Catechol-O-methyltransferase polymorphism is associated with increased uterine leiomyoma risk in different ethnic groups

Characterization of m6A Modifiers and RNA Modifications in Uterine Fibroids

Uterine leiomyoma or fibroids are prevalent noncancerous tumors of the uterine muscle layer, yet their origin and development remain poorly understood. We analyzed RNA expression profiles of 15 epigenetic mediators in uterine fibroids compared to myometrium using publicly available RNA sequencing (RNA-seq) data. To validate our findings, we performed RT-qPCR on a separate cohort of uterine fibroids targeting these modifiers confirming our RNA-seq data. We then examined protein profiles of key N6-methyladenosine (m6A) modifiers in fibroids and their matched myometrium, showing no significant differences in concordance with our RNA expression profiles. To determine RNA modification abundance, mRNA and small RNA from fibroids and matched myometrium were analyzed by ultra-high performance liquid chromatography-mass spectrometry identifying prevalent m6A and 11 other known modifiers. However, no aberrant expression in fibroids was detected. We then mined a previously published dataset and identified differential expression of m6A modifiers that were specific to fibroid genetic subtype. Our analysis also identified m6A consensus motifs on genes previously identified to be dysregulated in uterine fibroids. Overall, using state-of-the-art mass spectrometry, RNA expression, and protein profiles, we characterized and identified differentially expressed m6A modifiers in relation to driver mutations. Despite the use of several different approaches, we identified limited differential expression of RNA modifiers and associated modifications in uterine fibroids. However, considering the highly heterogenous genomic and cellular nature of fibroids, and the possible contribution of single molecule m6A modifications to fibroid pathology, there is a need for greater in-depth characterization of m6A marks and modifiers in a larger and diverse patient cohort.

The Influence of Race/Ethnicity on the Transcriptomic Landscape of Uterine Fibroids

The objective of this study was to determine if the aberrant expression of select genes could form the basis for the racial disparity in fibroid characteristics. The next-generation RNA sequencing results were analyzed as fold change [leiomyomas/paired myometrium, also known as differential expression (DF)], comparing specimens from White (n = 7) and Black (n = 12) patients. The analysis indicated that 95 genes were minimally changed in tumors from White (DF ≈ 1) but were significantly altered by more than 1.5-fold (up or down) in Black patients. Twenty-one novel genes were selected for confirmation in 69 paired fibroids by qRT-PCR. Among these 21, coding of transcripts for the differential expression of FRAT2, SOX4, TNFRSF19, ACP7, GRIP1, IRS4, PLEKHG4B, PGR, COL24A1, KRT17, MMP17, SLN, CCDC177, FUT2, MYO5B, MYOG, ZNF703, CDC25A, and CDCA7 was significantly higher, while the expression of DAB2 and CAV2 was significantly lower in tumors from Black or Hispanic patients compared with tumors from White patients. Western blot analysis revealed a greater differential expression of PGR-A and total progesterone (PGR-A and PGR-B) in tumors from Black compared with tumors from White patients. Collectively, we identified a set of genes uniquely expressed in a race/ethnicity-dependent manner, which could form the underlying mechanisms for the racial disparity in fibroids and their associated symptoms.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

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 Effect of Estrogen-Related Genetic Variants on the Development of Uterine Leiomyoma: Meta-analysis

Uterine leiomyoma is the most common benign gynecological tumor in women of reproductive age. It has been diagnosed approximately in 5 to 69% of women and was symptomatic in 30% of them. The underlying pathobiology of uterine leiomyoma is not well understood yet, but it can be defined as an estrogen-dependent tumor. Thus, this meta-analysis aimed to investigate ESR1rs9340799 (XbaI, A351G), ESR1rs2234693 (Pvull, T397C), and COMT rs4680 (Val158Met) polymorphisms, which affect estrogen functioning and metabolism, in association with UL risk. According to PRISMA protocol, systematic searching of databases resulted 24 included studies. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were used to evaluate associations of the three targeted polymorphisms with uterine leiomyoma risk in dominant model of inheritance. Meta-analysis included 4969 women diagnosed with uterine leiomyoma and 4934 controls. ESR1 (XbaI, A351G) polymorphism showed no significant association with uterine myeloma risk (OR = 1.19, 95% CI 0.98-1.45, P = 0.07). ESR1 (Pvull, T397C) was associated with a higher risk of uterine leiomyoma, but only in Asian (OR = 1.78, 95% CI 1.30-2.45, P = 0.0004) and COMT (Val158Met) according to our data is significantly associated with a lower risk of leiomyoma (OR = 0.83, 95% CI 0.71-0.97, P = 0.02). Our updated meta-analysis provided statistical evidence for the protective role of COMT (Val158Met) in association with the susceptibility to uterine leiomyoma and the possible role of ESR1 (Pvull, T397C) as a risk factor of this tumor.

Genetic and Epidemiological Similarities, and Differences Between Postoperative Intraperitoneal Adhesion Development and Other Benign Fibro-proliferative Disorders

Intraperitoneal adhesions complicate over half of abdominal-pelvic surgeries with immediate, short, and long-term sequelae of major healthcare concern. The pathogenesis of adhesion development is similar to the pathogenesis of wound healing in all tissues, which if unchecked result in production of fibrotic conditions. Given the similarities, we explore the published literature to highlight the similarities in the pathogenesis of intra-abdominal adhesion development (IPAD) and other fibrotic diseases such as keloids, endometriosis, uterine fibroids, bronchopulmonary dysplasia, and pulmonary, intraperitoneal, and retroperitoneal fibrosis. Following a literature search using PubMed database for all relevant English language articles up to November 2020, we reviewed relevant articles addressing the genetic and epidemiological similarities and differences in the pathogenesis and pathobiology of fibrotic diseases. We found genetic and epidemiological similarities and differences between the pathobiology of postoperative IPAD and other diseases that involve altered fibroblast-derived cells. We also found several genes and single nucleotide polymorphisms that are up- or downregulated and whose products directly or indirectly increase the propensity for postoperative adhesion development and other fibrotic diseases. An understanding of the similarities in pathophysiology of adhesion development and other fibrotic diseases contributes to a greater understanding of IPAD and these disease processes. At a very fundamental level, blocking changes in the expression or function of genes necessary for the transformation of normal to altered fibroblasts may curtail adhesion formation and other fibrotic disease since this is a prerequisite for their development. Similarly, applying measures to induce apoptosis of altered fibroblast may do the same; however, apoptosis should be at a desired level to simultaneously ameliorate development of fibrotic diseases while allowing for normal healing. Scientists may use such information to develop pharmacologic interventions for those most at risk for developing these fibrotic conditions.

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.

Oestrogen receptor alpha PvuII polymorphism and uterine fibroid incidence in Caucasian women

Introduction

Uterine fibroids (UFs) are benign, monoclonal tumours of the female genital tract that originate from the myometrium. They may be diagnosed in as many as 80% of women depending on the selected population. UFs depend mostly on steroid hormones. Elevated levels of oestrogens and progesterone are believed to be among the most important factors inducing their formation and growth. These facts suggest that oestrogen (ESR) and progesterone receptors are crucial in UF pathophysiology as well. Previous studies have shown that, in some populations, polymorphisms in ESR genes (e.g. PvuII) constitute an important risk factor for UFs.

Material and methods

The aim of our study was to investigate whether ESRα PvuII polymorphism is associated with an increased risk of UFs in Caucasian women of Polish origin. A total of 197 patients (114 UF-positive and 83 controls) were included in this retrospective cohort study. ESRα gene polymorphism PvuII (rs2234693) was assayed with PCR and restriction fragment length polymorphism (RFLP).

Results

Our study found no significant difference in the occurrence of ESR PvuII polymorphism between women with UFs and UF-free controls in the selected population.

Conclusions

Our results did not indicate a significant association between ESRα gene PvuII polymorphism and the risk of UFs in Caucasian women of Polish origin. More studies and comparisons between races are necessary to clarify the role of ESRα in the development and progression of UFs.

Selective progesterone receptor modulators for fertility preservation in women with symptomatic uterine fibroids

Uterine fibroids (UFs, AKA leiomyoma) are the most important benign neoplastic threat to women's health, with costs up to hundreds of billions of health care dollars worldwide. Uterine fibroids caused morbidities exert a tremendous health toll, impacting the quality of life of women of all ethnicities, especially women of color. Clinical presentations include heavy vaginal bleeding, pelvic pain, bulk symptoms, subfertility, and obstetric complications. Current management strategies heavily lean toward surgical procedures; nonetheless, the choice of treatment is generally subject to patient's age and her desire to preserve future fertility. Women with UF who desire to maintain future fertility potential face a dilemma because of the limited treatment choices that are currently available to help them achieve that goal. Recently, ulipristal acetate the first of the promising family of oral selective progesterone receptor modulators has been approved for UF treatment in Europe, Canada, and several other countries and is under review for possible approval in the USA. In this review article, we discuss recent advances in the management options against UF with a bend toward oral effective long-term treatment alternatives who are particularly suited for those seeking to preserve their future fertility potential. We also explore the transformative concept of primary and secondary UF prevention using these new anti-UF agents. We envision a remarkable shift in the management of UF in future years from surgical/invasive treatment to orally administrated options; clearly, this potential shift will require additional intense clinical research.

Catechol-O-methyltransferase Val158Met polymorphism is associated with increased risk of multiple uterine leiomyomas either positive or negative for MED12 exon 2 mutations

AIMS

To study the possible association of catechol-O-methyltransferase (COMT) Val158Met polymorphism with multiple and solitary uterine leiomyomas (ULs) and to check whether the COMT Val/Val genotype is associated with MED12 exon 2 mutations in fibroids.

METHODS

The COMT Val158Met allele and genotype frequencies were compared between age-matched women with ULs (n=104) and controls (n=59). Patients with UL were subcategorised by diagnosis of solitary (n=59) or multiple (n=45) fibroids and by the presence of somatic MED12 exon 2 mutations in at least one fibroid (n=32) or in neither fibroid (n=26). The association of COMT Val/Val genotype with the presence of any ULs, solitary/multiple ULs and ULs positive/negative for MED12 exon 2 mutations was evaluated by χ² tests using a dominant genotype model (G/G vs G/A+A/A) and expressed as ORs and 95% CIs.

RESULTS

The COMT Val/Val genotype frequency did not differ between the patients with UL and the controls (28.8% vs 18.6%, p=0.149, OR 1.77; CI 0.81 to 3.86). However, it was significantly higher in the patients who had multiple UL compared with the solitary UL (40% vs 20.3%, p=0.028, OR 2.61; CI 1.09 to 6.24) and to the controls (40% vs 18.6%, p=0.016, OR 2.91; CI 1.20 to 7.06). No association of the COMT Val/Val genotype with UL-specific MED12 exon 2 mutations was found (p=0.662, OR 0.77; CI 0.23 to 2.53).

CONCLUSIONS

Women with COMT Val/Val genotype are at high risk of developing multiple uterine fibroids either positive or negative for MED12 exon 2 mutations. These data are important to design new strategies for UL prophylaxis and treatment.

The Role of Complementary and Alternative Medicine for the Management of Fibroids and Associated Symptomatology

This article discusses the role of complementary and alternative medicine (CAM) in the management of fibroids and associated symptomatology. Since there is such a paucity of direct research related to fibroids, conditions that are implicated in the causation of uterine fibroids and symptomatology that CAM treatments may or have been shown to make a difference are also considered.

Role of vitamin D in uterine fibroid biology

OBJECTIVE

To provide a detailed summary of current scientific knowledge on uterine fibroids (leiomyomas) in vitro and in in vivo animal models, as well as to postulate the potential role of vitamin D3 as an effective, inexpensive, safe, long-term treatment option for uterine fibroids.

DESIGN

PubMed search articles were used to identify the most relevant studies on uterine fibroids, as well as effects of vitamin D3 on uterine fibroid cells and fibroid tumor growth in in vivo animal models.

SETTING

University research laboratory.

PATIENT(S)

Not applicable.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Not applicable.

RESULT(S)

Despite numerous publications available on uterine fibroids, information about the role that vitamin D3 plays in the regulation of uterine fibroids is limited. Most of the recent vitamin D3-related studies on uterine fibroids were published from our group. Recent studies have demonstrated that vitamin D deficiency plays a significant role in the development of uterine fibroids. Our recent studies have demonstrated that vitamin D3 reduces leiomyoma cell proliferation in vitro and leiomyoma tumor growth in in vivo animal models. These results postulate the potential role of vitamin D3 for an effective, safe, nonsurgical medical treatment option for uterine fibroids.

CONCLUSION(S)

This article reviews human and animal studies and uncovers new possibilities for understanding the vitamin D-based therapeutic option for an effective, safe, long-term treatment of uterine fibroids. On the basis of these results, a clinical trial with vitamin D3 or a hypocalcemic analog, paricalcitol, may be warranted for nonsurgical medical treatment of uterine fibroids.

Epidemiological and genetic clues for molecular mechanisms involved in uterine leiomyoma development and growth

BACKGROUND

Uterine leiomyomas (fibroids) are highly prevalent benign smooth muscle tumors of the uterus. In the USA, the lifetime risk for women developing uterine leiomyomas is estimated as up to 75%. Except for hysterectomy, most therapies or treatments often provide only partial or temporary relief and are not successful in every patient. There is a clear racial disparity in the disease; African-American women are estimated to be three times more likely to develop uterine leiomyomas and generally develop more severe symptoms. There is also familial clustering between first-degree relatives and twins, and multiple inherited syndromes in which fibroid development occurs. Leiomyomas have been described as clonal and hormonally regulated, but despite the healthcare burden imposed by the disease, the etiology of uterine leiomyomas remains largely unknown. The mechanisms involved in their growth are also essentially unknown, which has contributed to the slow progress in development of effective treatment options.

METHODS

A comprehensive PubMed search for and critical assessment of articles related to the epidemiological, biological and genetic clues for uterine leiomyoma development was performed. The individual functions of some of the best candidate genes are explained to provide more insight into their biological function and to interconnect and organize genes and pathways in one overarching figure that represents the current state of knowledge about uterine leiomyoma development and growth.

RESULTS

In this review, the widely recognized roles of estrogen and progesterone in uterine leiomyoma pathobiology on the basis of clinical and experimental data are presented. This is followed by fundamental aspects and concepts including the possible cellular origin of uterine fibroids. The central themes in the subsequent parts are cytogenetic aberrations in leiomyomas and the racial/ethnic disparities in uterine fibroid biology. Then, the attributes of various in vitro and in vivo, human syndrome, rodent xenograft, naturally mutant, and genetically modified models used to study possible molecular mechanisms of leiomyoma development and growth are described. Particular emphasis is placed on known links to fibrosis, hypertrophy, and hyperplasia and genes that are potentially important in these processes.

CONCLUSIONS

Menstrual cycle-related injury and repair and coinciding hormonal cycling appears to affect myometrial stem cells that, at a certain stage of fibroid development, often obtain cytogenetic aberrations and mutations of Mediator complex subunit 12 (MED12). Mammalian target of rapamycin (mTOR), a master regulator of proliferation, is activated in many of these tumors, possibly by mechanisms that are similar to some human fibrosis syndromes and/or by mutation of upstream tumor suppressor genes. Animal models of the disease support some of these dysregulated pathways in fibroid etiology or pathogenesis, but none are definitive. All of this suggests that there are likely several key mechanisms involved in the disease that, in addition to increasing the complexity of uterine fibroid pathobiology, offer possible approaches for patient-specific therapies. A final model that incorporates many of these reported mechanisms is presented with a discussion of their implications for leiomyoma clinical practice.

Effects of miRNA-197 overexpression on proliferation, apoptosis and migration in levonorgestrel treated uterine leiomyoma cells

BACKGROUND/AIMS

Uterine leiomyoma is the ahead benign tumor of the female genital tract, which resulted in menstrual abnormalities, recurrent pregnancy loss, and other serious gynecological disorders in women. Recently, as the process of exploring the brief molecular mechanisms of tumorgenesis, microRNAs (miRNAs) have attracted much more attention.

METHODS

In this study, we first confirmed that microRNA-197 (miR-197) was down-regulated significantly in human uterus leiomyoma by quantity real-time polymerase chain reaction, compared to normal uterus myometrium. Then we observed the potential effects of miR-197 overexpression on human uterus leiomyoma cells by cell counting kit 8, wound healing assay, and flow cytometric assessment separately.

RESULTS

The data showed that miR-197 could inhibit cell proliferation, induce cell apoptosis, and block cell migration in vitro. Coincidently, levonorgestrel (LNG), a well-known uterus leiomyoma therapy, could induce miR-197 expression in human uterus leiomyoma cells, and over-expression of miR-197 showed a synergy effect on human uterus leiomyoma cell proliferation and apoptosis with LNG.

CONCLUSION

In this study, the data showed that miR-197 could play an anti-oncogenic role in human uterus leiomyoma cells, and cooperate with LNG on the cell proliferation and apoptosis, which suggested that miR-197 might be a potential target and provided database for clinical treatment.

MicroRNAs in the development and pathobiology of uterine leiomyomata: does evidence support future strategies for clinical intervention?

BACKGROUND

Human leiomyomata (fibroids) are benign tumors of the uterus, represent the most common neoplasms of reproductive-aged women and have a prevalence of ∼70% in the general population. This disorder conveys a significant degree of morbidity and remains the leading indication for hysterectomy in the USA. Prior investigations of aberrant microRNA (miRNA) expression in various malignancies have provided invaluable insight into the role of this class of small non-coding RNAs in tumor growth. Evidence of irregular miRNA expression in uterine fibroids has garnered recent interest for diagnostic and therapeutic applications. Since miRNA gene targets modulate several processes implicated in the genesis of uterine fibroids, more focused investigation has the potential to elucidate the functional significance of miRNA in the genesis and pathology of the disease.

METHODS

Comprehensive electronic searches of peer reviewed published literature in PubMed (US National Library of Medicine, National Institute of Health; http://www.ncbi.nlm.nih.gov/pubmed/) were performed for content related to the biologic functions of miRNA, the roles of miRNA in human disease and studies investigating miRNA in the context of uterine leiomyomata. Herein, this article will review the current evidence supporting the use of miRNA expression profiling as an investigative tool to assess the pathobiology of uterine fibroids and will discuss potential future applications of miRNAs as biomarkers and therapeutic targets.

RESULTS

Mounting evidence supports a functional role for miRNA as either indirect or direct regulators of gene expression which impacts the pathobiology of uterine fibroids. Specifically, miRNAs let-7, 200a, 200c, 93, 106b and 21 have been implicated in cellular proliferation, apoptosis, extracellular matrix turnover, angiogenesis and inflammation. Preliminary data provide evidence to suggest that respective in vitro miRNA expression in leiomyomata and myometrium is regulated by sex steroids.

CONCLUSIONS

Collectively, the identification of aberrantly expressed miRNAs in uterine leiomyomata and accumulating data derived from mining of gene target prediction models and recent functional studies support the concept that miRNAs might impact the genesis and progression of disease. However, the specific biologic functions of differential miRNA expression have yet to be confirmed in vivo. Further functional studies and developing miRNA technology may provide the basis for future applications of miRNAs in clinical medicine as biomarkers and therapeutic targets.

Proceedings from the Third National Institutes of Health International Congress on Advances in Uterine Leiomyoma Research: comprehensive review, conference summary and future recommendations

BACKGROUND Uterine fibroids are the most common gynecologic tumors in women of reproductive age yet the etiology and pathogenesis of these lesions remain poorly understood. Age, African ancestry, nulliparity and obesity have been identified as predisposing factors for uterine fibroids. Symptomatic tumors can cause excessive uterine bleeding, bladder dysfunction and pelvic pain, as well as associated reproductive disorders such as infertility, miscarriage and other adverse pregnancy outcomes. Currently, there are limited noninvasive therapies for fibroids and no early intervention or prevention strategies are readily available. This review summarizes the advances in basic, applied and translational uterine fibroid research, in addition to current and proposed approaches to clinical management as presented at the 'Advances in Uterine Leiomyoma Research: 3rd NIH International Congress'. Congress recommendations and a review of the fibroid literature are also reported. METHODS This review is a report of meeting proceedings, the resulting recommendations and a literature review of the subject. RESULTS The research data presented highlights the complexity of uterine fibroids and the convergence of ethnicity, race, genetics, epigenetics and environmental factors, including lifestyle and possible socioeconomic parameters on disease manifestation. The data presented suggest it is likely that the majority of women with uterine fibroids will have normal pregnancy outcomes; however, additional research is warranted. As an alternative to surgery, an effective long-term medical treatment for uterine fibroids should reduce heavy uterine bleeding and fibroid/uterine volume without excessive side effects. This goal has not been achieved and current treatments reduce symptoms only temporarily; however, a multi-disciplined approach to understanding the molecular origins and pathogenesis of uterine fibroids, as presented in this report, makes our quest for identifying novel targets for noninvasive, possibly nonsystemic and effective long-term treatment very promising. CONCLUSIONS The Congress facilitated the exchange of scientific information among members of the uterine leiomyoma research and health-care communities. While advances in research have deepened our knowledge of the pathobiology of fibroids, their etiology still remains incompletely understood. Further needs exist for determination of risk factors and initiation of preventive measures for fibroids, in addition to continued development of new medical and minimally invasive options for treatment.

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.

The associations between the Val158Met in the catechol-O-methyltransferase (COMT) gene and the risk of uterine leiomyoma (ULM)

The Val158Met polymorphism of the COMT gene has been implicated in susceptibility to uterine leiomyoma (ULM), but the reported results were inconclusive. The aim of the study was to evaluate the Val158Met polymorphism of the COMT gene and the risk of ULM by meta-analysis. A comprehensive electronic search for relevant articles was conducted in Pubmed, Embase, CNKI, Wanfang, and Weipu databases. Statistical analysis was performed by using the Revman4.2 software and Stata10.0 software. A total of 7 articles including 12 case-control studies were identified in this meta-analysis. The results showed that the polymorphism was associated with decreased risk of ULM (Met/Met+Val/Met vs. Met/Met: OR=0.84, 95% CI=0.70-0.99, Z=2.07, p=0.04). In the subgroup analyses by ethnicity, significant decreased risk was found among the black populations (OR=0.68, 95% CI=0.48-0.97, Z=2.15, p=0.03). The current meta-analysis suggested that the Val158Met polymorphism in the COMT gene was associated with decreased risk of ULM, especially in the black population. Future studies are needed to validate our conclusions.

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.

Is fibroid heterogeneity a significant issue for clinicians and researchers?

The clinical and scientific literature overwhelmingly deals with fibroids as a single entity or disease. This convenient assumption of homogeneity may be an important oversight given that substantial evidence exists for heterogeneity between fibroids at many levels. Failure to recognize and accommodate fibroid heterogeneity can have significant ramifications for both clinical treatment decisions and research protocol design. The aim of this article is to review the current knowledge of fibroid heterogeneity and to identify key areas where fibroid heterogeneity should be taken into consideration both clinically and when designing research protocols. Uterine leiomyomata display significant and well-documented heterogeneity in symptoms, diagnostic imaging appearance, pathology, genetic background and therapeutic requirements. Additional research is needed to better understand fibroid heterogeneity as it relates to pathogenesis, molecular targets for potential new therapies, patient symptoms and, ultimately, treatment. To this list should also be added heterogeneity of genetics, lifestyle and individual clinical characteristics of the fibroid. Increasingly, an understanding of uterine leiomyoma heterogeneity will be of importance for clinicians who see patients with this common and costly disease.

Nanomedicine for uterine leiomyoma therapy

BACKGROUND

The purpose of this work was to engineer polymeric nanoparticles to encapsulate and deliver 2-methoxyestradiol, a potential antitumor drug for treatment of uterine leiomyoma (fibroids), the most common hormone-dependent pathology affecting women of reproductive age.

METHODS/RESULTS

Encapsulation efficiency and drug release from the nanoparticles were monitored by HPLC. Cell morphology and in vitro cytotoxicity experiments were carried out in a human leiomyoma cell line. The nanoparticles displayed high encapsulation efficiency (>86%), which was verified by differential scanning calorimetry and x-ray diffraction. Excellent long-term stability of the nanoparticles and gradual drug release without burst were also observed. Cellular uptake of fluorescent nanoparticles was confirmed by confocal imaging. The drug-loaded poly(lactic acid) and poly(lactic-co-glycolic acid) nanoparticles induced cytotoxicity in human leiomyoma cells to a significantly greater extent than the free drug at 0.35 µM.

CONCLUSION

This novel approach represents a potential fertility-preserving alternative to hysterectomy.

Polymorphism of catechol-o-methyltransferase and uterine leiomyoma

Uterine leiomyoma (ULM) is the most common gynecological benign tumor that is affecting around 20-50 % of women over the age of 30. Although its molecular pathogenesis is still unknown, ULM has a multifactorial etiology determined by both genetics and environmental factors. The present study was designed to find out whether Val158Met polymorphism in the catechol-o-methyltransferase (COMT) gene is associated with the risk of ULM. We analyzed COMT Val158Met polymorphism in 105 ULMs patients and 105 healthy subjects using a polymerase chain reaction-based restriction fragment length polymorphism assay. We found remarkably similar frequencies in ULM compared with controls for COMT Val158Met genotypes and alleles, and no association was found between ULM and this polymorphism (p = 0.46). The COMT 158 Met allele in patients with large (≥5 cm) fibroids was higher than in patients with small (<5 cm) fibroids, and significant association was found between fibroid size and COMT 158 Met allele (p = 0.011, OR 0.50, 95 %CI 0.28-0.90). Our results reflect that COMT Val158Met polymorphism is not associated with an increased risk of ULMs, but Val158Met polymorphism may be a risk factor for development of large fibroids in Turkish patients with ULM.

MED12 exon 2 mutations are common in uterine leiomyomas from South African patients

Uterine leiomyomas, or fibroids, are extremely common tumors. Regardless of their benign nature, fibroids can cause considerable morbidity. Women with African ancestry have a threefold increased risk of developing uterine leiomyomas with a greater symptom severity when compared to white women. Recently, we demonstrated that exon 2 of the MED12 gene is somatically altered in up to 70 per cent of uterine leiomyomas in a series of Finnish (Caucasian) patients. To validate these results in other populations, we sequenced a set of 28 uterine leiomyomas for MED12 exon 2 mutations from 18 different Black African or Coloured South African patients. We observed 14 mutation positive lesions (50%). When corrected by tumor size, these results are very similar to those derived in the Finnish material. This study confirms a major role of MED12 in the genesis of leiomyomas, regardless of ethnicity.

miR-93/106b and their host gene, MCM7, are differentially expressed in leiomyomas and functionally target F3 and IL-8

miR-93/106b and their host gene minichromosome maintenance complex component 7 (MCM7) reside at chr7q22, a region frequently rearranged in leiomyomas. We explored the expression of miR-93/106b in leiomyoma and paired myometrium (n = 63) from untreated and patients exposed to hormonal therapies (GnRH agonist, Depo-Provera, and oral contraceptives) from African-Americans and Caucasians and their regulatory functions in isolated paired (n = 15) leiomyoma and myometrial smooth muscle cells and the leiomyosarcoma cell line. At tissue level leiomyomas expressed significantly lower levels of miR-93 and elevated MCM7 as compared with myometrium with limited racial influence or hormonal exposure on their expression. Assessing the regulatory function of miR-93/106b through doxycycline-inducible lentiviral transduction in a microarray analysis, tissue factor (F3) and IL8 were identified as their possible targets. At the tissue level, leiomyomas expressed a significantly lower level of F3 and an elevated IL-8 level, which exhibited an inverse relationship with miR-93 but with limited racial or hormonal influences. The gain of function of miR-93/106b in leiomyoma smooth muscle cells, myometrial smooth muscle cells, and the leiomyosarcoma cell line dose dependently repressed F3 and IL8 through direct interactions with their respective 3'-untranslated region and indirectly through F3 repression inhibited IL8, CTGF, and PAI-1 expression, confirmed by using small interfering RNA silencing or factor Vlla (FVIIa) activation of F3, as well as reducing the rate of proliferation, while increasing caspase-3/7 activity. We concluded that differential expression of miR-93/106b and their direct and/or indirect regulatory functions on F3, IL8, CTGF, and PAI-1 expression, with key roles in inflammation and tissue turnover may be of significance in the outcome of leiomyoma growth and associated symptoms.

Medical treatment of uterine leiomyoma

Uterine leiomyomas (also called myomata or fibroids) are the most common gynecologic tumors in the United States. The prevalence of leiomyomas is at least 3 to 4 times higher among African American women than in white women. Pathologically, uterine leiomyomas are benign tumors that arise in any part of the uterus under the influence of local growth factors and sex hormones, such as estrogen and progesterone. These common tumors cause significant morbidity for women and they are considered to be the most common indication for hysterectomy in the world; they are also associated with a substantial economic impact on health care systems that amounts to approximately $2.2 billion/year in the United States alone. Uterine myomas cause several reproductive problems such as heavy or abnormal uterine bleeding, pelvic pressure, infertility, and several obstetrical complications including miscarriage and preterm labor. Surgery has traditionally been the gold standard for the treatment of uterine leiomyomas and has typically consisted of either hysterectomy or myomectomy. In recent years, a few clinical trials have evaluated the efficacy of orally administered medications for the management of leiomyoma-related symptoms. In the present review, we will discuss these promising medical treatments in further detail.

Catechol-O-methyltransferase Val158Met polymorphism associates with individual differences in sleep physiologic responses to chronic sleep loss

BACKGROUND

The COMT Val158Met polymorphism modulates cortical dopaminergic catabolism, and predicts individual differences in prefrontal executive functioning in healthy adults and schizophrenic patients, and associates with EEG differences during sleep loss. We assessed whether the COMT Val158Met polymorphism was a novel marker in healthy adults of differential vulnerability to chronic partial sleep deprivation (PSD), a condition distinct from total sleep loss and one experienced by millions on a daily and persistent basis.

METHODOLOGY/PRINCIPAL FINDINGS

20 Met/Met, 64 Val/Met, and 45 Val/Val subjects participated in a protocol of two baseline 10h time in bed (TIB) nights followed by five consecutive 4 h TIB nights. Met/Met subjects showed differentially steeper declines in non-REM EEG slow-wave energy (SWE)-the putative homeostatic marker of sleep drive-during PSD, despite comparable baseline SWE declines. Val/Val subjects showed differentially smaller increases in slow-wave sleep and smaller reductions in stage 2 sleep during PSD, and had more stage 1 sleep across nights and a shorter baseline REM sleep latency. The genotypes, however, did not differ in performance across various executive function and cognitive tasks and showed comparable increases in subjective and physiological sleepiness in response to chronic sleep loss. Met/Met genotypic and Met allelic frequencies were higher in whites than African Americans.

CONCLUSIONS/SIGNIFICANCE

The COMT Val158Met polymorphism may be a genetic biomarker for predicting individual differences in sleep physiology-but not in cognitive and executive functioning-resulting from sleep loss in a healthy, racially-diverse adult population of men and women. Beyond healthy sleepers, our results may also provide insight for predicting sleep loss responses in patients with schizophrenia and other psychiatric disorders, since these groups repeatedly experience chronically-curtailed sleep and demonstrate COMT-related treatment responses and risk factors for symptom exacerbation.

A single-nucleotide polymorphism in the fetal catechol-O-methyltransferase gene is associated with spontaneous preterm birth in African Americans

Catechol-O-methyltransferase (COMT) activity has been reported to be higher in African Americans (AA) than Caucasians (Cau). COMT converts 2- and 4-hydroxy (OH) estrogens to 2- and 4-methoxyestrogens, respectively, and can increase estrogenic milieu locally in tissues. To assess whether the increased incidence of preterm birth (PTB) among AA women is associated with single-nucleotide polymorphism (SNP) in the COMT gene, we examined variations in maternal and fetal COMT genes and their association with pregnancy outcomes (term vs preterm pregnancies) using 4 functional SNPs: rs4633, rs4680, rs4818, and rs6269 in both AA and Cau. We analyzed samples from 267 AA women (191 term and 76 preterm pregnancies) and 339 Cau (194 term and 145 preterm pregnancies) in this study. The results showed a significant difference (P < .05) in allele and genotype frequencies between term and preterm AA and Cau women in 3 SNPs in both maternal and fetal DNA. The analysis revealed that in AA fetal COMT genes, SNP rs4818 is associated with PTB at the allele (C; P < .001), genotype (C/C; P < .01), and 2- (P < .03) and 3 (P < .04)-window haplotype levels. Multidimensionality reduction analysis also showed a significant (P < .01) association between rs4818 and PTB. In conclusion, our study demonstrated that a synonymous polymorphism, rs4818 in the fetal COMT gene, is associated with PTB in AA.

Comparing focused ultrasound and uterine artery embolization for uterine fibroids-rationale and design of the Fibroid Interventions: reducing symptoms today and tomorrow (FIRSTT) trial

OBJECTIVE

To present the rationale, design, and methodology of the Fibroid Interventions: Reducing Symptoms Today and Tomorrow (FIRSTT) study.

DESIGN

Randomized clinical trial.

SETTING

Two academic medical centers.

PATIENT(S)

Premenopausal women with symptomatic uterine fibroids.

INTERVENTION(S)

Participants are randomized to two U.S. Food and Drug Administration-approved minimally invasive treatments for uterine leiomyomas: uterine artery embolization and magnetic resonance-guided focused ultrasound.

MAIN OUTCOME MEASURE(S)

The primary endpoint is defined as the need for an additional intervention for fibroid symptoms following treatment. Secondary outcomes consist of group differences in symptom alleviation, recovery trajectory, health-related quality of life, impairment of ovarian reserve, treatment complications, and the economic impact of these issues.

RESULT(S)

The trial is currently in the phase of active recruitment.

CONCLUSION(S)

This randomized clinical trial will provide important evidence-based information for patients and health care providers regarding optimal minimally invasive treatment approach for women with symptomatic uterine leiomyomas.

CLINICAL TRIAL REGISTRATION

NCT00995878.

Proceedings from theNational Institute of Child Health and Human Development conference on the Uterine Fibroid Research Update Workshop

The purpose of the National Institutes of Health conference Fibroid Research Workshop in September 2007 was to bring Eunice Kennedy Shriver National Institute of Child Health and Human Development-funded fibroid investigators together to discuss basic science and clinical research advances on uterine leiomyomata. General topics included advances in epidemiology, etiology, therapeutic approaches, and clinical trial challenges; suggestions for advancement of basic understanding, clinical intervention, clinical trials, and future directions were highlighted.

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.

Racial and ethnic disparities in benign gynecologic conditions and associated surgeries

Common gynecologic conditions and surgeries may vary significantly by race or ethnicity. Uterine fibroid tumors are more prevalent in black women, and black women may have larger, more numerous fibroid tumors that cause worse symptoms and greater myomectomy complications. Some, but not all, studies have found a higher prevalence of endometriosis among Asian women. Race and ethnicity are also associated with hysterectomy rate, route, and complications. Overall, the current literature has significant deficits in the identification of racial and ethnic disparities in the incidence of fibroid tumors, endometriosis, and hysterectomy. Further research is needed to better define racial and ethnic differences in these conditions and to examine the complex mechanisms that may result in associated health disparities.

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.

Estrogen receptor beta gene polymorphisms and susceptibility to uterine fibroids

Uterine fibroids are the most common benign tumors of the female genital tract. Steroid hormones, especially estradiol and progesterone, play an important role in the pathobiology of this frequent disease. Recent studies suggested that both expression levels and polymorphisms of estrogen receptor (ER) alpha and beta might affect development of uterine fibroids. In this study, we tested whether single nucleotide polymorphisms (SNPs) in the promoter of estrogen receptor beta gene (ESR2) are associated with susceptibility to uterine fibroids. For this purpose, we compared the frequency of three SNPs in the promoter region of ESR2 gene (rs2987983, rs3020450 and rs3020449) in 101 women with uterine fibroids and 102 healthy women serving as controls by means of allele-specific tetra-primer polymerase chain reaction (PCR). Regarding allele frequency, allele positivity, genotype and haplotype frequencies of these SNPs we did not observe any significant difference between healthy women and women with uterine fibroids. In conclusion, our data clearly suggest that the tested SNPs in the promotor region of human ESR2 gene are not associated with the development of uterine fibroids.

Racial diversity in uterine leiomyoma clinical studies

OBJECTIVE

To examine racial diversity in clinical studies on uterine leiomyomas included in a review of evidence-based practice because of the disproportionate burden of fibroids in Black women.

DESIGN

Review of 106 studies cited in the Agency for Healthcare Research and Quality (AHRQ) report on uterine leiomyomas.

SETTING

Academic medical centers.

PATIENT(S)

None.

INTERVENTION(S)

Estimation of the racial diversity of enrollment in studies on leiomyomas that did not report racial composition by two hypothetical models.

MAIN OUTCOME MEASURE(S)

Representation of Black women in studies from the AHRQ report.

RESULT(S)

Of the 106 analyzed studies, 81 studies did not report patients' race or ethnicity. Twenty-two of the 25 studies with reported race or ethnicity included Black participants. Analysis of studies reporting race and ethnicity, including studies specifically of African-American women, suggests that Black women comprise approximately half of all study participants. However, when estimating the proportion of Black women based on population demographics in each country, the representation of Black women in clinical leiomyoma studies appears to be closer to 15%.

CONCLUSION(S)

Most studies on uterine leiomyomas cited in the AHRQ evidence-based report did not report participation by race or ethnicity.

microRNA 21: response to hormonal therapies and regulatory function in leiomyoma, transformed leiomyoma and leiomyosarcoma cells

Aberrant expression of microRNAs (miRNAs), including miR-21, and alteration of their target genes stability have been associated with cellular transformation and tumorigenesis. We investigated the expression, regulation and function of miR-21 in leiomyomas which develop from myometrial cellular transformation. The results indicated that miR-21 is over-expressed in leiomyomas with specific elevation during the secretory phase of the menstrual cycle and in women who received Depo-Provera and oral contraceptives, but reduced due to GnRHa therapy (P < 0.05). Bioinformatic analysis of microarray gene expression profiles previously obtained from the above cohorts, and myometrial smooth muscle cells (MSMC) and leiomyoma smooth muscle cells (LSMC) treated with GnRHa, transforming growth factor (TGF)-β and TGF-β receptor type II (TGF-βRII) antisense oligomer, indicated that a number of miR-21-predicted target genes were co-expressed and differentially regulated in these cohorts. Gain- and loss-of-function of miR-21 in MSMC, LSMC, transformed LSMC and leiomyosarcoma cell line (SKLM-S1) resulted in differential expression of many genes, including some of the miR-21-predicted/validated target genes, PTEN, PDCD4 and E2F1, and TGF-βRII, in a cell-specific manner. Gain-of miR-21 function in MSMC and LSMC reduced TGF-β-induced expression of fibromodulin and TGF-β-induced factor (P < 0.05), and moderately altered the rate of cell growth and caspase-3/7 activity in these cells. We concluded that miR-21 is aberrantly expressed and hormonally regulated in leiomyomas where, through functional interaction with ovarian steroids and the TGF-β signaling pathway, either directly or indirectly regulates a number of genes whose products are critical in leiomyoma growth and regression as well as their potential cellular transformation.

Antiproliferative and proapoptotic effects of epigallocatechin gallate on human leiomyoma cells

OBJECTIVE

To investigate the effects of epigallocatechin gallate (EGCG), an extract of green tea on cultured human leiomyoma cells (HuLM).

DESIGN

Laboratory study.

SETTING

University hospitals.

PATIENT(S)

Not applicable.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

The HuLM cells were treated with various EGCG concentrations. Cell proliferation was assayed using Hoechst 33258 dye, and apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Total RNA was isolated, and gene expression profiling was performed on 84 key genes related to 18 different signal transduction pathways. The protein levels of PCNA, CDK4, BCL2, and BAX were examined by Western blot analysis.

RESULT(S)

The HuLM cells treated with EGCG showed a dose-dependent and time-dependent inhibition of cell proliferation. The TUNEL staining indicated a significant increase in apoptosis in HuLM cells treated with 100 μM of EGCG compared with untreated control. Gene expression profiling indicated that EGCG treatment up-regulated representative genes from the transforming growth factor β (TGF-β) and stress pathways, while inhibiting the survival pathway and NFκB-dependent inflammatory pathway. Western blot analysis confirmed that EGCG at ≥50 μM significantly decreased the expression of PCNA, CDK4, and BCL2 as well as increased the expression of the proapoptotic BAX in a dose-dependent manner.

CONCLUSION(S)

Epigallocatechin gallate inhibits the proliferation of HuLM cells and induces apoptosis. These results suggest that EGCG may be a potential anti-uterine fibroid agent acting through multiple signal transduction pathways.

Risk factors for surgically removed fibroids in a large cohort of teachers

OBJECTIVE

To describe reproductive and lifestyle correlates of surgically confirmed fibroids.

DESIGN

Prospective cohort study.

SETTING

The California Teachers Study, an ongoing prospective study of more than 133,000 female teachers and school administrators identified through the California State Teachers Retirement System.

PATIENT(S)

California Teachers Study cohort members, reporting no previous history of fibroids, were ascertained prospectively for surgical diagnosis of fibroids using hospital patient discharge records.

MAIN OUTCOME MEASURE(S)

Multivariable Cox proportional hazards regression methods were used to assess the association of self-reported menstrual, reproductive, and lifestyle characteristics with fibroids, using ages at the start and end of follow-up (in months) to define time on study. Hazard rate ratios, presented as relative risks (RR) with 95% confidence intervals (CI), were estimated.

RESULT(S)

The strongest risk factor we identified was African-American race/ethnicity, as compared to non-Latina white women. We observed a reduced risk of fibroids for postmenopausal women in comparison to premenopausal women, but use of hormone replacement therapies (regardless of formulation) were associated with an increased risk. Other risk factors included race, a family history of fibroids, being overweight, and drinking alcohol, Smoking and diabetes were associated with a decreased risk of fibroids.

CONCLUSION(S)

These observations provide a more detailed epidemiologic profile of women with surgically managed fibroids.

Racial differences in women who have a hysterectomy for benign conditions

OBJECTIVE

To evaluate if there are racial differences between African-American and Caucasian women who have hysterectomy for benign conditions in terms of (1) presenting symptoms (prolapse, vaginal bleeding, pain, and known history of leiomyomas), (2) serum estradiol and testosterone levels at the visit before hysterectomy, and (3) uterine weight.

METHODS

A multi-ethnic, multisite, community-based longitudinal cohort study of 3,302 women ages 42-52 at enrollment was conducted. During 9 years of follow-up, 203 African-American and Caucasian women reported a hysterectomy, 90 with evidence of uterine leiomyomas. Women were surveyed regarding their overall perceived health before and after hysterectomy, presenting symptoms, and their motivations for surgery. Serum estradiol and testosterone levels were measured. Uterine weight at time of hysterectomy and clinical pathology were determined via medical record abstraction.

RESULTS

Previously diagnosed leiomyomas were presenting symptoms more frequently in African-American women than Caucasian women (85% vs. 63%; p = .02). African-American women had less prolapse than Caucasian women (0% vs. 10%; p = 0.04). Chronic pain was a more frequent reason for hysterectomy in African-American women than in Caucasian women (49% vs. 29%; p = .05). There were no differences between the groups in levels of estradiol or testosterone. African-American women had almost twice the uterine weight as that of Caucasian women (448 vs. 240 g; p = .0005).

CONCLUSION

Racial differences in frequency of hysterectomy for benign conditions are consistent with differences in presenting symptoms, where African-American women seemingly have larger, more symptomatic fibroids.

The expression and potential regulatory function of microRNAs in the pathogenesis of leiomyoma

Leiomyomas are benign uterine tumors considered to arise from transformation of myometrial cells. What initiates the conversion of myometrial cells into leiomyoma is unknown, however cytogenetic analysis often shows occurrence of nonrandom chromosomal abnormalities that may account for their establishment. It is clear that ovarian steroids are essential for leiomyoma growth, and local expression of many autocrine/paracrine mediators serving as key regulators of cell-cycle progression, cellular hypertrophy, extracellular matrix accumulation, and apoptosis appear to play central roles in this capacity. However, the stability of the expression of these genes represents the hallmarks of leiomyoma establishment, growth, and regression. With the emergence of microRNA (miRNA) as a key regulator of gene expression stability, in this review we present evidence for the expression and potential regulatory functions on miRNAs in leiomyoma with particular emphasis on the expression of their selective target genes whose products influence various cellular activities critical to pathogenesis of leiomyomas.

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.

The catechol-O-methyltransferase (COMT) gene polymorphism and prevalence of uterine fibroids

OBJECTIVE

To assess the possible association between the catechol-O-methyltransferase (COMT) polymorphism and uterine fibroids in Brazilian women.

DESIGN

Case-control study.

SETTING

Department of Gynecology; teaching hospital.

PATIENT(S)

One hundred twenty-four premenopausal women with fibroids, and 193 postmenopausal controls not presenting the disease.

INTERVENTION(S)

The subjects were classified as white or non-white (black and mulatto), and COMT genotypes were determined. DNA was extracted from the uterus of cases and from peripheral blood of controls and submitted to polymerase chain reaction (PCR) and agarose gel electrophoresis.

MAIN OUTCOME MEASURE(S)

The presence of the COMT polymorphism was recorded for all patients, and the frequency and distribution among cases and controls were compared according to race. Binomial log regression models were used to estimate odds-ratios (OR) for uterine volumes of <290 cm(3) (small fibroids) vs. those >290 cm(3) (large fibroids). Potential confounding variables (age, race and parity) were added to the model.

RESULTS

Genotypes positive for the COMT polymorphism (heterozygous or mutant homozygous) were found in 45% of white and 28.9% of non-white women (p = .013) and the polymorphic allele frequencies in these groups were 27.2% and 16.3%, respectively (p = .006). However, there were no clear differences between patients and controls within the white subgroup with regard to the presence of COMT polymorphism-containing genotypes (41.5% vs. 46.0%, respectively) (p = .60), or for the polymorphic allele frequency (26.8% vs. 27.3%, respectively) (p = .92). For non-white women, there were also no differences between cases and controls for the frequency of polymorphic genotypes (28.9% vs. 28.9%, respectively) (p = .995), or for the polymorphic allele frequency (17.8 vs. 14.5, respectively) (p = .565). Estimated OR for small or large fibroids in association with the polymorphic allele revealed a positive association between the allele with lower activity and large fibroids (vs. small) (OR = 3.3; 95% confidence interval [CI] = 1.31-8.46). The adjusted OR was 4.35 (95% confidence interval [CI] = 1.58-11.9).

CONCLUSIONS

The catechol-O-methyltransferase polymorphism is a risk factor for the development of large uterine fibroids in Brazilian women suffering from fibroids.

Molecular genetics and racial disparities of uterine leiomyomas

Uterine leiomyomas (ULMs) are benign oestrogen-dependent tumours of the myometrium. They are the most common tumours of the female genital tract, affecting around 77% of the female population. ULMs are more common in Black women than White women. These tumours tend to develop earlier and be more numerous, larger in size and more symptomatic in Black women than other ethnic groups. The molecular mechanism underlying this ethnic disparity is not fully understood. Polymorphism of genes involved in oestrogen synthesis and/or metabolism (COMT, CYP17), variation in the expression levels or function of oestrogen and progesterone receptors or retinoic acid nuclear receptors (retinoid acid receptor-alpha, retinoid X receptor-alpha), or aberrant expression of micro-RNAs are some of the molecular mechanisms that may be involved.