This laboratory has identified an unusual non-polar, biosynthetic metabolite of estradiol, the lipoidal derivative, LE2, and showed it to be a heterogeneous family of fatty acid esters of estradiol, esterified specificity at C-17. These esters are biologically active and occur naturally in human blood. Studies are to be conducted to determine the physiological and pathophysiological role of LE2. The concentration of LE2 in serum of women will be measured to ascertain the effect of: menstrual cycle, menopause, pregnancy, obesity and cancer (endometrial, ovarian, breast). LE2 will also be assayed in human breast cyst fluid. The distribution of fatty acid esters of plasma LE2 will be determined and compared using radioimmunoassay in concert with high pressure liquid chromatography. Other experiments will ascertain whether these circulating compounds are estrogenic messengers that are specific for tissues containing esterases capable of releasing estradiol. A variety of C-17 esters of estradiol will be synthesized and their ability to bind to the estrogen receptor will be correlated with their structure as determined by x-ray crystallography. The biochemical mechanisms involved in the synthesis and hydrolysis of these unusual compounds will be investigated. Structural studies of a similar family of glucocorticoids will be initiated. This laboratory developed gamma-emitting estrogens capable of binding to the estrogen receptor with high affinity, the 16alpha halogenated analogs of estradiol. 16alpha-125I-Iodo-estradiol which we synthesized in carrier-free form (2200 Ci/mmol) is now used generally to measure estrogen receptor with great sensitivity. We have shown that this compound is specifically cytotoxic to estrogen sensitive cells. Further kinetic, in vitro studies are being performed to examine: the dose relationship of this cell killing; the possible role of DNA repair inhibitors in potentiating this effect; in vivo killing of estrogen sensitive cancers. The short range deoxynucliotide destruction caused by the 125I isotope will be used to identify the estrogen receptor DNA binding site. The uptake of the 125I-labelled estrogen and the correlation with tumor estrogen receptors is being measured in women undergoing surgery for ovarian or breast cancer. Analogs of 16alpha-125I estradiol which may be resistent to metabolism are being synthesized as possible superior probes for in vivo killing and imaging. 16alpha-123I-Estradiol will be used as a probe for the imaging of estrogen responsive tumors. Other classes of steroids labelled with 125I are to be synthesized as ligands for the androgen, progesterone and corticoid receptors.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA029591-08
Application #
3168771
Study Section
Reproductive Endocrinology Study Section (REN)
Project Start
1980-07-01
Project End
1992-01-31
Budget Start
1987-05-01
Budget End
1988-01-31
Support Year
8
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Yale University
Department
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Pahuja, S L; Kim, A H; Lee, G et al. (1995) Origin of estradiol fatty acid esters in human ovarian follicular fluid. Biol Reprod 52:625-30
Pahuja, S L; Hochberg, R B (1995) A comparison of the esterification of steroids by rat lecithin:cholesterol acyltransferase and acyl coenzyme A:cholesterol acyltransferase. Endocrinology 136:180-6
Larner, J M; Pahuja, S L; Shackleton, C H et al. (1993) The isolation and characterization of estradiol-fatty acid esters in human ovarian follicular fluid. Identification of an endogenous long-lived and potent family of estrogens. J Biol Chem 268:13893-9
Markiewicz, L; Hochberg, R B; Gurpide, E (1992) Intrinsic estrogenicity of some progestagenic drugs. J Steroid Biochem Mol Biol 41:53-8
Larner, J M; Pahuja, S L; Brown, V M et al. (1992) Aromatase and testosterone fatty acid esters: the search for a cryptic biosynthetic pathway to estradiol esters. Steroids 57:475-9
Zielinski, J E; Pahuja, S L; Larner, J M et al. (1991) Estrogenic action of estriol fatty acid esters. J Steroid Biochem Mol Biol 38:399-405
Pahuja, S L; Zielinski, J E; Giordano, G et al. (1991) The biosynthesis of D-ring fatty acid esters of estriol. J Biol Chem 266:7410-6
Hochberg, R B; Pahuja, S L; Zielinski, J E et al. (1991) Steroidal fatty acid esters. J Steroid Biochem Mol Biol 40:577-85
Littlefield, B A; Gurpide, E; Markiewicz, L et al. (1990) A simple and sensitive microtiter plate estrogen bioassay based on stimulation of alkaline phosphatase in Ishikawa cells: estrogenic action of delta 5 adrenal steroids. Endocrinology 127:2757-62
Petrazzuoli, M; Pahuja, S L; Larner, J M et al. (1990) Biological activity of the fatty acid ester metabolites of corticoids. Endocrinology 127:555-9

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