title: Isolation and characterization of epithelial progenitor cells from human fetal liver.
abstract: OBJECTIVE
  Hepatic progenitor cells can serve as an alternative source of hepatocytes for the treatment of liver diseases.
  
  
  METHODS
  We isolated and expanded the epithelial progenitor cells (EPC) from the human fetal liver and investigated the differentiation of EPC into hepatic cells by fluorescence-activated cell sorter (FACS), real-time polymerase chain reaction (PCR), immunofluorescence assay, western blotting, and periodic acid-Schiff staining.
  
  
  RESULTS
  Isolated EPC possessed highly proliferative ability and subpassaged for more than 25 passages. Real-time PCR showed that EPC expressed liver epithelial markers (cytokeratin [CK]8 and CK18) and biliary-specific markers (CK7 and CK19). FACS analysis indicated that these cells were positive for CD117, CD147, CD90, CD44, human leucocyte antigen class I and CD71, but negative for CD34 and CD45. The EPCpossessed multipotential indicated by differentiating into osteoblasts and adipocytes; when subjected to the hepatic differentiation condition, EPC could be induced to hepatocyte-like cells, which expressed albumin, alpha-fetoprotein, and CK18 proteins. Two months after EPC transplantation, we observed that the grafted cells differentiated into hepatocyte-like cells and there was no observable tumor mass.
  
  
  CONCLUSIONS
  We have isolated and characterized the human fetal liver-derived EPC and these cells may serve as an ideal cell source for cell-replacement therapy of diseased livers.
authors.affiliation: Department of Cell Biology, Peking University Health Science Center, and Peking University Stem Cell Research Center, Beijing, China.
authors.forename: Yi-Nan
authors.initials: YN
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Qi-Hua
authors.initials: QH
authors.lastname: He
authors.forename: Xin
authors.initials: X
authors.lastname: Dai
authors.forename: Li
authors.initials: L
authors.lastname: Shen