Iron may induce both DNA synthesis and repair in rat hepatocytes stimulated by EGF/pyruvate.
OBJECTIVE
Hepatocellular carcinoma develops frequently in the course of genetic hemochromatosis, and a role of iron overload in hepatic carcinogenesis is strongly suggested.


METHODS
The aim of our study was to investigate the effect of iron exposure on DNA synthesis of adult rat hepatocytes maintained in primary culture stimulated or not by EGF/pyruvate and exposed to iron-citrate complex.


RESULTS
In EGF/pyruvate-stimulated cultures, the level of [3H] methyl thymidine incorporation was strongly increased as compared to unstimulated cultures. The addition of iron to stimulated cultures increased [3H] methyl thymidine incorporation. The mitotic index was also significantly higher at 72 h. However, the number of cells found in the cell layer was not significantly different from iron-citrate free culture. By flow cytometry, no difference in cell ploidy was found between iron-treated and untreated EGF/pyruvate-stimulated cultures. A significant increase in LDH leakage reflecting a toxic effect of iron was found in the cell medium 48 h after cell seeding. In addition, [3H] methyl thymidine incorporation in the presence of hydroxyurea was increased in iron-treated compared to untreated cultures.


CONCLUSIONS
Our results show that DNA synthesis is increased in the presence of iron in rat hepatocyte cultures stimulated by EGF/pyruvate, and they suggest that DNA synthesis is likely to be related both to cell proliferation and to DNA repair. These observations may allow better understanding of the role of iron overload in the development of hepatocellular carcinoma.
Chenoufi
N
N
INSERM U 49, University Hospital Pontchaillou, Rennes, France.
Loréal
O
O
Drénou
B
B
Cariou
S
S
Hubert
N
N
Leroyer
P
P
Brissot
P
P
Lescoat
G
G
D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology; D002452:Cell Count; D018929:Cell Culture Techniques; D002455:Cell Division / Q000187:drug effects; D019343:Citric Acid / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005434:Flow Cytometry; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D019289:Pyruvic Acid / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000925:Anticoagulants; D007004:Hypoglycemic Agents; D007328:Insulin; D019343:Citric Acid; D004815:Epidermal Growth Factor; D019289:Pyruvic Acid; D004247:DNA; D007501:Iron; D007770:L-Lactate Dehydrogenase