Terashima I, Suzuki N, Shibutani S
Laboratory of Chemical Biology, Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA.
Biochemistry. 2001 Jan 9;40(1):166-72. doi: 10.1021/bi002273c.
DNA damage caused by catechol estrogens has been shown to play an etiologic role in tumor formation. Catechol estrogens are reactive to DNA and form several DNA adducts via their quinone forms. To explore the mutagenic properties of 2-hydroxyestrogen-derived DNA adducts in mammalian cells, N(2)-(2-hydroxyestrogen-6-yl)-2'-deoxyguanosine and N(6)-(2-hydroxyestrogen-6-yl)-2'-deoxyadenosine adducts induced by quinones of 2-hydroxyestrone, 2-hydroxyestradiol, or 2-hydroxyestriol were incorporated site-specifically into the oligodeoxynucleotides ((5)(')TCCTCCTCXCCTCTC, where X is dG, dA, 2-OHE-N(2)-dG, or 2-OHE-N(6)-dA). The modified oligodeoxynucleotides were inserted into single-stranded phagemid vectors followed by transfection into simian kidney (COS-7) cells. Preferential incorporation of dCMP, the correct base, was observed opposite all 2-OHE-N(2)-dG adducts. Only targeted G --> T transversions were detected; the highest mutation frequency (18.2%) was observed opposite the 2-OHE(2)-N(2)-dG adduct, followed by 2-OHE(1)-N(2)-dG (4.4%) and 2-OHE(3)-N(2)-dG (1.3%). When 2-OHE-N(6)-dA adducts were used, preferential incorporation of dTMP, the correct base, was observed. Targeted mutations representing A --> T transversions were detected, accompanied by small numbers of A --> G transitions. The highest mutation frequencies were observed with 2-OHE(1)-N(6)-dA and 2-OHE(3)-N(6)-dA (14.5 and 14.1%, respectively), while 2-OHE(2)-N(6)-dA exhibited a mutation frequency of only 6.0%. No mutations were detected with vectors containing unmodified oligodeoxynucleotides. Thus, 2-OHE quinone-derived DNA adducts are mutagenic, generating primarily G --> T and A --> T mutations in mammalian cells. The mutational frequency varied depending on the nature of the 2-OHE moiety.
儿茶酚雌激素引起的DNA损伤已被证明在肿瘤形成中起病因学作用。儿茶酚雌激素对DNA具有反应性，并通过其醌形式形成多种DNA加合物。为了探索2-羟基雌激素衍生的DNA加合物在哺乳动物细胞中的诱变特性，将由2-羟基雌酮、2-羟基雌二醇或2-羟基雌三醇的醌诱导产生的N(2)-(2-羟基雌激素-6-基)-2'-脱氧鸟苷和N(6)-(2-羟基雌激素-6-基)-2'-脱氧腺苷加合物位点特异性地掺入寡聚脱氧核苷酸((5)'TCCTCCTCXCCTCTC，其中X为dG、dA、2-OHE-N(2)-dG或2-OHE-N(6)-dA)。将修饰后的寡聚脱氧核苷酸插入单链噬菌粒载体，随后转染到猴肾(COS-7)细胞中。在所有2-OHE-N(2)-dG加合物的对面均观察到正确碱基dCMP的优先掺入。仅检测到靶向的G→T颠换；在2-OHE(2)-N(2)-dG加合物的对面观察到最高突变频率(18.2%)，其次是2-OHE(1)-N(2)-dG(4.4%)和2-OHE(3)-N(2)-dG(1.3%)。当使用2-OHE-N(6)-dA加合物时，观察到正确碱基dTMP的优先掺入。检测到代表A→T颠换的靶向突变，并伴有少量A→G转换。在2-OHE(1)-N(6)-dA和2-OHE(3)-N(6)-dA中观察到最高突变频率(分别为14.5%和14.1%)，而2-OHE(2)-N(6)-dA的突变频率仅为6.0%。在含有未修饰寡聚脱氧核苷酸的载体中未检测到突变。因此，2-OHE醌衍生的DNA加合物具有诱变作用，在哺乳动物细胞中主要产生G→T和A→T突变。突变频率因2-OHE部分的性质而异。
