Hormonal regulation of catechol-O-methyl transferase activity in women with uterine leiomyomas

Uterine fibroids: current research on novel drug targets and innovative therapeutic strategies

INTRODUCTION

Uterine fibroids, the most common nonmalignant tumors affecting the female genital tract, are a significant medical challenge. This article focuses on the most recent studies that attempted to identify novel non-hormonal therapeutic targets and strategies in UF therapy.

AREAS COVERED

This review covers the analysis of the pharmacological and biological mechanisms of the action of natural substances and the role of the microbiome in reference to UFs. This study aimed to determine the potential role of these compounds in UF prevention and therapy.

EXPERT OPINION

While there are numerous approaches for treating UFs, available drug therapies for disease control have not been optimized yet. This review highlights the biological potential of vitamin D, EGCG and other natural compounds, as well as the microbiome, as promising alternatives in UF management and prevention. Although these substances have been quite well analyzed in this area, we still recommend conducting further studies, particularly randomized ones, in the field of therapy with these compounds or probiotics. Alternatively, as the quality of data continues to improve, we propose the consideration of their integration into clinical practice, in alignment with the patient's preferences and consent.

Common Beverage Consumption and Benign Gynecological Conditions

The purpose of this article is to review the effects of four commonly consumed beverage types-sugar-sweetened beverages (SSBs), caffeinated beverages, green tea, and alcohol-on five common benign gynecological conditions: uterine fibroids, endometriosis, polycystic ovary syndrome (PCOS), anovulatory infertility, and primary dysmenorrhea (PD). Here we outline a plethora of research, highlighting studies that demonstrate possible associations between beverage intake and increased risk of certain gynecological conditions-such as SSBs and dysmenorrhea-as well as studies that demonstrate a possible protective effect of beverage against risk of gynecological condition-such as green tea and uterine fibroids. This review aims to help inform the diet choices of those with the aforementioned conditions and give those with uteruses autonomy over their lifestyle decisions.

Epigallocatechin Gallate for the Treatment of Benign and Malignant Gynecological Diseases-Focus on Epigenetic Mechanisms

The most common malignant gynecologic diseases are cervical, uterine, ovarian, vaginal, and vulvar cancer. Among them, ovarian cancer causes more deaths than any other cancer of the female reproductive system. A great number of women suffer from endometriosis, uterine fibroids (UFs), adenomyosis, dysmenorrhea, and polycystic ovary syndrome (PCOS), which are widespread benign health problems causing troublesome and painful symptoms and significantly impairing the quality of life of affected women, and they are some of the main causes of infertility. In addition to the available surgical and pharmacological options, the effects of supporting standard treatment with naturally occurring compounds, mainly polyphenols, are being studied. Catechins are responsible for the majority of potential health benefits attributed to green tea consumption. Epigallocatechin gallate (EGCG) is considered a non-toxic, natural compound with potential anticancer properties. Antioxidant action is its most common function, but attention is also drawn to its participation in cell division inhibition, apoptosis stimulation and epigenetic regulation. In this narrative review, we describe the role of EGCG consumption in preventing the development of benign reproductive disorders such as UF, endometriosis, and PCOS, as well as malignant gynecologic conditions. We discuss possible epigenetic mechanisms that may be related to the action of EGCG.

Current and Emerging Treatment Options for Uterine Fibroids

Uterine fibroids are the most common benign neoplasm of the female reproductive tract in reproductive age women. Their prevalence is age dependent and can be detected in up to 80% of women by the age of 50 years. Patients affected by uterine fibroids may experience a significant physical, emotional, social, and financial toll as well as losses in their quality of life. Unfortunately, curative hysterectomy abolishes future pregnancy potential, while uterine-sparing surgical and radiologic alternatives are variously associated with reduced long-term reproductive function and/or high tumor recurrence rates. Recently, pharmacological treatment against uterine fibroids have been widely considered by patients to limit uterine fibroid-associated symptoms such as heavy menstrual bleeding. This hormonal therapy seemed effective through blocking the stimulatory effects of gonadal steroid hormones on uterine fibroid growth. However, they are contraindicated in women actively pursuing pregnancy and otherwise effective only during use, which is limited because of long-term safety and other concerns. Accordingly, there is an urgent unmet need for safe, durable, and fertility-compatible non-surgical treatment options for uterine fibroids. In this review article, we cover the current pharmacological treatments for uterine fibroids including their comparable efficacy and side effects as well as emerging safe natural compounds with promising anti-uterine fibroid effects.

Contemporary approaches in the management of uterine leiomyomas

BACKGROUND

Leiomyomas (fibroids), the most common benign solid tumours in females, originate from the myometrium and are associated with poor quality of life for patients. The current management of uterine leiomyomas mainly includes surgical interventions such as hysterectomy and myomectomy, either by laparoscopy or laparotomy, which have several complications and are not ideal for preserving fertility. Therefore, there is a need to develop or repurpose medical treatments that do not require surgical intervention.

OBJECTIVE

Many drugs are used to treat the symptoms associated with uterine fibroids. The main objective of this systematic review is to give an up-to-date account of potential pharmacological agents (non-surgical methods) for the management of uterine leiomyomas.

SEARCH STRATEGY

PubMed was searched for scientific and clinical literature using the keyword 'uterine fibroids' along with the drug names described in each section. For example, 'uterine fibroids' and 'ulipristal acetate' were the keywords used to search for literature on ulipristal acetate (UPA).

RESULTS

Various preclinical and clinical studies have shown that some drugs and herbal formulations exhibit activity in the management of uterine leiomyomas. Recent studies found that drugs such as UPA, elagolix, EC313, asoprisnol, nutritional supplements and herbal preparations were helpful in treating the symptoms associated with uterine leiomyomas.

CONCLUSION

Many drugs show efficacy in patients with symptomatic uterine fibroids. UPA is one of the most studied and prescribed medicines for uterine fibroids; however, its usage has been restricted due to a few recent incidences of hepatic toxicity. Herbal drugs and natural supplements have also shown promising effects on uterine fibroids. The synergistic effects of nutritional and herbal supplements have been reported in certain cases, and should be studied in detail. Further research is warranted to identify the mode of action of the drugs, and to determine the precise conditions that would explain the causes of toxicity in some patients.

Green Tea and Benign Gynecologic Disorders: A New Trick for An Old Beverage?

Green tea is harvested from the tea plant Camellia sinensis and is one of the most widely consumed beverages worldwide. It is richer in antioxidants than other forms of tea and has a uniquely high content of polyphenolic compounds known as catechins. Epigallocatechin-3-gallate (EGCG), the major green tea catechin, has been studied for its potential therapeutic role in many disease contexts, including pathologies of the female reproductive system. As both a prooxidant and antioxidant, EGCG can modulate many cellular pathways important to disease pathogenesis and thus has clinical benefits. This review provides a synopsis of the current knowledge on the beneficial effects of green tea in benign gynecological disorders. Green tea alleviates symptom severity in uterine fibroids and improves endometriosis through anti-fibrotic, anti-angiogenic, and pro-apoptotic mechanisms. Additionally, it can reduce uterine contractility and improve the generalized hyperalgesia associated with dysmenorrhea and adenomyosis. Although its role in infertility is controversial, EGCG can be used as a symptomatic treatment for menopause, where it decreases weight gain and osteoporosis, as well as for polycystic ovary syndrome (PCOS).

Evidence-Based Management of Uterine Fibroids With Botanical Drugs-A Review

Uterine fibroids (UFs) are a common benign gynecological tumor that affect the majority of women over their lifetime. Several pharmacological agents are available to reduce the size of fibroids and ameliorate the symptoms of UF. However, these drugs are expensive and are usually associated with profound side effects. Thus, botanical drugs are gaining attention in this era due to their cost effectiveness with a comparable and more potent therapeutic efficacy while demonstrating lesser adverse effects. The objective of this review is to summarize the available information on the mechanism of various botanical drugs and polyherbal formulations with anti-uterine fibroid activity. A systematic search was performed on botanical drugs with anti-uterine fibroid activity using several search engines, which include PubMed, Google Scholar, and Science Direct. Based on the literatures identified, a total of five botanical drugs and three polyherbal formulations were included and discussed in this review, which yields useful information regarding the mechanism of different botanical drugs and polyherbal formulations in exerting anti-uterine fibroid activity for its potential use as an alternative treatment choice for uterine fibroids.

The Evolving Role of Natural Compounds in the Medical Treatment of Uterine Fibroids

Uterine fibroids (UFs) remain a significant health issue for many women, with a disproportionate impact on women of color, likely due to both genetic and environmental factors. The prevalence of UFs is estimated to be approximately 70% depending on population. UF-derived clinical symptoms include pelvic pain, excessive uterine bleeding, gastrointestinal and voiding problems, as well as impaired fertility. Nowadays numerous methods of UF treatment are available-from conservative treatment to invasive surgeries. Selecting an appropriate treatment option should be individualized and adjusted to the patient's expectations as much as possible. So far, the mainstay of treatment is surgery, but their negative impact of future fertility is clear. On the other hand, emerging new pharmaceutical options have significant adverse effects like liver function impairment, hot flashes, bone density loss, endometrial changes, and inability to attempt conception during treatment. Several natural compounds are found to help treat UFs and relieve their symptoms. In this review we summarize all the current available data about natural compounds that may be beneficial for patients with UFs, especially those who want to preserve their future fertility or have treatment while actively pursuing conception. Vitamin D, epigallocatechin gallate, berberine, curcumin, and others are being used as alternative UF treatments. Moreover, we propose the concept of using combined therapies of natural compounds on their own or combined with hormonal agents to manage UFs. There is a strong need for more human clinical trials involving these compounds before promoting widespread usage.

Expanded Somatic Mutation Spectrum of MED12 Gene in Uterine Leiomyomas of Saudi Arabian Women

MED12, a subunit of mediator complex genes is known to harbor genetic mutations, (mostly in exon 2), causal to the genesis of uterine leiomyomas among Caucasian, African American, and Asian women. However, the precise relationship between genetic mutations vs. protein or disease phenotype is not well-explained. Therefore, we sought to replicate the MED12 mutation frequency in leiomyomas of Saudi Arabian women, who represents ethnically and culturally distinct population. We performed molecular screening of MED12 gene (in 308 chromosomes belonging to 154 uterine biopsies), analyzed the genotype-disease phenotype correlations and determined the biophysical characteristics of mutated protein through diverse computational approaches. We discovered that >44% (34/77) leiomyomas of Arab women carry a spectrum of MED12 mutations (30 missense, 1 splice site, and 3 indels). In addition to known codon 44, we observed novel somatic mutations in codons 36, 38, and 55. Most genetically mutated tumors (27/30; 90%) demonstrated only one type of genetic change, highlighting that even single allele change in MED12 can have profound impact in transforming the normal uterine myometrium to leiomyomas. An interesting inverse correlation between tumor size and LH is observed when tumor is positive to MED12 mutation (p < 0.05). Our computational investigations suggest that amino acid substitution mutations in exon-2 region of MED12 might contribute to potential alterations in phenotype as well as the stability of MED12 protein. Our study, being the first one from Arab world, confirms the previous findings that somatic MED12 mutations are critical to development and progression of uterine leiomyomas irrespective of the ethnic background. We recommend that mutation screening, particularly codon 44 of MED12 can assist in molecular diagnostics of uterine leiomyomas in majority of the patients.

Racial and ethnic differences in the pathogenesis and clinical manifestations of uterine leiomyoma

Uterine leiomyomas are the most common benign gynecologic condition. The prevalence is three times more common among women of African ethnicity. Disparity in this disease is evidenced by earlier age of onset, greater severity of symptoms, and different response to treatment. Although the pathogenesis of disease development is not completely known, growing evidence focuses on investigating the molecular mechanisms in disease development and the influence of ethnicity. Variation in the expression levels or function of estrogen and progesterone receptors, polymorphism of genes involved in estrogen synthesis and/or metabolism (COMT, CYP17), retinoic acid nuclear receptors (retinoid acid receptor-α, retinoid X receptor-α), and aberrant expression of micro-RNAs (miRNAs) are some of the molecular mechanisms that may be involved. Nutritional factors, such as vitamin D deficiency, might also contribute to the higher incidence in dark skinned populations who are also commonly suffer from hypovitaminosis D. Culture and environmental difference might have a role in disease development. Further analysis and better understanding of these mechanisms will provide insight into the molecular basis of racial disparities in leiomyoma formation and will help to develop new innovations in leiomyoma treatment.

Treatment of symptomatic uterine fibroids with green tea extract: a pilot randomized controlled clinical study

Background

Uterine fibroids (UFs, also known as leiomyoma) affect 70% of reproductive-age women. Imposing a major burden on health-related quality-of-life (HRQL) of premenopausal women, UF is a public health concern. There are no effective medicinal treatment options currently available for women with symptomatic UF.

Objectives

To evaluate the efficacy and safety of green tea extract (epigallocatechin gallate [EGCG]) on UF burden and quality of life in women with symptomatic UF, in a double-blinded, placebo-controlled randomized clinical trial.

Methods

A total of 39 reproductive-age women (age 18–50 years, day 3 serum follicle-stimulating hormone <10 \U/mL) with symptomatic UF were recruited for this study. All subjects had at least one fibroid lesion 2 cm³ or larger, as confirmed by transvaginal ultrasonography. The subjects were randomized to oral daily treatment with either 800 mg of green tea extract (45% EGCG) or placebo (800 mg of brown rice) for 4 months, and UF volumes were measured at the end, also by transvaginal ultrasonography. The fibroid-specific symptom severity and HRQL of these UF patients were scored at each monthly visit, using the symptom severity and quality-of-life questionnaires. Student’s t-test was used to evaluate statistical significance of treatment effect between the two groups.

Results

Of the final 39 women recruited for the study, 33 were compliant and completed all five visits of the study. In the placebo group (n = 11), fibroid volume increased (24.3%) over the study period; however, patients randomized to green tea extract (n = 22, 800 mg/day) treatment showed significant reduction (32.6%, P = 0.0001) in total UF volume. In addition, EGCG treatment significantly reduced fibroid-specific symptom severity (32.4%, P = 0.0001) and induced significant improvement in HRQL (18.53%, P = 0.01) compared to the placebo group. Anemia also significantly improved by 0.7 g/dL (P = 0.02) in the EGCG treatment group, while average blood loss significantly decreased from 71 mL/month to 45 mL/month (P = 0.001). No adverse effects, endometrial hyperplasia, or other endometrial pathology were observed in either group.

Conclusion

EGCG shows promise as a safe and effective therapeutic agent for women with symptomatic UFs. Such a simple, inexpensive, and orally administered therapy can improve women’s health globally.

Towards non-surgical therapy for uterine fibroids: catechol-O-methyl transferase inhibitor shrinks uterine fibroid lesions in the Eker rat model

BACKGROUND

Uterine leiomyomas (fibroids) are the most common pelvic tumors in women. We assessed the potential therapeutic utility of Ro 41-0960, a synthetic catechol-O-methyl transferase inhibitor (COMTI), in the Eker rat.

METHODS

We randomized uterine fibroid-bearing Eker rats for treatment with Ro 41-0960 (150 mg/kg/12 h) versus vehicle for 2 and 4 weeks. The fibroids were measured by caliper and subjected to histological evaluation. Urinary levels of 2-hydroxy estrogen (E(2)), 16-hydroxy E2 and DPD (osteoporosis marker) and serum liver enzymes were evaluated. Expressions of Cyclin D1, proliferating cell nuclear antigen (PCNA), Poly [ADP-ribose] polymerase1 (PARP1), tumor suppressor gene (P53) and transforming growth factor (TGFβ3) were assessed in fibroids using immunohistochemical analysis or RT-PCR. Apoptosis was confirmed using terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL).

RESULTS

Ro 41-0960-treated rats exhibited fibroid volumes of 86 ± 7% and 105 ± 12% of initial burden, at 2 and 4 weeks post-treatment, respectively, significantly lower than control group (240 ± 15% and 300 ± 18%; P< 0.01). Ro 41-0960 increased the urinary 2-hydroxy E2/16-hydroxy E(2) ratio, level of p53 mRNA and TUNEL positivity (P< 0.05) and decreased PARP1, PCNA and cyclin D1 proteins and TGFβ3 mRNA (P< 0.05). Ro 41-0960 did not change normal tissue histology, liver functions or urinary DPD level.

CONCLUSIONS

Ro 41-0960 (COMTI) arrested growth/shrunk uterine fibroids in Eker rats. This result may be related to modulation of estrogen-dependent genes involved in apoptosis, proliferation and extracellular matrix deposition via accumulation of 2-hydroxy estrogen. The efficacy and safety of Ro 41-0960 in rats suggest its candidacy for treatment of uterine fibroids.

1,25-Dihydroxyvitamin D3 reduces TGF-beta3-induced fibrosis-related gene expression in human uterine leiomyoma cells

BACKGROUND

Uterine leiomyomas (fibroids) are the most common benign estrogen-dependent tumors of premenopausal women. TGF-β3 up-regulates the synthesis of many of extracellular matrix proteins that are associated with tissue fibrosis.

OBJECTIVE

To examine the effect of 1,25-dihydroxyvitamin D(3) (vitamin D(3)) on TGF-β3-induced fibrosis-related protein expression in immortalized human uterine leiomyoma (HuLM) cells.

METHODS

HuLM cells were treated with TGF-β3 with or without vitamin D(3). Western blot analyses were employed to test the effect of vitamin D(3) on TGF-β3-induced protein expression of collagen type 1, fibronectin, and plasminogen activator inhibitor-1 proteins. Western blots as well as immunofluorescence analyses were used to verify the effect of vitamin D(3) on TGF-β3-induced Smad activation involved in extracellular matrix protein synthesis and deposition, which ultimately lead to tissue fibrosis.

RESULTS

We observed that TGF-β3 induced fibronectin and collagen type 1 protein expression in HuLM cells, and that effect was suppressed by vitamin D(3). TGF-β3 also induced protein expression of plasminogen activator inhibitor-1, an important TGF-β target, in HuLM cells, which was also inhibited by vitamin D(3). Additionally, TGF-β3 induced phosphorylation of Smad2 as well as nuclear translocation of Smad2 and Smad3 in HuLM cells, whereas vitamin D significantly reduced all these TGF-β3-mediated effects. Therefore, our results suggest that vitamin D(3) has consistently reduced TGF-β3 effects that are involved in the process of fibrosis in human leiomyoma cells.

CONCLUSION

Vitamin D(3) is an antifibrotic factor that might be potentially useful as a novel therapeutic for nonsurgical treatment of benign uterine fibroids.

Vitamin D inhibits proliferation of human uterine leiomyoma cells via catechol-O-methyltransferase

OBJECTIVE

To evaluate the effects and mechanisms of action of vitamin D on human uterine leiomyoma (HuLM) cell proliferation in vitro.

DESIGN

Laboratory study.

SETTING

University hospitals.

PATIENTS(S)

Not applicable.

INTERVENTIONS(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

HuLM cells were treated with 1,25-dihydroxyvitamin D3 (vitamin D), and cell proliferation was assayed by the methylthiazolyl tetrazolium technique. proliferating cell nuclear antigen (PCNA), BCL-2, BCL-w, cyclin-dependent kinase (CDK) 1, and catechol-O-methyltransferase (COMT) protein levels were analyzed by Western blotting. COMT mRNA and enzyme activity were assayed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and high-performance liquid chromatography analysis, respectively. The role of COMT was evaluated in stable HuLM cells by silencing COMT expression.

RESULT(S)

Vitamin D inhibited the growth of HuLM cells by 47±0.03% at 1 μM and by 38±0.02% at 0.1 μM compared with control cells at 120 hours of treatment. Vitamin D inhibited extracellular signal-regulated kinase activation and down-regulated the expression of BCL-2, BCL-w, CDK1, and PCNA. Western blot, RT-PCR, and enzyme assay of COMT demonstrated inhibitory effects of vitamin D on COMT expression and enzyme activity. Silencing endogenous COMT expression abolished vitamin D-mediated inhibition of HuLM cell proliferation.

CONCLUSION(S)

Vitamin D inhibits growth of HuLM cells through the down-regulation of PCNA, CDK1, and BCL-2 and suppresses COMT expression and activity in HuLM cells. Thus, hypovitaminosis D appears to be a risk factor for uterine fibroids.

The role of MSP I CYP1A1 gene polymorphism in the development of uterine fibroids

The cytochrome P-450 1A1 (CYPA1A) gene plays an important role in the metabolization of estrogen and is therefore a candidate marker for fibroids. In a case-control study, we were unable to demonstrate any association between MSP I CYP1A1 polymorphism and the risk of leiomyoma in Brazilian women.

Green tea extract inhibits proliferation of uterine leiomyoma cells in vitro and in nude mice

OBJECTIVE

The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on rat leiomyoma (ELT3) cells in vitro and in a nude mice model.

STUDY DESIGN

ELT3 cells were treated with various concentrations of EGCG. Cell proliferation, proliferation cell nuclear antigen (PCNA), and cyclin-dependent kinase 4 (Cdk4) protein levels were evaluated. ELT3 cells were inoculated subcutaneously in female athymic nude mice. Animals were fed 1.25 mg EGCG (in drinking water)/mouse/day. Tumors were collected and evaluated at 4 and 8 weeks after the treatment.

RESULTS

Inhibitory effect of EGCG (200 micromol/L) on ELT3 cells was observed after 24 hours of treatment (P < .05). At > or = 50 micromol/L, EGCG significantly decreased PCNA and Cdk4 protein levels (P < .05). In vivo, EGCG treatment dramatically reduced the volume and weight of tumors at 4 and 8 weeks after the treatment (P < .05). The PCNA and Cdk4 protein levels were significantly reduced in the EGCG-treated group (P < .05).

CONCLUSION

EGCG effectively inhibits proliferation and induces apoptosis in rat ELT3 uterine leiomyoma cells in vitro and in vivo.

Influence of Catechol-O-Methyltransferase (COMT) Genotypes on the Prognosis of Canine Mammary Tumors

Catechol-O-methyltransferase (COMT) is an important enzyme involved in inactivation of catechol estrogens, which are metabolites with carcinogenic properties. Some investigations in human breast cancer associate a genetic polymorphism in the COMT gene (COMT val158met) with an increased risk and poor clinical progression of the disease. In dogs, there are 2 recognized single nucleotide polymorphisms in the COMT gene (COMTG216A and COMTG482A); however, their influence on the outcome of mammary neoplasms has never been investigated. The purpose of this study is to investigate the influence of COMT in the clinical progression of canine mammary tumors, namely in recurrence, metastasis and survival by testing 2 SNPs (G216A and G482A), and 2 genotypes of the COMT gene. A case series was conducted analyzing genomic DNA samples by polymerase chain reaction-restriction fragment length polymorphism from 80 bitches with mammary tumors. Animals were submitted to an active follow-up study for a period of 24 months after surgery. We observed that bitches carrying both genetic variations simultaneously are more likely to develop recurrence of mammary lesions. Our results demonstrate a possible role for COMT genotypes in the outcome of mammary neoplasms in the dog. Identifying a genetic factor predictive of recurrence may be useful in selecting the most effective surgical approach for canine mammary neoplasms.

Prepulse inhibition of the startle reflex depends on the catechol O-methyltransferase Val158Met gene polymorphism

BACKGROUND

Recent evidence suggests that dopamine (DA) agonist-induced disruption of prepulse inhibition (PPI) depends on basal PPI values, in a manner that suggests an inverted U-shaped relationship between PPI and prefrontal DA levels. This is the first study to examine possible genetic determinants of PPI and the catechol O-methyltransferase (COMT) Val158Met polymorphism, the main catabolic pathway of released DA in the prefrontal cortex (PFC).

METHOD

PPI was measured in 93 healthy males presented with 75-dB and 85-dB prepulses at 60-ms and 120-ms prepulse-pulse intervals. Subjects were grouped according to their COMT status into a Val/Val, a Val/Met and a Met/Met group.

RESULTS

ANOVAs showed that at all prepulse and interval conditions, Val/Val individuals had the lowest PPI, Met/Met the highest, and Val/Met were intermediate.

CONCLUSIONS

These results suggest that PPI is regulated by DA neurotransmission in the PFC and its levels depend on the COMT Val158Met gene polymorphism. These findings enhance the value of the PPI paradigm in examining individual variability of early information processing in healthy subjects and psychiatric disorders associated with changes in PFC DA activity and attentional deficits such as schizophrenia.

Role of glutathione S-transferase (GSTM1) gene polymorphism in development of uterine fibroids

Glutathione S-transferase (GSTM1) plays an important role in the excretion of catechol estrogens and is therefore a candidate marker for fibroids. However, this case-control study demonstrated no association between GSTM1 polymorphism and the risk of leiomyoma in Brazilian women.

Regulation of catechol O-methyltransferase expression in granulosa cells: a potential role for follicular arrest in polycystic ovary syndrome

OBJECTIVE

To investigate the regulation of catechol O-methyltransferase (COMT) expression in granulosa cells and assess potential effects of 2-methoxyestradiol (2-ME2) and COMT inhibitors on granulosa cell steroidogenesis and proliferation.

DESIGN AND SETTING

Controlled experimental study in an academic research laboratory.

INTERVENTION(S)

JC410 porcine and HGL5 human granulosa cell lines were used for in vitro experiments. Effects of 2-ME2 and COMT inhibitor treatment on DNA proliferation and steroidogenesis were assessed by using Hoechst dye and p450SCC-luciferase reporter assays. Effects of dihydrotestosterone (DHT), insulin, and all-trans retinoic acid (ATRA) on COMT messenger RNA expression were investigated by using COMTP1 promoter-luciferase reporter and Northern blot.

MAIN OUTCOME MEASURE(S)

Granulosa cell steroidogenesis and proliferation following COMP inhibitor and 2-ME2 treatment. Regulation of COMT expression with DHT, insulin, and ATRA.

RESULT(S)

2-Methoxyestradiol had a dual effect on granulosa cell proliferation and p450SCC- luciferase activity; low doses were stimulatory and high doses were inhibitory. Catechol O-methyltransferase inhibitor was associated with up to a 65% increase in JC410 cell number and a maximal 5.6-fold increase in p450SCC-luciferase activity at 20 micromol/L. Dihydrotestosterone, insulin, and ATRA all induced a dose-dependent increase in COMTP1-luciferase transactivation, as well as up-regulated COMT messenger RNA expression in granulosa cells.

CONCLUSION(S)

Catechol O-methyltransferase expression in granulosa cells was up-regulated by insulin, DHT, and ATRA. Catechol O-methyltransferase product, 2-ME2, decreased, whereas COMT inhibitor increased granulosa cell proliferation and steroidogenesis. These data suggest that COMT overexpression with subsequent increased level of 2-ME2 may lead to ovulatory dysfunction.

Progesterone-mediated regulation of catechol-O-methyl transferase expression in endometrial cancer cells

The effects of estrogen and progesterone on the expression of estrogen-metabolizing enzymes such as catechol-O-methyl transferase (COMT) are not known. COMT converts genotoxic catecholestrogens to anticarcinogenic methoxyestrogens in the endometrium. The aim of this study is to investigate the effect of progesterone on COMT expression in well-differentiated endometrial cancer cells. The wild-type Ishikawa cell line as well as progesterone receptor A- or progesterone receptor B-transfected Ishikawa cells were used for in vitro studies. The regulation of COMT expression by progesterone was studied using Western blots, Hoechst dye DNA proliferation studies, and wild-type and/or site-directed mutagenesis of COMT promoter 1-luciferase reporter gene. Progesterone upregulated COMT protein expression in Ishikawa cells through progesterone receptor A isoform. COMT promoter activity was differentially regulated by the 3 half-site progesterone response elements in the COMT promoter. High doses of 2-ME2 inhibited Ishikawa cell proliferation. These data suggest that COMT expression is hormonally regulated in well-differentiated human endometrial cancer cells. COMT regulation and 2-ME2 production in the endometrium may affect endometrial carcinogenesis.

Progesterone regulates catechol-O-methyl transferase gene expression in breast cancer cells: distinct effect of progesterone receptor isoforms

There is strong evidence that catechol-O-methyl transferase (COMT) protects breast cells against estrogen-induced cancer by detoxifying catecholestrogens, the carcinogenic estrogen metabolites. COMT gene expression is controlled by two promoters - a proximal promoter (COMTP1) and a distal promoter (COMTP2) - that regulate the expression of soluble (S-COMT) and membrane-bound (MB-COMT) isoforms, respectively. We investigated the transcriptional regulation of the COMT gene by progesterone/progesterone receptors in breast cancer cells. Our results indicated that progesterone (P4) downregulates COMT gene expression in breast cancer cell lines. In addition, the COMTP1 and COMTP2 harbor several progesterone response elements (PREs). Electrophoretic mobility shift assay (EMSA) indicated that nuclear extracts of T47D cells bind to the identified PREs in COMTP1. Site-directed mutagenesis of PREs in COMTP1 not only reversed the P4-induced inhibition of COMTP1, but also increased its basal activity. The two progesterone receptor isoforms, PR-A and PR-B, were found to have opposite effects on the regulation of P4 in COMT expression; PR-A is associated with P4-induced upregulation of COMT, while PR-B is associated with P4-induced downregulation of COMT. In summary, our data demonstrated that P4 downregulates the COMT gene expression through multiple PREs in the COMT promoters and that different progesterone receptor isoforms have distinctive effects on COMT gene expression.

Adenovirus-mediated delivery of a dominant-negative estrogen receptor gene in uterine leiomyoma cells abrogates estrogen- and progesterone-regulated gene expression

CONTEXT

Human uterine leiomyomas are very common smooth muscle cell tumors that occur in reproductive-age women and are the leading reason for performing hysterectomies. The present study was conducted to explore the potential mechanism behind the effects exerted by dominant-negative estrogen receptors (DNERs) delivered by adenovirus to leiomyoma cells to ascertain the utility of DNERs as a novel strategy for treatment of uterine fibroids.

OBJECTIVE AND METHODS

We investigated the ability of DNER to affect estrogen response element (ERE) activity induced by wild-type estrogen receptor (ER) by using the adenovirus ERE luciferase (Ad-ERE-luc) system in ELT3 cells and the effect of graded doses of DNER (10, 50, and 100 plaque-forming units/cell) on the expression of some selected genes controlling cultured human leiomyoma cell proliferation (cyclin D1, Cox2, PCNA, VEGF, and EGF), apoptosis (Bcl2 and Bax), estrogen metabolism (COMT), and extracellular matrix formation (MMP(1)) as well as progesterone receptors (A and B) were assessed using Western blot analysis. These genes are all regulated by estrogen and/or progesterone.

RESULTS

DNER has the ability to suppress the ERE luc activity induced by wild-type ER (P < 0.01) and significantly (P < 0.05) reverse the expression of all estrogen- and progesterone-regulated genes in this study.

CONCLUSIONS

These results suggest that interruption of the estrogen signaling pathway using DNER results in modulation of both estrogen- and progesterone-regulated genes that control leiomyoma cell apoptosis, proliferation, extracellular matrix formation, progesterone receptors, and estrogen metabolism, which might account for the DNER mechanism of action.

Lower levels of urinary 2-hydroxyestrogens in polycystic ovary syndrome

CONTEXT

Women with polycystic ovary syndrome (PCOS) have anovulation due to arrested follicular maturation. The substrate (2-hydroxyestrogen) and product (2-methoxyestrogen) of catechol-O-methyl transferase (COMT) have been shown to modulate proliferation and angiogenesis of granulosa cells.

OBJECTIVE

The objective of the study was to evaluate COMT ovarian expression as well as the production of estrogen metabolites (2-hydroxyestrogen and 2-methoxyestrogen) in subjects with PCOS.

DESIGN

Immunohistochemistry was used to assess COMT expression in ovarian tissues. Urinary levels of 10 different estrogens and estrogen metabolites were measured using enzyme-labeled immunoassays and/or liquid chromatography with tandem mass spectrometry.

SETTING

The study was conducted at a tertiary university referral center.

PATIENTS AND OTHER PARTICIPANTS

Ovarian tissues were obtained from six control subjects and six subjects with PCOS. Fasting first-void urinary samples were collected from 49 subjects with PCOS and 36 healthy control subjects.

MAIN OUTCOME MEASURE(S)

COMT protein expression in ovarian tissues was measured. Urinary levels of 2-hydroxyestrogen and 2-methoxyestrogen levels in PCOS patients were also measured.

RESULTS

Whereas immunohistochemistry showed that COMT was expressed in ovaries from control and PCOS subjects, its expression was significantly higher in ovaries from subjects with PCOS, in both the follicular structures and ovarian stroma. The urinary 2-hydroxyestrogen level was significantly lower in subjects with PCOS, compared with normal controls (P = 0.009). Additionally, urinary 2-hydroxyestrogen levels negatively correlated with serum insulin levels in subjects with PCOS (r = -0.333, P =0 .031).

CONCLUSIONS

Urinary 2-hydroxyestrogen is decreased in subjects with PCOS, which could be due in part to increased ovarian expression of COMT. Further studies are needed to ascertain the role of estrogen metabolism in PCOS before this information can be used in clinical settings.

Expression and cyclic variations of catechol-O-methyl transferase in human endometrial stroma

OBJECTIVE

To investigate the role of catechol-O-methyl transferase (COMT) in the regulation of estrogen metabolism in human endometrium.

DESIGN

Laboratory study.

SETTING

Academic research laboratory.

INTERVENTION(S)

Immunohistochemistry was used to localize COMT protein in human endometrial tissues. Catechol-O-methyl transferase promoter-luciferace reporter gene transactivation assay was used to assess COMT promoter activity in response to estrogen and progesterone treatment in primary human endometrial stroma (pHES) cells. Catechol-O-methyl transferase protein and mRNA expression were determined by Western blot and/or real-time polymerase chain reaction. The effect of 2-methoxy estrogen treatment on DNA proliferation, B-cell lymphoma 2, and vascular epithelial growth factor protein expression were assessed by Hoechst and Western blot analyses, respectively.

MAIN OUTCOME MEASURE(S)

Catechol-O-methyl transferase protein and mRNA subcellular localization and expression in human endometrial tissues and pHES cells.

RESULT(S)

Catechol-O-methyl transferase protein expression in human endometrial tissues was up-regulated in the proliferative phase and down-regulated in the midsecretory phase of the menstrual cycle. Estrogen induced a dose-dependent increase in COMT proximal promotor-luciferace transactivation in pHES cells whereas progesterone inhibited it. Estrogen up-regulated soluble COMT protein isoform expression whereas the addition of progesterone down-regulated it in pHES cells. High doses of 2-methoxy estrogen inhibited endometrial stroma cell proliferation, and down-regulated B-cell lymphoma 2 and vascular epithelial growth factor protein expression.

CONCLUSION(S)

Catechol-O-methyl transferase expression is hormonally regulated in human endometrial stroma. Catechol-O-methyl transferase product, 2-methoxy estrogen, inhibited endometrial stroma cell proliferation and decreased vascular epithelial growth factor and B-cell lymphoma 2 protein expression.