Mono-(2-ethyl-5-hydroxyhexyl) phthalate promotes uterine leiomyoma cell survival through tryptophan-kynurenine-AHR pathway activation.

Uterine leiomyoma is the most common tumor in women and causes severe morbidity in 15 to 30% of reproductive-age women. Epidemiological studies consistently indicate a correlation between leiomyoma development and exposure to endocrine-disrupting chemical phthalates, especially di-(2-ethylhexyl) phthalate (DEHP); however, the underlying mechanisms are unknown. Here, among the most commonly encountered phthalate metabolites, we found the strongest association between the urine levels of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), the principal DEHP metabolite, and the risk of uterine leiomyoma diagnosis (n = 712 patients). The treatment of primary leiomyoma and smooth muscle cells (n = 29) with various mixtures of phthalate metabolites, at concentrations equivalent to those detected in urine samples, significantly increased cell viability and decreased apoptosis. MEHHP had the strongest effects on both cell viability and apoptosis. MEHHP increased cellular tryptophan and kynurenine levels strikingly and induced the expression of the tryptophan transporters SLC7A5 and SLC7A8, as well as, tryptophan 2,3-dioxygenase (TDO2), the key enzyme catalyzing the conversion of tryptophan to kynurenine that is the endogenous ligand of aryl hydrocarbon receptor (AHR). MEHHP stimulated nuclear localization of AHR and up-regulated the expression of CYP1A1 and CYP1B1, two prototype targets of AHR. siRNA knockdown or pharmacological inhibition of SLC7A5/SLC7A8, TDO2, or AHR abolished MEHHP-mediated effects on leiomyoma cell survival. These findings indicate that MEHHP promotes leiomyoma cell survival by activating the tryptophan-kynurenine-AHR pathway. This study pinpoints MEHHP exposure as a high-risk factor for leiomyoma growth, uncovers a mechanism by which exposure to environmental phthalate impacts leiomyoma pathogenesis, and may lead to the development of novel druggable targets.

Urinary concentrations of phenols, parabens, and triclocarban in relation to uterine leiomyomata incidence and growth.

OBJECTIVE: To examine the association of urinary concentrations of phenols, parabens, and triclocarban with incidence and growth of uterine leiomyomata (UL; fibroids). DESIGN: Case-cohort study, nested within the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study. SETTING: Clinic visits at baseline and every 20 months for 60 months. PATIENT(S): 754 Black women aged 23-35 years residing in the Detroit, Michigan area (enrolled during 2010-2012). INTERVENTION: None. MAIN OUTCOME MEASURE(S): At each study visit, women underwent transvaginal ultrasound for measurement of UL incidence and growth and provided urine specimens in which we quantified concentrations of seven phenols, four parabens, and triclocarban. We used Cox proportional hazards regression to estimate hazard ratios and 95% confidence intervals (CIs) characterizing the relation of urinary biomarker concentrations with UL incidence during the 60 months of follow-up. In a subset of UL detected and measured at multiple time points, we used linear regression to assess the associations between biomarker concentrations and UL growth. RESULT(S): Urinary biomarker concentrations were generally inversely associated with UL incidence, but the associations were weak and nonmonotonic. For example, hazard ratios comparing concentrations ≥90th with <50th percentile were 0.77 (95% CI: 0.46, 1.27) for bisphenol A, 0.72 (95% CI: 0.40, 1.28) for bisphenol S, and 0.76 (95% CI: 0.43, 1.33) for methylparaben. Biomarker concentrations were not strongly associated with UL growth. CONCLUSION(S): In this study of reproductive-aged Black women, urinary phenols, parabens, and triclocarban biomarkers were neither strongly nor consistently associated with UL incidence and growth.

Phthalates exposure and uterine fibroid burden among women undergoing surgical treatment for fibroids: a preliminary study.

OBJECTIVES: To examine the association between phthalate exposure and two measures of uterine fibroid burden: diameter of largest fibroid and uterine volume. DESIGN: Pilot, cross-sectional study. SETTING: Academic medical center. PATIENT(S): Fifty-seven premenopausal women undergoing either hysterectomy or myomectomy for fibroids. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The diameter of the largest fibroid and uterine dimensions were abstracted from medical records. Spot urine samples were analyzed for 14 phthalate biomarkers using mass spectrometry. We estimated associations between fibroid outcomes and individual phthalate metabolites, sum of di(2-ethylhexyl) phthalate metabolites (∑DEHP), and a weighted sum of anti-androgenic phthalate metabolites (∑AA Phthalates) using linear regression, adjusting for age, race/ethnicity, and body mass index. Fibroid outcomes were also examined dichotomously (divided at the median) using logistic regression. RESULTS: Most women were of black ethnicity, overweight or obese, and college educated. In multivariable models, higher levels of mono-hydroxyisobutyl phthalate, monocarboxyoctyl phthalate, monocarboxynonyl phthalate, mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl phthalate) (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), ∑DEHP, and ∑AA Phthalates were positively associated with uterine volume. Associations were most pronounced for individual DEHP metabolites (MEHHP, MEOHP, MECPP), ∑DEHP, and ∑AA Phthalates. For example, a doubling in ∑DEHP and ∑AA Phthalates was associated with 33.2% (95% confidence interval 6.6-66.5) and 26.8% (95% confidence interval 2.2-57.4) increase in uterine volume, respectively. There were few associations between phthalate biomarkers and fibroid size. CONCLUSIONS: Exposure to some phthalate biomarkers was positively associated with uterine volume, which further supports the hypothesis that phthalate exposures may be associated with fibroid outcomes. Additional studies are needed to confirm these relationships.

Assessment of oxidant-antioxidant status alterations with tumor biomarkers and reproductive system hormones in uterine MYOMAS.

OBJECTIVES: Uterine myomas (UM) are responsible for significant morbidity and have adverse effects on quality of life in women. Reactive oxygen species (ROS) and antioxidant enzymes (AOE), as well as sex steroids play important roles in the reproductive physiology processes. Thus, we aimed to investigate the role of oxidant-antioxidant status in UM by measuring the AOE activities and lipid peroxidation (LPO) levels. This is the first study assessing these parameters together in UM based on also menopausal status and evaluating possible correlations between AOE activities, LPO markers, tumor biomarkers, female reproductive system hormone levels, comprehensively. STUDY DESIGN: The study group consisted of patients who have undergone surgical resection with confirmed pathology of uterine myoma (UM, n = 25) and divided into subgroups; premenopausal (UMpre) and postmenopausal (UMpost). Erythrocyte copper-zinc superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione peroxidase (GPx1) activities were measured along with plasma malondialdehyde (MDA) and urinary 8-epi-prostaglandin F2α (8-epi-PGF2α) levels in patients with UM. The obtained data were compared to the data of healthy individuals (C, n = 25) and its subgroups; premenopausal (Cpre) and postmenopausal (Cpost). RESULTS: All AOE activities were higher (∼40% for Cu,Zn-SOD, p = 0.003; ∼55% for CAT, p = 0.001; ∼15% for GPx1, p = 0.169) and the LPO levels were lower (∼60% for MDA, p = 0.011 and ∼45% for 8-epi-PGF2α, p = 0.055) in patients with UM vs control. Approximately similar alterations were observed in UMpre vs Cpre and in UMpost vs Cpost. A significant negative correlation between erythrocyte Cu,Zn-SOD activity and plasma MDA levels (r = -0.431, p = 0.005) was reported. CONCLUSION: Decreased LPO levels might be the consequence of compensator high antioxidant enzyme activities against mild oxidative stress in the circulation of patients with UM. The marked negative correlation between erythrocyte Cu,Zn-SOD activity and plasma MDA levels also supported this finding.

Association between urinary phthalate metabolites and risk of breast cancer and uterine leiomyoma.

OBJECTIVE: The objective of this study was to systematically assess the association between urinary phthalate metabolites and risk of breast cancer and uterine leiomyoma. METHODS: Standard meta-analysis and bioinformatics analysis were conducted based on electronic databases. RESULTS: No significant association was observed between total urinary phthalate metabolites and risk of breast cancer or uterine leiomyoma. However, MECPP was positively associated with breast cancer risk, and DEHP metabolites were associated with increased risk of breast cancer as well as uterine leiomyoma. Enrichment pathway analysis suggested p53 signaling pathway, mechanism of gene regulation by PPARα, apoptotic signaling in response to DNA damage and ATM signaling pathway might be involved to account for the association. CONCLUSION: Significantly positive association was observed between DEHP metabolites and risk of breast cancer and uterine leiomyoma, especially for MECPP in breast cancer.

In vitro effects of phthalate esters in human myometrial and leiomyoma cells and increased urinary level of phthalate metabolite in women with uterine leiomyoma.

OBJECTIVE: To investigate the possible role of phthalate, a ubiquitous chemical used in consumer products, in the pathogenesis of uterine leiomyoma. DESIGN: Experimental and prospective case-control study using human samples. SETTING: University hospital. PATIENT(S): Fifty-three women with histologic evidence of uterine leiomyoma and 33 surgical controls without leiomyoma. INTERVENTION(S): Human myometrial and leiomyoma cells were treated with di-(2-thylhexyl)-phthalate (DEHP). MAIN OUTCOME MEASURE(S): Cell viability assay and Western blot analyses after in vitro DEHP treatment; high-performance liquid chromatography electrospray ionization tandem mass spectrometry in cases and controls. RESULT(S): In vitro treatment with DEHP led to an increased viability and increased expressions of proliferating cell nuclear antigen, B-cell lymphoma 2 protein, and type I collagen in myometrial and leiomyoma cells. The urinary concentration of mono-(2-ethyl-5-carboxypentyl) phthalate was higher in women with leiomyoma compared with controls. CONCLUSION(S): These findings suggest that exposure to phthalate may play a role in the pathogenesis of uterine leiomyoma by enhancing proliferative activity, exerting an antiapoptotic effect, and increasing collagen contents in myometrial and leiomyoma cells.

Increased Urinary Phthalate Levels in Women with Uterine Leiomyoma: A Case-Control Study.

We assessed the urinary concentration of 16 phthalate metabolites in 57 women with and without uterine leiomyoma (n = 30 and 27; respectively) to determine the association between phthalate exposure and uterine leiomyoma. To evaluate exposure to di-(2-ethylhexyl) phthalate (DEHP); we calculated the molar sum of DEHP metabolites; ∑3-DEHP (combining mono-(2-ethylhexyl) phthalate (MEHP); mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP); and mono-(2-ethyl-5-oxohexyl) phthalate); ∑4-DEHP (∑3-DEHP plus mono-(2-ethyl-5-carboxypentyl) phthalate); and ∑5-DEHP (∑4-DEHP plus mono (2-(carboxylmethyl)hexyl) phthalate (2cx-MMHP)). The log transformed urinary levels of MEHP; MEHHP; 2cx-MMHP; ∑3-DEHP; ∑4-DEHP; and ∑5-DEHP in the leiomyoma group were significantly higher than those of controls. When we adjusted for age; waist circumference; and parity using multiple logistic regression analyses; we found log ∑3-DEHP (OR = 10.82; 95% CI = 1.25; 93.46) and ∑4-DEHP (OR = 8.78; 95% CI = 1.03; 75.29) were significantly associated with uterine leiomyoma. Our findings suggest an association between phthalate exposure and uterine leiomyoma. However; larger studies are needed to investigate potential interactions between phthalate exposure and uterine leiomyoma.

Phenolic environmental estrogens in urine and blood plasma from women with uterine leiomyoma: Epidemiological survey.

AIM: To explore the effect of phenolic environmental estrogens (EE) on women with uterine leiomyoma (UL). METHODS: Urine and blood plasma samples were collected from 300 patients diagnosed with UL at the Affiliated Zhongda Hospital of Southeast University between December 2013 and December 2014. Control urine and blood plasma samples were collected from 300 women who are either patients without UL or healthy volunteers presenting to the same hospital for physical examination during the same period. Bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) concentration in these samples was measured using solid phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry. RESULTS: The OP concentration in urine and blood plasma was significantly higher in the UL group compared with the control group (r = 0.224, P = 0.001). Urine BPA concentration was not significantly different between the UL group and the control group (r = 0.009, P = 0.896). There was also no statistically significant difference in urine NP concentration between the two groups (r = 0.057, P = 0.419). On logistic regression, exposure concentration of urine BPA (OR, 1.129; 95%CI: 1.081-1.179) and NP (OR, 1.165; 95%CI: 1.025-1.324) was associated with UL genesis (P < 0.05). Nevertheless, there was no significant difference in blood plasma concentration of BPA, OP and NP between the two groups (P > 0.05). CONCLUSION: Urine and blood plasma EE exposure levels in women, especially the urine level, was related to the incidence of UL.

Urinary isoflavone and lignan phytoestrogen levels and risk of uterine fibroid in Jamaican women.

BACKGROUND: Isoflavones and lignans are phytoestrogens, and therefore, are able to bind to and activate estrogen receptors. The resultant estrogenic or antiestrogenic effect is dependent on the concentration of these phytoestrogens relative to endogenous estrogens and the site of their action, among others. Thus, isoflavones and lignans act as selective estrogen receptor modulators; having a beneficial effect in some tissues while simultaneously causing deleterious changes in others. OBJECTIVE: This case-control study investigates the relationship between urinary concentrations of genistein, daidzein, equol, and enterolactone, and the presence of uterine leiomyomas (fibroids) in Jamaican women. DESIGN: Phytoestrogen concentration in spot urine samples from 157 uterine fibroid cases and 171 fibroid-free controls diagnosed by ultrasonography, were assessed by Time-resolved Fluoroimmnoassay. Statistical evaluations were performed using SPSS 12.0. RESULTS: The median concentration of urinary enterolactone was significantly different between uterine fibroid cases and controls (p=0.029). However, this was not observed to affect risk of uterine fibroid, as trends across quartiles of urine enterolactone did not differ significantly between cases and controls. Median urinary genistein (p=0.510), daidzein (p=0.838), equol (p=0.621), total isoflavones (0.510) and total phytoestrogens (p=0.084) were similar for both groups. Binary logistic regression analysis of quartiles of urine genistein, daidzein, equol, enterolactone, total isoflavones, and total phytoestrogens showed no association with uterine fibroid. CONCLUSIONS: Uterine fibroid cases had a higher median urine concentration of enterolactone compared with controls. However, this was not observed to affect ones risk of fibroid. Neither was urine genistein, daidzein, equol total isoflavones, and total phytoestrogens observed to be associated with risk of uterine fibroid.

Increased urinary cobalt and whole blood concentrations of cadmium and lead in women with uterine leiomyomata: Findings from the ENDO Study.

Multiple trace elements have estrogen receptor activity, but the association of these elements with uterine leiomyoma has not been defined. A cohort of 473 women aged 18-44 undergoing surgery for benign gynecologic indications provided whole blood and urine specimens for trace element analysis, which was performed by inductively coupled plasma mass spectrometry. Twenty elements were analyzed in blood and 3 in urine. The surgeon documented whether fibroids were present. Geometric mean concentrations were compared between women with and without fibroids, and logistic regression models were generated to assess the impact of the concentration of each trace element on the odds of fibroids. In multivariate regressions, odds of a fibroid diagnosis were higher with increased whole blood cadmium (AOR 1.44, 95% CI 1.02, 2.04) and lead (AOR 1.31 95% CI 1.02, 1.69), and urine cobalt (AOR 1.31, 95% CI 1.02, 1.70). Urinary cadmium and lead were not related to fibroid diagnosis. Increased exposure to trace elements may contribute to fibroid growth, and fibroids may serve as a reservoir for these elements. Differences between urinary and whole blood findings merit further investigation, as urinary cadmium has been considered a superior marker of exposure.

Measurement of phenolic environmental estrogens in human urine samples by HPLC-MS/MS and primary discussion the possible linkage with uterine leiomyoma.

A method was established for the determination of three phenolic environmental estrogens, namely bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP), in urine from women of uterine leiomyoma group (n=49) and control group (n=29), by using solid-phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Urine samples were spiked with 2,4,6-tribromophenyl-terminated tetrabromobisphenol-A carbonate oligomer (TBBPA) and nonylphenol D8 (NP-D8) as internal standard (I.S.) and de-conjugated by adding ß-glucuronidase and sulfatase before the SPE. The extraction recoveries of BPA, NP and OP were more than 73.3%; the standard curve was linear over the validated concentrations in the range of 1.0-100.0ng/mL and the limits of detection (LOD) of BPA, NP and OP were 0.32ng/mL, 0.18ng/mL and 0.15ng/mL, respectively. Moreover, by analysing quality control urine samples in 5 days, the results showed that the method was precise and accurate, for the intra- and inter-day CV% within 15.2%. Except that OP was not found (3). NP levels were significantly higher in uterine leiomyoma patients than control group in low gravidity subgroup. Though BPA levels in experimental and control groups were not significantly different, the mean levels and concentration distribution were different. The study suggested that there is certain relationship between exposure concentrations of phenolic environmental estrogens and uterine leiomyoma disease.

Lignan and isoflavone excretion in relation to uterine fibroids: a case-control study of young to middle-aged women in the United States.

BACKGROUND: Uterine fibroids are hormonally responsive; estradiol and progesterone stimulate their growth, and gonadotrophin-releasing hormone agonists shrink them. Phytoestrogens, including isoflavones and lignans, can act as weak estrogens or antiestrogens. OBJECTIVE: The objective of this case-control study was to evaluate the relation between uterine fibroid risk and phytoestrogen exposure. DESIGN: Two overnight urine collections (48 h apart) from 170 uterine fibroid cases and 173 controls were analyzed for isoflavonoids (ie, daidzein, genistein, equol, and O-desmethylangolensin) and lignans (enterodiol and enterolactone). Logistic regression was used to determine associations between the mean excretion of the 2 collections and the risk of uterine fibroids. RESULTS: Unadjusted isoflavone excretion did not differ significantly between cases and controls (2.33 +/- 5.82 and 2.60 +/- 5.90 nmol/mg Cr, respectively; P = 0.68), but cases excreted significantly less lignans than did controls (2.86 +/- 3.45 and 4.57 +/- 6.67 nmol/mg Cr, respectively; P < 0.01). The trend for a reduced risk of uterine fibroids with increasing quartiles of lignan excretion was significant (odds ratio for highest versus lowest quartile = 0.31; 95% CI: 0.17, 0.58; P for trend < 0.01). When adjusted for age, BMI, race, family history of uterine fibroids, and isoflavone excretion, this trend remained but was attenuated (P = 0.07). CONCLUSIONS: Our findings suggest a modest inverse association between lignan excretion and uterine fibroid risk. Whether this relation represents an effect of lignans per se or of other constituents of lignan-containing foods on the development of uterine fibroids remains to be determined. No association was found between isoflavone excretion and uterine fibroids; however, the intake of soy foods, the primary source of isoflavones, was low in this population.

Endogenous urinary steroids in premenopausal women with uterine leiomyomas.

OBJECTIVES: To study the effect of endogenous steroids on the presence of uterine leiomyomas. METHODS: Urine samples of 27 premenopausal women with leiomyomas and 25 age-matched healthy premenopausal women were collected. The concentration of estrogens and androgens in the urine samples of the two groups were determined using a gas chromatography mass spectrometer and the two groups were compared. To study metabolic changes in patients indirectly, the concentration ratios of precursor metabolite to product metabolite of the two groups were also compared. RESULTS: Urinary concentrations of 17beta-estradiol, 5-androstene-3beta, 16beta, 17beta, triol, 11-keto-ethiocholanolone, 11beta-hydroxy-androsterone, 11beta-hydroxy-etiocholanolone, THS, THA, THE, alpha-cortol and beta-cortol were significantly higher in patients than in controls. The concentration ratios of 17beta-estradiol/estrone and 11/beta-hydroxy-ethiocholanolone/11beta-hydroxy-androsterone increased in patients. CONCLUSIONS: The presence of uterine leiomyomas correlates with an increase in urinary concentrations of estrogens and androgens, and it appears to be caused by a decrease in patients' metabolism of steroids.

Gas chromatographic profiling and pattern recognition analysis of urinary organic acids from uterine myoma patients and cervical cancer patients.

An efficient organic acid profiling and pattern recognition method is described for the correlation between urinary organic acid profiles and uterine cervical cancer. After methoximation of keto acids in alkalinized urine samples, all free organic acids were recovered by a dual solid-phase extraction procedure, followed by conversion to tert.-butyldimethylsilyl derivatives for the profiling analysis by dual-capillary column gas chromatography (GC) with subsequent screening for acids by retention index (I) library matching. A total of 50 organic acids were positively identified in urine samples (0.25 ml) from 12 uterine myoma (benign tumor group) and 14 uterine cervical cancer (malignant tumor group) patients studied. When the GC profiles were simplified to their corresponding organic acid I spectra in bar graphical form, characteristic patterns were obtained for each average of benign and malignant tumor groups. Stepwise discriminant analysis performed on the GC data selected 16 acids as the variables discriminating between the two groups. Canonical discriminant analysis applied to these 16 variables correctly classified 26 urine samples into two separate clusters according to tumor types in the canonical plot.

Nocturnal urinary 6-sulphatoxymelatonin excretion is decreased in primary breast cancer patients compared to age-matched controls and shows negative correlation with tumor-size.

In previous studies a tumor-size dependent decline of the circadian amplitude of serum melatonin was found in primary unoperated breast cancer patients, which was not due to changes of the hepatic metabolism of melatonin since its main peripheral metabolite, 6-sulphatoxymelatonin (aMT6s), showed similar serum levels. The aim of the current study was to verify these previous results by measurements of the nocturnal excretion of aMT6s in urine. The determination of aMT6s was carried out by radioimmunoassay. 17 primary unoperated breast cancer (BC) patients and 34 age-matched control patients with different types of benign gynecological diseases awaiting operation (breast diseases, n=13; ovarian diseases, n=12; and uterine diseases, n=9) were analysed. The median nocturnal urinary aMT6s excretion (22:00-6:00 hr) was significantly lower (-48%, P = 0.033) in BC patients than in controls. Controls showed a significant negative linear regression with age (r = -0.419, P = 0.014). According to multivariate linear regression analysis, BC revealed no age-dependency but a significant negative effect of increasing tumor-size on aMT6s-excretion (P = 0.036) was detected. These results confirm previous findings of a decreased pineal melatonin secretion in BC patients as well as an inverse relationship with tumor-size excluding a possible distortion due to age. The mechanisms involved are unknown but indicate that BC may lead to an impaired production of pineal melatonin. The clinical relevance of these findings from therapeutic and diagnostic point of view is discussed.

[Studies on urinary excretion of gonadotropin (LH) in response to the treatment of uterine cervical cancer (author's transl)].

Because of contradictory results on urinary excretion of gonadotropin after gynecologic operation, the present experiment was performed in patients who received radical hysterectomy or radiation therapy for uterine cancer. To measure serum and urinary LH, radioimmunoassay and Hi-Gonavis (HAR) were used. 1. After radical hysterectomy, serum LH decreased lightly whereas urinary excretion of LH increased significantly. 2. Similar decrease of serum LH and increase of urinary LH were found after radiation therapy. 3. Under less severe operative procedures such as semiradical hysterectomy and simple hysterectomy, an increase of urinary excretion of LH was less marked. 4. Administration of hydrocortisone to normal subjects caused a similar increase of urinary excretion of LH. 5. Pituitary responsiveness to LH-RH and renal function were not altered under operation or radiation therapy. On the basis of these findings, it is suggested that urinary excretion of LH is increased by the excess of adrenal steroid produced by operative stress or radiation therapy.