Publications by authors named "Daniel Sepkovic"

The Luminal A subtype of breast cancer expresses the estrogen receptor (ER)-α and progesterone receptor (PR), but not the human epidermal growth factor receptor (HER)-2 oncogene. This subtype of breast cancer responds to endocrine therapy involving the use of selective estrogen receptor modulators and/or inhibitors of estrogen biosynthesis. However, these therapeutic agents are frequently associated with long-term systemic toxicity and acquired tumor resistance, emphasizing the need to identify non-toxic alternative treatments for chemo-endocrine therapy responsive breast cancer.

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In estrogen receptor (ER)+ MCF-7 cells, ER represents a ligand-activated transcription factor, and 17β-estradiol (E2) represents its physiological ligand. Maintenance of the human breast carcinoma-derived MCF-7 cells with 0.7% serum selected a proliferative sub-population of E2-responsive cells with transiently non-functional ER due to limited availability of E2.

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Hormonal exposures are known to influence breast cancer risk among women with a BRCA1 mutation. Thus, dietary factors that increase the 2-hydroxyestrone (OHE):16α-OHE ratio, a biomarker inversely related to breast cancer development, may also influence cancer risk. We conducted a dietary intervention study to evaluate the ability of 300 mg/day of 3,3'-diindolylmethane (DIM) to increase the urinary 2:16α-OHE ratio in 20 women with a BRCA1 mutation.

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Chemo-endocrine therapy for estrogen receptor positive (ER(+)) breast cancer exhibits acquired tumor resistance. Herbal medicines provide integrative support for breast cancer patients. Present study compared the efficacy of aqueous extracts from Lycium barbarum bark (LBB) and Lycium barbarum fruit (LBF) on ER(+) MCF-7 cells.

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Background: The effects of 3,3'-diindolylmethane (DIM) together with the Gardasil vaccine on cervical histology were evaluated using the K14-HPV16-transgenic mouse model. The possibility that DIM could enhance the efficacy of this preventive vaccine in this model was explored.

Materials And Methods: Transgenic mice were given 1000 mg/kg of DIM in the diet for 28 weeks.

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Background: Studies have shown associations of diabetes and endogenous hormones with exposure to a wide variety of organochlorines. We have previously reported positive associations of polychlorinated biphenyls (PCBs) and inverse associations of selected steroid hormones with diabetes in postmenopausal women previously employed in a capacitor manufacturing plant.

Methods: This paper examines associations of PCBs with diabetes and endogenous hormones in 63 men previously employed at the same plant who in 1996 underwent surveys of their exposure and medical history and collection of bloods and urine for measurements of PCBs, lipids, liver function, hematologic markers and endogenous hormones.

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Unlabelled: While cervical cancer incidence and mortality rates have declined in the United States, this cancer represents a worldwide threat. Human papilloma viral infection causes cervical neoplasia (CIN). 3,3'-Diindolylmethane (DIM) prevents or inhibits the progression from cervical dysplasia to cancer.

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The role of body fat as a risk factor for breast cancer has been well established. A decrease in the urinary 2/16α-hydroxyestrone ratio has also been shown to be a risk marker for breast cancer. These two observations are connected by the fact that obese women have decreased levels of 2-hydroxyestrone.

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There is an increasing body of literature showing associations of organochlorine exposure with risk of diabetes and insulin resistance. Some studies suggest that associations differ by gender and that diabetes risk, in turn, may be affected by endogenous steroid hormones. This report examines the relationships of serum PCBs and endogenous hormones with history of diabetes in a cohort of persons previously employed at a capacitor manufacturing plant.

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The human papilloma virus is the major cause of cervical cancer. Viral infection initiates cervical intraepithelial neoplasia, which progresses through several stages to cervical cancer. The objective of this study is to identify the minimum effective dose of diindolylmethane that prevents the progression from cervical dysplasia to carcinoma in situ.

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Background: The incidence of thyroid cancer is four to five times higher in women than in men, suggesting a role for estrogen (E₂) in the pathogenesis of thyroid proliferative disease (TPD) that comprises cancer and goiter. The objective of this study was to investigate the antiestrogenic activity of 3,3'-diindolylmethane (DIM), a bioactive compound derived from cruciferous vegetables, in patients with TPD.

Methods: In this limited phase I clinical trial study, patients found to have TPD were administered 300 mg of DIM per day for 14 days.

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Introduction: Both indole-3-carbinol and dietary lignans have beneficial effects on estrogen metabolism and breast cancer risk. There is no published literature on the effects of a combination product. This study was designed to investigate the impact of a combination product on estrogen metabolism.

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This study was designed to establish whether 3,3'-diindolylmethane (DIM) can inhibit cervical lesions, alter estrogen metabolism in favor of C-2 hydroxylation, and enhance immune function in the K14-HPV16 transgenic mouse model. Mice were bred, genotyped, implanted with E(2) pellets (0.25 mg/90-day release) under anesthesia, and divided into groups.

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Selective estrogen receptor modulators represent accepted therapy for estrogen receptor positive (ER+) breast cancer, exhibit adverse side effects, and reduce patient compliance. The use of phytoestrogen containing herbal medicines is limited because of efficacy and safety concerns. The ER+ MCF-7 model examined growth inhibitory effects of the medicinal herb Lycium barbarum (LB) and identified mechanistic leads for its efficacy.

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Seaweed and soy foods are consumed daily in Japan, where breast cancer rates for postmenopausal women are significantly lower than in the West. Likely mechanisms include differences in diet, especially soy consumption, and estrogen metabolism. Fifteen healthy postmenopausal women participated in this double-blind trial of seaweed supplementation with soy challenge.

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Although estradiol itself is primarily responsible for female development, the metabolites are responsible for many of the other positive and negative properties of estrogens. Phase I metabolism of estradiol is exclusively oxidative unlike the other steroid hormones and involves a series of hydroxylations. The specific hydroxylations can be induced or suppressed by endogenous or exogenous compounds that influence the cytochrome enzymes that act on specific sites on the molecule.

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Evidence suggests that 17beta-estradiol (E2) contributes to the risk of prostate cancer (PCa), whereas the phytochemicals genistein from soy and 3,3'-diindolylmethane (DIM), derived from indole-3-carbinol in cruciferous vegetables, decrease the risk of PCa. This study examined the potential of these phytochemicals to reduce the adverse effects of E2 on PCa. In LNCaP PCa cells (E2 sensitive), DIM decreased E2-induced proliferation.

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Long-chain 3-hydroxydicarboxylic acids (3-OHDCAs) are thought to arise via beta-oxidation of the corresponding dicarboxylic acids (DCAs), although long-chain DCAs are neither readily transported into nor beta-oxidized in mitochondria. We thus examined whether omega-hydroxylation of 3-hydroxy fatty acids (3-OHFAs), formed via incomplete mitochondrial oxidation, is a more likely pathway for 3-OHDCA production. NADPH-fortified human liver microsomes converted 3-hydroxystearate and 3-hydroxypalmitate to their omega-hydroxylated metabolites, 3,18-dihydroxystearate and 3,16-dihydroxypalmitate, respectively, as identified by GC-MS.

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We examined associations between polymorphisms in genes related to estrogen metabolism (CYP1B1 codon 432G --> C rs#1056836, CYP1B1 codon 453A --> G rs#1800440, COMT codon 158G --> A rs#4680) and biosynthesis (CYP17 T --> C promoter rs#743572, CYP19 exon 4 TTTA repeat) and urinary estrogen metabolites (2-hydroxyestrogens (2-OHE), 16alpha-hydroxyestrone (16alpha-OHE1), and their ratio) in a pilot study of 64 pre- and post-menopausal women with a family history of breast cancer. Women were participants in the Metropolitan New York Registry of Breast Cancer Families, one of six international sites of the National Cancer Institute's Breast Cancer Family Registry. We used linear regression to examine the effects of genetic variants on log-transformed urinary estrogen metabolites.

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Objective: To illustrate a relationship between proliferative thyroid disease and estrogen metabolism through the analysis of urinary estrogen metabolites.

Study Design And Setting: Case-control study of 49 subjects with proliferative thyroid disorders and matching them to 49 controls. Urinary estrogen metabolite ratios were obtained, measuring 2-hydroxyestrone, an anti-proliferative metabolite, to 16alpha-hydroxyestrone, a proliferative metabolite.

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Background: Specific pathways involved in estrogen metabolism may play a role in the etiology of breast cancer. We used data from a large population-based case-control study to assess the association of the urinary estrogen metabolites 2-hydroxyestrone (2-OHE1), 16alpha-hydroxyestrone (16-OHE1), and their ratio (2/16) with both invasive and in situ breast cancer.

Methods: Study participants from the Long Island Breast Cancer Study Project provided a spot urine specimen and completed a comprehensive interviewer-administered questionnaire.

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Introduction: Estrogen metabolites have been linked to risk of breast cancer, and we were interested in whether they are associated with prostate specific antigen (PSA) and other factors associated with prostate cancer. African-American (AA) men in South Carolina have among the highest prostate cancer rates in the world, and thus provide an ideal population in which to investigate this hypothesis.

Methods: We recruited AA men attending prostate cancer screenings in and around Columbia, South Carolina.

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Cytochrome P450 (CYP) is a multigene family of enzymes involved in important life functions; some of these genes are inducible and are implicated in the oxidative metabolic activation and detoxification of many endogenous and exogenous compounds. CYP1B1 codes for an enzyme that catalyses the production of a 2- and 4-hydroxyl group in estrone and estradiol, while CYP1A1 catalyzes the 2-hydroxylation of estradiol in endometrium. The two genes were evaluated in a cohort of 150 subjects: African-American women had significantly lower 2-hydroxyl estrone/16-hydroxyl estrone (2-OHE1/16-OHE1) urinary metabolite ratios than Caucasian women (2.

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A modified ELISA assay for measurement of the two estrogen metabolites 2-hydroxyestrone (2OHE1) and 16alpha-hydroxyestrone (16alphaOHE1) in plasma and serum has been developed. Previously, these have only been measured in urine. It is not known how well the measurements of these metabolites in urine and plasma are correlated.

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Controversy persists regarding the role of a low ratio of 2-hydroxyestone (2-OHE(1))/16alpha-hydroxyestrone (16alpha-OHE(1)) as a potential estrogen metabolism marker of increased risk for breast cancer. Most of the evidence has been provided by case-control studies, where tumor effects on hormone metabolism are not known. Studies in populations at various risk of breast cancer are not consistent, with some suggesting that levels of the ratio may be altered by changes in diet and exercise.

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