Chemical hepatocarcinogenesis in transgenic mice overexpressing mature TGF beta-1 in liver.
The role of transforming growth factor beta 1 (TGF-beta 1) in carcinogenesis is a controversial issue. Certain results suggest a promoter role of this growth factor whilst in other experimental models TGF-beta 1 seems to inhibit the process of tumorigenesis. In an attempt to resolve this problem, we have performed chemical hepatocarcinogenesis experiments on transgenic mice expressing a high level of active TGF-beta 1 in their liver. Transgenic production of TGF-beta 1 did not result in spontaneous tumour formation during our observation period. However, two carcinogens, thioacetamide and N-OH acetylaminofluorene, were more potent in transgenic than in wild-type mice, whereas aflatoxin B1 was equally effective in both groups. Our observations suggest that an increased level of TGF-beta 1 in the liver does not provide protection against the effect of chemical carcinogens.
Schnur
J
J
1st Institute of Pathology and Experimental Cancer Research, Semmelweis University of Medicine, Budapest, Hungary.
Nagy
P
P
Sebestyén
A
A
Schaff
Z
Z
Thorgeirsson
S S
SS
D015073:2-Acetylaminofluorene / Q000378:metabolism; D016604:Aflatoxin B1 / Q000378:metabolism; D000818:Animals; D002273:Carcinogens / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D002273:Carcinogens; D016212:Transforming Growth Factor beta; D015073:2-Acetylaminofluorene; D016604:Aflatoxin B1