Serum concentration and urinary excretion of "classical" estrogens, catecholestrogens and 2-methoxyestrogens in normal human pregnancy

Restoration of serum estradiol and reduced incidence of miscarriage in patients with low serum estradiol during pregnancy: a retrospective cohort study using a multifactorial protocol including DHEA

Background

Low serum estradiol in early pregnancy is associated with an elevated risk of miscarriage. We sought to determine whether efforts to restore low blood estradiol via estradiol or dehydroepiandrosterone (DHEA) supplementation would reduce the risk of miscarriage as part of a multifactorial symptom-based treatment protocol.

Methods

This retrospective cohort study included women with low serum estradiol levels in early pregnancy, defined as ≤50% of reference levels by gestational age. Estradiol or DHEA were administered orally, and the primary outcome measure was serum estradiol level, in reference to gestational age. The secondary outcome measures included miscarriage, birth weight, and gestational age at birth.

Results

We found no significant effect of estradiol supplementation on serum estradiol levels referenced to gestational age, while DHEA supplementation strongly increased estradiol levels. For pregnancies with low estradiol, the miscarriage rate in the non-supplemented group was 45.5%, while miscarriage rate in the estradiol and DHEA supplemented groups were 21.2% (p = 0.067) and 17.5% (p = 0.038), respectively. Birth weight, size, gestational age, and preterm deliveries were not significantly different. No sexual abnormalities were reported in children (n = 29) of DHEA-supplemented patients after 5-7 years follow-up.

Conclusions

In conclusion, DHEA supplementation restored serum estradiol levels, and when included in the treatment protocol, there was a statistically significant reduction in miscarriage.

Associations Between Parity and Cognition: Race/Ethnic Differences

BACKGROUND

Race/ethnicity is associated with differences in reproductive history and cognition individually, yet it remains an understudied factor in the relationship between parity and later-life cognition.

OBJECTIVE

To evaluate if the association between parity and cognition differs between racial/ethnic groups.

METHODS

Participants included 778 older, postmenopausal women from the Health and Nutrition Examination Survey (Latina: n = 178, Non-Latino Black [NLB]: n = 169, Non-Latino White [NLW]: n = 431) who self-reported at least one birth. Cognitive outcomes included working memory, learning memory, and verbal fluency. Covariates included age, education, cardiovascular and other reproductive health factors, adult socioeconomic status (SES) and depressive symptoms. We fit a series of linear models to examine a) whether parity was associated with cognitive functioning, b) if this association varied by race/ethnicity through parity by race/ethnicity interactions, and c) individual parity with cognition associations stratified by race/ethnicity.

RESULTS

In the full sample, parity was significantly negatively associated with Digit Symbol Substitution Test (DSST) performance (b = -0.70, p = 0.024) but not Animal Fluency or word-list learning and memory. Tests of race/ethnicity-by-parity interactions were not statistically significant (ps > 0.05). However, stratified analyses by race/ethnicity showed a differential effect of parity on DSST performance, such that parity was significantly negatively associated with DSST performance (b = -1.66, p = 0.007) among Latinas but not in NLWs (b = -0.16, p = 0.74) or NLBs (b = -0.81, p = 0.191).

CONCLUSION

Among Latina, but not NLB or NLW women, greater parity was associated with worse processing speed/executive functioning later in life. Further research is needed to understand the mechanisms driving racial/ethnic differences.

The scientific body of knowledge - Whose body does it serve? A spotlight on oral contraceptives and women's health factors in neuroimaging

Women constitute half of the world's population, yet neuroscience research does not serve the sexes equally. Fifty years of preclinical animal evidence documents the tightly-coupled relationship between our endocrine and nervous systems, yet human neuroimaging studies rarely consider how endocrine factors shape the structural and functional architecture of the human brain. Here, we quantify several blind spots in neuroimaging research, which overlooks aspects of the human condition that impact women's health (e.g. the menstrual cycle, hormonal contraceptives, pregnancy, menopause). Next, we illuminate potential consequences of this oversight: today over 100 million women use oral hormonal contraceptives, yet relatively few investigations have systematically examined whether disrupting endogenous hormone production impacts the brain. We close by presenting a roadmap for progress, highlighting the University of California Women's Brain Initiative which is addressing unmet needs in women's health research.

Applying a Women's Health Lens to the Study of the Aging Brain

A major challenge in neuroscience is to understand what happens to a brain as it ages. Such insights could make it possible to distinguish between individuals who will undergo typical aging and those at risk for neurodegenerative disease. Over the last quarter century, thousands of human brain imaging studies have probed the neural basis of age-related cognitive decline. "Aging" studies generally enroll adults over the age of 65, a historical precedent rooted in the average age of retirement. A consequence of this research tradition is that it overlooks one of the most significant neuroendocrine changes in a woman's life: the transition to menopause. The menopausal transition is marked by an overall decline in ovarian sex steroid production-up to 90% in the case of estradiol-a dramatic endocrine change that impacts multiple biological systems, including the brain. Despite sex differences in the risk for dementia, the influence that biological sex and sex hormones have on the aging brain is historically understudied, leaving a critical gap in our understanding of the aging process. In this Perspective article, we highlight the influence that endocrine factors have on the aging brain. We devote particular attention to the neural and cognitive changes that unfold in the middle decade of life, as a function of reproductive aging. We then consider emerging evidence from animal and human studies that other endocrine factors occurring earlier in life (e.g., pregnancy, hormonal birth control use) also shape the aging process. Applying a women's health lens to the study of the aging brain will advance knowledge of the neuroendocrine basis of cognitive aging and ensure that men and women get the full benefit of our research efforts.

2-Methoxyestradiol attenuates liver fibrosis in mice: implications for M2 macrophages

Liver fibrosis is a major health problem worldwide due to its serious complications including cirrhosis and liver cancer. 2-Methoxyestradiol (2-ME) is an end metabolite of estradiol with anti-proliferative, antioxidant, and anti-inflammatory activities. However, the protective role of 2-ME in liver fibrosis has not been fully investigated. The aim of this study was to determine the protective effect of 2-ME in carbon tetrachloride (CCl₄)-induced liver fibrosis in mice. Animals were injected intraperitoneally with CCl₄ twice weekly for 6 weeks. 2-ME 50 mg/kg or 100 mg/kg was administrated intraperitoneally every day over the same period. Our data showed that 2-ME reduced the extent of liver toxicity and fibrosis due to CCl₄ exposure. It restored the elevated serum liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels and ameliorated oxidative status. In addition, 2-ME significantly reduced collagen deposition and alpha-smooth muscle actin (α-SMA) protein expressions. Furthermore, 2-ME markedly lowered macrophage infiltration and macrophage alternative activation marker chitinase-like molecules (CHI3L3/YM1). The results of this study indicate an important protective activity of 2-ME in liver fibrosis and highlight the role of macrophage recruitment and alternative activation as a possible target.

Effect of Reproductive History and Exogenous Hormone Use on Cognitive Function in Mid- and Late Life

OBJECTIVES

To investigate the association between reproductive history indicators of hormonal exposure, including reproductive period, pregnancy, and use of hormonal contraceptives, and mid- and late-life cognition in postmenopausal women.

DESIGN

Analysis of baseline data from two randomized clinical trials: the Women's Isoflavone Soy Health and the Early vs Late Intervention Trial of Estradiol.

SETTING

University academic research center.

PARTICIPANTS

Naturally menopausal women (N = 830).

MEASUREMENTS

Participants were uniformly evaluated using a cognitive battery and a structured reproductive history questionnaire. Outcomes were composite scores for verbal episodic memory, executive function, and global cognition. Reproductive variables included ages at pregnancies, menarche, and menopause; reproductive period; number of pregnancies; and use of hormones for contraception and menopausal symptoms. Multivariable linear regression was used to evaluate associations between cognitive scores (dependent variable) and reproductive factors (independent variables), adjusting for age, race and ethnicity, income, and education.

RESULTS

On multivariable modeling, age at menarche of 13 and older was inversely associated with global cognition (P = .05). Last pregnancy after age 35 was positively associated with verbal memory (P = .03). Use of hormonal contraceptives was positively associated with global cognition (P trend = .04), and verbal memory (P trend = .007). The association between hormonal contraceptive use and verbal memory and executive function was strongest for more than 10 years of use. Reproductive period was positively associated with global cognition (P = .04) and executive function (P = .04).

CONCLUSION

In this sample of healthy postmenopausal women, reproductive life events related to sex hormones, including earlier age at menarche, later age at last pregnancy, longer reproductive period, and use of oral contraceptives are positively related to aspects of cognition in later life.

Recent Advances in chemistry and pharmacology of 2-methoxyestradiol: An anticancer investigational drug

2-Methoxyestradiol (2ME2), an estrogen hormone metabolite is a potential cancer chemotherapeutic agent. Presently, it is an investigational drug under various phases of clinical trials alone or in combination therapy. Its anticancer activity has been attributed to its antitubulin, antiangiogenic, pro-apoptotic and ROS induction properties. This anticancer drug candidate has been explored extensively in last twenty years for its detailed chemistry and pharmacology. Present review is an update of its chemistry and biological activity. It also extends an assessment of potential of 2ME2 and its analogues as possible anticancer drug in future.

Mass spectrometry methods measured androgen and estrogen concentrations during pregnancy and in newborns of mothers with polycystic ovary syndrome

OBJECTIVE

Little is known about the aetiology of polycystic ovary syndrome (PCOS). Some suggest that elevated maternal androgens during gestation play a causative role. This implies placental passage of androgens during pregnancy. The aim of this study is to compare androgen and estrogen concentrations in maternal serum during pregnancy and in umbilical cord blood, between mothers with PCOS and their offspring compared to controls.

DESIGN

Prospective case-control study.

METHODS

Maternal blood samples were collected around 20 weeks of gestation and at delivery. Umbilical cord blood was also taken at delivery. Androgens (testosterone (T), androstenedione (ADION), dehydroepiandrostenedione (DHEA)) and estrogens (estrone (E1), estradiol (E2), estriol (E3)) were measured using the liquid chromatography tandem mass spectrometry (LC-MS/MS) methods.

RESULTS

At 20 weeks of gestation: T (P=0.019) and ADION (P=0.034) were higher in the PCOS mothers (pregnant with a girl), whereas DHEA, E1, E2, and E3 were not different. Maternal concentration at birth: T (P=0.004) and ADION (P=0.009) were also higher in the subgroup of PCOS mothers that were pregnant with a girl compared to the girl pregnancy controls. DHEA, E1, E2 and E3 were not different. In umbilical cord blood, no differences were found for T, ADION, DHEA, E2, E3, and AMH between the PCOS mothers and the controls respectively. E1 was lower in girls from PCOS mothers (P=0.007).

CONCLUSIONS

Despite elevated maternal androgen concentrations during pregnancy in PCOS mothers, offspring showed no signs of elevated androgen concentrations in cord blood at birth using the latest highly specific LC-MS/MS methods.

2-methoxyestradiol plasma levels are associated with clinical severity indices and biomarkers of preeclampsia

We investigated whether clinical severity indices and biomarkers for preeclampsia (PE) are associated with low plasmatic 2-methoxyestradiol (2ME) in the third trimester of gestation. Blood was collected from 53 women with PE and 73 control pregnant women before parturition. The concentration of 2ME was significantly higher in controls than in patients with PE (2906.43 ± 200.69 pg/mL vs 1818.41 ± 189.25 pg/mL). The risk of PE decreased as 2ME levels increased. The 2ME values were negatively correlated with systolic peak arterial pressure and proteinuria in PE. Additionally, those women with PE with lower 2ME had a more serious clinical situation and needed a more aggressive therapy. Finally, 2ME levels (in patients with PE and total population) were significantly correlated with concentrations of soluble fms-like tyrosine kinase 1 and placental growth factor . Summarizing, patients with PE had lower 2ME levels that were correlated with different clinical indices and biomarkers of severity, indicating that 2ME could be taken into account for the clinical management of this syndrome.

Contraceptive options and their associated estrogenic environmental loads: relationships and trade-offs

This work explores the relationships between a user's choice of a given contraceptive option and the load of steroidal estrogens that can be associated with that choice. Family planning data for the USA served as a basis for the analysis. The results showed that collectively the use of contraception in the USA conservatively averts the release of approximately 4.8 tonnes of estradiol equivalents to the environment. 35% of the estrogenic load released over the course of all experienced pregnancies events and 34% the estrogenic load represented by all resultant legacies are a result of contraception failure and the non-use of contraception. A scenario analysis conducted to explore the impacts of discontinuing the use of ethinylestradiol-based oral contraceptives revealed that this would not only result in a 1.7-fold increase in the estrogenic loading of the users, but the users would also be expected to experience undesired family planning outcomes at a rate that is 3.3 times higher. Additional scenario analyses in which ethinylestradiol-based oral contraceptive users were modeled as having switched entirely to the use of male condoms, diaphragms or copper IUDs suggested that whether a higher or lower estrogenic load can be associated with the switching population depends on the typical failure rates of the options adopted following discontinuation. And, finally, it was estimated that, in the USA, at most 13% of the annual estrogenic load can be averted by fully meeting the contraceptive needs of the population. Therefore, while the issue of estrogen impacts on the environment cannot be addressed solely by meeting the population's contraceptive needs, a significant fraction of the estrogenic mass released to environment can be averted by improving the level with which their contraceptive needs are met.

Estimating estrogen release and load from humans and livestock in shanghai, china

The estrogens estrone (E1), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2) cause potent endocrine disruptive effects on aquatic wildlife. Currently, four sources of released estrogens exist in Shanghai: treated effluent from municipal wastewater treatment plants (WTPs); wastewater discharge from livestock farms; untreated or simply digested sewage from rural households; and runoff from farmland with livestock manure (LM) applied and irrigated with livestock wastewater (LW). A modified estimation method for estrogen release, in consideration of the difference in estrogen excretion rates between Caucasian and Oriental people and estrogen reduction in livestock wastes, was presented in the study. Based on the estimation method, we estimated the amount of estrogen release from humans and livestock and analyzed the spatially explicit distribution of estrogen loads. By comparing the four estrogen sources, the amount of estrogens released to water environments from livestock (56.8 g d), in terms of E2 equivalents (EEQ), was nearly twofold higher than the EEQ from humans (35.2 g d), which accounted for 61.0% of the total EEQ in Shanghai. Regarding the livestock EEQ, land-applied and irrigated EEQ via surface runoff to water environments (0.11 g d) was obviously low compared with the EEQ of LW directly released into adjacent waterways (56.7 g d). Therefore, the LW was the major contributor to estrogenic risk to the water environment in Shanghai. The spatial distribution of estrogen loads indicated that the highest EEQ loads were in the southern region of Pudong New Area and the eastern and central regions of Fengxian District.

Life long endogenous estrogen exposure and later adulthood cognitive function in a population of naturally postmenopausal women from Southern China: the Guangzhou Biobank Cohort Study

BACKGROUND

Estrogen has neurotrophic and neuroprotective properties in animal and in vitro studies. Epidemiological studies are inconclusive, but suggest a positive association between endogenous estrogen exposure (measured by reproductive period, the number of years between menarche and menopause) and later life cognitive function.

METHODS

Structural equation modeling was used in a cross-sectional study of 11,094 naturally postmenopausal multiparous Chinese older (≥50 years) women from the Guangzhou Biobank Cohort Study (phases 2 and 3) to assess the interrelationship of four proxies of higher endogenous estrogen exposure (longer reproductive period, older age of first pregnancy, lower parity and shorter average duration of breast feeding per child) with immediate and the delayed 10-word recall score in phases 2 and 3, and with the mini-mental state examination (MMSE) score in phase 3 (5641 women).

RESULTS

Adjusted for age, education, childhood and adulthood socio-economic position and physical activity, longer reproductive period was associated with higher scores (0.02 words per year, 95% confidence interval (CI) 0.008-0.02 for delayed recall and 0.05 MMSE score, 95%CI 0.04-0.07, respectively). Lower parity and shorter average duration of breast-feeding per child were also associated with better cognitive function.

CONCLUSIONS

In a large cohort of naturally postmenopausal Chinese women proxies of greater endogenous estrogen exposure were associated with better cognitive function. These findings support biological evidence for a cognitively protective role of endogenous estrogen.

Synergistic therapeutic effects of 2-methoxyestradiol with either sildenafil or bosentan on amelioration of monocrotaline-induced pulmonary hypertension and vascular remodeling

2-Methoxyestradiol (2ME) is a major nonestrogenic metabolite of estradiol. Our previous studies suggest that 2ME, in several models of cardiac and/or vascular injury, strongly inhibits cardiac and vascular remodeling. Furthermore, our most recent study shows that in male rats, 2ME attenuates the development and retards the progression of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH), and in female rats, 2ME eliminates the exacerbation of PAH and the increased mortality due to ovariectomy. The current standard of care of patients with PAH includes treatment with an endothelin receptor antagonist (eg, bosentan) or a phosphodiesterase5 inhibitor (eg, sildenafil). Moreover, combination therapy is often prescribed. Therefore, in the present study, we compared the efficacy of 2ME (10 μg · kg(-1) · h(-1), 2ME-10) to the effects of bosentan (200 mg/kg; BOS), sildenafil (50 mg/kg; SIL), and their respective combinations with 2ME-10 (2ME + BOS and 2ME + SIL groups, respectively). Treatments were initiated 12 days after administration of MCT (60 mg/kg). Twenty-eight days after MCT administration, right ventricular peak systolic pressure was measured and morphometric analysis was conducted. 2ME exhibited beneficial effects in pulmonary hypertensive animals and had efficacy comparable to that of BOS and SIL. Importantly, combination treatments had favorable effects on survival, vascular remodeling, and inflammatory response, and the 2ME + SIL combination was significantly more efficacious than any other treatment. These results indicate that 2ME is effective in experimental PAH and suggests that 2ME may provide additional therapeutic benefit over existing drugs used for the treatment of pulmonary hypertension.

Acute effects of 2-methoxyestradiol on endothelial aortic No release in male and ovariectomized female rats

The endogenous metabolites of 17beta-estradiol are thought to have protective vascular effects, especially in males and estrogen-deprived females. The present study evaluated the acute in vitro effects of the active metabolite 2-methoxyestradiol on endothelial NO release from ovariectomized female and intact male and female rat aortas. NO was measured electrochemically by differential normal pulse amperometry using carbon fiber microsensors, and also by fluorescence microscopy using 4,5-diaminofluorescein diacetate. 2-Methoxyestradiol alone induced a maintained increase in endothelial NO release in male and ovariectomized rats that was reduced by pretreatment with L-NAME. NO release induced by calcium ionophore alone (A23187) was lower in aortas from ovariectomized rats than from intact females, indicating that estrogen deprivation induces endothelial dysfunction. Pretreatment of aortas with 2-methoxyestradiol potentiated significantly the A23187-induced-NO release in ovariectomized as well as in males, but not in intact females. This potentiation was reduced or abolished by L-NAME. 2-Methoxyestradiol potentiated the vasodilatory effect of A23187 on intestinal arterioles, and also increased intestinal tissular laser-Doppler blood flow signal. These results demonstrate that 17beta-estradiol and its active metabolite 2-methoxyestradiol increase basal aortic endothelial NO production and also cause a potentiation of the calcium ionophore-stimulated NO release in male and ovariectomized, while it has no effects on intact females. 2-Methoxyestradiol appears to be a promising pharmacological agent capable of improving endothelial function in men and postmenopausal women.

Phase I trial of 2-methoxyestradiol NanoCrystal dispersion in advanced solid malignancies

PURPOSE

2-methoxyestradiol (2ME2; Panzem) is an endogenous, estradiol-17beta metabolite that at pharmacologic doses exerts antimitotic and antiangiogenic activities. Studies with a 2ME2 capsule formulation showed limited oral bioavailability. We report the results of a phase I study using a NanoCrystal Dispersion formulation of 2ME2 (2ME2 NCD).

EXPERIMENTAL DESIGN

Patients with refractory solid tumors received 2ME2 NCD orally. Patients received drug either every 6 hours (part A) or every 8 hours (part B). Doses were escalated in successive cohorts until the maximum tolerated dose (MTD) was identified. The primary objective was identifying the MTD. Secondary objectives were to evaluate the plasma pharmacokinetics of 2ME2 and efficacy.

RESULTS

In part A, 16 patients received a median of 4 cycles of 2ME2 NCD. Dose-limiting toxicities (DLT) included fatigue (2), hypophosphatemia (2), increased alanine aminotransferase (1), and muscle weakness (1). Trough levels at steady-state reached the minimum effective concentration in all cohorts. The MTD was determined to be 1,000 mg orally every 6 hours. In part B, 10 patients received a median of 1 cycle. DLTs included elevated gamma-glutamyltransferase (1), hyponatremia (1), fatigue (1), and anorexia (1). An MTD could not be defined for part B because 4 of 10 patients had DLTs at the initial dose level and dose reduction was not pursued. Thirteen patients had stable disease (A, 11; B, 2); there were no confirmed responses.

CONCLUSION

For 2ME2 NCD, the MTD and recommended phase II regimen is 1,000 mg orally every 6 hours. Treatment was generally well-tolerated.

Inhibition of rat aortic smooth muscle contraction by 2-methoxyestradiol

Recent studies suggest that 2-methoxyestradiol (2-ME), an estrogen metabolite, has a similar inhibitory effect as 17beta-estradiol (E2) on vascular tone. However, it is not known whether 2-ME mediates the effects of E2 or by what mechanism 2-ME regulates smooth muscle contraction. Therefore, we compared the effects of 2-ME and E2 on rat aortic smooth muscle contraction. A preincubation with 2-ME (10 microM) for 1 h inhibited phenylephrine (PE)-induced tension in endothelium-intact, but not -denuded, tissues, whereas E2 inhibited PE-induced contraction in both preparations. The effects of 2-ME and E2 on endothelium-intact preparations were prevented by L-NAME hydrochloride (a nitric oxide synthase inhibitor). The 2-ME treatment reduced PE-induced phosphorylation of the 20-kDa myosin regulatory light chain. The inhibitory effects of 2-ME and E2 were not affected by ICI-182780 (an estrogen receptor antagonist) or actinomycin D (a gene transcription inhibitor); however, the effect of 2-ME, but not E2, was prevented by cycloheximide (a protein synthesis inhibitor). Furthermore, the effect of E2 was not blocked by 1-aminobenzotriazole (a cytochrome P-450 inhibitor) or Ro 41-0960 (a catechol-O-methyltransferase inhibitor). The effect of 2-ME was not mimicked by microtubule-interfering agents (nocodazole or Taxol). We conclude that 2-ME inhibits smooth muscle contractility through an endothelium- and nitric oxide-dependent mechanism, which does not involve estrogen receptors or microtubule disruption. The effect of 2-ME, but not E2, involves de novo protein synthesis. 2-ME does not mediate the inhibitory effect of E2 on smooth muscle contraction. These results support a potentially important role of 2-ME in the regulation of smooth muscle tone in the vasculature.

Development and application of electrospray-active derivatization reagents for hydroxysteroids

New derivatization reagents, 1-(2,4-dinitro-5-fluorophenyl)-4-methylpiperazine (PPZ) and 4-(4-methyl-1-piperazyl)-3-nitrobenzoyl azide (APZ), were developed for the liquid chromatography-electrospray ionization-mass spectrometric (LC-ESI-MS) determination of steroids having a hydroxy group. PPZ reacted with a phenolic hydroxy group in estrogens. After quaternarization of the PPZ-estrogens with methyl iodide, the resulting derivatives provided more than a 2000-fold higher sensitivity compared to the intact estrogens. After derivatization of steroids having an alcoholic hydroxy group (5-ene-steroids or 5alpha-reduced steroids) with APZ followed by methylation, their detection responses increased more than 500 times. These derivatization procedures coupled with LC-ESI-MS/MS were successfully used for the determination of estrogens in the serum and prostatic 5alpha-dihydrotestosterone.

Functional maternal catechol-O-methyltransferase polymorphism and fetal growth restriction

OBJECTIVES

The pathophysiologic processes that occur at the cellular and molecular levels in intrauterine fetal growth restriction are largely unknown. Catechol-O-methyltransferase (COMT) is a phase II enzyme that inactivates catechol estrogens by transfer of a methyl group. A functional Val158Met polymorphism in the COMT gene has been known as a susceptible marker for breast cancer. The aim of this study was to examine the association between this polymorphism and fetal growth.

METHODS

A consecutive series of 412 women who experienced singleton deliveries was assessed in the birth cohort study. Genotyping of COMT and CYP17A1 polymorphisms was determined by allelic discrimination using fluorogenic probes and the 5'nuclease assay.

RESULTS

The adjusted odds ratio for the risk of low birth weight (<2.500 g) in women with homozygous low-activity (COMT-L) alleles was 2.98 (95% confidence interval, 1.10-8.11). The mean birth weight of infants whose mothers were homozygous for COMT-L was less than that of infants whose mothers had at least one high-activity (COMT-H) allele (2.610 versus 2.800 g, P=0.07). The odds ratio for the risk of intrauterine fetal growth restriction, defined as birth weight <10th percentile or <mean-1.5 SD, in women homozygous for COMT-L alleles was 2.63/2.57 (95% confidence interval, 1.14-6.05/0.96-6.88). In the recessive genotype model, the odds ratios for the risk of low birth weight and intrauterine fetal growth restriction in women homozygous for COMT-L were 3.36 (95% confidence interval, 1.30-8.65) and 2.89/2.65 (95% confidence interval, 1.31-6.34/1.06-6.65), respectively. A positive association exists between birth weight and the homozygous CYP17A1 A2 genotype (P<0.01). When both COMT and CYP17A1 genotypes were considered, the highest risk of low birth weight/intrauterine fetal growth restriction was found among women with the homozygous COMT-L and CYP17A1 A1 genotype. The odds ratio for the risk of intrauterine fetal growth restriction (<10th percentile) in those women was 5.35 (95% confidence interval, 1.15-25.0).

CONCLUSION

Our findings suggest that the allele encoding low-activity COMT may be a susceptible marker for intrauterine fetal growth restriction.

Plasma protein binding of the investigational anticancer agent 2-methoxyestradiol

2-Methoxyestradiol (2ME2) is an endogenously produced metabolite of estradiol currently being tested in phase I and II clinical trials as an anticancer agent. Here, we examined the role of protein binding as a possible determinant of the pharmacokinetic behavior of 2ME2. The distribution of 2ME2 in plasma was studied in vitro using plasma from healthy human volunteers and ex vivo using plasma from patients with cancer receiving the drug orally. The equilibrium dialysis method used to characterize plasma protein binding of 2ME2 utilized a tracer amount of [H]-2-methoxyestradiol on a 96-well microdialysis plate with a 5-kDa cutoff membrane and 250 mul of plasma. The time to equilibrium was approximately 24 h and the mean unbound fraction of 2ME2 (fu) over the observed concentration range in plasma of patients receiving 2ME2 orally was 0.019+/-0.0043. The mean fu was 0.027+/-0.0019 in plasma of healthy human volunteers. The binding was concentration independent, indicating a low-affinity, possibly nonspecific and nonsaturable process. The binding was also unaffected by the presence of 2-methoxyestrone, one of the major metabolites of 2ME2. 2ME2 was found to bind in decreasing order to plasma>albumin>alpha1-acid glycoprotein>sex-hormone-binding globulin. Plasma concentration-time profiles of total 2ME2 and unbound 2ME2 concentrations in a patient with cancer receiving 2ME2 as a single oral dose were parallel to each other. Thus, indicating that plasma protein binding is not an important consideration in pharmacokinetic monitoring of 2ME2.

2-Methoxyestradiol Induces Cell Cycle Arrest and Mitotic Cell Apoptosis in Human Vascular Smooth Muscle Cells

It has been shown that 2-methoxyestradiol (2-ME) inhibits cell proliferation and DNA synthesis in human aortic smooth muscle cells. However, the cellular mechanisms underlying the antiproliferative activity of 2-ME are unclear. The present study was performed to explore the cellular mechanisms whereby 2-ME leads to growth inhibition and apoptosis of human smooth muscle cells. Our results demonstrate that at 1 hour of treatment, 1 micromol/L 2-ME induces multiple spindles, overamplified centrosomes, and multipolar cytokinesis, whereas 10 micromol/L 2-ME causes completely damaged spindle, disorientated centrosomes, and missegregated chromosomes. At 6 hours of treatment, the mitotic index was increased and reached a maximal level, and cells with 4N DNA content (4N cells) began to accumulate. The increased mitotic cells induced by 2-ME were apoptotic as detected by both annexin V and TUNEL staining. Blockage of cells in G(1/0) phase by thymidine prevented 2-ME-induced apoptosis. In addition, the increased mitotic index declined concurrently when even more 4N cells accumulated at 12 to 48 hours of treatment with 10 micromol/L 2-ME. Furthermore, in response to 2-ME, cells delayed entry into the next cell cycle and exhibited aneuploidy or micronuclei. Some aneuploidy cells continued to synthesize DNA. We conclude that 2-ME treatment not only arrests cells in mitosis and promotes mitotic cell apoptosis, but also causes cells to undergo "mitotic slippage" and endoreduplication. The induction of mitotic cell arrest and apoptosis may be a major cellular mechanism by which 2-ME inhibits proliferation of human smooth muscle cells.

Newer Therapies in Advanced Prostate Cancer

Prostate cancer is a leading cause of morbidity and mortality among males. Androgen ablation as initial therapy for advanced prostate cancer provides high response rates but does not cure disease, as nearly all men with metastases will eventually progress to hormone-refractory prostate cancer (HRPC). Present chemotherapy regimens for HRPC can provide palliation and have recently demonstrated an increase in overall survival. Over the past 2 decades, these regimens represent clear advances in the treatment of metastatic prostate cancer but also demonstrate that newer therapies are needed. Studies are ongoing to provide viable alternatives among traditional cytotoxic therapies as well as among novel agents targeting specific molecular pathways. This article reviews some of the newer therapies being developed and evaluated, including the epothilone analogues, human epidermal growth factor receptor pathway inhibitors, angiogenesis inhibitors, and endothelin receptor antagonists.

Technical note: Measurement of total estrone content in foods. Application to dairy products

Estrone is a powerful growth-inducing hormone that is present in milk, mainly in the form of fatty acid esters, at concentrations that promote growth in experimental animals. We present here a method useful for the measurement of this natural hormone in foods and applied it to several common dairy products. Samples were frozen, finely powdered, and lyophilized then extracted with trichloromethane/methanol; the dry extract was saponified with potassium hydroxide. The free estrone evolved was extracted with ethyl acetate and was used for the estimation of total estrone content through radioimmunoassay. Application of the method to dairy products showed high relative levels of total estrone (essentially acyl-estrone) in milk, in the range of 1 microM, which were halved in skimmed milk. Free estrone levels were much lower, in the nanomolar range. A large proportion of estrone esters was present in all other dairy products, fairly correlated with their fat content. The amount of estrone carried by milk is well within the range, where its intake may exert a physiological response in the sucklings for which it is provided. These growth-inducing and energy expenditure-lowering effects may affect humans ingesting significant amounts of dairy products.

2-methoxyestradiol alters cell motility, migration, and adhesion

The effect of 2-methoxyestradiol, 2ME2, an endogenous metabolite of 17beta-estradiol (E2), on cell growth and cytoskeletal functions in a BCR-ABL-transformed cell line model was investigated. We determined the interaction of 2ME2 with STI571 (Gleevec, imatinib mesylate) in STI571 drug-sensitive and -resistant cell lines. In cells expressing BCR-ABL, STI571 cooperated with 2ME2 in reducing cell growth, and STI571-resistant cells were sensitive to 2ME2 treatment. 2ME2 also inhibited growth of several cancer cell lines by a mechanism independent of BCR-ABL. BCR-ABL transformation leads to altered motility, increased adhesion, and spontaneous migration in different in vitro model systems. 2ME2 was found to specifically inhibit the spontaneous motility of BCRABL-transformed Ba/F3 cells and to change the morphology and volume of treated cells. Cells attached to fibronectin-coated surfaces showed a reduced number of filipodia and lamellipodia. In addition, 2ME2 significantly reduced BCRABL-mediated adhesion to fibronectin. The spontaneous migration of BCR-ABL-transformed cells through a transwell membrane also was found to be significantly decreased by 2ME2. Cytoskeletal changes were accompanied by alteration of tubulin formation, distinct from paclitaxel treatment. These results demonstrate that 2ME2 treatment of transformed cells strongly reduces cytoskeletal functions and may also be useful for the treatment of cancers with high metastatic potential. Combination of 2ME2 with other anticancer drugs may be beneficial to treatment of drug-resistant cancers.

Interaction of Endogenous Compounds in Human and Rat Urine with P-glycoprotein

The effect of hydrophobic extracts of human and rat urine on in-vitro P-glycoprotein (P-gp) function was examined, in terms of intra-, inter-individual variations, and physiological states. Six urine samples out of 7, obtained from one male subject on different days, suppressed P-gp function with different potencies. Similarly, 11 samples out of 15 different individuals (8 males and 7 females) inhibited P-gp function. Among them, urine from one female, obtained 1 month after delivery, showed a potent inhibitory effect. Another urine from a pregnant female, obtained 1 week before delivery, showed further potent inhibition on P-gp function. In addition, urine from normal rats strongly inhibited P-gp function at much lower concentrations than human urine, and the inhibitory potencies varied in diseased states; control (without urine extract)=experimental acute renal failure<experimental acute hepatic failure<normal rat urine. When human urine extract was separated by a two-dimensional thin-layer chromatography, several spot fractions inhibited P-gp function, and equilin was identified in one fraction as an endogenous P-gp inhibitor. In conclusion, it was demonstrated that urine contains many endogenous P-gp inhibitors, and their inhibitory potencies on P-gp function vary with intra- and inter-individual variations, and under different physiological states.

Estimating steroid oestrogen inputs into activated sludge treatment works and observations on their removal from the effluent

A method to predict steroid oestrogen inputs into sewage works is described and tested against available data. For oestradiol (E2), 68% of the predictions were within 50% of the actual measured value, and for oestrone (E1), 52% of the estimations were within 50% of the measured value. Predictions for ethinyloestradiol (EE2), which are particularly sensitive to assumptions on the number of people taking the oral contraceptive, were less accurate. Five Italian and three Dutch activated sludge treatment works (STW) were sampled on two to three occasions for E2, E1, EE2 and E3 (E3 only in Italy) in both influent and effluent waters. High concentrations of E3 were found in the influent, as predicted, with a mean of 57 ng/1 and a mean of 10 ng/l in the effluent. Using the currently available data collected from composite samples, an average of 88% of E2 and 74% of E1 would appear to be removed by the activated sludge process.

Enzyme immunoassay for the measurement of 17alpha-estradiol 17-N-acetylglucosaminide in rabbit urine

17alpha-estradiol 17-N-acetylglucosaminide (17alphaE2 17NAG) is an estrogen metabolite hitherto obtained only in rabbits. To gain insight into this unique conjugate, an enzyme immunoassay (EIA) was established by using antiserum elicited against 3-[3-(1-carboxypropyl)] ether of 17alphaE2 17NAG-bovine serum albumin conjugate; horseradish peroxidase, as a label; and 3,3',5,5'-tetramethylbenzidine, as a chromogen. The method proved to be specific, and the detection range of the assay was 0.20-10.00 ng/ml. A proposed double conjugate, 3-glucuronide of 17alphaE2 17NAG, was synthesized to validate the EIA. The EIA was applied to the determination of the urinary level of 17alphaE2 17NAG in male and female (pregnant and non-pregnant) rabbits with and without beta-glucuronidase-sulfatase preparation from Helix pomatia. The results showed that 17alphaE2 17NAG was mainly excreted as a double conjugate (17alphaE2 17NAG 3-glucuronide and/or 3-sulfate) and that its level varies during pregnancy.

Urinary excretion of catecholestrogens, 2-methoxy-estrogens and "classical estrogens" throughout the normal menstrual cycle

Catecholestrogens, 2-methoxyestrogens and "classical" estrogens (estrone, estradiol, estriol) were measured simultaneously in urine samples of healthy women during the menstrual cycle. All estrogen values reach a preovulatory maximum at the time of the LH peak and show a marked increase during the luteal phase as compared to the follicular phase. Catecholestrogens and estrone seem to behave similarly supporting the assumption that catecholestrogens are predominantly metabolites of estrone. Daily measurements of urinary estrogens show large interindividual variations of 2- and 4-hydroxyestrogens as well as very differing 2-hydroxy-/2-methoxyestrogen ratios. The results obtained support the assumption, that catecholestrogens and their methylethers are excretory products with no additional regulatory functions.