In vivo cell lineage analysis during chemical hepatocarcinogenesis in rats using retroviral-mediated gene transfer: evidence for dedifferentiation of mature hepatocytes.
Feeding adult rats with a diet containing 2-acetylaminofluorene (2-AAF) results in suppression of hepatocyte proliferation and stimulation of oval cell proliferation. Although oval cells may be facultative liver stem cells, the actual relationship between oval cells and liver cancer has not been clearly established in vivo. Our goal was to label hepatic cells in vivo using retroviral vectors and follow their fate during the early steps of chemically induced hepatocarcinogenesis. Oval cell proliferation was induced by continuous feeding with a carcinogenic diet containing 2-AAF. We used two different strategies to genetically label hepatic cells: (a) labeling of proliferating cells in rats fed 2-AAF by injecting recombinant retroviral vectors containing the beta-galactosidase gene either in a peripheral vein or in the common bile duct at the peak of oval cell proliferation and (b) prelabeling of hepatocytes by intravenously injecting recombinant vectors 1 day after partial hepatectomy and 1 week before subsequent administration of 2-AAF. Using the first strategy, transgene expression occurred in both oval cells and hepatocytes. Using the second strategy, we could selectively label, and hence study the fate of, differentiated hepatocytes. In the latter case, we observed clusters of beta-galactosidase-positive hepatocytes, some of them also expressing preneoplastic markers such as gamma-glutamyl transpeptidase as well as the placental form of glutathione-S-transferase. These results demonstrate that preneoplastic foci can originate from mature hepatocytes and are consistent with the hypothesis that dedifferentiation of mature hepatocytes may occur during the course of carcinogenic regimen.
Gournay
Jérôme
J
Laboratoire de Thérapie Génique, Hôtel-Dieu, Centre Hospitalier Universitaire de Nantes, Nantes, France.
Auvigne
Isabelle
I
Pichard
Virginie
V
Ligeza
Catherine
C
Bralet
Marie-Pierre
MP
Ferry
Nicolas
N
D015073:2-Acetylaminofluorene / Q000633:toxicity; D000818:Animals; D014408:Biomarkers, Tumor; D002273:Carcinogens / Q000633:toxicity; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D019070:Cell Lineage; D002478:Cells, Cultured; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D007124:Immunoenzyme Techniques; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D012190:Retroviridae / Q000235:genetics*; D013234:Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D014408:Biomarkers, Tumor; D002273:Carcinogens; D015073:2-Acetylaminofluorene; D001616:beta-Galactosidase