-transparent.png){kind=logo}
The expression of gamma-glutamyltranspeptidase (gamma-GTP) and the relationship between this enzyme activity and tumorigenicity were studied in 38 tumorigenic and non-tumorigenic epithelial cell lines derived from livers of normal and aminoazo-dye-fed rats. Nine of 22 non-tumorigenic epithelial cell lines exhibited gamma-GTP-positive cells, whereas 9 of 16 tumorigenic epithelial cell lines did not exhibit gamma-GTP-positive cells. This finding revealed that no correlation existed between the acquisition of gamma-GTP activity and tumorigenicity. None of 10 spontaneously transformed epithelial cell lines, which consisted of 8 tumorigenic and 2 non-tumorigenic cell lines, exhibited gamma-GTP-positive cells. On the other hand, 16 of 28 transformed epithelial cell lines, which were derived from aminoazo-dye-fed rat livers and aminoazo-dye-treated cultures of normal rat liver cells, included gamma-GTP-positive cells in various percentages. As described above, in contrast to in vitro spontaneous transformation of rat liver cells, it is obvious that the carcinogen-induced transformation of rat liver cells in vitro as well as in vivo was frequently accompanied by the acquisition of gamma-GTP-activity. Therefore, it is concluded that the expression of gamma-GTP in liver cells may be mainly associated with exposure to chemical carcinogens.
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
September 1992,
Carcinogenesis,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
March 1990,
Cancer research,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
February 1984,
Biochimica et biophysica acta,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
March 1982,
Cancer research,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
April 1972,
Cancer research,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
July 1994,
Carcinogenesis,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
May 1981,
Research communications in chemical pathology and pharmacology,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
December 1989,
Tsitologiia,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
August 1986,
FEBS letters,
M Miyazaki, and
S Wahid, and
K Miyano, and
T Yabe, and
J Sato
January 1998,
Journal of biochemical and molecular toxicology,
