Journal Article

Activation of 17β-estradiol and estrone by dimethyldioxirane and inhibition of rat liver nuclear and nucleolar RNA synthesis <i>in vitro</i>

Fu-Li Yu and Wanda Bender

in Carcinogenesis

Volume 17, issue 9, pages 1957-1961
Published in print September 1996 | ISSN: 0143-3334
Published online September 1996 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/17.9.1957
Activation of 17β-estradiol and estrone by dimethyldioxirane
                    and inhibition of rat liver nuclear and nucleolar RNA synthesis in
                        vitro

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

17β-estradiol (E2), estrone and diethylstilbestrol (DES) had no effect on nuclear and nucleolar RNA synthesis in vitro. However, after reacting with dimethyldioxirane (DMDO), a versatile epoxide-forming oxidant, these estrogens were able to inhibit and in a dose-dependent manner nuclear and nucleolar RNA synthesis in vitro. It was also found that the time required for the maximal activation of these chemicals by DMDO varied: estrone, 10 min; E2, 30 min; DES, 60 min. Tamoxifen (TAM) was also able to inhibit nuclear and nucleolar RNA synthesis in a dose-dependent manner, but the mechanism of this inhibition was more complex. Control experiments clearly indicated, unlike E2, estrone and DES, TAM per se was able to directly inhibit RNA synthesis in vitro. TAM after activation by DMDO was able to further inhibit RNA synthesis contributing part of the total observed inhibition. These data show for the first time that E2, estrone, DES and TAM can be activated by DMDO and possibly to epoxides. We propose that epoxidation of E2 and estrone may be the underlying mechanism of carcinogenesis for these estrogens in vivo.

Journal Article.  0 words. 

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.