Influence of ursodeoxycholate-enriched diet on liver tumor growth in HBV transgenic mice.
Hepatitis B virus (HBV) transgenic mice (official designation, Tg [Alb-1 HBV] Bri 44) invariably develop macroscopically evident tumors within the 20th month of life. Sustained proliferative activity seems to play an important role in the development of these lesions. We previously showed that ursodeoxycholate (UDC) stimulates hepatocyte proliferation in various experimental settings. Herein, we tested the assumption that biological factors able to further increase liver cell proliferation, such as UDC, could accelerate tumor development in this animal model. For this study, 22 eight-week-old male transgenic mice were divided into 2 groups; 11 animals received a standard diet, and 11 received a UDC-enriched diet. The 2 groups were further divided into 2 subgroups of 5 and 6 animals each and were sacrificed at 3 and 15 months of age, respectively. These different times were chosen to exclude diet-related toxicity (in 3-month-old mice) and evaluate tumor growth (in 15-month-old mice). In addition, hepatocyte proliferation was assessed in all animals. In 3-month-old mice receiving UDC, cholestatic and cytolytic indices as well as liver histology were comparable to those in controls. At 15 months, all UDC-treated mice showed large multinodular tumors whereas only 33% of controls developed smaller uninodular neoplasms. Hepatocyte proliferation was increased in all animals receiving UDC compared with controls. In conclusion, the increase in serum UDC (undetectable in mice fed a standard diet), in the absence of any toxic effect on the liver, suggests the involvement of this bile salt in the stimulation of hepatocyte proliferation and tumor growth.
Barone
Michele
M
Section of Gastroenterology, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
Maiorano
Eugenio
E
Ladisa
Roberta
R
Cuomo
Rosario
R
Pece
Antonia
A
Berloco
Pasquale
P
Caruso
Maria Lucia
ML
Valentini
Anna Maria
AM
Iolascon
Achille
A
Francavilla
Antonio
A
Di Leo
Alfredo
A
Ierardi
Enzo
E
D018248:Adenoma, Liver Cell / Q000378:metabolism / Q000473:pathology* / Q000821:virology*; D000818:Animals; D001647:Bile Acids and Salts / Q000097:blood; D002756:Cholagogues and Choleretics / Q000008:administration & dosage*; D004032:Diet; D006509:Hepatitis B / Q000150:complications*; D006515:Hepatitis B virus / Q000235:genetics; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000821:virology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics; D009929:Organ Size; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D014580:Ursodeoxycholic Acid / Q000008:administration & dosage*
D001647:Bile Acids and Salts; D002756:Cholagogues and Choleretics; D018809:Proliferating Cell Nuclear Antigen; D014580:Ursodeoxycholic Acid