Uterine Leiomyoma Growth Research Articles

Spatially restricted ecto-5'-nucleotidase expression promotes the growth of uterine leiomyomas by modulating Akt activity.

Found in as many as 80% of women, uterine leiomyomas are a frequent cause of abnormal uterine bleeding, pelvic pain, and infertility. Despite their significant clinical impact, the mechanisms responsible for driving leiomyoma growth remain poorly understood. After obtaining IRB permission, expression of ecto-5'-nucleotidase (NT5E, CD73) was assessed in matched specimens of myometrium and leiomyoma by real-time qPCR, Western blot, and immunohistochemistry (IHC). Adenosine concentrations were measured by enzyme-linked assay. Primary cultures were used to assess the impact of adenosine and/or adenosine receptor agonists on proliferation, apoptosis, and patterns of intracellular signaling invitro. When compared to matched specimens of healthy myometrium, uterine leiomyomas were characterized by reduced CD73 expression. Largely limited to thin-walled vascular structures and the pseudocapsule of leiomyomas despite diffuse myometrial distribution. Restricted intra-tumoral CD73 expression was accompanied by decreased levels of intra-tumoral adenosine. Invitro, incubation of primary leiomyoma cultures with adenosine or its hydrolysis-resistant analog 2-chloro-adenosine (2-CL-AD) inhibited proliferation, induced apoptosis, and reduced proportion of myocytes in S- and G2-M phases of the cell cycle. Decreased proliferation was accompanied by reduced expression of phospho-Akt, phospho-Cdk2-Tyr15, and phospho-Histone H3. Enforced expression of the A2B adenosine receptor (ADORA2B) and ADORA2B-selective agonists similarly suppressed proliferation and inhibited Akt phosphorylation. Collectively, these observations broadly implicate CD73 and reducedextracellular concentrations ofadenosine as key regulators of leiomyoma growth and potentiallyidentify novel strategies for clinically managing these common tumors.

Genetic Mechanisms Driving Uterine Leiomyoma Pathobiology, Epidemiology, and Treatment.

Uterine leiomyomas (ULs) are the most common benign tumor of the uterus. They can be associated with symptoms including abnormal uterine bleeding, pelvic pain, urinary frequency, and pregnancy complications. Despite the high prevalence of UL, its underlying pathophysiology mechanisms have historically been poorly understood. Several mechanisms of pathogenesis have been suggested, implicating various genes, growth factors, cytokines, chemokines, and microRNA aberrations. The purpose of this study is to summarize the current research on the relationship of genetics with UL. Specifically, we performed a literature review of published studies to identify how genetic aberrations drive pathophysiology, epidemiology, and therapeutic approaches of UL. With regards to pathophysiology, research has identified MED12 mutations, HMGA2 overexpression, fumarate hydratase deficiency, and cytogenetic abnormalities as contributors to the development of UL. Additionally, epigenetic modifications, such as histone acetylation and DNA methylation, have been identified as contributing to UL tumorigenesis. Specifically, UL stem cells have been found to contain a unique DNA methylation pattern compared to more differentiated UL cells, suggesting that DNA methylation has a role in tumorigenesis. On a population level, genome-wide association studies (GWASs) and epidemiologic analyses have identified 23 genetic loci associated with younger age at menarche and UL growth. Additionally, various GWASs have investigated genetic loci as potential drivers of racial disparities in UL incidence. For example, decreased expression of Cytohesin 4 in African Americans has been associated with increased UL risk. Recent studies have investigated various therapeutic options, including ten-eleven translocation proteins mediating DNA methylation, adenovirus vectors for drug delivery, and "suicide gene therapy" to induce apoptosis. Overall, improved understanding of the genetic and epigenetic drivers of UL on an individual and population level can propel the discovery of novel therapeutic options.

Differential effect of estrogen and progesterone on <i>in vitro</i> growth of uterine leiomyoma cells with chromosome 7 deletions

BACKGROUND: The studies on how sex steroid hormones affect growth of uterine leiomyoma cells with chromosomal abnormalities is highly relevant for development of personalized tumor therapy.
 AIM: To study in vitro the isolated and combined effects of estrogen and progesterone on uterine leiomyoma cells with chromosomal aberrations — deletions in 7q.
 MATERIALS AND METHODS: The study was performed on 15 uterine leiomyomas, excised from 15 women of 26–44 years of age who were not treated with hormones. Uterine leiomyoma cells were cultured in hormone-free medium, in the medium supplemented with estrogen, progesterone or both hormones. The chromosome preparations were made and stained with QFH/AcD to perform conventional karyotyping and fluorescence in situ hybridization (FISH) to accurately describe chromosomal rearrangements. The frequency of uterine leiomyoma cells with chromosomal aberrations was assessed by interphase FISH.
 RESULTS: Deletions in 7q were identified in 6 out of 15 karyotyped uterine leiomyomas; four of them had one clone with deletion in 7q whereas two others comprised two clones with 7q deletions of different length. The frequency of cells carrying deletions in 7q greatly varied in uterine leiomyoma samples cultured in hormone-free medium: from 3.5% to 93.6%. Exposure of cell cultures to estrogen and progesterone resulted in a fold change frequency increase in some of the uterine leiomyomas and decrease in the others. The most significant changes in the frequency of cells with deletions in 7q were registered in response to the isolated estrogen and, to a lesser extent, to progesterone exposure; less significant changes were observed after combined hormonal effect.
 CONCLUSIONS: In uterine leiomyomas with deletions in 7q, the frequency of abnormal cells may either increase or decrease in response to estrogen and progesterone in vitro supplementation. The isolated effect of estrogen or progesterone on the frequency of uterine leiomyoma cells with deletion in 7q is more pronounced compared to the combined one.

Simvastatin induces degradation of the extracellular matrix in human leiomyomata: novel in vitro, in vivo, and patient level evidence of matrix metalloproteinase involvement

ObjectivesTo assess the effect of simvastatin on uterine leiomyoma growth and extracellular matrix (ECM) deposition. DesignLaboratory analysis of human leiomyoma cell culture, xenograft in a mouse model, and patient tissue from a clinical trial. SettingAcademic research center. Patient(s)Tissue culture from human leiomyoma tissue and surgical leiomyoma tissue sections from a placebo-controlled randomized clinical trial. Intervention(s)Simvastatin treatment. Main Outcome Measure(s)Serum concentrations, xenograft volumes, and protein expression. ResultsMice xenografted with 3-dimensional human leiomyoma cultures were divided as follows: 7 untreated controls, 12 treated with activated simvastatin at 10 mg/kg body weight, and 15 at 20 mg/kg body weight. Simvastatin was detected in serum from mice injected at the highest dose. Xenograft volumes were significantly smaller (mean 53% smaller at the highest concentration, p < 0.05). There was dissolution of compact ECM, decreased ECM formation, and lower collagen protein expression in xenografts. Membrane type 1 matrix metalloproteinase (MT1-MMP) was increased in vitro and in vivo. Matrix metalloproteinase 2 (MMP2) and low density lipoprotein receptor related protein 1 (LRP1) were increased in vitro. ConclusionsSimvastatin exhibited antitumoral activity, with extracellular matrix degradation and decreased leiomyoma tumor volume in vivo. Activation of the MMP2/MT1-MMP/LRP1 pathway may explain these findings.

MED12 mutation activates the tryptophan/kynurenine/AHR pathway to promote growth of uterine leiomyomas.

Uterine leiomyomas cause heavy menstrual bleeding, anemia, and pregnancy loss in millions of women worldwide. Driver mutations in the transcriptional mediator complex subunit 12 (MED12) gene in uterine myometrial cells initiate 70% of leiomyomas that grow in a progesterone-dependent manner. We showed a distinct chromatin occupancy landscape of MED12 in mutant MED12 (mut-MED12) versus WT-MED12 leiomyomas. Integration of cistromic and transcriptomics data identified tryptophan 2,3-dioxygenase (TDO2) as the top mut-MED12 target gene that was significantly upregulated in mut-MED12 leiomyomas when compared with adjacent myometrium and WT-MED12 leiomyomas. TDO2 catalyzes the conversion of tryptophan to kynurenine, an aryl hydrocarbon receptor (AHR) ligand that we confirmed to be significantly elevated in mut-MED12 leiomyomas. Treatment of primary mut-MED12 leiomyoma cells with tryptophan or kynurenine stimulated AHR nuclear translocation, increased proliferation, inhibited apoptosis, and induced AHR-target gene expression, whereas blocking the TDO2/kynurenine/AHR pathway by siRNA or pharmacological treatment abolished these effects. Progesterone receptors regulated the expression of AHR and its target genes. In vivo, TDO2 expression positively correlated with the expression of genes crucial for leiomyoma growth. In summary, activation of the TDO2/kynurenine/AHR pathway selectively in mut-MED12 leiomyomas promoted tumor growth and may inform the future development of targeted treatments and precision medicine.

Obesity Contributes to Transformation of Myometrial Stem-Cell Niche to Leiomyoma via Inducing Oxidative Stress, DNA Damage, Proliferation, and Extracellular Matrix Deposition.

Leiomyomas (fibroids) are monoclonal tumors in which myometrial stem cells (MSCs) turn tumorigenic after mutation, abnormal methylation, or aberrant signaling. Several factors contribute to metabolic dysfunction in obesity, including abnormal cellular proliferation, oxidative stress, and DNA damage. The present study aims to determine how adipocytes and adipocyte-secreted factors affect changes in MSCs in a manner that promotes the growth of uterine leiomyomas. Myometrial stem cells were isolated from the uteri of patients by fluorescence-activated cell sorting (FACS) using CD44/Stro1 antibodies. Enzyme-linked immunosorbent assay (ELISA), Western blot, and immunocytochemistry assays were performed on human adipocytes (SW872) co-cultured with MSCs and treated with leptin or adiponectin to examine the effects of proliferation, extracellular matrix (ECM) deposition, oxidative damage, and DNA damage. Co-culture with SW872 increased MSC proliferation compared to MSC culture alone, according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results. The expressions of PCNA and COL1A increased significantly with SW872 co-culture. In addition, the expression of these markers was increased after leptin treatment and decreased after adiponectin treatment in MSCs. The Wnt/β-catenin and TGF-β/SMAD signaling pathways promote proliferation and ECM deposition in uterine leiomyomas. The expression of Wnt4, β-catenin, TGFβ3, and pSMAD2/3 of MSCs was increased when co-cultured with adipocytes. We found that the co-culture of MSCs with adipocytes resulted in increased NOX4 expression, reactive oxygen species production, and γ-H2AX expression. Leptin acts by binding to its receptor (LEP-R), leading to signal transduction, resulting in the transcription of genes involved in cellular proliferation, angiogenesis, and glycolysis. In MSCs, co-culture with adipocytes increased the expression of LEP-R, pSTAT3/STAT3, and pERK1/2/ERK/12. Based on the above results, we suggest that obesity may mediate MSC initiation of tumorigenesis, resulting in leiomyomas.

A Missense Mutation c.1132G &gt; A in Fumarate Hydratase (FH) Leads to Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) Syndrome and Insights into Clinical Management in Uterine Leiomyomata

HLRCC syndrome is a hereditary cancer predisposition syndrome caused by heterozygous germline pathogenic variant of the fumarate hydratase (FH) gene and characterized by cutaneous leiomyomas (CL), uterine leiomyomas (UL), and renal cell carcinoma (RCC). Loss of function variant of FH gene inactivates the Kreb's cycle enzyme activity and predisposes individuals with such variant to the development of HLRCC. Next-generation sequencing (NGS) and Sanger confirmation were given to family members accessible. Following that, a functional study in vitro was performed to further confirm the pathogenicity of the variant. FH-Wild type (FH-WT) and FH-mutant (FH-MUT) (E378K) plasmid were constructed and transfected into 293T and uterine leiomyoma cell lines, respectively. Proliferation assessment was executed to show how this mutation affects the growth of uterine leiomyoma. qPCR and Western blotting were performed to investigate the change of transcription and translation of FH with mutation (E378K), and FH enzyme assay activity were tested in 293T cells with mutation and wild-type plasmids. Here, we presented two families with the same missense variant (c.1132G > A) that has not been reported as a germline mutation in hereditary uterine leiomyomas before and classified as VUS in gene databases. Our in vitro experiments supported the pathogenicity of this missense variant, especially in uterine leiomyomata. According to the American College of Medical Genetics (ACMG) guideline, the E378K variant was classified as likely pathogenic (with evidence PS4_support, PS3_support, PM2_support, PP1, PP3 and PP4 evidence). Further insights into clinical management in uterine leiomyomata were discussed and should be practiced in gynecological clinical settings.

High prevalence of vitamin D deficiency in Pakistan and its relation to uterine fibroids development and progression

Vitamin D insufficiency is a condition that affects more than a billion individuals globally and is escalating in prevalence. According to Riaz et al., 31.2% of Pakistan’s population had low vitamin D levels, while 53.5% of the country’s population had deficiencies. Recent research suggests that vitamin D insufficiency, a severe health problem with numerous effects, including a higher risk of female reproductive malignancies, may have an impact on the growth and progression of uterine leiomyomas. The most prevalent benign pelvic tumor, uterine fibroids, do not have an effective long-term medical solution. Surgery, such as hysterectomy and myomectomy, is currently the most common type of treatment for symptomatic UFs; however, these procedures increase the risk of an operation’s complications for patients and are exceedingly expensive for healthcare systems.The key is that vitamin D supplements can be utilized to prevent, treat, or reduce the size of UF and that vitamin D insufficiency is a significant risk factor for the onset and progression of UF. As a result, there is an urgent need to promote vitamin D supplementation as a prospective treatment for uterine fibroids and to fill the gap left by the lack of non-invasive options.

Loss of the repressor REST affects progesterone receptor function and promotes uterine leiomyoma pathogenesis

Uterine leiomyomas (UL) are benign tumors that arise in the myometrial layer of the uterus. The standard treatment option for UL is hysterectomy, although hormonal therapies, such as selective progesterone receptor modulators, are often used as temporary treatment options to reduce symptoms or to slow the growth of tumors. However, since the pathogenesis of UL is poorly understood and most hormonal therapies are not based on UL-specific, divergent hormone signaling pathways, hallmarks that predict long-term efficacy and safety of pharmacotherapies remain largely undefined. In a previous study, we reported that aberrant expression of repressor element 1 silencing transcription factor/neuron-restrictive silencing factor (REST/NRSF) target genes activate UL growth due to the near ubiquitous loss of REST. Here, we show that ablation of the Rest gene in mouse uterus leads to UL phenotype and gene-expression patterns analogous to UL, including altered estrogen and progesterone signaling pathways. We demonstrate that many of the genes dysregulated in UL harbor cis-regulatory elements bound by REST and progesterone receptor (PGR) adjacent to each other. Crucially, we identify an interaction between REST and PGR in healthy myometrium and present a putative mechanism for the dysregulation of progesterone-responsive genes in UL ensuing in the loss of REST. Using three Rest conditional knockout mouse lines, we provide a comprehensive picture of the impact loss of REST has in UL pathogenesis and in altering the response of UL to steroid hormones.

Curcumin inhibits human leiomyoma xenograft tumor growth and induces dissolution of the extracellular matrix

To determine whether a curcumin-supplemented diet would prevent and/or treat uterine leiomyoma growth in our mouse xenograft model. Animal study. Laboratory study. N/A. Curcumin-supplemented diet. Dietary intake, blood concentrations, tumor size, extracellular matrix protein concentrations, apoptosis markers. We found that curcumin was well tolerated as a dietary supplement, free curcumin and its metabolites were detected in the serum, and exposure resulted in approximately 60% less leiomyoma xenograft growth as well as dissolution of the peripheral extracellular matrix architecture of the xenografts. The production of matrix proteins, including collagens, decreased, whereas the number of apoptotic cells in the xenografts increased. Additionally, when xenografts were placed in a uterine intramural location, we found a significantly increased apoptotic response to curcumin in the diet. Mice on a diet supplemented with curcumin could achieve serum concentrations sufficient to regulate human leiomyoma xenograft growth, and curcumin could play both preventive and curative roles in the treatment of uterine leiomyoma as an oral nutritional supplement.

Benign Metastasizing Leiomyoma of The Lung: A Case Report

Introduction: Benign metastasizing leiomyoma of the lung which is categorized by the growth of uterine leiomyoma in the lung is an extremely exceptional disease.&#x0D; Case presentation: We report a 39-year-old woman who had a previous history of uterine leiomyoma. Chest computed tomography (CT) scan exhibited round nodules well-defined margins in both lungs. Thoracoscopic partial resection of the lung was done. Pathological and immunohistochemical examination showed that neoplastic tissue composed of spindle-shaped smooth muscle cells, compatible with uterine leiomyoma. Thus, these tumors can be reflected to be lung metastases from a uterine leiomyoma (benign metastasizing leiomyoma).&#x0D; Conclusion: It is an uncommon condition but it would be careful in women of reproductive age with a past medical history of uterine leiomyoma, who existing with pulmonary nodules.

In Silico Analysis of Plant-Based Bioactive Compounds Targeting Progesterone Receptors for the Treatment of Uterine Leiomyoma

Uterine leiomyomas are the most common benign gynaecological tumours that affect 50% - 60% of females belonging to reproductive age. The role of progesterone in the growth and development of leiomyomas is evident. Progesterone is regulated by progesterone receptors and it acts by activating PI3K/AKT pathway, by increasing proliferating cell nuclear antigen (PCNA) levels and Bcl-2 expression. Thus, modulating the receptor can help in the treatment of leiomyomas. The current study involves testing the efficiency of the various plant-based bioactive compounds to bind to the progesterone receptors, which may possess inhibitory or modulatory effects on or against progesterone receptors. These compounds can be further experimented with using other in vivo and in vitro methods to produce phytomedicine based on drugs for the treatment of uterine leiomyomas. This study is an in silico analysis performed using various bioinformatics databases and software. The receptor and ligand structures were retrieved from PDB and PubChem databases. Their pharmacokinetics and pharmacodynamics properties were analyzed using various databases. AutoDock4.2.6 was used for molecular docking, and the results were visualized using LigPlot+. Among 15 compounds selected, 8 compounds had higher binding energies than the control drug Ulipristal acetate i.e., -8.21Kcal/mol. Of which Ursolic acid, Vitamin-D2, and Betulinic acid had binding energies above -9.0 Kcal/mol. This concludes that these compounds can modulate the progesterone receptors, thus decreasing the proliferation and growth of uterine leiomyomas. Further studies can bring out the potential therapeutic effects of these bioactive compounds and they can act as a potential lead compound in the design of novel drug targets for the treatment of uterine leiomyoma.

Astragaloside IV Inhibits the Proliferation of Human Uterine Leiomyomas by Targeting IDO1.

Simple SummaryImmunotherapy is increasingly becoming a success strategy for oncology treatment. Indoleamine-2,3-dioxygenase1 (IDO1) is a tryptophan-degrading enzyme involved in immunological escape mechanisms, which is considered as a potential target for tumor therapy. However, the clinical efficacy of IDO1 inhibitors is not promising. Therefore, there is an urgent to investigate the mechanism between chemical drugs with antitumor effects and IDO1-mediated immunosuppression. The Chinese medicine AS-IV exerts antitumor effects with many advantages, including fewer toxic side effects and immunomodulatory effects. We noted the lack of studies of AS-IV on benign tumors. Therefore, our study demonstrates the Inhibitory effect of AS-IV on ULMs and elucidates the underlying mechanism.Astragaloside IV (AS-IV) is a chemical found in traditional Chinese medicine called Astragalus membranaceus (Fisch.) Bunge that has antitumor properties. However, the roles and mechanisms of AS-IV in uterine leiomyomas (ULMs) are unclear. The immunosuppressive enzyme indoleamine-2,3-dioxygenase-1 (IDO1) is involved in tumor formation. IDO1 is a new and reliable prognostic indicator for several cancers. In this work, AS-IV was applied to ULM cells in various concentrations. CCK-8, immunofluorescence, and flow cytometry were used to examine the proliferation and apoptosis of ULM cells caused by AS-IV. After lentiviral vector transduction with IDO1 short hairpin RNA (shRNA), the knockdown and overexpression of IDO1 were stable in ULM cells. To verify the antitumor effect of AS-IV in vivo, we established a rat model of uterine leiomyoma. HE staining, Masson staining, and transmission electron microscopy were used to observe pathological changes in the uterus, and the levels of serum sex hormones were measured by radio immune assay (RIA). The levels of CD3+T, CD4+T, and CD25+ Foxp3+Treg in rat peripheral blood were detected by flow cytometry. Western blotting and immunohistochemistry were used to examine protein expression. We found that AS-IV dramatically increased the apoptotic rate of ULM cells and reduced viability in a time- and dosage-dependent manner. After sh-IDO1 lentiviral transfection, we discovered that knocking down IDO1 reversed the effects of AS-IV on ULM cell proliferation and autophagy. We also found that AS-IV can effectively inhibit the growth of ULMs in vivo. AS-IV may promote apoptosis and autophagy in ULMs by activating PTEN/PI3K/AKT signaling through inhibition of IDO1. These findings imply that AS-IV exerts antifibroid effects, and the underlying mechanism may be IDO1, which is involved in proliferation, apoptosis, and autophagy.

Possible significance of degeneration and decreased expression of progesterone receptor in postmenopausal uterine leiomyoma

BackgroundThe growth of uterine leiomyomas is dependent on the levels of sex steroid hormones, and they usually shrink after menopause. However, there are cases in which leiomyomas continue to grow and/or surgery is required after menopause. In addition to estrogen, progesterone has recently been implicated in leiomyoma enlargement, but its relevance to postmenopausal leiomyoma remains unknown. Therefore, we investigated whether hormone receptor expression is associated with postmenopausal leiomyoma enlargement and characterized pathological findings of postmenopausal leiomyoma, which have not been clarified yet.MethodsNine cases that required total hysterectomy for leiomyomas after menopause were examined. Surgeries were conducted because of pelvic pressure, pelvic pain, suspected malignancy, or growing leiomyoma. Six cases of leiomyomas being incidentally found during total hysterectomy for postmenopausal uterine prolapse, and six patients who underwent hysterectomy for leiomyomas before menopause, were examined as controls. We evaluated the expression of estrogen receptor, progesterone receptor B, and progesterone receptor AB by immunohistochemical staining among the cases. We also analyzed the pathological findings of leiomyomas.ResultsIn postmenopausal leiomyomas, the expression of progesterone receptor was higher than that in the adjacent myometrium. Compared with premenopausal leiomyomas, the expression of progesterone receptor decreased. Postmenopausal leiomyomas that required surgery did not show elevated sex steroid hormone receptor expression, compared with the leiomyomas that did not require surgery.The degeneration frequency of leiomyomas was 92% in the group that underwent surgery for postmenopausal leiomyomas, 65% in the group that underwent surgery for reasons other than the presence of leiomyomas after menopause, and 47% in the group operated for leiomyomas before menopause.ConclusionsThese results suggest that sex steroid hormones are unlikely to be associated with the growth of leiomyomas after menopause. Since leiomyoma degeneration with increased extracellular matrix is likely to occur in postmenopausal women, the degeneration of leiomyomas may be the main mechanism for the growth of postmenopausal leiomyomas.

Simvastatin inhibits stem cell proliferation in human leiomyoma via TGF-β3 and Wnt/β-Catenin pathways.

Uterine leiomyoma (UL) is the most common gynaecologic tumour, affecting an estimated 70 to 80% of women. Leiomyomas develop from the transformation of myometrial stem cells into leiomyoma stem (or tumour‐initiating) cells. These cells undergo self‐renewal and differentiation to mature cells, both are necessary for the maintenance of tumour stem cell niche and tumour growth, respectively. Wnt/β‐catenin and TGF‐β/SMAD pathways, both overactive in UL, promote stem cell self‐renewal, crosstalk between stem and mature cells, cellular proliferation, extracellular matrix (ECM) accumulation and drive overall UL growth. Recent evidence suggests that simvastatin, an antihyperlipidemic drug, may have anti‐leiomyoma properties. Herein, we investigated the effects of simvastatin on UL stem cells. We isolated leiomyoma stem cells by flow cytometry using DyeCycle Violet staining and Stro‐1/CD44 surface markers. We found that simvastatin inhibits proliferation and induces apoptosis in UL stem cells. In addition, it also suppressed the expression of the stemness markers Nanog, Oct4 and Sox2. Simvastatin significantly decreased the production of the key ECM proteins, collagen 1 and fibronectin. Finally, it inhibited genes and/or proteins expression of TGF‐β1, 2 and 3, SMAD2, SMAD4, Wnt4, β‐Catenin, LRP6, AXIN2 and Cyclin D1 in UL stem cells, all are key drivers of the TGF‐β3/SMAD2 and Wnt4/β‐Catenin pathways. Thus, we have identified a novel stem cell‐targeting anti‐leiomyoma simvastatin effect. Further studies are needed to replicate these findings in vivo.

The Potential of Transforming Growth Factor-beta Inhibitor and Vascular Endothelial Growth Factor Inhibitor as Therapeutic Agents for Uterine Leiomyoma.

Background: Uterine leiomyoma is the most common benign tumor in women of reproductive age, and it can cause infertility. The growth of uterine leiomyoma is mediated by various steroids and growth factors. The purpose of this study was to evaluate the expression of various growth factors in uterine leiomyoma. Additionally, comparing the effects of existing medication and specific growth factor inhibitors on leiomyoma and the normal myometrium, we aimed to see the potential of transforming growth factor-beta (TGF-β) inhibitors and vascular endothelial growth factor (VEGF) inhibitors as therapeutic drugs for uterine leiomyoma.Methods: This in vitro study included uterine leiomyoma samples from 12 patients who underwent hysterectomy by laparoscopy or laparotomy at Seoul St. Mary's Hospital between May 2016 and March 2018. Normal myometrium and uterine leiomyoma tissue were obtained from each patient and the expression of growth factors was compared using immunohistochemical staining. After the primary culture of normal myometrial and leiomyoma cells, cell viability was evaluated following treatment with 100 nM ulipristal acetate (UPA) and mifepristone for 48 h. Western blot analysis was performed to determine the protein expression of each growth factor. Cell viability was determined following treatment with a 10-µM TGF-β inhibitor (LY364947) and a 5-µM VEGF inhibitor (axitinib) for 24 h in cultured normal myometrium and leiomyoma cells.Results: Immunohistochemical staining revealed the significantly higher intensity of TGF-β and VEGF in the leiomyoma tissue than in the normal myometrium (P < 0.05). Mifepristone treatment decreased VEGF expression by 62% in the leiomyoma cells (P < 0.05). According to the cell counting kit-8 (CCK-8) assay, cell viability was decreased after UPA, mifepristone, TGF-β1 inhibitor, and VEGF inhibitor treatments in the normal myometrium and leiomyoma tissue. The effects of the TGF-β1 inhibitor significantly differed between normal myometrium and leiomyoma tissue, with a greater decrease in cell survival in the leiomyoma tissue (P < 0.05). Post-hoc analysis showed that the TGF-β1 and VEGF inhibitors had a greater inhibitory effect on leiomyoma tissue compared with that of UPA.Conclusion: TGF-β and VEGF inhibitors significantly decreased the viability of uterine leiomyoma cells, showing stronger effects than the conventional drug, UPA. TGF-β1 inhibitors affect both leiomyoma tissue and the normal uterus; thus, targeted local treatment rather than systemic treatment should be considered.

Uterine Leiomyoma in Postmenopausal Women: Possible Reasons for Growth and Differential Diagnosis

Background: Uterine leiomyomas appear after menarche, typically grow during the reproductive years, and then stabilize or regress after menopause. However, there have been several reports of a considerable number of patients who have undergone surgery for uterine leiomyomas during the postmenopausal period. In this paper, we discuss two issues: the possible reasons for the growth of uterine leiomyomas and the differential diagnoses of presumed leiomyomas in postmenopausal women. Methods: PubMed was searched for studies about uterine leiomyomas and sarcomas with a focus on postmenopausal women. Main findings: Several hypotheses exist for the growth of postmenopausal leiomyomas. Among these, we propose the following as an important candidate: estrogen and progesterone do not necessarily work in a positive way. In addition, in postmenopausal patients, the incidence of malignant tumors is very high, and it is generally difficult to diagnose uterine sarcoma prior to surgery. Conclusion: We propose that in cases in which uterine sarcomas cannot be ruled out, physicians should proactively consider surgery, particularly for postmenopausal patients.

Growth of surgically confirmed leiomyomas in postmenopausal women: analysis of the influencing factors.

The aim of this study was to examine the growth of uterine leiomyomas in postmenopausal women and evaluate the influencing factors associated with fibroid growth. We retrospectively analyzed the medical records of postmenopausal women with fibroids between 2015 and 2020. All women received at least 2 transvaginal ultrasound examinations within a 6-month interval. All fibroids were verified via surgery. The postoperative pathology of all tumors was uterine fibroid. We calculated the fibroid volume using the ellipsoid volume formula and evaluated the growth rate of fibroids within 6 months simultaneously. Univariable analysis and a linear mixed-effects model were used to assess the factors influencing fibroid growth. A total of 102 postmenopausal women with a total of 132 fibroids were assessed. The median growth rate of surgically confirmed fibroids in postmenopausal women was 12.9% every 6 months (from -61.4% to 184.1%). Obesity was associated with fibroid growth (P < 0.05). Notably, the estimated growth rates of fibroids in obese and overweight women were 26.6% (95% confidence interval [CI]: 2.3-50.9) and 15.9% (95% CI: 0.4-31.4) higher than those in women of normal weight, respectively. The growth of fibroids varied by the initial tumor size (P < 0.05). The estimated growth rate of larger fibroids (≥5.0 cm diameter) was reduced 30.0% (95% CI: -52.4 to -7.5) compared with that of small fibroids (<3.0 cm diameter). Uterine fibroids continually grow in some postmenopausal women. Obesity and small fibroids (<3.0 cm diameter) may contribute to higher growth rates of fibroids.

SIMVASTATIN SUPPRESSES PROLIFERATION, EXTRACELLULAR MATRIX ACCUMULATION AND Wnt4/Β-CATENIN PATHWAYS IN HUMAN LEIOMYOMA STEM CELLS

Uterine leiomyomas (ULs) are the most common benign tumor, affecting approximately 70-80% of women in their reproductive age, and can cause heavy bleeding, pain, and infertility. Recent evidence suggests that simvastatin may have anti-leiomyoma properties. Leiomyoma arises from the transformation of myometrial stem cells into tumor-initiating cells that undergo self-renewal and differentiation to mature cells, necessary for tumor growth. Wnt/β-catenin pathways are overexpressed in UL, involved in stem cell self-renewal, cross-talk between stem and mature cells, cellular proliferation, extracellular matrix (ECM) accumulation and drive UL growth.

Differential regulatory effect of progesterone on the proliferation and apoptosis of uterine leiomyoma tissue explants and primary leiomyoma cell cultures.

ObjectiveThe growth of uterine leiomyomas is regulated by progesterone, although the underlying molecular mechanisms are not fully understood.MethodsPrimary leiomyoma cells were isolated by standard method from 16 samples of uterine leiomyoma tissue. Uterine leiomyoma explants and primary leiomyoma cell cultures were exposed to progesterone in concentrations of 0.01 µg/ml, 0.1 µg/ml and 1 µg/ml for 24 h. Cell apoptosis was assessed with Annexin V assays performed in cell cultures by flow cytometry. The expression of PR-A, PR-B, Ki67, Akt, ERK, PTEN and PPARγ mRNAs was estimated in cultured leiomyoma cells and tissue explants by real time RT-PCR.ResultsTreatment with progesterone promoted viability and proliferation of cultured leiomyoma cells in a dose-dependent manner. Low and high doses of progesterone decreased early apoptosis of leiomyoma cells. High concentrations of progesterone increased the number of living cells in Annexin V assays. High doses of progesterone increased the expression of Ki67 mRNA, while low doses increased the expression of PR-A mRNA in cultured leiomyoma cells and tissue explants. In cell cultures, low doses of progesterone increased the expression of PR-B mRNA and the expression of PTEN and PPARγ mRNAs in a dose-dependent manner. Exposure of leiomyoma tissue explants to progesterone led to increased expression of PR-B and ERK mRNAs in a dose-dependent manner.ConclusionsThe effects of progesterone on the apoptosis and proliferation of leiomyoma cells was dose-dependent and different in cell cultures and leiomyoma explants, possibly as a result of impacts derived from the tumor microenvironment.