Estrogen-dependent Cancer Research Articles

Metformin inhibits estrogen-dependent endometrial cancer cell growth by activating the AMPK-FOXO1 signal pathway.

Metformin is an oral biguanide commonly used for treating type II diabetes and has recently been reported to possess antiproliferative properties that can be exploited for the prevention and treatment of a variety of cancers. The mechanisms underlying this effect have not been fully elucidated. Our study shows a marked loss of AMP‐activated protein kinase (AMPK) phosphorylation and nuclear human Forkhead box O1 (FOXO1) protein in estrogen‐dependent endometrial cancer (EC) tumors compared to normal control endometrium. Metformin treatment suppressed EC cell growth in a time‐dependent manner in vitro; this effect was cancelled by cotreatment with an AMPK inhibitor, compound C. Metformin decreased FOXO1 phosphorylation and increased FOXO1 nuclear localization in Ishikawa and HEC‐1B cells, with non‐significant increase in FOXO1 mRNA expression. Moreover, compound C blocked the metformin‐induced changes of FOXO1 and its phosphorylation protein, suggesting that metformin upregulated FOXO1 activity by AMPK activation. Similar results were obtained after treatment with insulin. In addition, transfection with siRNA for FOXO1 cancelled metformin‐inhibited cell growth, indicating that FOXO1 mediated metformin to inhibit EC cell proliferation. A xenograft mouse model further revealed that metformin suppressed HEC‐1B tumor growth, accompanied by downregulated ki‐67 and upregulated AMPK phosphorylation and nuclear FOXO1 protein. Taken together, these data provide a novel mechanism of antineoplastic effect for metformin through the regulation of FOXO1, and suggest that the AMPK–FOXO1 pathway may be a therapeutic target to the development of new antineoplastic drugs.

Downregulation of estrogen receptor and modulation of growth of breast cancer cell lines mediated by paracrine stromal cell signals.

Breast cancers have a poorer prognosis if estrogen receptor expression was lost during recurrence. It is unclear whether this conversion is cell autonomous or whether it can be promoted by the microenvironment during cancer dormancy. We explored the ability of marrow-derived stromal cell lines to arrest co-cultured breast cancer cells and suppress estrogen receptor alpha (ER) expression during arrest, facilitating the emergence of estrogen-independent breast cancer clones. Cancer cell growth, ER protein, microRNA, and mRNA levels were measured in breast cancer cell lines exposed to conditioned medium from marrow stromal lines in the presence and absence of estrogen and of signaling pathway modulators. We demonstrate that paracrine signaling from the stromal cell line HS5 downregulated ER in T47D and MCF7 breast cancer cells. This occurred at the mRNA level and also through decreased ER protein stability. Additionally, conditioned medium (CM) from HS5 arrested the breast cancer cells in G0/G1 in part through interleukin-1 (IL1) and inhibited cancer cell growth despite the activation of proliferative pathways (Erk and AKT) by the CM. Similar findings were observed for CM from the hFOB 1.19 osteoblastic cell line but not from two other fibroblastic marrow lines, HS27A and KM101. HS5-CM inhibition of MCF7 proliferation could not be restored by exogenous ER, but was restored by the IL1-antagonist IL1RA. In the presence of IL1RA, HS5-CM activation of AKT and Erk enabled the outgrowth of breast cancer cells with suppressed ER that were fulvestrant-resistant and estrogen-independent. We conclude that marrow-derived stromal cells can destabilize estrogen receptor protein to convert the ER status of growth-arrested ER+ breast cancer cell lines. The balance between stromal pro- and anti-proliferative signals controlled the switch from a dormant phenotype to estrogen-independent cancer cell growth.

Childhood body mass index growth trajectories and endometrial cancer risk.

Previously, we found that excess weight already in childhood has positive associations with endometrial cancer; however, associations with changes in body mass index (BMI) during childhood are not well understood. Therefore, we examined whether growth in childhood BMI is associated with endometrial cancer and its sub‐types. A cohort of 155,505 girls from the Copenhagen School Health Records Register with measured weights and heights at the ages of 6–14 years and born 1930–1989 formed the analytical population. BMI was transformed to age‐specific z scores. Using linear spline multilevel models, each girl's BMI growth trajectory was estimated as the deviance from the average trajectory for three different growth periods (6.25–7.99, 8.0–10.99, 11.0–14.0 years). Via a link to health registers, 1,020 endometrial cancer cases were identified, and Cox regressions were performed. A greater gain in BMI during childhood was positively associated with endometrial cancer but no differences between the different growth periods were detected in models adjusted for baseline BMI. The hazard ratios for the associations with overall growth during childhood per 0.1 z score increase were 1.15 (95% confidence interval [CI]: 1.07–1.24) for all endometrial cancers, 1.12 (95% CI: 1.04–1.21) for estrogen‐dependent cancers, 1.16 (95% CI: 1.06–1.26) for endometrioid adenocarcinomas and 1.46 (95% CI: 1.16–1.84) for non‐estrogen‐dependent cancers. Growth in BMI in early life is positively linked to later endometrial cancer risk. We did not identify any sensitive childhood growth period, which suggests that excess gain in BMI during the entire childhood period should be avoided.

Aromatase inhibitors pharmacological importance

This review is devoted to the different generations aromatase inhibitors characteristics, their place in clinical practice and in the cancer treatment. Drugs from this group are able to inactivate aromatase enzyme, and causes estrogen synthesis inhibition. High effective and selective aromatase inhibitors of 3rd generation, have recently entered the market, could compete with tamoxifen - "gold standard" of the breast cancer management. A successful clinical trials of letrozole and anastrozole have identified new approaches to the treatment of estrogen-dependent cancers and to the enlargement of the scope of these drugs using.

Endocrine disrupting chemicals as potential risk factor for estrogen-dependent cancers.

Civilization, industrialization, and urbanization create an environment where humans are continuously exposed to endocrine disrupting chemicals (EDCs). Some of breast cancers and endometrial cancer, which are the most common female malignant neoplasms, are estrogen-dependent tumors. Prolonged exposure to estrogens or substances with estrogenic properties may be a risk factor for their development. This paper aimed to discuss the potential adverse effect of EDCs on human health, including the role of EDCs in hormone-dependent carcinogenesis. A review of literature regarding the sources of environmental exposure to EDCs and molecular mechanisms of their action was performed. We analyzed the possible mechanisms of how these substances alter the function of the endocrine system, resulting in adverse health effects. Hundreds of substances with endocrine disrupting potential have been identified in our environment. There is accumulating evidence linking exposure to EDCs with the development of mammary and endometrial cancer. By interacting with steroid receptors, EDCs can impact the cellular processes potentially leading to carcinogenesis. There are also data showing the effect of EDCs on immune dysfunction. During lifespan, people are usually exposed to a mixture of various EDCs, which complicates the assessment of individual substances or compounds implicated in cancer development. As the prevalence of hormone-dependent tumors among women continues to increase, their successful prevention is of human benefit. Institutions representing medicine, science, industry, and governments should develop joint strategies to decrease exposure to EDC, and thus to reduce the risk of hormonedependent tumors in women.

Perspectives on targeting the phosphatidylinositol 3-kinase pathway for personalized medicine in endometrial and ovarian cancers

Abstract Endometrial and ovarian cancers show similar genetic and pathological backgrounds. In particular, high frequencies of activating mutations in the phosphatidylinositol 3-kinase (PI3K) pathway, including mutations in PIK3CA and PTEN , are found in both estrogen-dependent endometrial cancer (type I endometrioid carcinomas) and ovarian clear cell and endometrioid carcinomas. In this review, we focus on the PI3K pathway as a potential molecular target for personalized therapies in endometrial and ovarian cancers. We found that targeting the PI3K/mammalian target of rapamycin (mTOR) pathway produced anti-tumor effects in endometrial cancer upon suppression of the PI3K pathway. The presence of KRAS mutations may be a marker for resistance to the inhibition of the PI3K/mTOR pathway. However, the combination of a PI3K/mTOR pathway inhibitor and a MAPK pathway inhibitor, such as a MEK inhibitor, has been shown to suppress cell proliferation synergistically in certain endometrial cancers. In addition, PI3K/mTOR pathway inhibition sensitized endometrial cancer cells to ionizing radiation and produced anti-tumor effects in ovarian clear cell carcinomas in both in vitro and in vivo studies. Moreover, inhibition reduced the phosphorylation levels of MDM2 (a negative regulator of TP53), stabilized TP53, and induced TP53-mediated apoptosis. The activation of TP53 was associated with increased phosphorylation of TP53 on Ser-46, and its downstream target genes, such as TP53AIP1 . These findings demonstrate that targeting of the PI3K pathway in both endometrial and ovarian clear cell carcinomas warrants further investigation, including in clinical trials.

FOXP1 forkhead transcription factor is associated with the pathogenesis of endometrial cancer

Endometrial cancers are mostly estrogen-dependent. FOXP1 is a P subfamily of forkhead box (FOX), and known as an estrogen-responsive transcription factor. The aims of this study were to examine histological location of FOXP1 in normal and malignant endometrium, and to investigate a possible association between FOXP1 and other factors considered to be involved in pathogenesis of endometrial cancer. The levels of FOXP1, estrogen receptor (ER)α, and ERβ expression were examined immunohistochemically in normal and malignant endometrium obtained from 75 women (8 normal, 8 atypical endometrial hyperplasia, and 59 endometrial cancers from grade 1 to 3). The effects of estrogen on ERα, FOXP1, KRAS, and PTEN expression were analyzed in telomerase-immortalized human endometrial stromal cells (T HESCs) by Western blotting. Western blotting was also used to examine the effect of FOXP1 plasmid DNA or siRNA transfection on KRAS and PTEN expression in Ishikawa cells (well differentiated endometrioid adenocarcinoma), HEC-50B cells (poorly differentiated endometrioid adenocarcinoma), and T HESCs, respectively. FOXP1 was expressed in normal and malignant endometrium, but the rate of expression was different depending upon menstrual cycle and pathological grade of malignancy. FOXP1 expression in nucleus and cytoplasm of grade 3 endometrioid cancers was significantly lower than that of grade 1 and 2 ones. Estradiol increased levels of FOXP1 and KRAS expression in a dose- and time-dependent manner in T HESCs cells, and FOXP1 transfection or knockdown led to increase or decrease of KRAS expression but not PTEN. KRAS expression level was significantly related to FOXP1 and ERα levels in cancer tissues. Estradiol did not affect KRAS expression in T HESCs cells transfected with FOXP1 siRNA. These results suggest that FOXP1 is involved in estrogen dependent endometrial cancers through KRAS pathway.

Childhood body mass index and height and risk of histologic subtypes of endometrial cancer.

Background:Endometrial cancer risk factors include adult obesity and taller stature, but the influence of size earlier in life is incompletely understood. We examined whether childhood body mass index (BMI; kg m−2) and height were associated with histologic subtypes of endometrial cancer.Methods:From the Copenhagen School Health Records Register, 155 505 girls born 1930–1989 with measured weights and heights from 7 to 13 years were linked to health registers. BMI and height were transformed to age-specific z-scores. Hazard ratios (HRs) and 95% confidence intervals were estimated by Cox regressions.Results:A total of 1020 endometrial cancers were recorded. BMI was non-linearly associated with all endometrial cancers, oestrogen-dependent cancers and the subtype of endometrioid adenocarcinomas; associations were statistically significant and positive above a z-score=0 and non-significant below zero. Compared with a 7-year-old girl with a BMI z-score=0, an equally tall girl who was 3.6 kg heavier (BMI z-score=1.5) had a hazard ratio=1.53 (95% confidence interval: 1.29–1.82) for endometrioid adenocarcinoma. BMI was not associated with non-oestrogen-dependent cancers, except at the oldest childhood ages. Height at all ages was statistically significant and positively associated with all endometrial cancers, except non-oestrogen-dependent cancers. At 7 years, per ~5.2 cm (1 z-score), the risk of endometrioid adenocarcinoma was 1.18 (95% confidence interval: 1.09–1.28). Among non-users of unopposed oestrogens, associations between BMI and endometrioid adenocarcinoma strengthened, but no effects on height associations were observed.Conclusions:Endometrial carcinogenesis is linked to early-life body size, suggesting that childhood BMI and height may be useful indicators for the risk of later development of endometrial cancer and might aid in the early prevention of obesity-related endometrial cancers.

Effects of flaxseed and Hypericum perforatum on hot flash, vaginal atrophy and estrogen-dependent cancers in menopausal women: a systematic review and meta-analysis.

In this study, we aimed at evaluation of the efficacy of Hypericum perforatum and flaxseed on hot flash, vaginal atrophy and estrogen-dependent cancers in menopausal women. We searched MEDLINE, Scopus, and the Cochrane Central Register of Controlled Trials (RCT) to explore trials that assessed the effectiveness of H. perforatum and flaxseed on hot flash, vaginal atrophy and estrogen-dependent cancers. In this regard, the following terms were used "menopause AND H. perforatum OR flaxseed OR Linum usitatissimum. Only randomized controlled trials were included in the study. Nine RCTs were included in this systematic review. Based on the literature, flaxseed showed beneficial effect on hot flash frequency and intensity, which was not statistically significant. According to two trials, flaxseed showed estrogenic effects; however, no conclusion regarding cancer promoting or protecting effects can be made. The evidence of the efficacy of the flaxseed on alleviating vaginal atrophy was also limited due to inconsistent findings in this regard. One trial declared that Vitex agnus-castus and H. perforatum showed comparable decrease in the frequency of hot flashes. The results of our systematic review suggest beneficial effect on vasomotor symptom with both of flaxseed and H. perforatum. Consistent conclusion regarding estrogen-dependent cancers and maturation value is limited due to small number of trials related to flaxseed. Further trials are still needed to confirm the results of our systematic review.

Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides.

The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 –lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu–lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis.

Steroid Sulfatase Inhibitor Reduces Proliferation of Ishikawa Endometrial Cancer Cells in Co-Culture Systems

Objectives: Estrogens significantly contribute toward the growth and development of endometrial cancers. Two principal pathways have been implicated in the final steps of estrogen synthesis: the steroid sulfatase (STS) and aromatase pathways. In this study, we aimed to evaluate the possible effects of tumor-stromal interactions on local estrogen biosynthesis in endometrial cancer. We also assessed the biological effects of inhibitors of steroid sulfatase and aromatase in the co-culture system compared with usual monocultures. Methods/Materials: We isolated stromal cells from endometrial cancer patients to examine local biosynthesis of estrogens and tumor-stromal interactions. Next we examined the effects of steroid sulfatase inhibitor and aromatase inhibitor in monoculture of endometrial cancer cell line (Ishikawa) and in a co-culture system involving an Ishikawa cells and stromal cells. Results: Estrogen receptor and steroid sulfatase mRNA levels in cancer cells were significantly higher in the co-cultures compared with the monocultures of endometrial cancer cells. Estradiol and androstenediol concentrations were also significantly higher in the co-cultured cells. Proliferation of the cancer cells was significantly increased through the steroid sulfatase pathway, which metabolizes androgens, estrone sulfate, and estradiol sulfate as its substrates. However, its proliferation was significantly decreased by the treatment of steroid sulfatase or aromatase inhibitors. The significant growth inhibition by the steroid sulfatase and aromatase inhibitors were also observed in the co-culture system. Conclusions: We evaluated the effects of STS inhibitor and aromatase inhibitors on the proliferation of estrogen-dependent endometrial cancer cells. Considering that intratumoral estrogen metabolism plays an important role, our co-culture systems provide an environment similar to that of the tumor in living patients in terms of metabolism and synthesis of intratumoral estrogens. The results of this study may aid in achieving improved clinical responses from patients treated with STS inhibitors.

Association between Exposure to Estrogenic Endocrine Disruptors - Polychlorinated Biphenyls, Phthalates, and Bisphenol A and Gynecologic Cancers- Cervical, Ovarian, Uterine Cancers

Introduction: Estrogen is a driver in the growth and progression of gynecologic cancers (cervical, ovarian, and uterine). A number of estrogenically active chemicals are suspected to contribute in the development of gynecologic lesions, including an increased risk of estrogen-dependent cancer in women. Humans are exposed to estrogenic endocrine disruptors (EEDs), such as- polychlorinated biphenyls (PCBs), phthalates and bisphenol A (BPA). Therefore, we examined the cross-sectional relationship between exposure to PCBs, phthalates, and BPA and gynecologic cancers (cervical, ovarian, and uterine). Methods: We analyzed data from female participants (20 years of age and older) who provided blood and urine samples for the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey (NHANES) between 1999 and 2010. Exposure was examined based on lipid adjusted serum levels of 6 individual PCB congeners (74, 99, 118, 138, 153, and 180), the sum of dioxin-like PCBs (074 and 118), the sum of non-dioxin-like PCBs (099+138+153+187), 8 urinary phthalate metabolites (MNP, MEP, MEHP, MBzP, MCPP, MEHHP, MEOHP, and MIB), the sum of DEHP metabolites (MHP+MHH+MOH), the sum of total phthalates, and urinary BPA in conjunction with data obtained from the medical and reproductive health questionnaires. We calculated geometric means to compare EEDs concentrations in women who self-reported a cervical, ovarian, or uterine cancer diagnosis vs. women who self-reported never being diagnosed with cancer. We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between exposure to EEDs and r gynecologic cancers. We also evaluated age, race/ethnicity, body mass index (BMI; kg/m2), and age at menarche as potential confounding variables in our final models. Results: Separate analyses showed weighted geometric mean (GM) levels of individual PCB congeners to be significantly higher among women with ovarian cancer, and uterine cancer when compared to the rest of the study population. Mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was found to be significantly higher and BPA was higher among women with ovarian cancer compared to women never diagnosed with any gynecologic cancer. After adjusting for age, race, BMI, and age at menarche, we found that PCB 138 was significantly associated with cervical cancer, and uterine cancer [odds ratios of 3.05, 95% CI: 1.21-7.69; and 5.83, 95% CI: 1.63-20.9], respectively. PCB 74 and 118 however, were significantly associated with ovarian cancer with an odds ratios of 6.47, 95% CI: 1.23-3.41 (for PCB 74) and 6.68, 95% CI: 1.39-32.3 (for PCB 118). We also found the sum of non-dioxin-like PCBs to be significantly associated with uterine cancer (OR of 1.12, 95% CI: 1.03-1.23) and the sum of dioxin-like PCBs to be significantly associated with ovarian cancer (OR of 2.02, 95% CI: 1.06-3.85). We did not find significant associations between urinary phthalates and BPA and gynecologic cancers. Conclusions: Our findings point to a possible association between environmental exposure to PCBs and an increased risk of cervix, ovarian and uterine cancer. However, these findings should be interpreted cautiously because of self-reported cross sectional data and a limited sample size of gynecologic cancers.

Estrogen Receptor Ligands: A Review (2013-2015).

Estrogen receptors (ERs) are a group of compounds named for their importance in both menstrual and estrous reproductive cycles. They are involved in the regulation of various processes ranging from tissue growth maintenance to reproduction. Their action is mediated through ER nuclear receptors. Two subtypes of the estrogen receptor, ERα and ERβ, exist and exhibit distinct cellular and tissue distribution patterns. In humans, both receptor subtypes are expressed in many cells and tissues, and they control key physiological functions in various organ systems. Estrogens attract great attention due to their wide applications in female reproductive functions and treatment of some estrogen-dependent cancers and osteoporosis. This paper provides a general review of ER ligands published in international journals patented between 2013 and 2015. The broad physiological profile of estrogens has attracted the attention of many researchers to develop new estrogen ligands as therapeutic molecules for various clinical purposes. After the discovery of the ERβ receptor, subtype-selective ligands could be used to elicit beneficial estrogen-like activities and reduce adverse side effects, based on the different distributions and relative levels of the two ER subtypes in different estrogen target tissues. Therefore, recent literature has focused on selective estrogen ligands as highly promising agents for the treatment of some types of cancer, as well as for cardiovascular, inflammatory, and neurodegenerative diseases. Estrogen receptors are nuclear transcription factors that are involved in the regulation of many complex physiological functions in humans. Selective estrogen ligands are highly promising targets for treatment of some types of cancer, as well as for cardiovascular, inflammatory and neurodegenerative diseases. Extensive structure-activity relationship studies of ER ligands based on small molecules indicate that many different structural scaffolds may provide high-affinity compounds, provided that some basic structural requirements are present.

Abstract LB-A12: New target for cancer metabolism : Steroid Sulfatase

Abstract Steroid sulfatase (STS) expression has been considered to play a pivotal role in estrogen-dependent cancers. STS is known as a target enzyme for suppressing estrogen-mediated carcinogenesis. STS is able to convert estrogen sulfate to estrone form, like dehydroepiandrosterone sulfate (DHEA-S) to its' active form dehydroepiandrosterone (DHEA). Aerobic glycolysis is a hallmark of cancer metabolism. Lactic acid production was also increased by STS and DHEA.STS and its' major product DEHA reduced Oxygen consumption rate. STX064, a STS specific inhibitor inhibited DHEA formation and lactic acid production, recovered mitochondria resperation in HeLa cells. Hypoxia inducing factor 1 subunit HIF1α is recognized as an important regulator of aerobic glycolysis. To elucidate whether STS is able to regulate cancer metabolism, the effects on aerobic glycolysis were determined. STS overexpression significantly converted DHEA-S to DHEA. STS and the major product DHEA enhanced HIF1α protein, mRNA, promoter activity in HeLa cells. Glycolytic enzymes such as hexokinase 2 (HK-2) and glucose transporter (GLUT) were increased by STS overexpression and DHEA treatment in protein and mRNA levels. When cells were treated with HIF1α siRNA, all glycolytic enzymes induced by STS and DHEA were down-regulated. STS also regulated pyruvate kinase M (PKM)splicing. STS up-regulated PKM2 level and inhibited PKM1 level through transcription factor c-Myc. Phosphorylation of PKM2 was also induced by STS. In conclusion, STS and the major product DHEA may regulate aerobic glycolysis via HIF1α induction and c-Myc related PKM2 alternative splicing. Citation Format: sangyun shin, Yeo-Jung Kwon, Dong-Jin Ye, Hyoung-Seok Baek, Young-Jin Chun. New target for cancer metabolism : Steroid Sulfatase. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A12.

Association of environmental chemicals & estrogen metabolites in children

BackgroundThe prevalence of pediatric hormonal disorders and hormonally-sensitive cancers are rising. Chemicals including bisphenol A (BPA), phthalates, parabens, 4-nonylphenol (4NP) and triclosan have been linked to disruption of endocrine pathways and altered hormonal status in both animal and human studies. Additionally, changes in estrogen metabolism have been associated with pediatric endocrine disorders and linked to estrogen-dependent cancers. The main objective of the study was to measure the presence of these environmental chemicals in prepubescent children and assess the relationship between chemical metabolites and estrogen metabolism.Methods50 subjects (25 male, 25 female) were recruited from the principal investigator’s existing patient population at his pediatric primary care office. The first 5 boys and 5 girls in each age group (4 through 8 years old inclusive) who presented for annual examinations were included, as long as they were Tanner Stage I (prepubertal) on physical exam, without diagnosis of hormonally-related condition and/or cancer and able to give a urine sample. Urine samples were collected in glass containers for analysis of chemical and estrogen metabolites. Study kits and lab analysis were provided by Genova Diagnostics (Duluth, GA).Summary statistics for the concentrations of each chemical metabolite as well as estrogen metabolites were computed (minimum, maximum, median and inter-quartile range) for males only, for females only and for all subjects. Comparisons between groups (e.g. males v. females) were assessed using the nonparametric Wilcoxon test, since the data was skewed. The correlation between concentrations of chemical metabolites and estrogen metabolites in prepubescent children were examined by the Spearman’s correlation coefficient (ρ).Results100 % of subjects had detectable levels of at least one chemical in their urine, and 74 % had detectable levels of eight or more chemicals. 28 % of subjects had measurable levels of 4NP. No associations were found between the urine levels of chemicals and estrogen metabolites.ConclusionsEndocrine disrupting environmental chemicals were detected in all children in the study, with measurable levels of 4NP in nearly 1/3 of subjects. This is the first known published study of 4NP levels in American children. No associations were found between the urine levels of chemicals tested and estrogen metabolites. The presence of multiple chemicals in a majority of children’s urine coupled with increasing prevalence of pediatric hormonal disorders warrants further research to elucidate potential causal mechanisms in pre- and post-pubertal children.

Osteopontin promotes aromatase expression and estradiol production in human adipocytes.

Breast and endometrial cancer are often estrogen dependent, and their incidence and mortality are increased by obesity in postmenopausal women. Osteopontin (OPN) is a cytokine strongly upregulated in adipose tissue (AT) in obesity. OPN function is potentiated by cleavage by matrix metalloproteinases (MMP). OPN and MMPs play a role in cancer development and are prognostic markers in breast cancer progression. While induction of the estrogen-synthesizing enzyme aromatase by TNFa and IL1 has been shown in preadipocytes, an impact of OPN on aromatase expression in AT has not been investigated yet. Gene expression was determined in AT samples of 21 morbidly obese and matched non-obese subjects. Primary human adipocytes were treated with full-length OPN or MMP-cleaved OPN (cOPN). Protein and mRNA expressions were analyzed from cell lysates, or cells were subsequently supplied with testosterone to determine estradiol production and for indirect co-culture with the estrogen-dependent MCF-7 cell line. Aromatase expression strongly correlated with gene expression of OPN and various MMPs in visceral and MMPs in subcutaneous AT, but not with TNFα expression in both tissues. In vitro, cOPN more effectively than full-length OPN upregulated aromatase mRNA in adipocytes and significantly increased aromatase protein level and estradiol production, leading to increased MCF-7 growth in indirect co-culture. OPN and MMPs are upregulated in AT in obesity, and MMP-cleaved OPN is particularly effective in inducing aromatase activity in human adipocytes. Thereby, obesity-induced OPN expression in AT may contribute to estradiol production and thus to the association of obesity with estrogen-dependent cancers.

Relationship between Carotenoids, Retinol, and Estradiol Levels in Older Women.

Background. In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. Methods. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998–2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. Results. After adjustment for age, α-carotene (β ± SE = −0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = −0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = −1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = −0.29 ± 0.08, p = 0.0009), and E2 persisted whereas the relationship between α-carotene and T/E2 ratio was attenuated (β ± SE = 0.22 ± 0.12, p = 0.07). In a fully adjusted model (Model 3), only β-carotene (β ± SE = −0.05 ± 0.02, p = 0.03) was significantly and inversely associated with E2 levels independent of α-carotene. No association was found between retinol, total non-pro-vitamin A carotenoids, lutein, zeaxanthin, and lycopene, and E2 levels. Conclusions: In older women, β-carotene levels are independently and inversely associated with E2.

Almost half of women with endometrial cancer or hyperplasia do not know that obesity affects their cancer risk

An estimated 52,630 cases of endometrial cancer were diagnosed in 2014 (Siegel et al., 2014), and up to 40% of these are attributable to obesity (Polednak, 2008). Women of low socioeconomic status and minority race, especially Hispanic and African-American women, are disproportionally obese and at increased risk (Ogden et al., 2010). Most cases of endometrial cancer, particularly type 1, estrogen-dependent cancers, will be curable with surgery with or without adjuvant therapy (Sorosky, 2012). The leading cause of death after treatment for endometrial cancer is cardiovascular disease (Ward et al., 2012) and the link between obesity and death from cardiovascular disease is well established (Malnick and Knobler, 2006). Obesity is also linked to increased risk of postmenopausal breast cancer and infertility (Malnick and Knobler, 2006). While over 90% of the general public is aware of the impact of obesity on cardiovascular disease (Lake S. Perry and Associates, 2003), studies show that as few as 18–42% of women are aware of the association between endometrial cancer and obesity (Cardozo et al., 2012a, Cardozo et al., 2012b, Soliman et al., 2008). These studies evaluated populations that largely consisted of White and African-American, college-educated women. Additionally, no study has specifically evaluated knowledge in women who had been diagnosed with endometrial hyperplasia or cancer. The purpose of this study was to evaluate knowledge of obesity's health risks in a population of underserved, predominantly Hispanic women. We sought to determine baseline health literacy with regard to obesity's cardiovascular and reproductive health risks, and to compare knowledge between women with endometrial hyperplasia and cancer versus unaffected controls.

Peroxisome Proliferator-Activated Receptor as a Therapeutic Target in Human Breast Cancer

Objective: Peroxisome proliferator-activated receptor γ (PPARγ) is aberrantly expressed in most breast tumors, suggesting the potential of agents that target this receptor in treatment and chemoprevention of breast cancer. However, whether PPARγ leads to the promotion or reduction of tumor formation has remained controversial and is further complicated by the ability of its available thiazolidinedione (TZD) ligands to activate another PPAR subtype, PPARδ. Method: To examine the role of each receptor in breast cancer biology, we performed a systematic evaluation of PPARγ and PPARδ agonists on the growth of human estrogen receptor (ER)-positive and -negative breast cancer cells. Results: In this manner we found that TZD-activated PPARγ was highly effective in suppressing the proliferation of estrogen-dependent cancer cells. Activated PPARδ, however, displayed growth-enhancing effects independent of estradiol and regardless of the ER status of the cells. Strikingly, in ER-negative cancer cells expressing a favorable PPARδ/γ ratio, TZDs promoted growth in a PPAR γ-independent manner by direct activation of PPARδ. A screen for ligands with increased receptor selectivity compared to TZDs revealed that GW7845 functioned as a full agonist of PPARγ, yet this agent lacked the ability to activate PPARδ and elicit its associated mitogenic effects. Conclusion: These studies indicate that selective PPAR γ modulators (SPPARγMs) that lack agonist activity on PPARδ may be clinically useful in future cancer treatment and chemoprevention.

3D QSAR studies, pharmacophore modeling and virtual screening on a series of steroidal aromatase inhibitors.

Aromatase inhibitors are the most important targets in treatment of estrogen-dependent cancers. In order to search for potent steroidal aromatase inhibitors (SAIs) with lower side effects and overcome cellular resistance, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were performed on a series of SAIs to build 3D QSAR models. The reliable and predictive CoMFA and CoMSIA models were obtained with statistical results (CoMFA: q2 = 0.636, r2ncv = 0.988, r2pred = 0.658; CoMSIA: q2 = 0.843, r2ncv = 0.989, r2pred = 0.601). This 3D QSAR approach provides significant insights that can be used to develop novel and potent SAIs. In addition, Genetic algorithm with linear assignment of hypermolecular alignment of database (GALAHAD) was used to derive 3D pharmacophore models. The selected pharmacophore model contains two acceptor atoms and four hydrophobic centers, which was used as a 3D query for virtual screening against NCI2000 database. Six hit compounds were obtained and their biological activities were further predicted by the CoMFA and CoMSIA models, which are expected to design potent and novel SAIs.