Clinicopathological analysis of CD133+ and NCAM+ human hepatic stem/progenitor cells in damaged livers and hepatocellular carcinomas

Aim:  Hepatic stem cells are capable of dramatically changing and differentiating to form mature hepatocytes in acute and chronically damaged livers; however, the clinicopathological characteristics of these heterogeneous cell populations have not been sufficiently analyzed.
Methods:  In this study, cells in tissue sections from 12 cases of acute damaged livers and 31 cases of hepatocellular carcinomas (HCC), and the surrounding chronically damaged liver tissues, were analyzed by immunohistochemistry using the previously reported hepatic stem/progenitor cell marker CD133 (AC133) and the neural cell adhesion molecule (NCAM) marker.
Results:  In both the acute and chronically damaged livers, CD133⁺ cells and NCAM⁺ cells were present in ductular reactions (DR), which include hepatic stem/progenitor cells, and became more apparent in proportion to the degree of fibrosis or histological damage. Analysis of their distribution and morphological similarities revealed that the NCAM⁺ cell population included cells that were closer to, and morphologically more similar to, hepatocytes than were CD133⁺ cells. Analysis of HCC using these markers revealed that 9.7% of HCC expressed NCAM (two cases had abundant NCAM⁺ cells), while CD133⁺ HCC were not detected.
Conclusion:  These results suggest that CD133 and NCAM can be employed to enrich for hepatic stem/progenitor cells and that DR can be distinguished in greater detail using these markers. NCAM⁺ HCC were detected, but their function remains unresolved. Expression of CD133, a potent stem cell marker, may be extremely rare in the common human HCC examined.