Molecular genetics and racial disparities of uterine leiomyomas

Multiomic analysis of uterine leiomyomas in self-described Black and White women: molecular insights into health disparities

BACKGROUND

Black women are at an increased risk of developing uterine leiomyomas and experiencing worse disease prognosis than White women. Epidemiologic and molecular factors have been identified as underlying these disparities, but there remains a paucity of deep, multiomic analysis investigating molecular differences in uterine leiomyomas from Black and White patients.

OBJECTIVE

To identify molecular alterations within uterine leiomyoma tissues correlating with patient race by multiomic analyses of uterine leiomyomas collected from cohorts of Black and White women.

STUDY DESIGN

We performed multiomic analysis of uterine leiomyomas from Black (42) and White (47) women undergoing hysterectomy for symptomatic uterine leiomyomata. In addition, our analysis included the application of orthogonal methods to evaluate fibroid biomechanical properties, such as second harmonic generation microscopy, uniaxial compression testing, and shear-wave ultrasonography analyses.

RESULTS

We found a greater proportion of MED12 mutant uterine leiomyomas from Black women (>35% increase; Mann-Whitney U, P<.001). MED12 mutant tumors exhibited an elevated abundance of extracellular matrix proteins, including several collagen isoforms, involved in the regulation of the core matrisome. Histologic analysis of tissue fibrosis using trichrome staining and secondary harmonic generation microscopy confirmed that MED12 mutant tumors are more fibrotic than MED12 wild-type tumors. Using shear-wave ultrasonography in a prospectively collected cohort, Black patients had fibroids that were firmer than White patients, even when similar in size. In addition, these analyses uncovered ancestry-linked expression quantitative trait loci with altered allele frequencies in African and European populations correlating with differential abundance of several proteins in uterine leiomyomas independently of MED12 mutation status, including tetracoidpeptide repeat protein 38.

CONCLUSION

Our study shows that Black women have a higher prevalence of uterine leiomyomas harboring mutations in MED12 and that this mutational status correlates with increased tissue fibrosis compared with wild-type uterine leiomyomas. Our study provides insights into molecular alterations correlating with racial disparities in uterine leiomyomas and improves our understanding of the molecular etiology underlying uterine leiomyoma development within these populations.

Racial disparity in uterine leiomyoma: new insights of genetic and environmental burden in myometrial cells

Uterine leiomyoma (LM), also known as uterine fibroids, are common gynecological tumors and can reach a prevalence of 70% among women by the age of 50 years. Notably, the LM burden is much higher in Black women with earlier onset, a greater tumor number, size, and severity compared to White women. Published knowledge shows that there are genetic, environmental, and lifestyle-based risk factors associated with racial disparity for LM. Significant strides have been made on genomic, epigenomic, and transcriptomic data levels in Black and White women to elucidate the underlying pathomolecular reasons of racial disparity in LM development. However, racial disparity of LM remains a major area of concern in gynecological research. This review highlights risk factors of LM and their role in different races. Furthermore, we discuss the genetics and uterine myometrial microenvironment in LM development. Comparative findings revealed that a major racial difference in the disease is linked to myometrial oxidative burden and altered ROS pathways which is relevant to the oxidized guanine in genomic DNA and MED12 mutations that drive the LM genesis. Considering the burden and morbidity of LM, we anticipate that this review on genetic risk and myometrial microenvironment will strengthen understanding and propel the growth of research to address the racial disparity of LM burden.

Uterine fibroids and longitudinal profiles of the vaginal microbiota in a cohort presenting for transvaginal ultrasound

Bacterial vaginosis, characterized in part by low levels of vaginal Lactobacillus species, has been associated with pro-inflammatory cytokines which could fuel uterine fibroid development. However, prior work on the associations between uterine fibroids and vaginal bacteria is sparse. Most studies have focused on assessment of individual taxa in a single sample. To address research gaps, we sought to compare short, longitudinal profiles of the vaginal microbiota in uterine fibroid cases versus controls with assessment for hormonal contraceptives (HCs), a possible confounder associated with both protection from fibroid development and increases in Lactobacillus-dominated vaginal microbiota. This is a secondary analysis of 83 reproductive-age cisgender women who presented for transvaginal ultrasound (TVUS) and self-collected mid-vaginal swabs daily for 1-2 weeks before TVUS (Range: 5-16 days, n = 697 samples). Sonography reports detailed uterine fibroid characteristics (N = 21 cases). Vaginal microbiota was assessed by 16S rRNA gene amplicon sequencing and longitudinal microbiota profiles were categorized by hierarchical clustering. We compared longitudinal profiles of the vaginal microbiota among fibroid cases and controls with exact logistic regression. Common indications for TVUS included pelvic mass (34%) and pelvic pain (39%). Fibroid cases tended to be older and report Black race. Cases less often reported HCs versus controls (32% vs. 58%). A larger proportion of cases had low-Lactobacillus longitudinal profiles (48%) than controls (34%). In unadjusted analysis, L. iners-dominated and low-Lactobacillus profiles had higher odds of fibroid case status compared to other Lactobacillus-dominated profiles, however these results were not statistically significant. No association between vaginal microbiota and fibroids was observed after adjusting for race, HC and menstruation. Results were consistent when number of fibroids were considered. There was not a statistically significant association between longitudinal profiles of vaginal microbiota and uterine fibroids after adjustment for common confounders; however, the study was limited by small sample size.

Computational Image and Molecular Analysis Reveal Unique Prognostic Features of Immune Architecture in African Versus European American Women with Endometrial Cancer

Endometrial cancer (EC) disproportionately affects African American (AA) women in terms of progression and death. In our study, we sought to employ computerized image and bioinformatic analysis to tease out morphologic and molecular differences in EC between AA and European-American (EA) populations. We identified the differences in immune cell spatial patterns between AA and EA populations with markers of tumor biology, including histologic and molecular subtypes. The models performed best when they were trained and validated using data from the same population. Unsupervised clustering revealed a distinct association between immune cell features and known molecular subtypes of endometrial cancer that varied between AA and EA populations. Our genomic analysis revealed two distinct and novel gene sets with mutations associated with improved prognosis in AA and EA patients. Our study findings suggest the need for population-specific risk prediction models for women with endometrial cancer.

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.

Assessing the Hepatic Safety of Epigallocatechin Gallate (EGCG) in Reproductive-Aged Women

A similar abstract of the interim analysis was previously published in Fertility and Sterility. EPIGALLOCATECHIN GALLATE (EGCG) FOR TREATMENT OF UNEXPLAINED INFERTILITY ASSOCIATED WITH UTERINE FIBROIDS (PRE-FRIEND TRIAL): EARLY SAFETY ASSESSMENT. Uterine fibroids are the most common cause of unexplained infertility in reproductive-aged women. Epigallocatechin gallate (EGCG), a green tea catechin, has demonstrated its ability to shrink uterine fibroids in prior preclinical and clinical studies. Hence, we developed an NICHD Confirm-funded trial to evaluate the use of EGCG for treating women with fibroids and unexplained infertility (FRIEND trial). Prior to embarking on that trial, we here conducted the pre-FRIEND study (NCT04177693) to evaluate the safety of EGCG in premenopausal women. Specifically, our aim was to assess any adverse effects of EGCG alone or in combination with an ovarian stimulator on serum liver function tests (LFTs) and folate level. In this randomized, open-label prospective cohort, participants were recruited from the FRIEND-collaborative clinical sites: Johns Hopkins University, University of Chicago, University of Illinois at Chicago, and Yale University. Thirty-nine women, ages ≥18 to ≤40 years, with/without uterine fibroids, were enrolled and randomized to one of three treatment arms: 800 mg of EGCG daily alone, 800 mg of EGCG daily with clomiphene citrate 100 mg for 5 days, or 800 mg of EGCG daily with Letrozole 5 mg for 5 days. No subject demonstrated signs of drug induced liver injury and no subject showed serum folate level outside the normal range. Hence, our data suggests that a daily dose of 800 mg of EGCG alone or in combination with clomiphene citrate or letrozole (for 5 days) is well-tolerated and is not associated with liver toxicity or folate deficiency in reproductive-aged women.

Risk of uterine leiomyoma based on BET1L rs2280543 single nucleotide polymorphism and vegetarian diet

Background

Bet1 Golgi vesicular membrane trafficking protein-like (BET1L) rs2280543 single nucleotide polymorphism (SNP) and diet have been independently associated with uterine leiomyoma (UL). However, whether the SNP and diet could jointly influence the risk of UL is yet to be assessed. Therefore, we investigated the independent and interactive effects of vegetarian diet and BET1L rs2280543 on uterine fibroids in Taiwanese women.

Methods

We linked participants’ electronic data in the Taiwan Biobank (TWB) database to their medical records in the National Health Insurance Research Database (NHIRD). The TWB had genotypic, lifestyle, and biochemical data between 2008 and 2015 and the NHIRD had data on disease diagnoses between 1998 and 2015. In this study, we included 1997 premenopausal women with complete data.

Results

Compared  to participants with the BET1L rs2280543 CC genotype (wildtype), those with CT/CC genotype had an odds ratio (OR) of 0.69 and a 95% confidence interval (CI) of 0.51–0.93. Vegetarian diet and UL were not significantly associated: OR = 1.09 and 95% CI = 0.77–1.55. However, the test for interaction between rs2280543 and vegetarian diet was significant (p = 0.046). Compared to individuals with the CC genotype, the risk of UL was lower among vegetarians with the CT/TT genotype: OR (95% CI) = 0.15 (0.05–0.47).

Conclusion

The BET1L rs2280543 CT/TT genotype was associated with a lower risk of UL especially among vegetarians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01721-1.

Uterine Fibroids: Assessing Unmet Needs from Bench to Bedside

Uterine fibroids (leiomyomas) are noncancerous growths that can have deleterious effects on the health and quality of life for millions of women. Attempts to better understand the factors that influence prevalence and disparities associated with fibroids have been made; however, significant knowledge gaps continue to persist, which hinder care for individuals living with fibroids. The Society for Women's Health Research convened an interdisciplinary Uterine Fibroids Working Group to review the current state of knowledge about uterine fibroids and recommend areas in which to prioritize efforts to address research gaps and improve diagnosis, treatment, and access to care for patients with this chronic disease. Throughout a 2-day roundtable meeting, participants discussed updates on key literature, research, clinical practice, and public health data on uterine fibroids. Overarching themes and recommendations were identified and determined by consensus agreement of the participants at the conclusion of the meeting. Systematic studies of the etiology and pathology of uterine fibroids are needed to address important knowledge gaps and unmet clinical needs regarding the multifaceted management of fibroids and their effects on overall health and quality of life. The Working Group recommends addressing key deficits within the spheres of research, clinical care, and federal policy. Immediate needs include increasing research investment, improving fibroid assessment using pelvic imaging, implementing longitudinal study designs, addressing factors that contribute to disease disparities (especially among women of color), developing fertility-friendly treatment options, expanding awareness and education beyond gynecologic specialists, and advancing personalized patient care through shared decision-making approaches.

Frequency of MED12 Mutation in Relation to Tumor and Patient's Clinical Characteristics: a Meta-analysis

Mediator complex subunit 12 (MED12) is the most frequently mutated gene in uterine leiomyomas (ULs)-with a frequency of up to 85%-suggesting that it plays key roles in the pathogenesis of ULs. However, there is no established relationship between genetic alteration and other risk factors of UL pathogenesis such as the patient's age, weight, and race. In this meta-analysis, we established an association between these risk factors and the frequency of MED12 mutation. We also established the relationship between MED12 mutation with the number and size of tumors in a patient. A systematic literature search was performed for studies published by May 2020 and performed a meta-analysis according to PRISMA guidelines. Twenty-five studies were included in the analysis, representing 3151 tissue samples. MED12 mutations were more common in Black (74.5%) as compared to White (65.8%) and Asian (53.2%) patients. There was no significant relationship between the patient's age and the frequency of mutations (OR 0.73, 95% CI 0.38 to 1.41). MED12 mutations were common in patients barring small-sized (OR 1.46, 95% CI 1.09 to 1.95) multiple (OR 0.39, 95% CI 0.17 to 0.92) tumors. For the patient's weight, studies were few and the outcome was not statistically significant. This meta-analysis provides valuable information on the relationship between the patient's clinical characteristics and frequency of MED12 mutation among patients barring ULs, which is relevant for understanding the pathogenesis of ULs.Protocol registration: The protocol was registered in PROSPERO with registration number CRD42019123439.

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.

Transcriptome Analysis of mRNA in Uterine Leiomyoma Using Next-generation RNA Sequencing

Background:

Uterine leiomyoma is a benign smooth muscle tumor of monoclonal nature in the female reproductive tract and is one of the major health problems. More than 70% of the female population suffers from uterine leiomyoma in their lifetime and in the advanced condition, it is associated with pregnancy complications and infertility.

Objective:

Characterization and relative expression of mRNA transcripts through transcriptome profiling in uterine leiomyoma and adjacent normal myometrium.

Methods:

Uterine leiomyoma tissue of an Indian female, age 32 years, with a family history of leiomyoma (evident from mother’s hysterectomy for the same pathology) was used. Patient showed 9 multiple large lesions appearing heterogeneously, deforming the uterine contour and causing distortion and splaying of the endometrial cavity showing disease aggressiveness was taken for Next-generation sequencing (NGS) to develop whole transcriptome profile along with the adjacent normal myometrium as control. The validation of the relative expression of the selective transcripts was done using Real-Time PCR.

Results:

The transcriptome profile indicated 128 genes up-regulated and 98 down-regulated, with the Log2 fold change ≥ 2 and P ≤ 0.05, highlighting the molecular network closely associated with focal adhesion, hyaluronan and MAPK-signaling pathways. The mean relative fold change obtained from quantitative PCR as well as the P-values of 10 selected transcripts evaluated from student’s t-test were as follows: BCAN: 7.93 fold (p-value =0.0013); AAK1: 2.2 fold (p-value =0.0036); PCBP3: 3.4 fold (p-value =0.0197); MOV10L1: 3.4 fold (p-value =0.0062); TWISTNB: 1.8 fold (p-value =0.006); TMSB15A: 2.1 fold (p-value =0.0023); SMAD1: 0.8 fold (p-value =0.0112); ANXA1: 0.6 fold (p-value =0.0012); FOS: 0.6 fold (p-value =0.0191); SLFN11: 0.56 fold (p-value =0.0001).

Conclusion:

The present study provides a roadmap, towards the analysis of genes and their roles in corresponding pathways throwing light on their possible involvement in the pathology of the disease.

Burden of Uterine Fibroids: An African Perspective, A Call for Action and Opportunity for Intervention

Black women carry the burden of uterine fibroids, (AKA uterine leiomyomas), at a much higher rate than their racial counterparts. Thus, increasing awareness and discovering a solution to an endemic problem that plagues Sub-Saharan Africa is of critical importance, not only for the region itself, but also for the medical community globally. A collaborative, patient oriented, cost effective, and culturally sensitive approach must be at the forefront of this endeavor. While the exact pathogenesis of uterine fibroid development remains elusive, the racial disparity is well documented. Moreover, in the developed world, women are able to seek treatment through surgical and non-surgical means; however, sub-Saharan regions face their own challenges that, if not addressed, can ultimately extinguish the lives of many suffering women. Unfortunately, the literature is scarce on how to prevent fibroid development, which may be critical for women who do not have access to effective interventions. Recent research from our group and others has shown that vitamin D deficiency plays an important role in fibroid development and may be a preventable risk factor. Daily vitamin D supplementation is a low cost, effective intervention that could be implemented throughout the Sub-Saharan region. Similarly, education and increased awareness as to the nature and symptoms of uterine fibroids could improve the quality of life, remove negative social stigma, and reduce morbidity and mortality rates in women who seek medical care with advanced uterine fibroids.

Haplotypes of CYP1B1 and CCDC57 genes in an Afro-Caribbean female population with uterine leiomyoma

Uterine leiomyomas (UL) are prevalent benign tumors, especially among women of African ancestry. The disease also has genetic liability and is influenced by risk factors such as hormones and obesity. This study investigates the haplotypes of the Cytochrome P450 1B1 gene (CYP1B1) related to hormones and coiled-coil domain containing 57 gene (CCDC57) related to obesity in Afro-Caribbean females. Each haplotype was constructed from unphased sequence data using PHASE v.2.1 software and Haploview v.4.2 was used for linkage disequilibrium (LD) studies. There were contrasting LD observed among the single nucleotide polymorphisms of CYP1B1 and CCDC5. Accordingly, the GTA haplotype of CYP1B1 was significantly associated with UL risk (P = 0.02) while there was no association between CCDC57 haplotypes and UL (P = 0.2) for the ATG haplotype. As such, our findings suggest that the Asp449Asp polymorphism and GTA haplotype of CYP1B1 may contribute to UL susceptibility in women of Afro-Caribbean ancestry in this population.

Leiomyomatous uterus and preterm birth: an exposed/unexposed monocentric cohort study

BACKGROUND

The risk of preterm birth may increase in the presence of uterine leiomyomas during pregnancy. Whether myomectomy abrogates this risk has never been studied.

OBJECTIVE

Our aim was to evaluate the association between the presence of uterine leiomyomas during pregnancy and preterm birth and, if an association exists, to evaluate its persistence in case of a history of myomectomy.

STUDY DESIGN

This exposed/unexposed monocentric retrospective cohort study included all women with singleton pregnancies delivering >22 weeks in a tertiary university hospital maternity unit from January 2011 through September 2015. Women with a leiomyomatous uterus were compared to women with no myomas. Women in the leiomyomatous uterus group were women with uterine leiomyoma(s) during pregnancy (≥1 leiomyoma, measuring ≥20 mm or multiple leiomyomas whatever the size) seen on at least 1 obstetric ultrasound without history of myomectomy, or women with a history of myomectomy (removal of ≥1 leiomyoma, measuring ≥20 mm or multiple leiomyomas whatever the size) by hysteroscopy, laparoscopy, or laparotomy with or without persistent leiomyomas. The association between leiomyomatous uterus and preterm birth was assessed through univariate and multivariable logistic regression.

RESULTS

Among the 19,866 women in the cohort, 301 (1.5%) had a leiomyomatous uterus (154 unoperated women and 147 operated women). The rate of premature delivery was 12.0% in the leiomyomatous uterus group and 8.4% in the nonleiomyomatous uterus group. After adjusting for the risk factors for preterm birth, leiomyomatous uterus was significantly associated with preterm birth (adjusted odds ratio, 2.5; 95% confidence interval, 1.7-3.7). This association was significant for unoperated women (adjusted odds ratio, 2.7; 95% confidence interval, 1.6-4.6) as well as operated women (adjusted odds ratio, 2.3; 95% confidence interval, 1.3-3.9) when compared to the nonleiomyomatous uterus group.

CONCLUSION

Uterine leiomyomas are associated with preterm birth and this association persists after myomectomy.

Human uterine leiomyoma contains low levels of 1, 25 dihdroxyvitamin D3, and shows dysregulated expression of vitamin D metabolizing enzymes

OBJECTIVES

To evaluate tissue concentration of 1, 25 dihydroxyvitamin D3, and gene expression level of CYP27B1 that codes for 1-α hydroxylase (vitamin D activating enzyme), and CYP24A1 that codes for 24-hydroxylase (vitamin D catabolizing enzyme) in human uterine leiomyoma (ULM), its adjacent myometrium (Myo-F), and normal myometrium (Myo-N).

STUDY DESIGN

Levels of 1, 25 dihydroxyvitamin D3 were measured using HPLC and Diode detectors whereas CYP27B1, and CYP24A1 expressions were assessed using Real-Time PCR in ULM, Myo-F, and Myo-N. Non-parametric statistics were used.

RESULTS

ULMs contained significantly less 1, 25 dihydroxy vitamin D3 compared to Myo-F (3.0, IQR: 1.0-9.0 versus 6.0, IQR: 3.0-13.0 μg/ kg, P value is 0.03). No significant difference was detected between ULM and Myo-N, or Myo-F and Myo-N. Intratumoral level of the active form of vitamin D did not differ according to the type of ULM (submucous or interstitial/subserous), or to the ULM volume. CYP27B1 was expressed in ULM (2.17, IQR: 0.65-4.9), Myo-F (4.94, IQR: 1.04-22.59), and Myo-N (0.99, IQR: 0.49-1.71) to a comparable level. CYP24A1 expression was significantly higher in ULM compared to Myo-N (2.00, IQR: 0.69-10.77 versus 0.22, IQR: 00- 0.96, respectively, P value is 0.04).

CONCLUSIONS

Human ULMs contain significantly lower 1, 25 dihydroxyvitamin D3 than its adjacent myometrium. ULM, Myo-F, and Myo-N express CYP27B1 and CYP24A1. ULMs express significantly higher level of CYP24A1 than normal myometrium indicating that over expression of 24-hydroxylase is a mechanism by which ULMs sustain a relative state of hypovitaminosis D.

Expanding upon the Human Myometrial Stem Cell Hypothesis and the Role of Race, Hormones, Age, and Parity in a Profibroid Environment

Uterine fibroids (UFs) are clonal, hormonally regulated, benign smooth-muscle myometrial tumors that severely affect female reproductive health, although their unknown etiology limits effective care. UFs occur fourfold more commonly in African American women than in Caucasian women, and African American women generally have earlier disease onset and greater UF tumor burden, although the mechanism of this ethnic disparity has not been identified. Recent findings have linked cancer (ie, tumor) risk to increased tissue-specific stem cell division and self-renewal and suggest that somatic mutations in myometrial stem cells (MyoSCs) convert them into tumor-initiating cells, leading to UF. Specifically, preliminary results in paraffin-embedded myometrial tissues have shown increased STRO-1⁺/CD44⁺ MyoSCs in African American versus Caucasian women. Using specific methods of flow cytometry and automated quantitative pathology imaging, a large cohort of myometrial samples were investigated to determine how the STRO-1⁺/CD44⁺ MyoSCs change with regard to a patient's race, age, parity, fibroid and hormone statuses, and the location of UFs within the uterus. We confirmed that the STRO-1⁺/CD44⁺ MyoSC population is expanded in African American women, is correlated with parity and fibroid number, and fluctuates with cyclic menstrual cycle hormone changes and age. Our data suggest that an expanded MyoSC population increases the formation of tumor-initiating cells, ultimately contributing to increased UF prevalence and burden in African American women.

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.

Establishment of a novel mouse xenograft model of human uterine leiomyoma

Uterine leiomyoma is the most common benign tumour in women, and an appropriate animal model for leiomyoma would be useful for exploring new therapeutic strategies. Therefore, we have been challenged to develop a new simple mouse model for human leiomyoma. Leiomyoma tissues were harvested from myomas resected by different surgical procedures with or without gonadotropin-releasing hormone agonist (GnRHa) treatment and were subcutaneously implanted into BALB/c nude mice with an estradiol/progesterone-releasing pellet. The implanted leiomyoma tissues that were obtained from the marginal site of large myomas resected by abdominal myomectomy with GnRHa treatment exhibited sufficient tumour growth in the transplanted mice. The leiomyomas that were treated with GnRHa highly expressed the estrogen/progesterone receptor genes, insulin-like growth factor 2 (IGF2) and embryonic smooth muscle myosin heavy chain (SMemb), which suggests that these factors are critical in the establishment of a mouse model of growing leiomyoma. As a result, this model will be useful for the development of new therapeutic strategies.

PROGINS Polymorphism of the Progesterone Receptor Gene and the Susceptibility to Uterine Leiomyomas: A Systematic Review and Meta-Analysis

AIMS

Steroid hormones play a central role in modulating the growth of uterine leiomyoma, and several studies have suggested that polymorphisms in genes encoding these hormones and their receptors may be risk factors for developing the disease. Progesterone is a potent antagonist of estrogen-induced proliferation in the endometrium, and the PROGINS polymorphisms have been associated with leiomyoma, but the results are inconsistent. In this study, we aimed to investigate the possible associations between the PROGINS polymorphisms and uterine leiomyoma.

MATERIALS AND METHODS

MEDLINE using PubMed, Science Direct, and Google Scholar databases was searched using the terms "PROGINS," "progesterone receptor," "polymorphism," and "leiomyoma." We estimated risk with odds ratios [ORs] and 95% confidence intervals using standard genetic models (homozygous, recessive, dominant, and codominant).

RESULTS

Six studies were included in this meta-analysis based on 837 cases and 1011 controls. Subjects in three studies were Asian (365 cases/391 controls), and five were non-Asian (472 cases/620 controls). Our findings showed no association between PROGINS and leiomyoma in the overall analysis (OR 0.91-1.07, p = 0.15-0.57) nor in either of the subgroups (Asian: OR 0.84-1.04, p = 0.68-0.98; or non-Asian: OR 0.77-1.34, p = 0.33-0.93), in all genetic models.

CONCLUSION

The PROGINS polymorphisms cannot be considered a risk factor for developing uterine leiomyoma.

Developmental Exposure to Endocrine Disruptors Expands Murine Myometrial Stem Cell Compartment as a Prerequisite to Leiomyoma Tumorigenesis

Despite the high prevalence and major negative impact of uterine fibroids (UFs) on women's health, their pathogenesis remains largely unknown. While tumor-initiating cells have been previously isolated from UFs, the cell of origin for these tumors in normal myometrium has not been identified. We isolated cells with Stro1/CD44 surface markers from normal myometrium expressing stem cell markers Oct-4/c-kit/nanog that exhibited the properties of myometrial stem/progenitor-like cells (MSCs). Using a murine model for UFs, we showed that the cervix was a hypoxic "niche" and primary site (96%) for fibroid development in these animals. The pool size of these MSCs also responded to environmental cues, contracting with age and expanding in response to developmental environmental exposures that promote fibroid development. Translating these findings to women, the number of MSCs in unaffected human myometrium correlated with risk for developing UFs. Caucasian (CC) women with fibroids had increased numbers of MSCs relative to CC women without fibroids, and African-American (AA) women at highest risk for these tumors had the highest number of MSCs: AA-with fibroids > CC-with fibroids > AA-without fibroids > CC-without fibroids. These data identify Stro1⁺ /CD44⁺ MSCs as MSC/progenitor cell for UFs, and a target for ethnic and environmental factors that increase UF risk. Stem Cells 2017;35:666-678.

Identification and potential role of telocytes in human uterine leiomyoma

Background

Telocytes are specialized interstitial tissue cell type. Our aim is to characterize telocytes in human uterine leiomyoma (ULM) and its adjacent myometrium (Myo-F) as well as normal myometrium (Myo-N).

Methods

ULMs and Myo-F tissues were taken from hysterectomy specimens done to treat symptomatic uterine fibroids (N = 20). Myo-N is isolated from hysterectomies done on ULM- free uteri for other benign indications (N = 15).

Telocytes were detected using immunohistochemistry to detect c-Kit (CD-117), as a surface marker expressed on telocytes, and electron microscopic examination to identify telocytes characteristic ultrastructure. Cellular count and electron microscopic features of telocytes in each of the studied tissues were compared.

Results

Telocytes could be detected in ULMs, Myo-F and Myo-N using c-KIT immunostaining. Electron microscopy confirmed the presence of telocytes in the three types of tissues identifying their characteristic features including small triangular or fusiform cell bodies with extensive cellular prolongations. ULM telocytes showed ultrastructural features suggestive of high cellular activities. Cell counts of ULM telocytes (3.35 ± 0.39) were significantly higher (P value = 0.00039) than that of Myo-F (1.39 ± 0.13). Myo-N (2.6 ± 0.36) contained higher telocyte numbers than Myo-F (1.39 ± 0.13), but the difference did not reach statistical significance (P value = 0.19).

Conclusions

Telocytes are detected in higher numbers and activity in ULMs than Myo-F or Myo-N. In ULMs, telocytes can work as a hormonal sensors for stem cells, provide scaffold for newly formed myocytes, or control important downstream signaling pathways.

Vitamin D and benign gynaecological diseases: a critical analysis of the current evidence

Vitamin D is a fat-soluble pro-hormone that plays an important role in bone homeostasis; beside this principal function, vitamin D promotes modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. In addition, several in vitro and in vivo studies have demonstrated that vitamin D deficiency could increase the risk of cancer, autoimmune and cardiovascular diseases. Moreover, vitamin D plays also an important role in female reproduction, because vitamin D receptors are expressed in ovarian tissue, endometrium, fallopian epithelial cells as well as in decidua and placenta. We aimed to review the most updated evidence, which suggests a link between vitamin D metabolism and the development of some gynaecological diseases, such as endometriosis, uterine fibroids and polycystic ovary syndrome.

Efficacy of Tranexamic Acid on Myomectomy-Associated Blood Loss in Patients With Multiple Myomas: A Randomized Controlled Clinical Trial

OBJECTIVE

To evaluate the efficacy of tranexamic acid (TA) in decreasing blood loss during and after open myomectomy for patients with 3 or more uterine fibroids.

METHODS

This prospective randomized trial was conducted among 132 women subjected to abdominal myomectomy. Patients were equally divided into 2 groups by simple randomization. The study group received perioperative intravenous TA while the control group did not. Intraoperative blood loss was calculated by measuring the volume in the suction apparatus and weighing the surgical swabs in addition to postoperative blood loss collected via a suction drain. Hemoglobin and hematocrit values were determined preoperatively and on the third postoperative day for all cases. Any adverse effects were recorded in both groups.

RESULTS

No significant difference was found between the two groups regarding age, body mass index, number, and size of myomas removed. The TA group showed lower amount of blood loss (407 mL) when compared to control group (677 mL; P < .01). Risk estimation has revealed that treatment with TA resulted in decrease in risk of perioperative blood loss by 40%. In the study group, 13 (19.7%) patients required blood transfusion in contrast to 23 (34.8%) patients in the control group (P < .01). Hemoglobin and hematocrit levels were significantly lower in the control group on the third postoperative day (P value = .001) .

CONCLUSION

The TA reduces blood loss during and after myomectomy for patients with multiple uterine fibroids.

Epidemiology of Uterine Myomas: A Review

Myomas are the most common benign tumors of the genital organs in women of childbearing age, causing significant morbidity and impairing their quality of life. In our investigation, we have reviewed the epidemiological data related to the development of myomas in order to homogenize the current data. Therefore, a MEDLINE and PubMed search, for the years 1990-2013, was conducted using a combination of keywords, such as "myoma," "leiomyoma," "fibroids," "myomectomy," "lifestyle," "cigarette," "alcohol," "vitamins," "diet," and "hysterectomy". Randomized controlled studies were selected based upon the authors’ estimation. Peer-reviewed articles examining myomas were sorted by their relevance and included in this research. Additional articles were also identified from the references of the retrieved papers and included according to authors’ estimation.

Many epidemiologic factors are linked to the development of myomas; however, many are not yet fully understood. These factors include age, race, heritage, reproductive factors, sex hormones, obesity, lifestyle (diet, caffeine and alcohol consumption, smoking, physical activity and stress), environmental and other influences, such as hypertension and infection. Some of the epidemiological data is conflicting. Thus, more research is needed to understand all the risk factors that contribute to myoma formation and how they exactly influence their onset and growth.

Risk for estrogen-dependent diseases in relation to phthalate exposure and polymorphisms of CYP17A1 and estrogen receptor genes

Evidence has shown that polymorphisms of various genes known to be involved in estrogen biosynthesis and function are associated with estrogen-dependent diseases (EDDs). These genes include CYP17A1, estrogen receptor 1 (ESR1), and 2 (ESR2). Phthalates are considered estrogenic endocrine disruptors, and recent research has suggested that they may act as a risk factor for EDDs. However, extremely few studies have assessed the effects of gene-environment interaction on these diseases. We recruited 44 patients with endometriosis or adenomyosis, 36 patients with leiomyoma, and 69 healthy controls from a medical center in Taiwan between 2005 and 2007. Urine samples were collected and analyzed for seven phthalate metabolites using liquid chromatography tandem mass spectrometry. Peripheral lymphocytes were used for DNA extraction to determine the genotype of CYP17A1, ESR1, and ESR2. Compared to controls, patients with leiomyoma had significantly higher levels of total urinary mono-ethylhexyl phthalate (ΣMEHP) (52.1 vs. 29.6 μg/g creatinine, p = 0.040), mono-n-butyl phthalate (MnBP) (75.4 vs. 51.3 μg/g creatinine, p = 0.019), and monoethyl phthalate (MEP) (103.7 vs. 59.3 μg/g creatinine, p = 0.031). In contrast, patients with endometriosis or adenomyosis showed a marginally increased level of urinary MEHP only. Subjects who were homozygous for both the ESR1 C allele (rs2234693) and CYP17A1 C allele (rs743572) showed a significantly increased risk for leiomyoma (OR = 19.8; 95 % CI, 1.70; 231.5; p = 0.017) relative to subjects with other genotypes of ESR1 and CYP17A1. These results were obtained after adjusting for age, cigarette smoking, MEHP level, GSTM1 genotype and other covariates. Our results suggested that both CYP17A1 and ESR1 polymorphisms may modulate the effects of phthalate exposure on the development of leiomyoma.

Matrix production and remodeling as therapeutic targets for uterine leiomyoma

Uterine leiomyoma, commonly known as fibroids, is a benign neoplasm of smooth muscle in women. The incidence of clinically symptomatic fibroids in reproductive-age women is approximately 20 %, with nearly 80 % of black women suffering from this condition. Symptoms include severe pain and hemorrhage; fibroids are also a major cause of infertility or sub-fertility in women. Uterine leiomyoma consist of hyperplastic smooth muscle cells and an excess deposition of extracellular matrix, specifically collagen, fibronectin, and sulfated proteoglycans. Extracellular matrix components interact and signal through integrin-β1 on the surface of uterine leiomyoma smooth muscle cells, provide growth factor storage, and act as co-receptors for growth factor-receptor binding. ECM and growth factor signaling through integrin-β1 and growth factor receptors significantly increases cell proliferation and ECM deposition in uterine leiomyoma. Growth factors TGF-β, IGF, PDGF, FGF and EGF are all shown to promote uterine leiomyoma progression and signal through multiple pathways to increase the expression of genes encoding matrix or matrix-modifying proteins. Decreasing integrin expression, reducing growth factor action and inhibiting ECM action on uterine leiomyoma smooth muscle cells are important opportunities to treat uterine leiomyoma without use of the current surgical procedures. Both natural compounds and chemicals are shown to decrease fibrosis and uterine leiomyoma progression, but further analysis is needed to make inroads in treating this common women's health issue.

Distribution of CYP17α polymorphism and selected physiochemical factors of uterine leiomyoma in Barbados

Uterine leiomyoma is a major reproductive health disease among women and in particular Black women. The present study sought to determine whether a single nucleotide polymorphism (SNP) of CYP17 (rs743572) was associated with the risk of developing uterine leiomyoma (UL) in affected women in Barbados; a majority Black population. It also sought to determine if BMI, waist circumference and oestradiol levels were associated with UL in this group. A total of 96 random persons were assessed in a case–control study using a PCR-RFLP assay, and measurements of body mass index, waist circumference, and oestradiol levels were also assessed. Our results showed no genetic association with the risk of UL and this gene. The genetic distribution of CYP 17α- alleles resembled a normal Hardy–Weinberg distribution, and a relatively low risk of 0.25 at a confidence interval at 95%, of UL disease development. However, a significant association was found between oestradiol levels and fibroids, as well as oestradiol levels and BMI, at P < 0.05 among cases. Therefore our study indicates that significant associations between physiochemical factors comprising BMI, waist circumference, and oestrogen levels are disease indicators in this population. In conclusion, our findings suggest that obesity and its associated risk factors are important in a majority Black Caribbean population, although the sample size needs to be increased.

The health disparities of uterine fibroid tumors for African American women: a public health issue

Uterine fibroid tumors (leiomyomas) are the most common benign pelvic tumors in women and are the major indication for hysterectomy. Fibroid tumors are more common and more severe among African American women. Although this disease disproportionately affects the African American population, we understand little about what causes the disparity. Fibroid tumors should be considered a public health issue, given the magnitude of the problem and the costs of health care for this disease. In this review, we examine the burden of disease from fibroid tumors in the African American population and review the natural history, diagnosis, and treatment of uterine fibroid tumors, with emphasis on how these can differ, depending on race. We also focus on the socioeconomic burden caused by the disease and describe the anticipated influence of new health care reforms and funding mechanisms for fibroid tumor research.

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.

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.

Comparison of characteristics of fibroids in African American and white women undergoing premenopausal hysterectomy

OBJECTIVE

To compare pathologic characteristics and epidemiologic risk factors for uterine fibroids in African American and white women undergoing hysterectomy.

DESIGN

Cross-sectional analysis of women undergoing premenopausal hysterectomy.

SETTING

Two university-associated hospitals in North Carolina.

PATIENT(S)

African American (n = 225) and white women (n = 135) with fibroid diagnosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Data were obtained from an in-person interview and abstracted from operative and pathologic reports. Analysis of variance and multiple linear regression models were used to identify characteristics associated with higher uterine weight, greater number of fibroids, and size of the largest fibroid.

RESULT(S)

African American women had substantially more fibroids (9.9 vs. 4.5) with a concomitant higher mean uterine weight (477 vs. 267 g). Although African American women had a higher prevalence of established risk factors for fibroids, such as high body mass index (BMI) and hypertension, these factors were not associated with larger uteri or more numerous fibroids. In multiple linear regression models, the only factors statistically significantly associated with higher uterine weight, larger fibroids, and more numerous fibroids were race and nulligravidity.

CONCLUSION(S)

The presentation of fibroids as measured by uterine size or number of fibroids is more severe in African American women compared with white women. The differences in presentation cannot be explained by racial differences in the prevalence of known risk factors. Additional research is needed on environmental and genetic factors that may increase the risk for fibroids.

Functional gene polymorphism of matrix metalloproteinase-1 is associated with benign hyperplasia of myo- and endometrium in the Russian population

AIMS

Estrogen-dependent hyperplasia of myo- and endometrium manifests as uterine leiomyoma or adenomyosis. We studied possible associations between common polymorphisms of matrix metalloproteinase (MMP) genes and clinical features of uterine hyperplasia.

PATIENTS AND METHODS

One hundred seventy female patients with uterine leiomyoma (46.6±0.5 years) were observed. Clinical diagnosis was based on physical examination, ultrasonography, and histological data. MMP-1 (-1607 1G/2G, rs1799750) and MMP-3 (-1171 5A/6A, rs3025058) were genotyped with allele-specific polymerase chain reaction (PCR) of leukocyte DNA. Clinical and genetic data were evaluated using nonparametric statistics.

RESULTS

Distributions of MMP-1 and MMP-3 promoter alleles among patients and population controls were similar and corresponded to the Hardy-Weinberg equilibrium (HWE). Detectable tumor growth and adenomyosis were observed, respectively, in 71% and 55% of cases. Steady-state leiomyoma correlated with a higher prevalence of the MMP-1 1G/1G genotype (p=0.02 by χ(2) test). Accelerated tumor growth correlated with higher frequency of the MMP-1 2G allele [odds ratio (OR)=2.048, p=0.039, χ(2)=4.2611, confidence interval (CI)=(1.032-4.062)]. MMP-1 2G was also associated with multinodular growth [OR=3.561, p=0.01249, χ(2)=6.24, CI=(1.261-10.058)]. The MMP-1 2G allele tended to increase in patients with adenomyosis [OR=1.525, p=0.054, χ(2)=3.71, CI=(0.992-2.345)].

CONCLUSION

Our pilot study suggests that the 2G (-1607)MMP-1 genotype may be a potential risk marker of myo- and endometrial hyperplasia.

Role of stem cells in human uterine leiomyoma growth

Background

Uterine leiomyoma is the most common benign tumor in reproductive-age women. Each leiomyoma is thought to be a benign monoclonal tumor arising from a single transformed myometrial smooth muscle cell; however, it is not known what leiomyoma cell type is responsible for tumor growth. Thus, we tested the hypothesis that a distinct stem/reservoir cell-enriched population, designated as the leiomyoma-derived side population (LMSP), is responsible for cell proliferation and tumor growth.

Principal Findings

LMSP comprised approximately 1% of all leiomyoma and 2% of all myometrium-derived cells. All LMSP and leiomyoma-derived main population (LMMP) but none of the side or main population cells isolated from adjacent myometrium carried a mediator complex subunit 12 mutation, a genetic marker of neoplastic transformation. Messenger RNA levels for estrogen receptor-α, progesterone receptor and smooth muscle cell markers were barely detectable and significantly lower in the LMSP compared with the LMMP. LMSP alone did not attach or survive in monolayer culture in the presence or absence of estradiol and progestin, whereas LMMP readily grew under these conditions. LMSP did attach and survive when directly mixed with unsorted myometrial cells in monolayer culture. After resorting and reculturing, LMSP gained full potential of proliferation. Intriguingly, xenografts comprised of LMSP and unsorted myometrial smooth muscle cells grew into relatively large tumors (3.67±1.07 mm³), whereas xenografts comprised of LMMP and unsorted myometrial smooth muscle cells produced smaller tumors (0.54±0.20 mm³, p<0.05, n = 10 paired patient samples). LMSP xenografts displayed significantly higher proliferative activity compared with LMMP xenografts (p<0.05).

Conclusions

Our data suggest that LMSP, which have stem/reservoir cell characteristics, are necessary for in vivo growth of leiomyoma xenograft tumors. Lower estrogen and progesterone receptor levels in LMSP suggests an indirect paracrine effect of steroid hormones on stem cells via the mature neighboring cells.

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.

Adipocytes enhance the proliferation of human leiomyoma cells via TNF-α proinflammatory cytokine

OBJECTIVE

Obesity is a well-documented risk factor for uterine leiomyoma with a major impact on women health and health care system of the nation. Obesity is associated with increased secretion of adipokines that significantly influence growth and proliferation of tumor stroma and malignant cells. Adipokines, such as tumor necrosis factor α (TNF-α), are produced in the adipose tissue with concomitant expression in other organs and tissues. Increased and sustained cytokine production is associated with alterations in cell growth and differentiation. We, therefore, explored the influence of human adipocytes (SW872 cells)-mediated biological humoral factors on human uterine leiomyoma (HuLM) cells.

METHODS

We measured cell proliferation and expression of cell-proliferating proteins (proliferating cell nuclear antigen [PCNA], cyclin D1, and B-cell lymphoma 2 [BCL-2]) in human leiomyoma cells cocultured with SW872 cells. SW872-conditioned media was neutralized for TNF-α and proliferation of HuLM cells was observed along with antiapoptotic marker, BCL-2, using Western immunoblot.

RESULTS

We found that both SW872-conditioned media and coculture with SW872 cells increased HuLM cell proliferation significantly (P < .05). We determined that this effect was associated with the upregulation of specific markers for proliferation, such as PCNA, cyclin D1, and BCL-2 (P < .05). Furthermore, the addition of neutralizing antibodies, anti-TNF-α, to SW872-conditioned media reversed the proliferation of leiomyoma cells and induced apoptosis as indicated by the reduced expression of antiapoptotic marker BCL-2.

CONCLUSIONS

SW872 cells secrete TNF-α, which is associated with a proliferative gene profile in HuLM cells and may play a role in initiation and/or progression of uterine leiomyoma.

Innovative oral treatments of uterine leiomyoma

Uterine fibroids (leiomyoma), the benign tumors of the uterine wall, are very common cause of morbidity in reproductive age women usually in the form of excessive vaginal bleeding, chronic pelvic pain, miscarriage and infertility. These tumors are the leading indication for hysterectomy in the United States. Uterine fibroids are about 4 times higher in blacks compared to whites and constitute a major health disparity challenge. The estimated cost of uterine fibroids is up to $34.4 billion annually. Additionally, women who suffer from this disease and desire to maintain their future fertility have very limited treatment choices. Currently, there is no effective long-term medicinal treatment for uterine fibroids. While surgery has traditionally been the gold standard for the treatment of uterine fibroids, there is growing interest towards orally administered medications for the management of leiomyoma-related symptoms. In this paper, we will discuss these promising innovative oral medical treatments in detail.

Efficacy and tolerability of CDB-2914 treatment for symptomatic uterine fibroids: a randomized, double-blind, placebo-controlled, phase IIb study

OBJECTIVE

To evaluate the efficacy and tolerability of the P receptor modulator CDB-2914 (Ulipristal, CDB).

DESIGN

Randomized, placebo-controlled double-blind clinical trial.

SETTING

Clinical research center.

PATIENT(S)

Premenopausal women with symptomatic uterine fibroids.

INTERVENTION(S)

Once-daily oral CDB (10 or 20 mg) or placebo (PLC) for 12 weeks (treatment 1). A second 3-month treatment with CDB (treatment 2) was offered. A computer-generated blocked randomization was used.

MAIN OUTCOME MEASURE(S)

Magnetic resonance imaging (MRI)-determined total fibroid volume (TFV) change was the primary outcome; amenorrhea and quality of life (QOL) were secondary end points.

RESULT(S)

Treatment 1 TFV increased 7% in the PLC group, but decreased 17% and 24% in the CDB10 and CDB20 groups. The TFV decreased further in treatment 2 (-11%). Amenorrhea occurred in 20/26 women taking CDB and none on PLC. Ovulation resumed after CDB. Hemoglobin improved only with CDB (11.9 ± 1.5 to 12.9 ± 1.0 g/dL) as did the Fibroid QOL Questionnaire symptom severity, energy/mood, and concern subscores, and overall QOL scores. The CDB was well tolerated, with no serious adverse events. Adverse events were unchanged during treatments.

CONCLUSION(S)

Administration of CDB-2914 for 3-6 months controls bleeding, reduces fibroid size, and improves QOL.