HETEROGENEITY OF ALPHA-FETOPROTEIN (AFP) AND ALBUMIN CONTAINING CELLS IN NORMAL AND PATHOLOGICAL PERMISSIVE STATES FOR AFP PRODUCTION - AFP CONTAINING CELLS INDUCED IN ADULT-RATS RECAPITULATE THE APPEARANCE OF AFP CONTAINING HEPATOCYTES IN FETAL RATS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 1  (2) , 93-105
Abstract
The cellular localization of .alpha.-fetoprotein (AFP) and albumin (ALB) in permissive states for AFP synthesis was examined. The cells containing AFP associated with permissive states in the adult are similar in appearance to cells that are present during the development of fetal liver. In fetal liver, AFP is seen in most developing hepatocytes ranging from small oval-like cells to larger, dividing hepatocytes, and in cells organized in glandular structures. Following exposure to some chemical hepatocarcinogens, AFP can also be seen in small oval cells, ductal-like cells and larger, atypical hepatocytes that form glandular-like structures. Following partial hepatectomy or galactosamine-induced liver injury, AFP is seen in a few large parenchymal cells, usually containing identifiable chromatin. Cells which contain AFP almost always contain ALB as well, but for each cell type there are many more ALB-containing cells than AFP-containing cells. ALB- and AFP-containing hepatoma cells are more frequently located adjacent to tumor vessels, and AFP production by hepatoma 777 in vitro is associated with the growth state of the tumor. The AFP-containing cells that are seen during resitutive proliferation most likely arise from deregulation of proliferating adult hepatocytes. The nonhepatoma AFP-containing cells that appear early during carcinogenesis may arise in the adult by retrodifferentiation of hepatocytes, or by proliferation of stem cells. These morphologically different AFP-containing cells may or may not be precursors of the hepatocellular carcinomas which develop later.