کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10847746 | 1070455 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Slow loss of deoxyribose from the N7deoxyguanosine adducts of estradiol-3,4-quinone and hexestrol-3â²,4â²-quinone.
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
DMFTFAADEGUA4-OHE22′-deoxyguanosine - 2'-deoxyguanosine4-Hydroxyestradiol - 4-هیدروکسی استرادیولMS/MS - MS / MSN,N-dimethylformamide - N، N-dimethylformamideAdenine - آدنینEstradiol - استرادیولTrifluoroacetic acid - اسید TrifluoroaceticHES - او هستTandem mass spectrometry - طیف سنجی جرمی پشت سر هم یا متوالیHexestrol - هگزاسترولGuanine - گوانین
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A variety of evidence has been obtained that estrogens are weak tumor initiators. A major step in the multi-stage process leading to tumor initiation involves metabolic formation of 4-catechol estrogens from estradiol (E2) and/or estrone and further oxidation of the catechol estrogens to the corresponding catechol estrogen quinones. The electrophilic catechol quinones react with DNA mostly at the N-3 of adenine (Ade) and N-7 of guanine (Gua) by 1,4-Michael addition to form depurinating adducts. The N3Ade adducts depurinate instantaneously, whereas the N7Gua adducts depurinate with a half-life of several hours. Only the apurinic sites generated in the DNA by the rapidly depurinating N3Ade adducts appear to produce mutations by error-prone repair. Analogously to the catechol estrogen-3,4-quinones, the synthetic nonsteroidal estrogen hexestrol-3â²,4â²-quinone (HES-3â²,4â²-Q) reacts with DNA at the N-3 of Ade and N-7 of Gua to form depurinating adducts. We report here an additional similarity between the natural estrogen E2 and the synthetic estrogen HES, namely, the slow loss of deoxyribose from the N7deoxyguanosine (N7dG) adducts formed by reaction of E2-3,4-Q or HES-3â²,4â²-Q with dG. The half-life of the loss of deoxyribose from the N7dG adducts to form the corresponding 4-OHE2-1-N7Gua and 3â²-OH-HES-6â²-N7Gua is 6 or 8Â h, respectively. The slow cleavage of this glycosyl bond in DNA seems to limit the ability of these adducts to induce mutations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Steroids - Volume 70, Issue 1, January 2005, Pages 29-35
Journal: Steroids - Volume 70, Issue 1, January 2005, Pages 29-35
نویسندگان
Muhammad Saeed, Muhammad Zahid, Sandra J. Gunselman, Eleanor Rogan, Ercole Cavalieri,