, proposed serum and bile biomarkers could help in the screening and surveillance of categories at risk and in diagnosing CCA at an early stage. The molecular mechanisms triggering neoplastic transformation and growth of biliary epithelium are still undefined, but significant progress has been achieved in the last few years. This review deals with the most recent advances on epidemiology, biology, and clinical management of CCA.

BACKGROUND: Efforts to identify cell sources and approaches for cell therapy of liver diseases are ongoing, taking into consideration the limits recognized for adult liver tissue and for other forms of stem cells. In the present study, we described the first procedure of via hepatic artery transplantation of human fetal biliary tree stem cells in patients with advanced cirrhosis. METHODS: The cells were immune-sorted from human fetal biliary tree by protocols in accordance with current good manufacturing practice (cGMP) and extensively characterized. Two patients with advanced liver cirrhosis (Child-Pugh C) have been submitted to the procedure and observed through a 12 months follow-up. RESULTS: The resulting procedure was found absolutely safe. Immuno-suppressants were not required, and the patients did not display any adverse effects correlated with cell transplantation or suggestive of immunological complications. From a clinical point of view, both patients showed biochemical and clinical improvement during the 6 month follow-up and the second patient maintained a stable improvement for 12 months. CONCLUSION: This report represents proof of the concept that the human fetal biliary tree stem cells are a suitable and large source for cell therapy of liver cirrhosis. The isolation procedure can be carried out under cGMP conditions and, finally, the infusion procedure is easy and safe for the patients. This represents the basis for forthcoming controlled clinical trials.