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Expression of gamma‐glutamyltranspeptidase in cultures of spontaneously and chemically transformed rat liver cells
Author(s) -
Miyazaki Masahiro,
Wahid Syarifuddin,
Miyano Keiko,
Yabe Tamae,
Sato Jiro
Publication year - 1983
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910320318
Subject(s) - gtp' , cell culture , in vitro , in vivo , carcinogen , cell , chemistry , malignant transformation , microbiology and biotechnology , biology , enzyme , biochemistry , cancer research , genetics
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 nontumorigenic 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.