Identification of Estrogen-Modified Nucleosides from Calf Thymus DNA Reacted with 6-Hydroxyestrogen 6-Sulfates
摘要:
Two estrogen sulfates, pyridinium 3-methoxyestra-1,3,5(10)-trien-6 alpha-yl sulfate (3MeE-6 alpha-S) and its GP-isomer (3MeE-6 beta-S), synthesized as model compounds to demonstrate the carcinogenesis of estrogen, were found to react with calf thymus DNA to produce steroid-modified DNA adducts. Digestion of the DNA by nuclease P1 and phosphodiesterase I followed by alkaline phosphatase gave a deoxyribonucleoside fraction, of which N-2-[3-methoxyestra-1,3,5( 10)-trien-6 alpha-yl]deoxyguanosine, N-2-[3-methoxyestra-1,3,5( 10)-trien-6 beta-yl]deoxyguanosine, N-6-[3-methoxyestra-1,3,5(10)-trien-6 alpha-yl]deoxyadenosine, and N-6-[3-methoxyestra-1,3,5(10)trien-6 alpha-yl]deoxyadenosine (identified as a base adduct) were identified using HPLC by comparing them with authentic specimens prepared by reacting dG; and dA with both sulfates. No steroid-dC adduct was detected in the digestion products of the DNA adduct, although dC reacted with the sulfates to form N-4-[3-methoxyestra-1,3,5(10)-trien-G beta-yl] deoxycytidine, These results mean that estrogen B-sulfate has an ability to modify DNA via the amino group of a guanine or adenine residue in DNA. The present studies imply that a sequential metabolism (hydroxylation and sulfation) at the Cs-position of the estrogen molecule causes damage to DNA.
Identification of Estrogen-Modified Nucleosides from Calf Thymus DNA Reacted with 6-Hydroxyestrogen 6-Sulfates
摘要:
Two estrogen sulfates, pyridinium 3-methoxyestra-1,3,5(10)-trien-6 alpha-yl sulfate (3MeE-6 alpha-S) and its GP-isomer (3MeE-6 beta-S), synthesized as model compounds to demonstrate the carcinogenesis of estrogen, were found to react with calf thymus DNA to produce steroid-modified DNA adducts. Digestion of the DNA by nuclease P1 and phosphodiesterase I followed by alkaline phosphatase gave a deoxyribonucleoside fraction, of which N-2-[3-methoxyestra-1,3,5( 10)-trien-6 alpha-yl]deoxyguanosine, N-2-[3-methoxyestra-1,3,5( 10)-trien-6 beta-yl]deoxyguanosine, N-6-[3-methoxyestra-1,3,5(10)-trien-6 alpha-yl]deoxyadenosine, and N-6-[3-methoxyestra-1,3,5(10)trien-6 alpha-yl]deoxyadenosine (identified as a base adduct) were identified using HPLC by comparing them with authentic specimens prepared by reacting dG; and dA with both sulfates. No steroid-dC adduct was detected in the digestion products of the DNA adduct, although dC reacted with the sulfates to form N-4-[3-methoxyestra-1,3,5(10)-trien-G beta-yl] deoxycytidine, These results mean that estrogen B-sulfate has an ability to modify DNA via the amino group of a guanine or adenine residue in DNA. The present studies imply that a sequential metabolism (hydroxylation and sulfation) at the Cs-position of the estrogen molecule causes damage to DNA.
Two estrogen sulfates, pyridinium 3-methoxyestra-1,3,5(10)-trien-6 alpha-yl sulfate (3MeE-6 alpha-S) and its GP-isomer (3MeE-6 beta-S), synthesized as model compounds to demonstrate the carcinogenesis of estrogen, were found to react with calf thymus DNA to produce steroid-modified DNA adducts. Digestion of the DNA by nuclease P1 and phosphodiesterase I followed by alkaline phosphatase gave a deoxyribonucleoside fraction, of which N-2-[3-methoxyestra-1,3,5( 10)-trien-6 alpha-yl]deoxyguanosine, N-2-[3-methoxyestra-1,3,5( 10)-trien-6 beta-yl]deoxyguanosine, N-6-[3-methoxyestra-1,3,5(10)-trien-6 alpha-yl]deoxyadenosine, and N-6-[3-methoxyestra-1,3,5(10)trien-6 alpha-yl]deoxyadenosine (identified as a base adduct) were identified using HPLC by comparing them with authentic specimens prepared by reacting dG; and dA with both sulfates. No steroid-dC adduct was detected in the digestion products of the DNA adduct, although dC reacted with the sulfates to form N-4-[3-methoxyestra-1,3,5(10)-trien-G beta-yl] deoxycytidine, These results mean that estrogen B-sulfate has an ability to modify DNA via the amino group of a guanine or adenine residue in DNA. The present studies imply that a sequential metabolism (hydroxylation and sulfation) at the Cs-position of the estrogen molecule causes damage to DNA.