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

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.

Safety and efficacy of sirolimus in recurrent intravenous leiomyomatosis, pulmonary benign metastatic leiomyomatosis, and leiomyomatosis peritonealis disseminata: a pilot study

BACKGROUND

Intravenous leiomyomatosis (IVL), pulmonary benign metastatic leiomyomatosis (PBML), and leiomyomatosis peritonealis disseminata (LPD) are leiomyomas with special growth patterns and high postoperative recurrence rates. We report the safety and efficacy of a pilot study of sirolimus in the treatment of recurrent IVL, PBML, and recurrent LPD.

METHODS

This was a pilot study to evaluate the safety and efficacy of sirolimus in the treatment of leiomyomatosis (ClinicalTrials.gov identifier NCT03500367) conducted in China. Patients received oral sirolimus 2 mg once a day for a maximum of 60 months or until disease progression, intolerable toxicity, withdrawal of consent, or investigator decision to stop. The primary end point of this study was the objective response rate. Secondary end points included safety and tolerability, disease control rate, and progression-free survival.

RESULTS

A total of 15 patients with leiomyomatosis were included in the study, including five with recurrent IVL, eight with PBML and two with recurrent LPD. The median follow-up time was 15 months (range 6-54 months), nine patients (60%) had treatment-related adverse events (including all levels), and two patients had treatment-related grade 3 or 4 adverse events. The objective response rate was 20.0% (95% CI, 7.1-45.2%), and the disease control rate was 86.7% (95% CI, 62.1-96.3%). Partial response was achieved in three patients. The median response time in the three partial response patients was 33 months (range 29-36 months), and the sustained remission time of these three patients reached 0, 18, and 25 months, respectively.

CONCLUSIONS

Sirolimus was safe and effective in the treatment of recurrent IVL, PBML, and recurrent LPD.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03500367. Registered on 18 April 2018.

Global and regional trends in the incidence and prevalence of uterine fibroids and attributable risk factors at the national level from 2010 to 2019: A worldwide database study

BACKGROUND

Uterine fibroids (UFs), the most common tumors in women worldwide, may reduce quality of life and daily activities and even lead to adverse fertility and general health events in patients, causing significant societal health and financial burdens. The objective was to evaluate the global burden through epidemiological trends and examine the potential risk factors for UFs at the national level.

METHODS

Data on the incidence, prevalence, disability-adjusted life years (DALYs), age-standardized incidence rates (ASIRs), age-standardized prevalence rates (ASPRs), and age-standardized DALY rates for UFs were collected, and the associations with the Human Development Index (HDI) and fertility were evaluated. The age trends in the average annual percent change (AAPC) of the incidence and prevalence rates of UFs were evaluated by joinpoint regression analysis. The associations between lifestyle, metabolic, and socioeconomic factors and the ASIRs of UFs were examined using multivariable linear regression analysis.

RESULTS

The worldwide incidence and prevalence of UFs have been increasing in the past decade, with AAPCs of 0.27% in the incidence rate and 0.078% in the prevalence rate. During 2010-2019, significant increasing trends in UF ASIR were observed in 52 of 88 countries. The age-specific incidence and prevalence of UFs in most age groups showed increasing trends except for 45-54-year-old women which showed no significant trend. Ecological analysis demonstrated no relationship between the incidence of UFs and the HDI but an inverse association with fertility. The incidence of UFs was positively correlated with alcohol intake, hypertension, overweight, and obesity and negatively correlated with smoking.

CONCLUSION

With the increasing incidence and prevalence worldwide, effective targeted prevention and control of relevant risk factors at the national level should be encouraged to reduce the disease burden of UFs.

Causal relationship between female reproductive factors, sex hormones and uterine leiomyoma: a Mendelian randomization study

RESEARCH QUESTION

Are the observed associations between female reproductive factors and sex hormones with the risk of uterine leiomyoma truly causal associations?

DESIGN

The putative causal relationships between female reproductive factors and sex hormones with uterine leiomyoma were investigated using two-sample Mendelian randomization. Statistics on exposure-associated genetic variants were obtained from genome-wide association studies (GWAS). The uterine leiomyoma GWAS from the FinnGen and FibroGENE consortia were used as outcome data for discovery and replication analyses, respectively. Results were pooled by meta-analysis. Sensitivity analyses ensured robustness of the Mendelian randomization analysis.

RESULTS

When FinnGen GWAS were used as outcome data, a causal relationship was found between age at menarche (OR 0.84, P < 0.0001), age at menopause (OR 1.08, P < 0.0001), number of live births (OR 0.25, P < 0.001) and total testosterone levels (OR 0.90, P < 0.001) with the risk of uterine leiomyoma. When FibroGENE GWAS were used as outcome data, Mendelian randomization results for age at menopause, the number of live births and total testosterone levels were replicated. In the meta-analysis, a later age at menopause (OR 1.08, P < 0.0001) was associated with an increased risk of uterine leiomyoma. A higher number of live births (OR 0.25, P < 0.0001) and higher total testosterone levels (OR 0.90, P < 0.0001) were associated with a decreased risk of uterine leiomyoma.

CONCLUSIONS

A causal relationship between later age at menopause, lower number of live births and lower total testosterone levels with increased risk of uterine leiomyoma was found.

The Effect of Race/Ethnicity and MED12 Mutation on the Expression of Long Non-Coding RNAs in Uterine Leiomyoma and Myometrium

The objective of this study was to elucidate the expression of long non-coding RNA (lncRNA) in leiomyomas (Lyo) and paired myometrium (Myo) and explore the impact of race and MED12 mutation. Fold change analysis (Lyo/paired Myo) indicated the expression of 63 lncRNAs was significantly altered in the mutated group but not in the non-mutated Lyo. Additionally, 65 lncRNAs exhibited an over 1.5-fold change in the Black but not the White group. Fifteen differentially expressed lncRNAs identified with next-generation sequencing underwent qRT-PCR confirmation. Compared with Myo, the expression of TPTEP1, PART1, RPS10P7, MSC-AS1, SNHG12, CA3-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was significantly higher, while the expression of ZEB2-AS1, LINC00957, and LINC01186 was significantly lower. Comparison of normal Myo with diseased Myo showed significant differences in the expression of several lncRNAs. Analysis based on race and Lyo MED12 mutation status indicated a significantly higher expression of RPS10P7, SNHG12, LINC01449, LINC02433, and LINC02624 in Lyo from Black patients. The expression of TPTEP1, PART1, RPS10P7, MSC-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was higher, while LINC01186 was significantly lower in the MED12-mutated group. These results indicate that Lyo are characterized by aberrant lncRNA expression, which is further impacted by race and Lyo MED12 mutation status.

Oxidative stress mediates the inhibitory effects of Manzamine A on uterine leiomyoma cell proliferation and extracellular matrix deposition via SOAT inhibition

Uterine fibroids, the most common benign tumors of the myometrium in women, are characterized by abnormal extracellular matrix deposition and uterine smooth muscle cell neoplasia, with high recurrence rates. Here, we investigated the potential of the marine natural product manzamine A (Manz A), which has potent anti-cancer effects, as a treatment for uterine fibroids. Manz A inhibited leiomyoma cell proliferation in vitro and in vivo by arresting cell cycle progression and inducing caspase-mediated apoptosis. We performed target prediction analysis and identified sterol o-acyltransferases (SOATs) as potential targets of Manz A. Cholesterol esterification and lipid droplet formation were reduced by Manz A, in line with reduced SOAT expression. As a downstream target of SOAT, Manz A also prevented extracellular matrix deposition by inhibiting the β-catenin/fibronectin/metalloproteinases axis and enhanced autophagy turnover. Excessive free fatty acid accumulation by SOAT inhibition led to reactive oxygen species to impair mitochondrial oxidative phosphorylation and trigger endoplasmic reticulum stress via PERK/eIF2α/CHOP signaling. The inhibitory effect of ManzA on cell proliferation was partially restored by PERK knockdown and eliminated by tauroursodeoxycholic acid, suggesting oxidative stress plays a critical role in the mechanism of action of Manz A. These findings suggest that targeting SOATs by Manz A may be a promising therapeutic approach for uterine fibroids.

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.

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.

Characterization of m6A modifiers and RNA modifications in uterine fibroids

Uterine leiomyoma or fibroids are the most common prevalent noncancerous tumors of the uterine muscle layer. Common symptoms associated with fibroids include pelvic pain, heavy menstrual bleeding, anemia, and pelvic pressure. These tumors are a leading cause of gynecological care but lack long-term therapy as the origin and development of fibroids are not well understood. Several next-generation sequencing technologies have been performed to identify the underlying genetic and epigenetic basis of fibroids. However, there remains a systemic gap in our understanding of molecular and biological process that define uterine fibroids. Recent epitranscriptomics studies have unraveled RNA modifications that are associated with all forms of RNA and are thought to influence both normal physiological functions and the progression of diseases. We quantified RNA expression profiles by analyzing publicly available RNA-seq data for 15 known epigenetic mediators to identify their expression profile in uterine fibroids compared to myometrium. To validate our findings, we performed RT-qPCR on a separate cohort of uterine fibroids targeting these modifiers confirming our RNA-seq data. We then examined protein profiles of key m6A modifiers in fibroids and their matched myometrium. In concordance with our RNA expression profiles, no significant differences were observed in these proteins in uterine fibroids compared to myometrium. To determine abundance of RNA modifications, mRNA and small RNA from fibroids and matched myometrium were analyzed by UHPLC MS/MS. In addition to the prevalent N6-methyladenosine (m6A), we identified 11 other known modifiers but did not identify any aberrant expression in fibroids. We then mined a previously published dataset and identified differential expression of m6A modifiers that were specific to fibroid genetic sub-type. Our analysis also identified m6A consensus motifs on genes previously identified to be dysregulated in uterine fibroids. Overall, using state-of-the-art mass spectrometry, RNA expression and protein profiles, we characterized and identified differentially expressed m6A modifiers in relation to driver mutations. Despite the use of several different approaches, we identified limited differential expression of RNA modifiers and associated modifications in uterine fibroids. However, considering the highly heterogenous genomic and cellular nature of fibroids, and the possible contribution of single molecule m6A modifications to fibroid pathology, there is a need for greater in-depth characterization of m6A marks and modifiers in a larger and varied patient cohort.

Serum versican as a potential biomarker in patients with uterine fibroids: A study from Eastern India

Objective

Versican is a chondroitin sulphate proteoglycan with raised expression at site of inflammation, and uterine fibroids are associated with local inflammation. Hence, this study aimed to estimate serum Versican levels in pre-menopausal women with uterine fibroids to evaluate its diagnostic efficiency.

Materials and Methods

This case-control study included forty uterine fibroid cases and 40 healthy controls. Cases clinically evaluated with USG findings, that is number, location of fibroid and volume calculated by prolate ellipse formula a × b × c × 0.523 (a - height, b - width, c - depth). Biochemical investigations, that is serum Versican levels, were estimated by ELISA with total cholesterol, HDLc and LDLc. Triglycerides by fully automated chemistry analysers. Serum biochemical parameters were compared and correlated with volume of fibroid. Area under receiver operating characteristic curve was calculated along with cut-off value to determine diagnostic potential of Versican, differentiating women with fibroids.

Results

In the present study, patients with fibroids had decreased levels of serum Versican (79.43 ± 18.60) as compared to healthy controls (101.81 ± 28.24, P < 0.001). There was a statistically significant negative correlation (r = - 0. 307, P = 0.04) between serum Versican level and volume of fibroid. Area under ROC was 0.726 (95% CI: 0.616-0.836; P = 0.001). The best cut-off value for serum Versican level was 96.90 ng/ml with 90% sensitivity and 48% specificity.

Conclusion

Serum Versican levels were found significantly lower in women with fibroid with a negative correlation with volume of fibroid uterus. Furthermore, extensive study would help in substantiating diagnostic potential of serum Versican in fibroid uterus patients.

Increased Risk of Breast Fibroadenomas Among Obese and Postmenopausal Women With Uterine Fibroids

Introduction Uterine fibroids and breast fibroadenomas are common female benign neoplasms that are similarly derived from a single clonal origin and are modulated by estradiol concentration in blood. However, the association between these neoplasms has not yet been explored. Hence, this study aims to investigate the relationship between uterine fibroids and breast fibroadenomas.  Methods A total of 199 women (cases: 72 women with uterine fibroids, control: 127 women without uterine fibroids) were included in this study. Ultrasound was used to screen for uterine fibroids, and both ultrasound and biopsy were utilized to diagnose breast fibroadenomas. Logistic regression analysis was used to investigate the association between uterine fibroids and breast fibroadenomas and the factors associated with the relationship. Results Women with uterine fibroids have more than two times higher odds of having breast fibroadenomas among older women (p=0.03), more than twofold increased odds of breast fibroadenomas among obese females (p=0.05), and higher odds of having breast fibroadenomas among postmenopausal transition participant groups (OR=9.6; 95% CI 1.98-30.14; p-value=0.005).  Conclusion The association between uterine fibroids and breast fibroadenomas is significantly pronounced among older, obese, and postmenopausal women. This relationship might be driven by the indirect stimulation of estrogen hormone receptors via adipose tissue or other lifestyle as well as genetic factors. Therefore, further larger prospective studies considering these factors are needed to replicate the current findings.

A heterozygous missense variant in DLX3 leads to uterine leiomyomas and pregnancy losses in a consanguineous Iranian family

Uterine leiomyomas (ULs) are benign solid tumors arising from the uterine myometrium. They are the most common pelvic tumors among females of reproductive age. Despite the universal prevalence of ULs and its huge impact on women's lives, the exact etiology and pathophysiologic mechanisms have not been fully understood. Numerous studies indicate that genetic factors play a crucial role in ULs development. This study aims to identify the probable genetic causes of ULs in a consanguineous Iranian family. Whole-exome sequencing (WES) on five family members with ULs revealed a likely pathogenic missense variant encoding for Y88C in the transactivation (TA) domain of DLX3 gene (c.263A > G; p.Y88C). Sanger sequencing of a total of 9 affected and non-affected family members indicated a segregation with disease with autosomal dominant inheritance. Moreover, targeted Sanger sequencing on 32 additional non-related patients with ULs showed none was heterozygous for this variant. MutPred2 predicted the pathogenicity of candidate variant by both phosphorylation and sulfation loss as actionable hypotheses. Project HOPE revealed that the identified variant residue is smaller and more hydrophobic comparing to the wild-type residue. I-TASSER and UCSF Chimera were also used for modeling and visualizing the predicted variant, respectively. This WES analysis is the first to report a variant in DLX3 variation associated with ULs pathogenicity in Iranian population highlighting the effectiveness of WES as a strong diagnostic method. However, further functional studies on this variant are needed to confirm the potential pathogenicity of this mutation.

Pulmonary benign metastasizing leiomyoma in patients aged 45 years and younger: clinical features and novelty in treatment

BACKGROUND

Pulmonary benign metastasizing leiomyoma (PBML) is the most common extrauterine spread of uterine leiomyoma, and its biological behavior is traditionally thought to be hormone dependent. Studies on older PBML patients have been previously reported, but limited literature has been published regarding the clinical features and treatment of PBML in young women.

METHODS

A total of 65 cases of PBML in women aged 45 years and younger were reviewed, including 56 cases selected from PubMed and 9 cases from our hospital. The clinical characteristics and management of these patients were analyzed.

RESULTS

The median age of all the patients at diagnosis was 39.0 years. PBML most commonly presented as bilateral solid lesions (60.9%), with other rare imaging manifestations. The median interval time from a pertinent gynecologic procedure to diagnosis was 6.0 years. A total of 16.7% of patients received careful observation, and all achieved stable status in a median follow-up time of 18.0 months. A total of 71.4% of patients were administered anti-estrogen therapies, including surgical castration (33.3%), gonadotropin-releasing hormone analog (23.8%) and anti-estrogen drugs (14.3%). Eight of 42 patients underwent surgical resection of metastatic lesions. Patients who underwent curative surgery for the removal of pulmonary lesions combined with adjuvant anti-estrogen therapies had favorable outcomes compared with those who only underwent surgical resection. The disease control rates of surgical castration, gonadotropin-releasing hormone analog, and anti-estrogen drugs were 85.7%, 90.0%, and 50.0%, respectively. For two patients, sirolimus (rapamycin) achieved successful relief of symptoms and control of pulmonary lesions without lowering hormone levels and causing estrogen deficiency symptoms.

CONCLUSIONS

In the absence of standard treatment guidelines for PBML, maintaining a low-estrogen environment using different kinds of antiestrogen therapies has been the mainstream strategy and has satisfying curative effects. A wait-and-see strategy might be an option, but therapeutic approaches must be contemplated when complications or symptoms progress. For PBML in young women, the negative effect on ovarian function of anti-estrogen treatment, especially surgical castration, should be considered. Sirolimus might be a new treatment option for young PBML patients, especially for those who want to preserve ovarian function.

The Effects of Periostin Expression on Fibroid-Like Transition of Myometrial Cells

Fibroids, benign tumors of the myometrium, are the most common tumors in women and are associated with spontaneous abortion, preterm birth, placenta abruption, and infertility, among others. The incidence of fibroids in reproductive aged women is 20-89%. Fibroids are characterized by high production of extracellular matrix (ECM), particularly collagens, which play a role in their growth. However, their pathogenesis is poorly understood. Recently, we and others have found periostin (POSTN), a regulatory ECM protein, to be overexpressed in the majority of fibroids analyzed. Periostin is an ECM protein that is a critical regulator and well-established biomarker for fibrosis in tissues such as the lung, skin, and kidney. Our hypothesis was that periostin plays a role in the fibrotic transition of myometrial cells to fibroid cells. To test this, we evaluated the effects of POSTN overexpression in myometrial cells. Telomerase-immortalized myometrial cells were transduced with control or POSTN-overexpression lentivirus particles, generating one control (dCas9-Mock) and two overexpression (dCas9-POSTN-01, dCas9-POSTN-02) cell lines. Overexpression of POSTN in immortalized myometrial cells resulted in a change in phenotype consistent with fibroid cells. They upregulated expression of key fibroid genes and had increased proliferation, adhesion, and migration in vitro. Here, we show a potential role for periostin in the transition of myometrial cells to fibroid cells, giving rationale for future investigation into the role of periostin in fibroid pathogenesis and its potential as a therapeutic target.

Racial differences in transcriptomics and reactive oxygen species burden in myometrium and leiomyoma

STUDY QUESTION

Are there differences in Mediator Complex Subunit 12 mutations (MED12) mutation, transcriptomics, and protein expression in uterine myometrium and leiomyomas of Black and White women?

SUMMARY ANSWER

RNA sequencing, tissue microarray, and immunohistochemistry data revealed that Black and White women have significant differences in their myometrium and leiomyoma profiles.

WHAT IS KNOWN ALREADY

Black women develop uterine leiomyoma earlier than White women, and are more likely to be anemic, have multiple tumors, undergo hysterectomy at an earlier age, have a higher uterine weight, and report very severe pelvic pain.

STUDY DESIGN, SIZE, DURATION

Uterine tissues were collected from premenopausal women undergoing hysterectomy or myomectomy at Northwestern University Prentice Women's Hospital (Chicago, IL) from 2010 to 2021. Tissues were collected from a total of 309 women, including from 136 Black women, 135 White women, and 38 women from other racial groups. A total of 529 uterine leiomyomas (290 from Black women, 184 from White women, and 55 from women of other racial groups) were subjected to molecular analysis. Leiomyoma and matched myometrium from a total of 118 cases including 60 Black women and 58 White women, were used for tissue microarrays, along with 34 samples of myometrium without leiomyoma from White women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Tissues from the above patient cohorts were analyzed by tissue microarray, immunohistochemistry, RNA sequencing, and mutation analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

The results indicated that leiomyoma from Black women have a higher rate of MED12 mutations (79.0%) than those from White women (68.5%) (*P ≤ 0.05). RNA-sequencing analysis in myometrium revealed differentially expressed genes (270 upregulated, 374 downregulated) dependent on race, wherein reactive oxygen species, hypoxia, and oxidative phosphorylation pathways were positively correlated with samples derived from Black patients. The levels of proteins associated with oxidative DNA damage and repair, 8-hydroxyguanosine (8-OHdG), 8-oxoguanine glycosylase (OGG1), heme oxygenase-1 (HO-1), and kelch-like ECH-associated protein 1 (KEAP1), were higher in leiomyoma and matched myometrium, particularly those from Black patients, compared to the control myometrium (with leiomyoma) (***P ≤ 0.001).

LARGE SCALE DATA

The datasets are available in the NCBI (The BioProject number: PRJNA859428).

LIMITATIONS, REASONS FOR CAUTION

Myometrium without leiomyoma derived from White patients was used as a control in the tissue microarray analysis, as myometrium without leiomyoma from Black patients was not accessible in large numbers. The RNA sequencing was performed on myometrium tissue with leiomyoma present from 10 White and 10 Black women. However, one sample from a Black woman yielded low-quality RNA-sequencing data and was excluded from further analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Women with symptomatic leiomyomas have a considerable loss in their quality of life. This study provides information on underlying genetic and molecular defects that may be necessary for future therapeutics targeted at leiomyomas.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from NCI (R01CA254367) and NICHD (P01HD057877). The authors declare no conflict of interest.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

Gene Expression Profile of Uterine Leiomyoma from Women Exposed to Different Air Pollution Levels in Metropolitan Cities of Sao Paulo, Brazil

Leiomyomas (LMs) are the most frequent uterine benign tumors, representing the leading cause of hysterectomy indications worldwide. They are highly associated with women's reproductive complications, and endocrine disruptors may influence their etiology. In this sense, air pollution represents a relevant hormonal disruptor that acts on key signaling pathways, resulting in tumor development and infertility. Our goal was to evaluate submucosal LM samples from patients living in the metropolitan and Sao Paulo city regions, focusing on genes involved in tumor development and infertility features. Twenty-four patients were selected based on their region of residence and clinical information availability. Several genes were differentially expressed between women living in metropolitan areas and Sao Paulo city. Significant associations were observed between BCL-2, DVL1, FGFR3, and WNT5b downregulation and contraceptive use in the samples from women living in Sao Paulo city. ESR1 and HHAT downregulation was associated with ethnicity. WNT5b and GREM were associated with LM treatment and related pathologies, respectively. In the samples from women living in other cities of the metropolitan region, abortion occurrence was associated with BMP4 upregulation. Although further studies may be necessary, our results showed that air pollution exposure influences the expression of genes related to LM development and female reproductive features.

Prevalence and clinical significance of co-existing mutations in MED12 and FH in uterine fibroids of Australian women

Uterine fibroids are exceedingly common benign tumours of the female reproductive system and cause severe symptoms, including acute pain, bleeding, and infertility. Fibroids are frequently associated with genetic alterations affecting mediator complex subunit 12 (MED12), fumarate hydratase (FH), high mobility group AT-hook 2 (HMGA2) and collagen, type IV alpha 5 and alpha 6 (COL4A5-COL4A6). Recently, we reported MED12 exon 2 mutations in 39 out of 65 uterine fibroids (60%) from 14 Australian patients. The aim of this study was to evaluate the status of FH mutations in MED12 mutation-positive and mutation-negative uterine fibroids. FH mutation screening of altogether 65 uterine fibroids and corresponding adjacent normal myometrium (n = 14) was carried out by Sanger sequencing. Three out of 14 patients displayed somatic mutations in FH exon 1 in addition to harbouring MED12 mutation in uterine fibroids. This study is the first to report that the mutations in MED12 and FH co-exist in uterine fibroids of Australian women.

Effects of bisphenol A on uterine leiomyoma: In vitro and in vivo evaluation with mechanistic insights related to XBP1

The incidence rate of human uterine leiomyomas is over 70% in the women of childbearing age, which has caused serious health and financial burden. Our previous study confirmed that Bisphenol A (BPA)，representative environmental estrogen, promoted the proliferation of human uterine leiomyomas and up-regulated the expression of cell proliferation-related genes. In this study, by combining ChIP-seq and RNA-seq, it was shown that after BPA intervention, H3K27ac modification levels and gene expression levels were altered in uterine leiomyomas cells. Moreover experimental verification found that BPA can regulate ITGA2 through the transcription factor XBP1, activate the downstream PI3K/AKT signaling pathway, eventually promote the proliferation of uterine leiomyomas. The present study provides new insights into the pathogenesis associated with exposure to BPA and other endocrine disruptors with similar effects by defining XBP1 as an important regulator, and which may act as an intervention and treatment target for uterine leiomyomas.

Transcriptome and DNA methylome analyses reveal underlying mechanisms for the racial disparity in uterine fibroids

Uterine fibroids (leiomyomas) affect Black women disproportionately compared with women of other races and ethnicities in terms of prevalence, incidence, and severity of symptoms. The causes of this racial disparity are essentially unknown. We hypothesized that myometria of Black women are more susceptible to developing fibroids, and we examined the transcriptomic and DNA methylation profiles of myometria and fibroids from Black and White women for comparison. Myometrial samples cluster by race in both their transcriptome and DNA methylation profiles, whereas fibroid samples only cluster by race in the latter. More differentially expressed genes (DEGs) were detected in the Black and White myometrial sample comparison than in the fibroid comparison. Leiomyoma gene set expression analysis identified 4 clusters of DEGs, including a cluster of 24 genes with higher expression in myometrial samples from Black women. One of the DEGs in this group, von Willibrands factor (VWF), was significantly hypomethylated in both myometrial samples from Black women and in all fibroids at 2 CpG probes that are near a putative enhancer site and that are correlated with VWF expression levels. These results suggest that the molecular basis for the disparity in fibroid disease between Black and White women could be found in the myometria before fibroid development and not in the fibroids themselves.

Epigenetic Features in Uterine Leiomyosarcoma and Endometrial Stromal Sarcomas: An Overview of the Literature

There is a consensus that epigenetic alterations play a key role in cancer initiation and its biology. Studies evaluating the modification in the DNA methylation and chromatin remodeling patterns, as well as gene regulation profile by non-coding RNAs (ncRNAs) have led to the development of novel therapeutic approaches to treat several tumor types. Indeed, despite clinical and translational challenges, combinatorial therapies employing agents targeting epigenetic modifications with conventional approaches have shown encouraging results. However, for rare neoplasia such as uterine leiomyosarcomas (LMS) and endometrial stromal sarcomas (ESS), treatment options are still limited. LMS has high chromosomal instability and molecular derangements, while ESS can present a specific gene fusion signature. Although they are the most frequent types of “pure” uterine sarcomas, these tumors are difficult to diagnose, have high rates of recurrence, and frequently develop resistance to current treatment options. The challenges involving the management of these tumors arise from the fact that the molecular mechanisms governing their progression have not been entirely elucidated. Hence, to fill this gap and highlight the importance of ongoing and future studies, we have cross-referenced the literature on uterine LMS and ESS and compiled the most relevant epigenetic studies, published between 2009 and 2022.

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

Simple Summary

Immunotherapy 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.

Abstract

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.

Genome-wide causal mediation analysis identifies genetic loci associated with uterine fibroids mediated by age at menarche

STUDY QUESTION

Could the direct contribution of genetic variants to the pathophysiology of uterine fibroids and the contribution mediated by age at menarche be different?

SUMMARY ANSWER

Age at menarche plays a mediation role in the genetic influence on uterine fibroids, and four causal genetic mechanisms underlying the age at menarche-mediated effects of common genetic loci on uterine fibroid development were identified.

WHAT IS KNOWN ALREADY

Uterine fibroids are common benign tumors developing from uterine smooth muscle. Genome-wide association studies (GWASs) have identified over 30 genetic loci associated with uterine fibroids in different ethnic populations. Several genetic variations in or nearby these identified loci were also associated with early age at menarche, one of the major risk factors of uterine fibroids. Although the results of GWASs reveal how genetic variations affect uterine fibroids, the genetic mechanism of uterine fibroids mediated by age at menarche remains elusive.

STUDY DESIGN, SIZE, DURATION

In this study, we conducted a genome-wide causal mediation analysis in two cohorts covering a total of 69 552 females of Han Chinese descent from the Taiwan Biobank (TWB). TWB is an ongoing community- and hospital-based cohort aiming to enroll 200 000 individuals from the general Taiwanese population between 30 and 70 years old. It has been enrolling Taiwanese study participants since 2012 and has extensive phenotypic data collected from 148 291 individuals as of May 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We recruited individuals in two cohorts, with 13 899 females in TWB1 and 55 653 females in TWB2. The two sets of individuals are almost distinct, with only 730 individuals enrolled in both cohorts. Over 99% of the participants are Han Chinese. Approximately 21% of participants developed uterine fibroids. DNA samples from both cohorts were genotyped using two different customized chips (TWB1 and TWB2 arrays). After quality control and genotype imputation, 646 973 TWB1 single-nucleotide polymorphisms (SNPs) and 686 439 TWB2 SNPs were assessed in our analysis. There were 99 939 SNPs which overlapped between the TWB1 and TWB2 arrays, 547 034 TWB1 array-specific SNPs and 586 500 TWB2 array-specific SNPs. We performed GWASs for screening potential risk SNPs for age at menarche and for uterine fibroids. We subsequently identified causal mediation effects of risk SNPs on uterine fibroids mediated by age at menarche.

MAIN RESULTS AND THE ROLE OF CHANCE

In addition to known loci at LIN28B associated with age at menarche and loci at WNT4 associated with uterine fibroids, we identified 162 SNPs in 77 transcripts that were associated with menarche-mediated causal effects on uterine fibroids via four different causal genetic mechanisms: a both-harmful group with 52 SNPs, a both-protective group with 34 SNPs, a mediator-harmful group with 22 SNPs and a mediator-protective group with 54 SNPs. Among these SNPs, rs809302 in SLK significantly increased the risk of developing uterine fibroids by 3.92% through a mechanism other than age at menarche (P < 10-10), and rs371721345 in HLA-DOB was associated with a 2.70% decreased risk (P < 10-10) in the occurrence of uterine fibroids, mediated by age at menarche. These findings provide insights into the mechanism underlying the effect of genetic loci on uterine fibroids mediated by age at menarche.

LIMITATIONS, REASONS FOR CAUTION

A potential issue is that the present study relied upon self-reported age at menarche and uterine fibroid information. Due to the experimental design, the consistency between self-reports and medical records for uterine fibroids in Taiwan cannot be checked. Fortunately, the literature support that self-reporting even years later remains a practical means for collecting data on menarche and uterine fibroids. We found that the impact of under-reporting of uterine fibroids is less in our study. In addition, the rate of reporting a diagnosis of uterine fibroids was within the rates of medical diagnosis based on national health insurance data. Future work investigating the consistency between self-reports and medical records in Taiwan can remedy this issue.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to investigate whether and to what extent age at menarche mediates the causal effects of genetic variants on uterine fibroids by using genome-wide causal mediation analysis. By treating age at menarche as a mediator, this report provides an insight into the genetic risk factors for developing uterine fibroids. Thus, this article represents a step forward in deciphering the role of intermediated risk factors in the genetic mechanism of disease.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the China Medical University, Taiwan (CMU110-ASIA-13 and CMU107-Z-04), the Ministry of Science and Technology, Taiwan (MOST 110-2314-B-039-058) and the International Joint Usage/Research Center, the Institute of Medical Science, the University of Tokyo, Japan (K2104). The authors have no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Single-cell sequencing reveals novel cellular heterogeneity in uterine leiomyomas

STUDY QUESTION

What are the cellular composition and single-cell transcriptomic differences between myometrium and leiomyomas as defined by single-cell RNA sequencing?

SUMMARY ANSWER

We discovered cellular heterogeneity in smooth muscle cells (SMCs), fibroblast and endothelial cell populations in both myometrium and leiomyoma tissues.

WHAT IS KNOWN ALREADY

Previous studies have shown the presence of SMCs, fibroblasts, endothelial cells and immune cells in myometrium and leiomyomas. However, there is no information on the cellular heterogeneity in these tissues and the transcriptomic differences at the single-cell level between these tissues.

STUDY DESIGN, SIZE, DURATION

We collected five leiomyoma and five myometrium samples from a total of eight patients undergoing hysterectomy. We then performed single-cell RNA sequencing to generate a cell atlas for both tissues. We utilized our single-cell sequencing data to define cell types, compare cell types by tissue type (leiomyoma versus myometrium) and determine the transcriptional changes at a single-cell resolution between leiomyomas and myometrium. Additionally, we performed MED12-variant analysis at the single-cell level to determine the genotype heterogeneity within leiomyomas.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We collected five MED12-variant positive leiomyomas and five myometrium samples from a total of eight patients. We then performed single-cell RNA sequencing on freshly isolated single-cell preparations. Histopathological assessment confirmed the identity of the samples. Sanger sequencing was performed to confirm the presence of the MED12 variant in leiomyomas.

MAIN RESULTS AND ROLE OF CHANCE

Our data revealed previously unknown heterogeneity in the SMC, fibroblast cell and endothelial cell populations of myometrium and leiomyomas. We discovered the presence of two different lymphatic endothelial cell populations specific to uterine leiomyomas. We showed that both myometrium and MED12-variant leiomyomas are relatively similar in cellular composition but differ in cellular transcriptomic profiles. We found that fibroblasts influence the leiomyoma microenvironment through their interactions with endothelial cells, immune cells and SMCs. Variant analysis at the single-cell level revealed the presence of both MED12 variants as well as the wild-type MED12 allele in SMCs of leiomyomatous tissue. These results indicate genotype heterogeneity of cellular composition within leiomyomas.

LARGE SCALE DATA

The datasets are available in the NCBI Gene Expression Omnibus (GEO) using GSE162122.

LIMITATIONS, REASONS FOR CAUTION

Our study focused on MED12-variant positive leiomyomas for single-cell RNA sequencing analyses. Leiomyomas carrying other genetic rearrangements may differ in their cellular composition and transcriptomic profiles.

WIDER IMPLICATIONS FOR THE FINDINGS

Our study provides a cellular atlas for myometrium and MED12-variant positive leiomyomas as defined by single-cell RNA sequencing. Our analysis provides significant insight into the differences between myometrium and leiomyomas at the single-cell level and reveals hitherto unknown genetic heterogeneity in multiple cell types within human leiomyomas. Our results will be important for future studies into the origin and growth of human leiomyomas.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by funding from the National Institute of Child Health and Human Development (HD098580 and HD088629). The authors declare no competing interests.

A mediator complex subunit 12 gain-of-function mutation induces partial leiomyoma cell properties in human uterine smooth muscle cells

OBJECTIVE

To clarify whether a mediator complex subunit 12 (MED12) gain-of-function mutation induces leiomyoma cell properties in human uterine smooth muscle cells (USMCs).

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing hysterectomy for leiomyoma.

INTERVENTION(S)

CRISPR/Cas9-mediated genome editing to introduce an MED12 gain-of-function mutation (G44D) into human USMCs.

MAIN OUTCOME MEASURE(S)

Cell proliferation, collagen production, and in vivo tumorigenicity of USMCs with vs. without the MED12 mutation.

RESULT(S)

Uterine smooth muscle cells isolated from the uterine myometrium of a 44-year-old patient were subjected to lentiviral vector-mediated gene transduction of the fluorescent protein Venus, followed by long-term passage. Uterine smooth muscle cells with a normal female karyotype, high cell proliferative activity, and Venus expression, but without stem/progenitor cell populations, were obtained and designated as USMC44. Using CRISPR/Cas9-mediated genome editing, mtUSMC44 (MED12, 131G>A, p.G44D) and mock USMC44 without MED12 mutation (wtUSMC44) were established from USMC44. wtUSMC44 and mtUSMC44 showed similar cell proliferation activity, even in the presence of estradiol and progesterone (EP) together with transforming growth factor-beta 3 (TGFB3). In addition, wtUSMC44 and mtUSMC44 generated similar tiny smooth muscle-like tissue constructs when xenotransplanted beneath the kidney capsule in immunodeficient mice treated with EP alone or TGFB3. In contrast, mtUSMC44 produced more collagen type I than wtUSMC in vitro, and this production was likely enhanced by EP and TGFB3.

CONCLUSION(S)

The results suggest that the MED12 gain-of-function mutation is involved in collagen production. Although approximately 70% of leiomyomas have MED12 mutations, additional factors and/or events other than MED12 and/or myometrial stem/progenitor cells may be required for fully inducing leiomyoma cell properties, including transformation, in USMCs.

Exploring Potential Causal Genes for Uterine Leiomyomas: A Summary Data-Based Mendelian Randomization and FUMA Analysis

Objective: To explore potential causal genetic variants and genes underlying the pathogenesis of uterine leiomyomas (ULs).

Methods: We conducted the summary data-based Mendelian randomization (SMR) analyses and performed functional mapping and annotation using FUMA to examine genetic variants and genes that are potentially involved in the pathogenies of ULs. Both analyses used summarized data of a recent genome-wide association study (GWAS) on ULs, which has a total sample size of 244,324 (20,406 cases and 223,918 controls). We performed separate SMR analysis using CAGE and GTEx eQTL data.

Results: Using the CAGE eQTL data, our SMR analysis identified 13 probes tagging 10 unique genes that were pleiotropically/potentially causally associated with ULs, with the top three probes being ILMN_1675156 (tagging CDC42, PSMR = 8.03 × 10⁻⁹), ILMN_1705330 (tagging CDC42, PSMR = 1.02 × 10⁻⁷) and ILMN_2343048 (tagging ABCB9, PSMR = 9.37 × 10⁻⁷). Using GTEx eQTL data, our SMR analysis did not identify any significant genes after correction for multiple testing. FUMA analysis identified 106 independent SNPs, 24 genomic loci and 137 genes that are potentially involved in the pathogenesis of ULs, seven of which were also identified by the SMR analysis.

Conclusions: We identified many genetic variants, genes, and genomic loci that are potentially involved in the pathogenesis of ULs. More studies are needed to explore the exact underlying mechanisms in the etiology of ULs.

Differential Expression of Super-Enhancer-Associated Long Non-coding RNAs in Uterine Leiomyomas

Super-enhancer-associated long non-coding RNAs (SE-lncRNAs) are a specific set of lncRNAs transcribed from super-enhancer (SE) genomic regions. Recent studies have revealed that SE-lncRNAs play essential roles in tumorigenesis through the regulation of oncogenes. The objective of this study was to elucidate the expression profile of SE-lncRNAs with concurrent assessment of associated mRNAs in leiomyomas and paired myometrium. Arraystar SE-lncRNAs arrays were used to systematically profile the differentially expressed SE-lncRNAs along with the corresponding SE-regulated protein coding genes in eight leiomyomas and paired myometrium. The analysis indicated 7680 SE-lncRNAs were expressed, of which 721 SE-lncRNAs were overexpressed, while 247 SE-lncRNAs were underexpressed by 1.5-fold or greater in leiomyoma. Thirteen novel SE-lncRNAs and their corresponding protein coding genes were selected, and their expression was confirmed in eighty-one paired leiomyoma tissues by quantitative real-time PCR. The thirteen pairs of SE-lncRNAs and their corresponding protein coding genes included RP11-353N14.2/CBX4, SOCS2-AS1/SOCS2, RP1-170O19.14/HOXA11, CASC15/PRL, EGFLAM-AS1/EGFLAM, RP11-225H22/NEURL1, RP5-1086K13.1/CD58, AC092839.3/SPTBN1, RP11-69I8.3/CTGF, TM4SF1-AS1/TM4SF1, RP11-373D23/FOSL2, RP11-399K21.11/COMTD1, and CTB-113P19.1/SPARC. Among these SE-lncRNAs, the expression of SOCS2-AS1/SOCS2, RP11-353N14.2/CBX4, RP1-170O19.14/HOXA11, and RP11-225H22/NEURL1 was significantly higher in African Americans as compared with Caucasians. The expression of RP11-353N14.2/CBX4, SOCS2-AS1/SOCS2, CASC15/PRL, and CTB-113P19.1/SPARC was significantly higher in tumors with MED12-mutation-positive as compared with MED12-mutation-negative tumors. Collectively, our results indicate that the differential expression of SE in leiomyomas is another mechanism contributing to dysregulation of protein coding genes in leiomyomas and that race and MED12 mutation can influence the expression of a select group of SE.

Human Myometrial and Uterine Fibroid Stem Cell-Derived Organoids for Intervening the Pathophysiology of Uterine Fibroid

Uterine fibroids (UFs) (leiomyomas or myomas) are the most common clonal neoplasms of the uterus in women of reproductive age worldwide. UFs originate from myometrium consist of smooth muscle and fibroblast components, in addition to a substantial amount of fibrous extracellular matrix which all contribute to the pathogenetic process. Current treatments are primarily limited to surgical and interventional. Here, we have established a novel and promising organoid model from both normal and patient myometrial stem cells (MMSCs). MMSCs embedded in Matrigel in stem cell media swiftly formed organoids which successfully proliferate and self-organized into complex structures developing a sustainable organoid culture that maintain their capacity to differentiate into the different cell types recapitulating their tissue of origin and shows responsiveness to the reproductive hormones (estrogen and progesterone). Gene expression analysis and structural features indicated the early onset of uterine fibrosis led to the accumulation of extracellular matrix suggesting the potential use of this model in better understanding of the pathophysiology associated with UFs and inventing novel therapeutics for the treatment of UFs.

Uterine Fibroid Patients Reveal Alterations in the Gut Microbiome

The gut microbiota is associated with reproductive disorders in multiple ways. This research investigated possible differences in gut microbiome compositions between patients with uterine fibroids (UFs) and healthy control subjects in order to further provide new insight into its etiology. Stool samples were collected from 85 participants, including 42 UF patients (case group) and 43 control subjects (control group). The gut microbiota was examined with 16S rRNA quantitative arrays and bioinformatics analysis. The α-diversity in patients with UFs was significantly lower than that of healthy controls and negatively correlated with the number of tumorigeneses. The microbial composition of the UF patients deviated from the cluster of healthy controls. Stool samples from patients with UFs exhibited significant alterations in terms of multiple bacterial phyla, such as Firmicutes, Proteobacteria, Actinobacteria, and Verrucomicrobia. In differential abundance analysis, some bacteria species were shown to be downregulated (e.g., Bifidobacteria scardovii, Ligilactobacillus saerimneri, and Lactococcus raffinolactis) and upregulated (e.g., Pseudomonas stutzeri and Prevotella amnii). Furthermore, the microbial interactions and networks in UFs exhibited lower connectivity and complexity as well as higher clustering property compared to the controls. Taken together, it is possible that gut microbiota dysbiosis has the potential as a risk factor. This study found that UFs are associated with alterations of the gut microbiome diversity and community network connectivity. It provides a new direction to further explore the host–gut microbiota interplay and to develop management and prevention in UF pathogenesis.

Is Single Nucleotide Polymorphism ADIPOQ (NM_004797.4):c.214+62G>T (rs1501299) Associated With Uterine Leiomyomas? A Pilot Study

Objective: Although polymorphisms of adiponectin gene (ADIPOQ) in obesity-related conditions have been the target of research efforts, little is known about this genetic marker in uterine leiomyomas. The aim of this pilot study was to analyze the frequencies of alleles and genotypes of Single Nucleotide Polymorphism ADIPOQ (NM_004797.4):c.214+62G>T (rs1501299) and to correlate it with the risk of uterine fibroids. Study Design: The Test Group comprised 90 women treated surgically for uterine leiomyomas in the Department of Operative Gynecology, Endoscopy and Gynecologic Oncology, Polish Mother's Memorial Hospital-Research Institute. 90 disease-free individuals were used as Controls. Patients within both groups were additionally stratified into lean, overweight and obese, according to Body Mass Index. Statistical analysis was performed between the two major groups and, furthermore, within the abovementioned subgroups. Results: The study revealed no statistically significant differences in the distribution of alleles and genotypes of SNP ADIPOQ (NM_004797.4):c.214+62G>T (rs1501299) between the two main groups. A weak correlation within distributions of alleles was observed between obese Test Patients and lean Controls. Conclusion: This pilot study has revealed no association between SNP ADIPOQ (NM_004797.4):c.214+62G>T (rs1501299) and uterine fibroids. Further studies on larger groups are warranted to elucidate whether this SNP may be correlated with uterine leiomyomas.

Epigenomic and enhancer dysregulation in uterine leiomyomas

BACKGROUND

Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prevalence of this tumor in women by the age of 50 years. Black women are particularly affected, with an increased incidence, earlier age of onset, larger and faster growing fibroids and greater severity of symptoms as compared to White women. Although advances in identifying genetic and environmental factors to delineate these fibroids have already been made, only recently has the role of epigenomics in the pathogenesis of this disease been considered.

OBJECTIVE AND RATIONALE

Over recent years, studies have identified multiple epigenomic aberrations that may contribute to leiomyoma development and growth. This review will focus on the most recent discoveries in three categories of epigenomic changes found in uterine fibroids, namely aberrant DNA methylation, histone tail modifications and histone variant exchange, and their translation into altered target gene architecture and transcriptional outcome. The findings demonstrating how the altered 3D shape of the enhancer can regulate gene expression from millions of base pairs away will be discussed. Additionally, translational implications of these discoveries and potential roadblocks in leiomyoma treatment will be addressed.

SEARCH METHODS

A comprehensive PubMed search was performed to identify published articles containing keywords relevant to the focus of the review, such as: uterine leiomyoma, uterine fibroids, epigenetic alterations, epigenomics, stem cells, chromatin modifications, extracellular matrix [ECM] organization, DNA methylation, enhancer, histone post-translational modifications and dysregulated gene expression. Articles until September 2021 were explored and evaluated to identify relevant updates in the field. Most of the articles focused on in the discussion were published between 2015 and 2021, although some key discoveries made before 2015 were included for background information and foundational purposes. We apologize to the authors whose work was not included because of space restrictions or inadvertent omission.

OUTCOMES

Chemical alterations to the DNA structure and of nucleosomal histones, without changing the underlying DNA sequence, have now been implicated in the phenotypic manifestation of uterine leiomyomas. Genome-wide DNA methylation analysis has revealed subsets of either suppressed or overexpressed genes accompanied by aberrant promoter methylation. Furthermore, differential promoter access resulting from altered 3D chromatin structure and histone modifications plays a role in regulating transcription of key genes thought to be involved in leiomyoma etiology. The dysregulated genes function in tumor suppression, apoptosis, angiogenesis, ECM formation, a variety of cancer-related signaling pathways and stem cell differentiation. Aberrant DNA methylation or histone modification is also observed in altering enhancer architecture, which leads to changes in enhancer-promoter contact strength, producing novel explanations for the overexpression of high mobility group AT-hook 2 and gene dysregulation found in mediator complex subunit 12 mutant fibroids. While many molecular mechanisms and epigenomic features have been investigated, the basis for the racial disparity observed among those in the Black population remains unclear.

WIDER IMPLICATIONS

A comprehensive understanding of the exact pathogenesis of uterine leiomyoma is lacking and requires attention as it can provide clues for prevention and viable non-surgical treatment. These findings will widen our knowledge of the role epigenomics plays in the mechanisms related to uterine leiomyoma development and highlight novel approaches for the prevention and identification of epigenome targets for long-term non-invasive treatment options of this significantly common disease.

A Call-to-Action for Clinicians to Implement Evidence-Based Best Practices When Caring for Women with Uterine Fibroids

Uterine fibroids are common benign tumors that occur in up to 80% of women. Approximately half of the women affected experience considerable physical, psychological, and economic burdens and impact on quality of life due to symptoms such as heavy menstrual bleeding, pelvic pain, and infertility. Several medical and surgical options are available to treat uterine fibroids; however, healthcare providers may benefit from practical guidance in the development of individualized treatment plans based on a personalized approach. Medical treatments and minimally invasive procedures are generally preferred by most patients before considering more invasive, higher risk surgical interventions. In general, patient-centered, uterine-preserving procedures may be prioritized based on the patient’s goals and the clinical scenario. Occasionally, hysterectomy may be the preferred treatment option for some patients who require definitive treatment. This call-to-action highlights recent challenges to patient care, including radical shifts in physician–patient interactions due to the COVID-19 pandemic and recent changes to evidence-based, clinically approved therapies. This report also reviews contemporary recommendations for women’s health providers in the diagnosis and medical and surgical management of uterine fibroids. This call-to-action aims to empower healthcare providers to optimize the quality of care for women with uterine fibroids utilizing the best available evidence and best practices.

Vitamin D and green tea extracts for the treatment of uterine fibroids in late reproductive life: a pilot, prospective, daily-diary based study

OBJECTIVE

The beneficial effects of Vitamin D (VD) and Epigallocatechin gallate (EGCG), a polyphenol of green tea, on the growth of uterine fibroids (UF) were previously described in vitro and in vivo. We have decided to investigate their simultaneous administration in women with UFs in late reproductive life.

METHODS

>40 years old n = 16 premenopausal women with intramural (IM) or subserosal (SS) UF of ≥3 cm or several UFs of different sizes, even smaller but with a total diameter ≥3 cm but <10 cm, without further concomitant organic causes of abnormal uterine bleeding, treated with EGCG 300 mg, Vitamin B6 10 mg and VD 50 µg/day for 90 days. Women completed a diary on a daily basis to obtain information about bleeding and pelvic pain.

RESULTS

We have observed a significant reduction in UF's mean size both at patient's (-17.8%, p = .03) and at single UF's level (-37.3%, p = .015). The effect was more evident in women with predominant IM (p = .016) in comparison to SS UFs. No significant changes were observed for uterine and ovarian volume and endometrial thickness during treatment. We reported a significant decrease in menstrual flow length of 0.9 day (p = .04) with no modification in cycle length, menstrual flow intensity and menstrual pain intensity. The satisfaction with treatment was in general very high, with no adverse effects reported.

CONCLUSION

The concomitant administration of VD and EGCG represents a promising treatment of UF in women of late reproductive life for which hormonal manipulation is not foreseen.

Uterine Fibroids: Hiding in Plain Sight

Uterine fibroids (leiomyomas) are present in >75% of women and can cause serious morbidity. They are by far the leading cause of hysterectomy. Fibroids are a complex mixture of cells that include fibroblasts and smooth muscle cells. Rich in extracellular matrix, they typically arise through somatic mutations, most commonly MED12. Their lack of growth inhibition and their ability to have facets of malignancy yet be histologically and biologically benign provide opportunities to explore basic processes. To date, the mechanisms responsible for growth and development of leiomyomas are an enigma. This review provides an overview of current understanding and future directions for clinical and basic research of fibroids.

Body mass index and vitamin D as risk factors for the development of uterine leiomyomas in Mexican women

Objective:

The objective of the present study was to determine if body mass index and vitamin D levels are risk factors for the development of uterine leiomyomas in Mexican women.

Methods:

A cross-sectional study was designed. Inclusion criteria were women between 20 and 55 years with a suspect of uterine leiomyomas. Transvaginal ultrasonography was made to confirm the diagnosis and clinical variables were collected. Vitamin D levels were measured in serum by chemiluminescence immunoassay. Binary linear regression analysis was conducted to assess the predictors of uterine leiomyomas.

Results:

A total of 106 patients were evaluated, the mean age was 41.4 ± 8.0 years. The serum levels of vitamin D were insufficient in 94 (88.7%) and 82 (77.3%) has overweight or obesity. However, only 50 (47.2%) of participants have a diagnostic of uterine leiomyomas. BMI not increased the probability of having insufficient levels of vitamin D or uterine leiomyomas. Only, age (> 45 years) and levels of vitamin D (<30 ng/mL) were predictors of uterine leiomyomas (OR 10.345, 95% CI 2.737–39.095; p = 0.001; and OR 2.26, 95% CI 1.011–5.073; p = 0.014), respectively.

Conclusions:

Insufficient levels of vitamin D are common in Mexican women. Age and hypovitaminosis D are possible risk factors in the development of uterine leiomyomas in Mexican women.

Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison

We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body.

Identification and characterization of the mediator kinase-dependent myometrial stem cell phosphoproteome

OBJECTIVE

To identify, in myometrial stem/progenitor cells, the presumptive cell of origin for uterine fibroids, substrates of Mediator-associated cyclin dependent kinase 8/19 (CDK8/19), which is known to be disrupted by uterine fibroid driver mutations in Mediator complex subunit 12 (MED12).

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing hysterectomy for uterine fibroids.

INTERVENTION(S)

Stable isotopic labeling of amino acids in cell culture (SILAC) coupled with chemical inhibition of CDK8/19 and downstream quantitative phosphoproteomics and transcriptomic analyses in myometrial stem/progenitor cells.

MAIN OUTCOME MEASURE(S)

High-confidence Mediator kinase substrates identified by SILAC-based quantitative phosphoproteomics were determined using an empirical Bayes analysis and validated orthogonally by in vitro kinase assay featuring reconstituted Mediator kinase modules comprising wild-type or G44D mutant MED12 corresponding to the most frequent uterine fibroid driver mutation in MED12. Mediator kinase-regulated transcripts identified by RNA sequencing were linked to Mediator kinase substrates by computational analyses.

RESULT(S)

A total of 296 unique phosphosites in 166 proteins were significantly decreased (≥ twofold) upon CDK8/19 inhibition, including 118 phosphosites in 71 nuclear proteins representing high-confidence Mediator kinase substrates linked to RNA polymerase II transcription, RNA processing and transport, chromatin modification, cytoskeletal architecture, and DNA replication and repair. Orthogonal validation confirmed a subset of these proteins, including Cut Like Homeobox 1 (CUX1) and Forkhead Box K1 (FOXK1), to be direct targets of MED12-dependent CDK8 phosphorylation in a manner abrogated by the most common uterine fibroid driver mutation (G44D) in MED12, implicating these substrates in disease pathogenesis. Transcriptome-wide profiling of Mediator kinase-inhibited myometrial stem/progenitor cells revealed alterations in cell cycle and myogenic gene expression programs to which Mediator kinase substrates could be linked directly. Among these, CUX1 is an established transcriptional regulator of the cell cycle whose corresponding gene on chromosome 7q is the locus for a recurrent breakpoint in uterine fibroids, linking MED12 and Mediator kinase with CUX1 for the first time in uterine fibroid pathogenesis. FOXK1, a transcriptional regulator of myogenic stem cell fate, was found to be coordinately enriched along with kinase, but not core, Mediator subunits in myometrial stem/progenitor cells compared with differentiated uterine smooth muscle cells.

CONCLUSION(S)

These studies identify a new catalog of pathologically and biologically relevant Mediator kinase substrates implicated in the pathogenesis of MED12 mutation-positive uterine fibroids, and further uncover a biochemical basis to link Mediator kinase activity with CUX1 and FOXK1 in the regulation of myometrial stem/progenitor cell fate.

Nerolidol inhibits proliferation of leiomyoma cells via reactive oxygen species-induced DNA damage and downregulation of the ATM/Akt pathway

Nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol), a sesquiterpene alcohol present in aromatic essential oils of numerous plants, has been reported to possess anticancer activity. The potential therapeutic effect of nerolidol on uterine fibroids (UF), the most common benign tumor of the uterus worldwide, is unknown. In this study, we examined the anti-UF potential of nerolidol in ELT3 cells, a rat leiomyoma cell line widely used as an in vitro model, to identify the potential therapeutic agents for UF. We observed that treatment with cis- or trans-nerolidol inhibited cell proliferation in a dose-dependent manner and induced cell cycle arrest in the G1 phase, which was accompanied by reduction in Akt phosphorylation and downregulation of cyclin D1, cyclin-dependent kinase 4 (CDK4), and CDK6 protein expression. The proliferation-inhibiting activity of nerolidol correlated with the generation of intracellular reactive oxygen species (ROS), which was suppressed by N-acetyl-l-cysteine, a ROS inhibitor. Nerolidol treatment also increased the percentage of cells for which tail moment could be calculated using an alkaline comet assay, and induced p-γH2AX^ser139 expression, which indicated induction of DNA damage. We also observed downregulation of ATM and its phosphorylation after nerolidol treatment; furthermore, treatment with KU-55933, an ATM kinase inhibitor, mimicked the inhibitory effects of nerolidol treatment on cell proliferation and Akt phosphorylation. In conclusion, nerolidol displayed anti-UF activity in a leiomyoma cell model via ROS-induced DNA damage and G1 phase cell cycle arrest by inhibiting the expression and activation of the ATM/Akt pathway. Our data suggests that nerolidol is a potential therapeutic agent for UF.

Gonadotropin-releasing hormone agonist versus expectant management for treating multiple leiomyomas after myomectomy: the study protocol for a multicentre, prospective, randomised controlled clinical trial

INTRODUCTION

Leiomyoma recurrence is a major concern for long-term myomectomy management, especially for multiple leiomyomas. Gonadotropin-releasing hormone agonist (GnRHa) is one of the most effective medications to reduce the volume of fibroids and the uterus. However, its role in preventing recurrence after conservative surgery remains unclear. At present, there is no randomised clinical trial determining the efficacy of GnRHa treatment for preventing multiple leiomyomas recurrence after myomectomy.

METHODS AND ANALYSIS

We are conducting a phase IV randomised controlled trial in women aged 18-45 undergoing myomectomy for multiple leiomyomas. After surgery, women whose pathological result confirms multiple leiomyomas are randomised in a 1:1 ratio into an observation or GnRHa group. The primary outcome is the recurrence of either clinical symptoms or fibroids on imaging. Patients will be assessed for adverse events during the follow-up.

ETHICS AND DISSEMINATION

The study was approved by the Medical Ethics Committee of the Tongji Hospital Affiliated with the Tongji Medical College of Huazhong University of Science and Technology (TJ-IRB20180311) according to the submitted study protocol (V.1.0, 10 November 2017) and informed consent (V.1.0, 10 November 2017). The results will be presented at domestic and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR-IPR-17012992.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

Uterine fibroids continually grow in some postmenopausal women. Obesity and small fibroids (<3.0 cm diameter) may contribute to higher growth rates of fibroids.

Uterine leiomyoma is associated with the risk of developing endometriosis: A nationwide cohort study involving 156,195 women

Objective

Evidence for an association between uterine leiomyoma and increased risk of endometriosis is limited by small sample sizes and short follow-up periods. We assessed this association in a large nationwide sample with 14 years of data.

Design

Data were sourced from Taiwan’s Longitudinal Health Insurance Database 2000 (LHID2000).

Materials and methods

We identified 31,239 women aged ≥20 years diagnosed with uterine leiomyoma (International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] code 218) between Jan 1, 2000 and Dec 31, 2012, who were matched with 124,956 controls (1:4) by 5-year age groups and year of diagnosis. Follow-up was from the date of LHID2000 entry to the first occurrence of endometriosis, loss to follow-up, insurance termination, or until December 31, 2013, whichever was earlier.

Results

In Cox regression analysis, the adjusted hazard ratio (aHR) for endometriosis in women with uterine leiomyoma was 6.44 (95% CI, 6.18, 6.72) compared with controls. The risk of endometriosis was significantly increased in women with uterine leiomyoma and comorbidities of tube-ovarian infection (aHR 2.86; 95% CI, 1.28, 6.36), endometritis (1.14; 1.06, 1.24), infertility (1.26; 1.16, 1.37), or allergic diseases (1.11; 1.05, 1.17). Having both uterine leiomyoma and endometritis significantly increased the risk of endometriosis (aHR 6.73; 95% CI, 6.07, 7.45) versus having only uterine leiomyoma (6.61; 6.33, 6.91) or endometritis (1.49; 1.31, 1.69). Similarly, having both uterine leiomyoma and infertility significantly increased the risk of endometriosis (aHR 6.95; 95% CI, 6.21, 7.78) versus having only uterine leiomyoma (6.66; 6.38, 6.96) or infertility (1.78; 1.57, 2.02).

Conclusions

A diagnosis of uterine leiomyoma appears to increase the risk of endometriosis. Patients presenting with uterine fibroids should be encouraged to give informed consent for possible simultaneous surgical treatment of endometriosis.

Evidence that geographic variation in genetic ancestry associates with uterine fibroids

Uterine fibroids disproportionately impact Black women. Evidence suggests Black women have earlier onset and higher cumulative risk. This risk disparity may be due an imbalance of risk alleles in one parental geographic ancestry subgroup relative to others. We investigated ancestry proportions for the 1000 Genomes phase 3 populations clustered into 6 geographic groups for association with fibroid traits in Black women (n=583 cases, 797 controls) and White women (n=1,195 cases, 1,164 controls). Global ancestry proportions were estimated using ADMIXTURE. Dichotomous (fibroids status and multiple fibroid status) and continuous outcomes (volume and largest dimension) were modeled for association with ancestry proportions using logistic and linear regression adjusting for age. Effect estimates are reported per 10% increase in genetically inferred ancestry proportion. Among AAs, West African (WAFR) ancestry was associated with fibroid risk, East African ancestry was associated with risk of multiple fibroids, Northern European (NEUR) ancestry was protective for multiple fibroids, Southern European ancestry was protective for fibroids and multiple fibroids, and South Asian (SAS) ancestry was positively associated with volume and largest dimension. In EAs, NEUR ancestry was protective for fibroids, SAS ancestry was associated with fibroid risk, and WAFR ancestry was positively associated with volume and largest dimension. These results suggest that a proportion of fibroid risk and fibroid trait racial disparities are due to genetic differences between geographic groups. Further investigation at the local ancestry and single variant levels may yield novel insights about disease architecture and genetic mechanisms underlying ethnic disparities in fibroid risk.

Several Fusion Genes Identified in a Spermatic Cord Leiomyoma With Rearrangements of Chromosome Arms 3p and 21q

BACKGROUND/AIM

Benign smooth-muscle tumors, leiomyomas, occur in nearly every organ but are most common in the uterus. Whereas much is known about the genetics of uterine leiomyomas, little genetic information exists about leiomyomas of other organs. Here, we report and discuss the genetic findings in a para-testicular leiomyoma.

MATERIALS AND METHODS

Cytogenetic, array comparative genomic hybridization (aCGH) RNA sequencing, reverse-transcription polymerase chain reaction (RT- PCR), and Sanger sequencing analyses were performed on a leiomyoma of the spermatic cord removed from a 61-year-old man.

RESULTS

The karyotype was 48~50,XY,add(3) (p21),+4,+7,+8,+9,add(21)(q22)[cp9]/46,XY[2]. aCGH confirmed the trisomies and also detected multiple gains and losses from 3p and 21q. RNA sequencing detected the chimeras ARHGEF3-CACNA2D2, TRAK1-TIMP4, ITPR1- DT-NR2C2, CLASP2-IL17RD, ZNF621-LARS2, CNTN4- RHOA, and NR2C2-CFAP410. All chimeras were confirmed by RT-PCR and Sanger sequencing.

CONCLUSION

Our data, together with those previously published, indicate that a group of leiomyomas may be cytogenetically characterized by aberrations of 3p and the formation of fusion genes.

Correlation Analysis Between MTHFR C677T Polymorphism and Uterine Fibroids: A Retrospective Cohort Study

Background

Uterine fibroids(UF) are the most common benign tumors in women, with high incidence and unknown causes. We aimed to explore the correlation between Methylenetetra-hydrofolate reductase (MTHFR) C677T polymorphism and UF.

Methods

This is a retrospective cohort study. Data were collected from 2411 women detected for MTHFR C677T polymorphism in the Fifth Affiliated Hospital of Sun Yat-sen University from 2018 to 2020. B-ultrasound (BU) and the first page of medical records were used to analyze whether they had ever been diagnosed with UF. The collected data were analyzed. Using the chi-square test and regression analysis to explore the correlation, and the risk factors was screened by multifactor logistic regression analysis.

Results

A total of 2411 pregnant women were in the MTHFR C677T polymorphism detection. Among them, 226(9.37%) were diagnosed as UF by BU or clinical diagnosis. The allele and genotype of MTHFR C677T were significantly different between the case and control group (p<0.05), and the distribution of the allele was following Hardy-Weinberg (H-W) equilibrium. Comparing with the wild-type (C/C), the mutant group (C/T+T/T) was more likely to form UF(OR,1.43;OR95%CI,1.07-1.89). After adjusting for confoundings, the heterozygous mutant (C/T) was more susceptible to UF than the wild-type (aOR,1.41;aOR95%CI,1.41-1.91). In the case group, BMI, gravidity and parity were not associated with the size and number of UF and the MTHFR C677T polymorphism (p>0.05). However, older maternal age was associated with the incidence of UF, especially the multiple UF (p<0.05).

Conclusion

Our results found that MTHFR C677T polymorphism was associated with UF occurrence for the first time. This could imply that it may increase the risk of forming UF in women of gestational age.