Specific Markers for Hepatic Progenitor Cells

One of mammalian organs that has remarkable ability to regenerate, liver, regenerates through the proliferation of hepatocytes or proliferation and differentiation of the stem cells resident. Some literatures states that these stem cells, the Hepatic Progenitor Cells (HPCs), are oval cells that have bipotential ability to be cholangiocytes and hepatocytes. However, the mechanisms of programming, activation of proliferation and maturation/differentiation have not completely understood. There are still disagreements on the sources and characterictics of HPCs. Consequently, these lead to a question on the characteristic (specific marker) of HPCs. To summarize the specific markers for HPCs that have ever been identified, the writers did a systematic review on 12 papers that fulfilled the research criteria and concluded that the markers used to identify HPCs are a combination of classic HPCs markers, i.e., oval cells (OV6 and OC2) progenitor/immature cells (CD56, Oct-3/4, DLK1, EFNA1 and Chrom-A), hepatocytes and cholangiocytes marker (Alb, AFP, CK7, CK8, CK18, CK19, GGT, EpCAM, CD24 and CD44) and hematopoietic stem cells markers (CD34, CD45, CD109, CD133, c-kit and Thy-1) since HPCs may share similar lineage as hematopoietic stem cells, hepatocytes and cholangiocytes. Precise markers for HPCs could not yet be determined; therefore, several markers should be combined to identify the HPCs. Difficulties in finding precise markers for HPCs might be caused by different expression of markers based on the HPCs differentiation and maturity.