Earlier studies indicated that cigarette smokers have a decreased risk of uterine endometrial cancer and an increased risk of osteoporosis which are thought to be caused by an inhibitory effect of cigarette smoking on estrogen action. Some but not all studies have indicated that cigarette smokers have lower plasma levels of estradiol and enhanced systemic 2-hydroxylation of this estrogen. A major focus of this proposal is to characterize the effects of cigarette smoking on NADPH-dependent metabolism of estradiol to multiple hydroxylated and keto metabolites by human liver and, in particular, by extrahepatic estrogen target organs such as uterine endometrium and placenta. In addition, we will characterize the profile of multiple estradiol metabolites formed by placentas from women exposed accidentally to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans which are potent inducers of microsomal monooxygenases. Our proposed studies should not only enhance our understanding of the antiestrogenic effect of cigarette smoking in women, but they should also provide us with useful information on the inducibility of cytochrome P450 enzymes that catalyzed the formation of various estradiol metabolites (including hormonally- active and/or genotoxic metabolites) in human liver as well as in human target organs for estrogen action. We plan to: (l).Determine the profile of NADPH-dependent estradiol metabolites formed by uterine endometrial microsomes from cigarette smokers and matched nonsmokers. (2).Determine the profile of NADPH-dependent estradiol metabolites formed by placental microsomes from cigarette smokers and matched nonsmokers. (3).Determine the profile of NADPH-dependent estradiol metabolites formed by liver microsomes from cigarette smokers and matched nonsmokers. (4).Determine the profile of NADPH-dependent estradiol metabolites formed by placental microsomes from women exposed accidentally to polychlorinated biphenyls and polychlorinated dibenzofurans. (5).Determine the effects of selective inhibitory antibodies to various cytochrome P450 isoforms on the pathways of estradiol metabolism observed in the studies described above. (6).Determine the effects of cigarette smoking on the concentration of unmetabolized estradiol in human uterine endometrium.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA074787-02
Application #
2700757
Study Section
Special Emphasis Panel (ZES1-CKS-B (M1))
Program Officer
Seifried, Harold E
Project Start
1997-05-01
Project End
1998-09-30
Budget Start
1998-05-01
Budget End
1998-09-30
Support Year
2
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Rutgers University
Department
Biology
Type
Schools of Pharmacy
DUNS #
038633251
City
New Brunswick
State
NJ
Country
United States
Zip Code
08901
Zhu, Bao Ting; Gallo, Michael A; Burger Jr, Conney W et al. (2008) Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin administration and high-fat diet on the body weight and hepatic estrogen metabolism in female C3H/HeN mice. Toxicol Appl Pharmacol 226:107-18
Zhu, Bao Ting; Lee, Anthony J (2005) NADPH-dependent metabolism of 17beta-estradiol and estrone to polar and nonpolar metabolites by human tissues and cytochrome P450 isoforms. Steroids 70:225-44
Lee, Anthony J; Conney, Allan H; Zhu, Bao Ting (2003) Human cytochrome P450 3A7 has a distinct high catalytic activity for the 16alpha-hydroxylation of estrone but not 17beta-estradiol. Cancer Res 63:6532-6
Lee, Anthony J; Cai, May Xiaoxin; Thomas, Paul E et al. (2003) Characterization of the oxidative metabolites of 17beta-estradiol and estrone formed by 15 selectively expressed human cytochrome p450 isoforms. Endocrinology 144:3382-98
Lee, Anthony J; Mills, Laura H; Kosh, Joseph W et al. (2002) NADPH-dependent metabolism of estrone by human liver microsomes. J Pharmacol Exp Ther 300:838-49
Zhu, Bao Ting; Cai, May Xiaoxin; Spink, David C et al. (2002) Stimulatory effect of cigarette smoking on the 15 alpha-hydroxylation of estradiol by human term placenta. Clin Pharmacol Ther 71:311-24
Lee, A J; Kosh, J W; Conney, A H et al. (2001) Characterization of the NADPH-dependent metabolism of 17beta-estradiol to multiple metabolites by human liver microsomes and selectively expressed human cytochrome P450 3A4 and 3A5. J Pharmacol Exp Ther 298:420-32
Zhu, B T; Kosh, J W; Fu, J et al. (2000) Strong inhibition of estrone-3-sulfatase activity by pregnenolone 16alpha-carbonitrile but not by several analogs lacking a 16alpha-nitrile group. Steroids 65:521-7
Zhu, B T; Patel, U K; Cai, M X et al. (2000) O-Methylation of tea polyphenols catalyzed by human placental cytosolic catechol-O-methyltransferase. Drug Metab Dispos 28:1024-30
Zhu, B T; Loder, D P; Cai, M X et al. (1998) Dietary administration of an extract from rosemary leaves enhances the liver microsomal metabolism of endogenous estrogens and decreases their uterotropic action in CD-1 mice. Carcinogenesis 19:1821-7