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Estrogen‐induced cell transformation and DNA adduct formation in cultured Syrian hamster embryo cells
Author(s) -
Hayashi Nobuko,
Hasegawa Koko,
Komine Akiko,
Tanaka Yuriko,
McLachlan John A.,
Barrett J. Carl,
Tsutsui Takeki
Publication year - 1996
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/(sici)1098-2744(199607)16:3<149::aid-mc5>3.0.co;2-c
Subject(s) - biology , diethylstilbestrol , deoxyguanosine , hamster , somatic cell , dna damage , dna , microbiology and biotechnology , carcinogen , adduct , estrogen , biochemistry , chemistry , endocrinology , gene , organic chemistry
To study the possible involvement of DNA damage in cell transformation induced by estrogens, we examined whether DNA adduct formation is elicited in cultured Syrian hamster embryo (SHE) cells treated with estrogens and their derivatives by means of the 32 P‐postlabeling assay. Morphological transformation of the cells was induced by treatment with diethylstilbestrol (DES) at 1–10 μg/mL for 24 h but not by treatment with its derivatives trans, trans ‐dienestrol (α‐DIES) or cis, cis ‐dienestrol (β‐DIES) at 1–10 μg/mL for 24 h. Similarly, DNA adduct formation was elicited by exposure of SHE cells to DES at 1–10 μg/mL for 24 h but not by either α‐DIES or β‐DIES. Treatment of SHE cells with DES at 1–10 μg/mL for 2 h in the presence of exogenous metabolic activation with rat liver post‐mitochondrial supernatant enhanced morphological transformation in a dose‐dependent manner. Our previous studies have demonstrated that exposure of SHE cells to DES under the same conditions with exogenous metabolic activation induces somatic mutations at the Na + /K + ATPase locus. Therefore, we examined whether with exogenous metabolic activation DES induced DNA adduct formation in SHE cells. DNA adducts were not detected when SHE cells were treated with DES at 1–10 μg/mL for 2 h in the presence of exogenous metabolic activation. Treatment with 17β‐estradiol (E 2 ), 2‐hydroxyestradiol (2‐OH E 2 ), or 4‐hydroxyestradiol (4‐OH E 2 ) at 1 μg/mL for 24 h induced DNA adduct formation in the cells, in parallel with the induction of cell transformation. The rank order of DNA adduct formation was 4‐OH E 2 > 2‐OH E 2 > E 2 . The results indicate that estrogens induce DNA adduct formation in cultured SHE cells, but the induction may not be the only mechanism relevant to the initiation of cell transformation. © 1996 Wiley‐Liss, Inc.