FOXO3a deregulation in uterine smooth muscle tumors

OBJECTIVE

The present study aimed to investigate FOXO3a deregulation in Uterine Smooth Muscle Tumors (USMT) and its potential association with cancer development and prognosis.

METHODS

The authors analyzed gene and protein expression profiles of FOXO3a in 56 uterine Leiomyosarcomas (LMS), 119 leiomyomas (comprising conventional and unusual leiomyomas), and 20 Myometrium (MM) samples. The authors used techniques such as Immunohistochemistry (IHC), FISH/CISH, and qRT-PCR for the present analyses. Additionally, the authors conducted an in-silico analysis to understand the interaction network involving FOXO3a and its correlated genes.

RESULTS

This investigation revealed distinct expression patterns of the FOXO3a gene and protein, including both normal and phosphorylated forms. Expression levels were notably elevated in LMS, and Unusual Leiomyomas (ULM) compared to conventional Leiomyomas (LM) and Myometrium (MM) samples. This upregulation was significantly associated with metastasis and Overall Survival (OS) in LMS patients. Intriguingly, FOXO3a deregulation did not seem to be influenced by EGF/HER-2 signaling, as there were minimal levels of EGF and VEGF expression detected, and HER-2 and EGFR were negative in the analyzed samples. In the examination of miRNAs, the authors observed upregulation of miR-96-5p and miR-155-5p, which are known negative regulators of FOXO3a, in LMS samples. Conversely, the tumor suppressor miR-let7c-5p was downregulated.

CONCLUSIONS

In summary, the outcomes of the present study suggest that the imbalance in FOXO3a within Uterine Smooth Muscle Tumors might arise from both protein phosphorylation and miRNA activity. FOXO3a could emerge as a promising therapeutic target for individuals with Unusual Leiomyomas and Leiomyosarcomas (ULM and LMS), offering novel directions for treatment strategies.

Genetic contribution of reproductive traits to risk of uterine leiomyomata: a large-scale, genome-wide, cross-trait analysis

BACKGROUND

Although phenotypic associations between female reproductive characteristics and uterine leiomyomata have long been observed in epidemiologic investigations, the shared genetic architecture underlying these complex phenotypes remains unclear.

OBJECTIVE

We aimed to investigate the shared genetic basis, pleiotropic effects, and potential causal relationships underlying reproductive traits (age at menarche, age at natural menopause, and age at first birth) and uterine leiomyomata.

STUDY DESIGN

With the use of large-scale, genome-wide association studies conducted among women of European ancestry for age at menarche (n=329,345), age at natural menopause (n=201,323), age at first birth (n=418,758), and uterine leiomyomata (ncases/ncontrols=35,474/267,505), we performed a comprehensive, genome-wide, cross-trait analysis to examine systematically the common genetic influences between reproductive traits and uterine leiomyomata.

RESULTS

Significant global genetic correlations were identified between uterine leiomyomata and age at menarche (rg, -0.17; P=3.65×10-10), age at natural menopause (rg, 0.23; P=3.26×10-07), and age at first birth (rg, -0.16; P=1.96×10-06). Thirteen genomic regions were further revealed as contributing significant local correlations (P<.05/2353) to age at natural menopause and uterine leiomyomata. A cross-trait meta-analysis identified 23 shared loci, 3 of which were novel. A transcriptome-wide association study found 15 shared genes that target tissues of the digestive, exo- or endocrine, nervous, and cardiovascular systems. Mendelian randomization suggested causal relationships between a genetically predicted older age at menarche (odds ratio, 0.88; 95% confidence interval, 0.85-0.92; P=1.50×10-10) or older age at first birth (odds ratio, 0.95; 95% confidence interval, 0.90-0.99; P=.02) and a reduced risk for uterine leiomyomata and between a genetically predicted older age at natural menopause and an increased risk for uterine leiomyomata (odds ratio, 1.08; 95% confidence interval, 1.06-1.09; P=2.30×10-27). No causal association in the reverse direction was found.

CONCLUSION

Our work highlights that there are substantial shared genetic influences and putative causal links that underlie reproductive traits and uterine leiomyomata. The findings suggest that early identification of female reproductive risk factors may facilitate the initiation of strategies to modify potential uterine leiomyomata risk.

Leiomyoma and the importance of genetic variation on genes related to the vasculature system - CβS, MTHFR, NOS3, CYBA, and ACE1

OBJECTIVE

The link between the systemic vasculature system and tumor biology is here investigated by studying the contribution of CβS (844ins68), MTHFR (677C > T), NOS3 (4a/4b), CYBA (C242T), and ACE1 (I/D) genes to leiomyoma onset, uterus and leiomyoma volumes.

METHODS

DNA samples from 130 women with leiomyomas and 527 from healthy women were genotyped by PCR or PCR-RFLP. Qui-square (χ2) or Fisher's exact test were used to test associations. All the mentioned tests were performed in IBM® SPSS® Statistics Version 28. Statistical significance was defined as a p-value < 0.05.

RESULTS

Results revealed that CβS (in the codominant and allelic models, p = 0.044 and, p = 0.015, OR = 1.791 [1.114-2.879], respectively), MTHFR (in the codominant, allelic and dominant models, p = 0.009, p = 0.002, OR = 0.585 [0.416-0.824] and p = 0.003, OR = 0.527 [0.346-0.802], respectively) and ACE1 (dominant model, p = 0.045, OR = 0.639 [0.411-0.992]) genes are associated with leiomyoma onset. NOS3 4a4a genotype is associated with a lower uterus volume (p = 0.004). This study also uncovers intriguing epistatic interactions among some genes that further accentuate their roles in disease modulation. Indeed, the epistatic interactions between the CC genotype (MTHFR) and (+/+) (CβS; p = 0.003), 4b4b (NOS3; p = 0.006, OR = 2.050 [1.223-3.439]) or DD (ACE1; p < 0.001, OR = 2.362 [1.438-3.880]) were shown to be associated with the disease, while 4a presence (NOS3) in epistasis with I presence (ACE1), increased the effect protection having just the I allele presence (p = 0.029, OR = 0.446 [0.214-0.930]).

CONCLUSIONS

We conclude that variation in genes related to the systemic vascular system can play a role in the onset and development of leiomyoma.

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

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

The Mediator Complex Subunit 12 (MED-12) Gene and Uterine Fibroids: a Systematic Review

Uterine leiomyomas are the most common tumor of reproductive-age women worldwide. Although benign, uterine fibroids cause significant morbidity and adversely impact the quality of life for affected women. Somatic mutations in the exon 2 of the mediator complex subunit 12 (MED-12) gene represent the most common single gene mutation associated with uterine leiomyomas. The objective of this review was to evaluate the current role of MED-12 mutation in the pathophysiology of uterine fibroids, to assess the prevalence of MED-12 mutation among different populations, and to identify the most common subtypes of MED-12 mutations found in uterine fibroids. A comprehensive search was conducted using Pubmed, Embase, Scopus, and the Web of Science. English-language publications that evaluated MED-12 mutation and uterine fibroids in humans, whether experimental or clinical, were considered. We identified 380 studies, of which 23 were included, comprising 1353 patients and 1872 fibroid tumors. Of the total number of tumors analyzed, 1045 (55.8%) harbored a MED-12 mutation. Among the 23 studies included, the frequency of MED-12 mutation varied from 31.1 to 80% in fibroid samples. The most common type of MED-12 mutation was a heterozygous missense mutation affecting codon 44 of exon 2, specifically the nucleotide 131. Studies reported that MED-12 mutation acts by increasing levels of AKT and disrupting the cyclin C-CDK8/19 kinase activity. The overall average prevalence of MED-12 mutation in uterine fibroids was found to be 55.8% across the global population, though the frequency varied greatly among different countries.

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.

Bromodomain-Containing Protein 9 Regulates Signaling Pathways and Reprograms the Epigenome in Immortalized Human Uterine Fibroid Cells

Bromodomain-containing proteins (BRDs) are involved in many biological processes, most notably epigenetic regulation of transcription, and BRD dysfunction has been linked to many diseases, including tumorigenesis. However, the role of BRDs in the pathogenesis of uterine fibroids (UFs) is entirely unknown. The present study aimed to determine the expression pattern of BRD9 in UFs and matched myometrium and further assess the impact of a BRD9 inhibitor on UF phenotype and epigenetic/epitranscriptomic changes. Our studies demonstrated that the levels of BRD9 were significantly upregulated in UFs compared to matched myometrium, suggesting that the aberrant BRD expression may contribute to the pathogenesis of UFs. We then evaluated the potential roles of BRD9 using its specific inhibitor, I-BRD9. Targeted inhibition of BRD9 suppressed UF tumorigenesis with increased apoptosis and cell cycle arrest, decreased cell proliferation, and extracellular matrix deposition in UF cells. The latter is the key hallmark of UFs. Unbiased transcriptomic profiling coupled with downstream bioinformatics analysis further and extensively demonstrated that targeted inhibition of BRD9 impacted the cell cycle- and ECM-related biological pathways and reprogrammed the UF cell epigenome and epitranscriptome in UFs. Taken together, our studies support the critical role of BRD9 in UF cells and the strong interconnection between BRD9 and other pathways controlling the UF progression. Targeted inhibition of BRDs might provide a non-hormonal treatment option for this most common benign tumor in women of reproductive age.

Serum-Resistant Ternary DNA Polyplexes for Suicide Gene Therapy of Uterine Leiomyoma

Uterine leiomyoma (UL) is a prevalent benign tumor in women that frequently gives rise to a multitude of reproductive complications. The use of suicide gene therapy has been proposed as a highly promising method for treating UL. To achieve successful gene therapy, it is essential to develop carriers that can efficiently transport nucleic acids into targeted cells and tissues. The instability of polyplexes in blood and other biological fluids is a crucial factor to consider when using non-viral carriers. In this study, we present serum-resistant and cRGD-modified DNA complexes for targeted delivery genes to UL cells. Ternary polyplexes were formed by incorporating cystine-cross-linked polyglutamic acid modified with histidine residues. We employed two techniques in the production of cross-linked polyanionic coating: matrix polymerization and oxidative polycondensation. In this study, we investigated the physicochemical properties of ternary DNA complexes, including the size and zeta-potential of the nanoparticles. Additionally, we evaluated cellular uptake, toxicity levels, transfection efficiency and specificity in vitro. The study involved introducing the HSV-TK gene into primary UL cells as a form of suicide gene therapy modeling. We have effectively employed ternary peptide-based complexes for gene delivery into the UL organtypic model. By implementing in situ suicide gene therapy, the increase in apoptosis genes expression was detected, providing conclusive evidence of apoptosis occurring in the transfected UL tissues. The results of the study strongly suggest that the developed ternary polyplexes show potential as a valuable tool in the implementation of suicide gene therapy for UL.

A differential diagnosis between uterine leiomyoma and leiomyosarcoma using transcriptome analysis

BACKGROUND

The objective of this study was to estimate the accuracy of transcriptome-based classifier in differential diagnosis of uterine leiomyoma and leiomyosarcoma. We manually selected 114 normal uterine tissue and 31 leiomyosarcoma samples from publicly available transcriptome data in UCSC Xena as training/validation sets. We developed pre-processing procedure and gene selection method to sensitively find genes of larger variance in leiomyosarcoma than normal uterine tissues. Through our method, 17 genes were selected to build transcriptome-based classifier. The prediction accuracies of deep feedforward neural network (DNN), support vector machine (SVM), random forest (RF), and gradient boosting (GB) models were examined. We interpret the biological functionality of selected genes via network-based analysis using GeneMANIA. To validate the performance of trained model, we additionally collected 35 clinical samples of leiomyosarcoma and leiomyoma as a test set (18 + 17 as 1st and 2nd test sets).

RESULTS

We discovered genes expressed in a highly variable way in leiomyosarcoma while these genes are expressed in a conserved way in normal uterine samples. These genes were mainly associated with DNA replication. As gene selection and model training were made in leiomyosarcoma and uterine normal tissue, proving discriminant of ability between leiomyosarcoma and leiomyoma is necessary. Thus, further validation of trained model was conducted in newly collected clinical samples of leiomyosarcoma and leiomyoma. The DNN classifier performed sensitivity 0.88, 0.77 (8/9, 7/9) while the specificity 1.0 (8/8, 8/8) in two test data set supporting that the selected genes in conjunction with DNN classifier are well discriminating the difference between leiomyosarcoma and leiomyoma in clinical sample.

CONCLUSION

The transcriptome-based classifier accurately distinguished uterine leiomyosarcoma from leiomyoma. Our method can be helpful in clinical practice through the biopsy of sample in advance of surgery. Identification of leiomyosarcoma let the doctor avoid of laparoscopic surgery, thus it minimizes un-wanted tumor spread.

DNA methylation of ICAM4 and NOXO1 participate in the formation of uterine fibroids via regulating immune cell infiltration

This atudy aimed to reveal the effect of DNA methylation on immune infiltration of uterine fibroids (UFs) and to further classify UFs based on transcriptomic characteristics. The transcriptome and DNA methylation data of UFs were collected from the GEO database. After taking the intersection of the differentially expressed genes in these two types of data, the intersection gene was used to draw ROC curves and to filtrate the candidate genes with AUC≥0.8. Immune infiltration analysis was performed in the online tool EPIC. The correlation between gene with AUC≥0.8 and the abundance of each immune cell type was calculated with |R|>0.3 and P<0.05. ConsensusClusterPlus package in R software was used to further cluster the samples of UFs. In this study, a total of 41 RNA-seq data (10 normal uterine samples and 31 UFs samples) and 34 DNA methylation data (10 from normal subjects and 24 from patients with UFs) were involved. The significantly down-regulated ICAM4, SPECC1L, and NOXO1 were the top three methylated drive genes of UFs. Therefore, NOXO1 and ICAM4 present an intimate correlation to immune cell infiltration. Besides, UFs could be clustered into two subtypes, including a TSAB1 up-regulated subtype and a FOSB up-regulated subtype. DNA methylation of ICAM4 and NOXO1 are involved in the pathogenesis of UFs via regulating immune cell infiltration. Further classification based on transcriptomic characteristics could divide UFs into sexual steroids-related and biomechanics-related subtypes, which would promote its non-invasive treatment.

RISING STARS: Role of MED12 mutation in the pathogenesis of uterine fibroids

Abstract

Uterine fibroids (UFs) are benign tumors arising from the uterus, characterized by accumulation of abundant extracellular matrix (ECM) and sex steroid-dependent growth. Women with symptomatic UFs have reduced quality of life and decreased labor productivity. Among the driver gene mutations identified in UFs, mutations in MED12, a component of the cyclin-dependent kinase (CDK) Mediator module, are the most common and observed in 50-80% of UFs. They are gain-of-function mutations and are more frequently observed in Black women and commonly observed even in small UFs. MED12 mutation-positive UFs (MED12-UFs) often develop multiple rather than solitary and have distinct gene expression profiles, DNA methylomes, transcriptomes, and proteomes. Gene expressions related to ECM organization and collagen-rich ECM components are upregulated, and impaired Mediator kinase activity and dysregulation of Wnt/β-catenin signaling are identified in MED12-UFs. Clinically, the UF shrinking effect of gonadotropin-releasing hormone agonists and ulipristal acetate is dependent on the MED12 mutation status. Understanding of characteristics of MED12-UFs and functions of MED12 mutations for UF tumorigenesis may elucidate the pathophysiology of UFs, leading to the development of new therapeutic options in women with symptomatic UFs.

Endocrine-disrupting chemicals and epigenetic reprogramming in developmental origin of uterine fibroids

Endocrine-disrupting chemicals (EDCs) are a class of exogenous substances that mimic the effects of hormones in the body, inducing hormonal dysregulation and contributing to various disorders. Epigenome regulation has emerged as an important mechanism for maintaining organ function in health and disease. Dissecting epigenomic and resultant gene expression changes provides unprecedented insight into the chromatin state, which underlines disease development and shapes risk and phenotypic plasticity in response to the environment and internal cues. The cutting-edge, high throughput technologies provide new routes to understanding the etiology of disease and new footholds on the promising path to better treatment and disease prevention. We have recently revealed that myometrial stem cells (MMSCs), the cell origin of UFs, are the target of developmental EDC exposure. The EDC-induced epigenetic changes in MMSCs identified by multi-omics approaches include DNA methylation and histone modification modulated by DNA methyltransferases and MLL1, which characterized the molecular mechanism underlying EDC-related risk in hormone-dependent UFs. Future studies are needed to determine the link between real-life exposures to EDCs and their impact on the development of human diseases and transgenerational epigenetic inheritance, which can help explore strategies that may prevent adverse outcomes linked to EDC exposure.

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.

Uterine leiomyomata and keloids fibrosis origins: a mini-review of fibroproliferative diseases

Diseases such as uterine leiomyomata (fibroids and benign tumors of the uterus) and keloids (raised scars) may share common etiology. Fibroids and keloids can co-occur in individuals, and both are highly heritable, suggesting they may share common genetic risk factors. Fibroproliferative diseases are common and characterized by scarring and overgrowth of connective tissue, impacting multiple organ systems. These conditions both have racial disparities in prevalence, with the highest prevalence observed among individuals of African ancestry. Several fibroproliferative diseases are more severe and common in populations of sub-Saharan Africa. This mini-review aims to provide a broad overview of the current knowledge of the evolutionary origins and causes of fibroproliferative diseases. We also discuss current hypotheses proposing that the increased prevalence of these diseases in African-derived populations is due to the selection for profibrotic alleles that are protective against helminth infections and provide examples from knowledge of uterine fibroid and keloid research.

Heterogeneous graph framework for predicting the association between lncRNA and disease and case on uterine fibroid

Long non-coding RNAs (lncRNAs) play crucial regulatory roles in various cellular processes, including gene expression, chromatin remodeling, and protein localization. Dysregulation of lncRNAs has been linked to several diseases, making it essential to understand their functions in disease mechanisms and therapeutic strategies. However, traditional experimental methods for studying lncRNA function are time-consuming, expensive, and offer limited insights. In recent years, computational methods have emerged as valuable tools for predicting lncRNA functions and their associations with diseases. However, many existing methods focus on constructing separate networks for lncRNA and disease similarity, resulting in information loss and insufficient processing capacity for isolated nodes. To address this, we developed 'RGLD' by combining Random Walk with restarting (RWR), Graph Neural Network (GNN), and Graph Attention Networks (GAT) to predict lncRNA-disease associations in a heterogeneous network. RGLD achieved an impressive AUC of 0.88, outperforming other methods. It can also predict novel associations between lncRNAs and diseases. RGLD identified HOTAIR, MEG3, and PVT1 as lncRNAs associated with uterine fibroids. Biological experiments directly or indirectly verified the involvement of these three lncRNAs in uterine fibroids, validating the accuracy of RGLD's predictions. Furthermore, we extensively discussed the functions of the target genes regulated by these lncRNAs in uterine fibroids, providing evidence for their role in the development and progression of the disease.

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.

TGFβ signaling links early life endocrine-disrupting chemicals exposure to suppression of nucleotide excision repair in rat myometrial stem cells

Environmental exposure to endocrine-disrupting chemicals (EDCs) is linked to the development of uterine fibroids (UFs) in women. UFs, non-cancerous tumors, are thought to originate from abnormal myometrial stem cells (MMSCs). Defective DNA repair capacity may contribute to the emergence of mutations that promote tumor growth. The multifunctional cytokine TGFβ1 is associated with UF progression and DNA damage repair pathways. To investigate the impact of EDC exposure on TGFβ1 and nucleotide excision repair (NER) pathways, we isolated MMSCs from 5-month-old Eker rats exposed neonatally to diethylstilbestrol (DES), an EDC, or to vehicle (VEH). EDC-MMSCs exhibited overactivated TGFβ1 signaling and reduced mRNA and protein levels of NER pathway components compared to VEH-MMSCs. EDC-MMSCs also demonstrated impaired NER capacity. Exposing VEH-MMSCs to TGFβ1 decreased NER capacity while inhibiting TGFβ signaling in EDC-MMSCs restored it. RNA-seq analysis and further validation revealed decreased expression of Uvrag, a tumor suppressor gene involved in DNA damage recognition, in VEH-MMSCs treated with TGFβ1, but increased expression in EDC-MMSCs after TGFβ signaling inhibition. Overall, we demonstrated that the overactivation of the TGFβ pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased genetic instability, arise of mutations, and fibroid tumorigenesis. We demonstrated that the overactivation of the TGFβ pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased fibroid incidence.

Developmental reprogramming of myometrial stem cells by endocrine disruptor linking to risk of uterine fibroids

BACKGROUND

The stage, when tissues and organs are growing, is very vulnerable to environmental influences, but it's not clear how exposure during this time causes changes to the epigenome and increases the risk of hormone-related illnesses like uterine fibroids (UFs).

METHODS

Developmental reprogramming of myometrial stem cells (MMSCs), the putative origin from which UFs originate, was investigated in vitro and in the Eker rat model by RNA-seq, ChIP-seq, RRBS, gain/loss of function analysis, and luciferase activity assays.

RESULTS

When exposed to the endocrine-disrupting chemical (EDC) diethylstilbestrol during Eker rat development, MMSCs undergo a reprogramming of their estrogen-responsive transcriptome. The reprogrammed genes in MMSCs are known as estrogen-responsive genes (ERGs) and are activated by mixed lineage leukemia protein-1 (MLL1) and DNA hypo-methylation mechanisms. Additionally, we observed a notable elevation in the expression of ERGs in MMSCs from Eker rats exposed to natural steroids after developmental exposure to EDC, thereby augmenting estrogen activity.

CONCLUSION

Our studies identify epigenetic mechanisms of MLL1/DNA hypo-methylation-mediated MMSC reprogramming. EDC exposure epigenetically targets MMSCs and leads to persistent changes in the expression of a subset of ERGs, imparting a hormonal imprint on the ERGs, resulting in a "hyper-estrogenic" phenotype, and increasing the hormone-dependent risk of UFs.

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.

Oxidatively generated DNA damage mediates the associations of exposure to phthalates with uterine fibroids and endometriosis: Findings from TREE cohort

BACKGROUND

Epidemiological studies on phthalate exposures in associations with uterine fibroids (UF) and endometriosis (EMT) are inconsistent. The underlying mechanisms are poorly understood.

OBJECTIVES

To investigate the relationships of urinary phthalate metabolites with UF and EMT risks, and further to examine the mediating role of oxidative stress.

METHODS

This study included 83 and 47 women separately diagnosed with UF and EMT, as well as 226 controls from the Tongji Reproductive and Environmental (TREE) cohort. Two spot urine samples from each woman were analyzed for two oxidative stress indicators and eight urinary phthalate metabolites. Unconditional logistic regression models or multivariate regression models were fitted to evaluate the associations among phthalate exposures, oxidative stress indicators, and the risks of UF and EMT. The potential mediating role of oxidative stress was estimated by the mediation analyses.

RESULTS

We observed that each ln-unit increase in urinary mono-benzyl phthalate (MBzP) concentrations was associated with increased UF risk [adjusted OR (aOR): 1.56, 95% CI: 1.20, 2.02], and that each ln-unit increase in urinary MBzP (aOR: 1.48, 95% CI: 1.09, 1.99), mono-isobutyl phthalate (MiBP) (aOR: 1.83, 95% CI: 1.19, 2.82), and mono-2-ethylhexyl phthalate (MEHP) (aOR: 1.66, 95% CI: 1.19, 2.31) concentrations were associated with increased EMT risk (all FDR-adjusted P < 0.05). Moreover, we observed that all tested urinary phthalate metabolites were positively associated with two oxidative stress indicators [4-hydroxy-2-nonenal-mercapturic acid (4-HNE-MA) and 8-hydroxy-2-deoxyguanosine (8-OHdG)], in which 8-OHdG was associated with increased risks of UF and EMT (all FDR-adjusted P < 0.05). The mediation analyses showed that 8-OHdG mediated the positive relationships of MBzP with UF risk, and of MiBP, MBzP, and MEHP with EMT risk, with the estimated intermediary proportion ranging from 32.7% to 48.1%.

CONCLUSIONS

Oxidatively generated DNA damage may mediate the positive associations of certain phthalate exposures with the risks of UF and EMT. However, further investigation is warranted to confirm these findings.

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.

EZH2 activates Wnt/β-catenin signaling in human uterine fibroids, which is inhibited by the natural compound methyl jasmonate

OBJECTIVE

To investigate the link between EZH2 and Wnt/β-catenin signaling and its role in uterine fibroids (UFs) pathogenesis and explore the potential effect of natural compound methyl jasmonate (MJ) against UFs.

DESIGN

EZH2 overexpression or inhibition was achieved in human uterine leiomyoma (HuLM) cells using EZH2-expressing adenovirus or chemical EZH2 inhibitor (DZNep), respectively. The HuLM and normal uterine smooth muscle cells were treated with 0.1-3 mM of MJ, and several experiments were employed.

SETTING

Laboratory study.

PATIENTS(S)

None.

INTERVENTION(S)

Methyl jasmonate.

MAIN OUTCOME MEASURE(S)

Protein expression of EZH2, β-catenin, and proliferating cell nuclear antigen (PCNA) was measured by Western blot as well as gene expression alterations of Wnt ligands (Wnt5A, Wnt5b, and Wnt9A), WISP1, CTNNB1, and its responsive gene PITX2 using quantitative real-time polymerase chain reaction. The protein and ribonucleic acid (RNA) levels of several markers were measured in MJ-treated or untreated HuLM cells, including EZH2 and β-catenin, extracellular matrix markers collagen type 1 (COL1A1) and fibronectin (FN), proliferation markers cyclin D1 (CCND1) and PCNA, tumor suppressor marker p21, and apoptotic markers (BAX, cytochrome c, and cleaved caspase 3).

RESULT(S)

EZH2 overexpression significantly increased the gene expression of several Wnt ligands (PITX2, WISP1, WNT5A, WNT5B, and WNT9A), which increased nuclear translocation of β-catenin and PCNA and eventually HuLM cell proliferation. EZH2 inhibition blocked Wnt/β-catenin signaling activation where the aforementioned genes significantly decreased as well as PCNA, cyclin D1, and PITX2 protein expression compared with those in untreated HuLM. Methyl jasmonate showed a potent antiproliferative effect on HuLM cells in a dose- and time-dependent manner. Interestingly, the dose range (0.1-0.5 mM) showed a selective growth inhibitory effect on HuLM cells, not on normal uterine smooth muscle cells. Methyl jasmonate treatment at 0.5 mM for 24 hours significantly decreased both protein and RNA levels of EZH2, β-catenin, COL1A1, FN, CCND1, PCNA, WISP1, and PITX2 but increased the protein levels of p21, BAX, cytochrome, c and cleaved caspase 3 compared with untreated HuLM. Methyl jasmonate-treated cells exhibited down-regulation in the RNA expression of 36 genes, including CTNNB1, CCND1, Wnt5A, Wnt5B, and Wnt9A, and up-regulation in the expression of 34 genes, including Wnt antagonist genes WIF1, PRICKlE1, and DKK1 compared with control, confirming the quantitative real-time polymerase chain reaction results.

CONCLUSION(S)

Our studies provide a novel link between EZH2 and the Wnt/β-catenin signaling pathway in UFs. Targeting EZH2 with MJ interferes with the activation of wnt/β-catenin signaling in our model. Methyl jasmonate may offer a promising therapeutic option as a nonhormonal and cost-effective treatment against UFs with favorable clinical utility, pending proven safe and efficient in human clinical trials.

Genetic liability to multiple factors and uterine leiomyoma risk: a Mendelian randomization study

Background and objective

Uterine leiomyoma is the most common benign tumor in females of reproductive age. However, its causes have never been fully understood. The objective of our study was to analyze the causal association between various factors and uterine leiomyoma using Mendelian randomization (MR).

Methods

Genetic variables associated with risk factors were obtained from genome-wide association studies. Summary-level statistical data for uterine leiomyoma were obtained from FinnGen and the UK Biobank (UKB) consortium. We used inverse variance weighted, MR-Egger, and weighted median methods in univariate analysis. Multivariable MR analysis was used to identify independent risk factors. A fixed-effect model meta-analysis was used to combine the results of the FinnGen and UKB data.

Results

In the FinnGen data, higher genetically predicted age at natural menopause, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting insulin were associated with an increased risk of uterine leiomyoma, while higher age at menarche was associated with a reduced risk of uterine leiomyoma. Multivariable MR analysis of SBP and DBP showed that higher DBP might be an independent risk factor of uterine leiomyoma. In the UKB data, the results for age at natural menopause, SBP, DBP, and age at menarche were replicated. The result of the meta-analysis suggested that uterine leiomyoma could also be affected by polycystic ovary syndrome (PCOS), endometriosis, and 2-hour glucose level.

Conclusion

Our MR study confirmed that earlier menstrual age, hypertension, obesity, and elevated 2-hour glucose post-challenge were risk factors for uterine leiomyoma, and the causal relationship between smoking and uterine leiomyoma was ruled out. In addition, later age of menopause and endometriosis were found to increase the risk of uterine leiomyoma, while PCOS was found to decrease the risk.

Epigenetic Modulation of Inflammatory Pathways in Myometrial Stem Cells and Risk of Uterine Fibroids

The period during which tissue and organ development occurs is particularly vulnerable to the influence of environmental exposures. However, the specific mechanisms through which biological pathways are disrupted in response to developmental insults, consequently elevating the risk of hormone-dependent diseases, such as uterine fibroids (UFs), remain poorly understood. Here, we show that developmental exposure to the endocrine-disrupting chemical (EDC), diethylstilbestrol (DES), activates the inflammatory pathways in myometrial stem cells (MMSCs), which are the origin of UFs. Significantly, the secretome of reprogrammed MMSCs enhances the expression of critical inflammation-related genes in differentiated myometrial cells through the paracrine mechanism, which amplifies pro-inflammatory and immune suppression signaling in the myometrium. The expression of reprogrammed inflammatory responsive genes (IRGs) is driven by activated mixed-lineage leukemia protein-1 (MLL1) in MMSCs. The deactivation of MLL reverses the reprogramming of IRG expression. In addition, the inhibition of histone deacetylases (HDACs) also reversed the reprogrammed IRG expression induced by EDC exposure. This work identifies the epigenetic mechanisms of MLL1/HDAC-mediated MMSC reprogramming, and EDC exposure epigenetically targets MMSCs and imparts an IRG expression pattern, which may result in a "hyper-inflammatory phenotype" and an increased hormone-dependent risk of UFs later in life.

Clinicopathologic and Molecular Characteristics of Epstein-Barr Virus-Associated Smooth Muscle Tumor Compared With Those of Leiomyoma and Leiomyosarcoma

Epstein-Barr virus (EBV)-associated smooth muscle tumors (EBV-SMTs) are rare smooth muscle neoplasms exclusively associated with immunosuppression, such as in patients with HIV/AIDS, posttransplant, and congenital immunodeficiency. However, the genomic landscape of EBV-SMTs is poorly understood. Leiomyosarcomas harbor genomic instability and multiple recurrent DNA copy number alterations, whereas leiomyomas lack such changes. Thus, this study aimed to fill this knowledge gap by characterizing copy number alterations in EBV-SMTs and correlating this information with clinicopathologic characteristics. Our study investigated and compared the pathologic characteristics and copy number profiles of 9 EBV-SMTs (from 7 post-transplant and AIDS patients), 6 leiomyomas, and 7 leiomyosarcomas, using chromosomal microarray platforms. Our results showed a lower copy number alteration burden in EBV-SMTs and leiomyoma than in leiomyosarcoma. This contrast in the molecular profile between EBV-SMTs and leiomyosarcoma is concordant with the different clinical behaviors and pathologic characteristics exhibited by these tumors. Despite having an overall copy number alteration profile closer to leiomyoma, recurrent copy number gain of oncogenes, such as RUNX1, CCND2, and ETS2, was found in EBV-SMTs. Epigenetic alterations may play an important role in tumorigenesis as recurrent copy number gains were found in histone deacetylases. A gene enrichment analysis also demonstrated enrichment of genes involved in the host response to viral infection, suggesting that the tumor immune microenvironment may play an important role in EBV-SMT tumorigenesis.

Leiomyoma-like Morphology in Metastatic Uterine Inflammatory Myofibroblastic Tumors

Uterine inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms that frequently harbor ALK gene rearrangements and have a low risk of metastasis. We reported 3 of these tumors mimicking the appearance of leiomyoma in their recurrence. These patients were 34, 43, and 45 years old. Two uterine tumors demonstrated classic morphology, with combined myxoid, compact fascicular, and hyalinized patterns and spindled cells with bipolar cytoplasmic processes, moderate atypia, and lymphoplasmacytic inflammatory infiltrates. The third had a "leiomyoma-like" appearance, with fascicles of plump spindled cells and a sparse lymphoplasmacytic infiltrate. ALK immunohistochemistry was positive in all the tumors, and all demonstrated ALK rearrangements using fluorescence in situ hybridization (n = 2) and/or RNA sequencing (n = 2). Two classic IMTs recurred at 3 and 50 months in the lung and abdomen, respectively, and recurrent tumors had a "leiomyoma-like" appearance, with 0 and 1 mitosis per 10 high-power fields, no inflammation in 1, and a sparse lymphocytic infiltrate in the other. ALK was positive in both tumors; 1 with available tissue showed an IGFBP5::ALK fusion using RNA sequencing. The third patient, who had a "leiomyoma-like" uterine tumor, experienced multiple recurrences, first in the abdomen at 100 months showing a similar appearance. Subsequent recurrence at 105 months showed transmural invasion of the sigmoid colon and a similar microscopic appearance but with the addition of infiltrative borders, moderate cellularity, mild-to-moderate atypia, and 10 mitoses per 10 high-power fields. Both recurrences were positive for ALK, and RNA sequencing revealed the same ACTG2::ALK fusion transcript identified in the primary tumor. The patient was treated with crizotinib, resulting in prolonged clinical remission, with no evidence of disease at 168 months from the initial surgery. Although "leiomyoma-like" uterine IMTs have been recently described, to our knowledge, this is the first report of recurrence of these tumors and the first report of a "leiomyoma-like" appearance in the recurrences of conventional uterine IMTs. A low threshold for performing ALK immunohistochemistry on recurrent uterine tumors can identify patients who may benefit from tyrosine kinase inhibitors.

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.

Molecular subclass of uterine fibroids predicts tumor shrinkage in response to ulipristal acetate

Precision medicine carries great potential for management of all tumor types. The aim of this retrospective study was to investigate if the two most common genetically distinct uterine fibroid subclasses, driven by aberrations in MED12 and HMGA2 genes, respectively, influence response to treatment with the progesterone receptor modulator ulipristal acetate. Changes in diameter and mutation status were derived for 101 uterine fibroids surgically removed after ulipristal acetate treatment. A significant difference in treatment response between the two major subclasses was detected. MED12 mutant fibroids had 4.4 times higher odds of shrinking in response to ulipristal acetate treatment as compared to HMGA2 driven fibroids (95% confidence interval 1.37-13.9; P = 0.013), and in a multivariate analysis molecular subclassification was an independent predictive factor. Compatible with this finding, gene expression and DNA methylation analyses revealed subclass specific differences in progesterone receptor signaling. The work provides a proof-of-principle that uterine fibroid treatment response is influenced by molecular subclass and that the genetic subclasses should be taken into account when evaluating current and future uterine fibroid therapies.

Association between ESR1 rs2234693 single nucleotide polymorphism and uterine fibroids in Taiwanese premenopausal and postmenopausal women

BACKGROUND

Uterine fibroids (UFs) are uterine smooth muscle neoplasms that affect women, especially during the reproductive stage. Both genetic and lifestyle factors affect the onset of the disease. We examined the association between the estrogen receptor 1 (ESR1) rs2234693 variant (whose genotypes are TT, TC, and CC) and UFs in Taiwanese premenopausal and postmenopausal women.

METHODS

We linked individual-level data of 3588 participants from the Taiwan Biobank to the National Health Insurance Research Database at the Health and Welfare Data Science Center. The association of the ESR1 rs2234693 variant and other variables with UFs was determined by multiple logistic regression, and the results were presented as odds ratios and 95% confidence intervals (CIs).

RESULTS

The 3588 participants comprised 622 cases and 2966 controls. In all the participants, the ESR1 rs2234693 TC and CC genotypes compared to the reference genotype (TT) were associated with a lower risk of UFs. However, the results were significant only for the CC genotype (OR; 95% CI = 0.70; 0.52-0.93). Noteworthy, the association of TC and CC with UFs was dose-dependent (p-trend = 0.012). Based on menopausal status, both TC and CC were significantly and dose-dependently associated with a lower risk of UFs in premenopausal women (OR; 95% CI = 0.76; 0.59-0.98 for TC and 0.64; 0.43-0.95 for CC: p-trend = 0.010).

CONCLUSION

The TC and CC genotypes of the ESR1 rs2234693 variant may reduce susceptibility to UFs, especially in premenopausal women.

Inherited mutations affecting the SRCAP complex are central in moderate-penetrance predisposition to uterine leiomyomas

Uterine leiomyomas (ULs) are benign smooth muscle tumors that are common in premenopausal women. Somatic alterations in MED12, HMGA2, FH, genes encoding subunits of the SRCAP complex, and genes involved in Cullin 3-RING E3 ligase neddylation are mutually exclusive UL drivers. Established predisposition genes explain only partially the estimated heritability of leiomyomas. Here, we examined loss-of-function variants across 18,899 genes in a cohort of 233,614 White European women, revealing variants in four genes encoding SRCAP complex subunits (YEATS4, ZNHIT1, DMAP1, and ACTL6A) with a significant association to ULs, and YEATS4 and ZNHIT1 strikingly rank first and second, respectively. Positive mutation status was also associated with younger age at diagnosis and hysterectomy. Moderate-penetrance UL risk was largely attributed to rare non-synonymous mutations affecting the SRCAP complex. To examine this disease phenotype more closely, we set out to identify inherited mutations affecting the SRCAP complex in our in-house sample collection of Finnish individuals with ULs (n = 860). We detected one individual with an ACTL6A splice-site mutation, two individuals with a YEATS4 missense mutation, and four individuals with DMAP1 mutations: one splice-site, one nonsense, and two missense variants. These individuals had large and/or multiple ULs, were often diagnosed at an early age, and many had family history of ULs. When a somatic second hit was found, ACTL6A and DMAP1 were silenced in tumors by somatic mutation and YEATS4 by promoter hypermethylation. Decreased H2A.Z staining was observed in the tumors, providing further evidence for the pathogenic nature of the germline mutations. Our results establish inactivation of genes encoding SRCAP complex subunits as a central contributor to moderate-penetrance UL predisposition.

Differential Expression of MED12-Associated Coding RNA Transcripts in Uterine Leiomyomas

Recent studies have demonstrated that somatic MED12 mutations in exon 2 occur at a frequency of up to 80% and have a functional role in leiomyoma pathogenesis. The objective of this study was to elucidate the expression profile of coding RNA transcripts in leiomyomas, with and without these mutations, and their paired myometrium. Next-generation RNA sequencing (NGS) was used to systematically profile the differentially expressed RNA transcripts from paired leiomyomas (n = 19). The differential analysis indicated there are 394 genes differentially and aberrantly expressed only in the mutated tumors. These genes were predominantly involved in the regulation of extracellular constituents. Of the differentially expressed genes that overlapped in the two comparison groups, the magnitude of change in gene expression was greater for many genes in tumors bearing MED12 mutations. Although the myometrium did not express MED12 mutations, there were marked differences in the transcriptome landscape of the myometrium from mutated and non-mutated specimens, with genes regulating the response to oxygen-containing compounds being most altered. In conclusion, MED12 mutations have profound effects on the expression of genes pivotal to leiomyoma pathogenesis in the tumor and the myometrium which could alter tumor characteristics and growth potential.

MED12 mutations in uterine leiomyomas: prediction of volume reduction by gonadotropin-releasing hormone agonists

BACKGROUND

Gonadotropin-releasing hormone agonists are used to treat premenopausal uterine leiomyomas; however, leiomyoma volume reduction is not always achieved. The reduction rate after this treatment varies for each leiomyoma, even in the same patient. Therefore, an effective method for predicting uterine leiomyoma volume reduction is required to reduce the adverse hypoestrogenic effects and drug-related economic burden related to gonadotropin-releasing hormone agonists.

OBJECTIVE

This study aimed to determine the predictive use of MED12 mutations for evaluating the effect of gonadotropin-releasing hormone agonist treatment concerning reducing uterine leiomyoma volume and to predict the MED12 mutation status based on the findings of magnetic resonance imaging performed before treatment.

STUDY DESIGN

MED12 exon 2 mutation and erythropoietin expression in uterine leiomyomas were evaluated concerning volume reduction, as measured using magnetic resonance imaging. We developed a system for classifying leiomyomas according to T2-weighted magnetic resonance imaging signals to noninvasively predict the presence or absence of MED12 mutations in leiomyomas. Leiomyoma samples (>5 cm) were obtained from 168 patients during surgery (hysterectomy or myomectomy) between 2005 and 2021 at Yokohama City University Hospital. To analyze the rate of leiomyoma volume reduction, 41 patients had been preoperatively administered the gonadotropin-releasing hormone agonist (leuprorelin acetate 3.75 mg, monthly subcutaneous injection) for 3 months; magnetic resonance imaging was performed before and after treatment without contrast material.

RESULTS

Patients with MED12 exon 2 mutations had smaller volume reduction after treatment with the gonadotropin-releasing hormone agonist (P<.001, Mann-Whitney U test) and displayed lower signal intensity on T2-weighted images than those with leiomyomas expressing wild-type MED12 exon 2. The newly proposed magnetic resonance imaging-based classification system showed that MED12 exon 2 mutations were more frequent in the low-signal group than in the high-signal group, with nearly equal proportions of mutated and wild-type MED12 exon 2 leiomyomas noted in the intermediate group. The low-signal group had significantly lower erythropoietin expression levels than the high-signal group (P<.001, Kruskal-Wallis test with the Dunn posthoc analysis).

CONCLUSION

MED12 mutation status can be a candidate marker for predicting the effect of gonadotropin-releasing hormone agonists on uterine leiomyoma reduction. Magnetic resonance imaging findings can be used to determine MED12 mutation status as a noninvasive strategy to select patients who will most likely benefit from gonadotropin-releasing hormone agonist treatment.

Evidence of a causal effect of genetic tendency to gain muscle mass on uterine leiomyomata

Uterine leiomyomata (UL) are the most common tumours of the female genital tract and the primary cause of surgical removal of the uterus. Genetic factors contribute to UL susceptibility. To add understanding to the heritable genetic risk factors, we conduct a genome-wide association study (GWAS) of UL in up to 426,558 European women from FinnGen and a previous UL meta-GWAS. In addition to the 50 known UL loci, we identify 22 loci that have not been associated with UL in prior studies. UL-associated loci harbour genes enriched for development, growth, and cellular senescence. Of particular interest are the smooth muscle cell differentiation and proliferation-regulating genes functioning on the myocardin-cyclin dependent kinase inhibitor 1 A pathway. Our results further suggest that genetic predisposition to increased fat-free mass may be causally related to higher UL risk, underscoring the involvement of altered muscle tissue biology in UL pathophysiology. Overall, our findings add to the understanding of the genetic pathways underlying UL, which may aid in developing novel therapeutics.

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.

Further characterization of tryptophan metabolism and its dysregulation in fibroids

OBJECTIVE

To determine the expression of enzymes in tryptophan (Trp) catabolism in fibroids and matched myometrium and determine the effects of race and mediator complex subunit 12 gene (MED12) mutation on their expression.

DESIGN

Experimental laboratory study.

SETTING

Academic research laboratory.

PATIENT(S)

Women of reproductive age who underwent hysterectomy while on no hormonal medications before surgery.

INTERVENTION(S)

Fibroids and matched myometrium were obtained from patients who underwent hysterectomy from different race or ethnic groups.

MAIN OUTCOME MEASURE(S)

The expression of enzymes in the Trp catabolic pathway, tryptophan transporters, and the cytochrome P450 1B1 gene (CYP1B1) in the fibroids and matched myometrium of women from different race and ethnic groups and in tumors bearing the MED12 mutation and tumors without the mutation was determined using quantitative reverse-transcription polymerase chain reaction. The levels of serotonin, kynurenic acid (KYNA), and nicotinamide adenine dinucleotide (NAD) were determined using enzyme-linked immunosorbent assay.

RESULT(S)

In fibroids, the expression of tryptophan hydroxylase 1 (TPH1), kynurenine amino transferase (KAT)2, large neutral amino acid transporter small subunit 2 (SLC7A8), and large neutral amino acid transporter small subunit 1 (SLC7A5) messenger RNA (mRNA) was high and that of kynureninase (KYNU) and tryptophanyl-tRNA ligase (WARS1) mRNA was low, with no changes in the expression of WARS2, kynurenine formamidase (AFMID), kynurenine 3-monooxygenase (KMO), KAT1, KAT3, and KAT4 compared with that in the matched myometrium (n = 81). The expression of CYP1B1 mRNA, a marker of the activation of the aryl hydrocarbon receptor, was higher in fibroids. Tumors bearing the MED12 mutation expressed higher levels of CYP1B1 and lower levels of WARS1, KAT1, KAT3, and KAT4 mRNAs compared with tumors without the MED12 mutation. Race or ethnicity affected the expression of KYNU, with tumors from African American and Hispanic patients expressing lower levels of KYNU mRNA compared with those from Caucasian patients. We also quantified the levels of serotonin, KYNA, and NAD, which are the end products of Trp catabolism. There were no significant differences in the levels of serotonin and KYNA, whereas the levels of NAD were lower in fibroids than in the paired myometrium. This reduction in the levels of NAD was independent of race or ethnicity.

CONCLUSION(S)

In addition to the expression of tryptophan 2,3-dioxygenase or indoleamine-pyrrole 2,3-dioxygenase, there was marked dysregulation in the expression of other enzymes in the Trp metabolic pathway and Trp transporters in fibroids. Both MED12 mutation status and race or ethnicity had selective effects on the expression of the components of this pathway. Additional functional studies are necessary to establish the physiologic significance of the tryptophan degradation pathway in the pathogenesis of fibroids and its potential as a target for novel therapies.

Uterine fibroid polygenic risk score (PRS) associates and predicts risk for uterine fibroid

Uterine fibroids (UF) are common pelvic tumors in women, heritable, and genome-wide association studies (GWAS) have identified ~ 30 loci associated with increased risk in UF. Using summary statistics from a previously published UF GWAS performed in a non-Hispanic European Ancestry (NHW) female subset from the Electronic Medical Records and Genomics (eMERGE) Network, we constructed a polygenic risk score (PRS) for UF. UF-PRS was developed using PRSice and optimized in the separate clinical population of BioVU. PRS was validated using parallel methods of 10-fold cross-validation logistic regression and phenome-wide association study (PheWAS) in a seperate subset of eMERGE NHW females (validation set), excluding samples used in GWAS. PRSice determined pt < 0.001 and after linkage disequilibrium pruning (r2 < 0.2), 4458 variants were in the PRS which was significant (pseudo-R2 = 0.0018, p = 0.041). 10-fold cross-validation logistic regression modeling of validation set revealed the model had an area under the curve (AUC) value of 0.60 (95% confidence interval [CI] 0.58-0.62) when plotted in a receiver operator curve (ROC). PheWAS identified six phecodes associated with the PRS with the most significant phenotypes being 218 'benign neoplasm of uterus' and 218.1 'uterine leiomyoma' (p = 1.94 × 10-23, OR 1.31 [95% CI 1.26-1.37] and p = 3.50 × 10-23, OR 1.32 [95% CI 1.26-1.37]). We have developed and validated the first PRS for UF. We find our PRS has predictive ability for UF and captures genetic architecture of increased risk for UF that can be used in further studies.

A transcriptome-wide association study of uterine fibroids to identify potential genetic markers and toxic chemicals

Uterine fibroid is one of the most prevalent benign tumors in women, with high socioeconomic costs. Although genome-wide association studies (GWAS) have identified several loci associated with uterine fibroid risks, they could not successfully interpret the biological effects of genomic variants at the gene expression levels. To prioritize uterine fibroid susceptibility genes that are biologically interpretable, we conducted a transcriptome-wide association study (TWAS) by integrating GWAS data of uterine fibroid and expression quantitative loci data. We identified nine significant TWAS genes including two novel genes, RP11-282O18.3 and KBTBD7, which may be causal genes for uterine fibroid. We conducted functional enrichment network analyses using the TWAS results to investigate the biological pathways in which the overall TWAS genes were involved. The results demonstrated the immune system process to be a key pathway in uterine fibroid pathogenesis. Finally, we carried out chemical–gene interaction analyses using the TWAS results and the comparative toxicogenomics database to determine the potential risk chemicals for uterine fibroid. We identified five toxic chemicals that were significantly associated with uterine fibroid TWAS genes, suggesting that they may be implicated in the pathogenesis of uterine fibroid. In this study, we performed an integrative analysis covering the broad application of bioinformatics approaches. Our study may provide a deeper understanding of uterine fibroid etiologies and informative notifications about potential risk chemicals for uterine fibroid.

Molecular Insights in Uterine Leiomyosarcoma: A Systematic Review

Uterine fibroids (UFs) are the most common benign tumors of female genital diseases, unlike uterine leiomyosarcoma (LMS), a rare and aggressive uterine cancer. This narrative review aims to discuss the biology and diagnosis of LMS and, at the same time, their differential diagnosis, in order to distinguish the biological and molecular origins. The authors performed a Medline and PubMed search for the years 1990–2022 using a combination of keywords on the topics to highlight the many genes and proteins involved in the pathogenesis of LMS. The mutation of these genes, in addition to the altered expression and functions of their enzymes, are potentially biomarkers of uterine LMS. Thus, the use of this molecular and protein information could favor differential diagnosis and personalized therapy based on the molecular characteristics of LMS tissue, leading to timely diagnoses and potential better outcomes for patients.

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.

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.

Histopathologic and Molecular Characterization of Uterine Leiomyoma-like Inflammatory Myofibroblastic Tumor: Comparison to Molecular Subtypes of Uterine Leiomyoma

Uterine leiomyoma (UL) is a common benign neoplasm which can sometimes be difficult to differentiate from the uterine inflammatory myofibroblastic tumor (IMT) based on morphology alone. IMT is a myofibroblastic/fibroblastic neoplasm which has typically been considered to be rare in the uterus. Its clinical behavior is usually indolent although aggressive variants exist. The majority of IMTs harbor genomic rearrangement of anaplastic lymphoma kinase ( ALK ), while ALK fusion has not been thus far detected in ULs. We analyzed 2263 ULs of which 9 (0.4%) had tyrosine-kinase activation. Seven of the samples were ALK immunopositive: 6 had an ALK fusion gene and 1 overexpressed an ALK transcript skipping exons 2 to 3, Moreover, 1 sample had a RET , and 1 a PDGFRB fusion gene. While no recurrent somatic mutations were found, 1 patient had an ALK germline mutation. Seven tumors showed leiomyoma-like morphology, 1 tumor had slightly loose, and 1 fibrous growth pattern. Six tumors had mild to moderate lymphocyte infiltration, while no immune cell infiltration was detected in 3 cases. None of the tumors showed aggressive behavior. Except for strong ALK positivity (7/9 tumors) the protein expression profile of the tumors was identical to ULs and distinct from other mesenchymal uterine tumors. In gene expression level, these tumors and the known UL subclasses did not separate perfectly. However, vitamin C metabolism and epithelial-mesenchymal transition pathways were uniquely enriched in these lesions. The overall similarity of the analyzed tumors to UL raises the question whether an UL diagnosis would be more proper for a subset of uterine IMTs.

Investigating the shared genetic architecture of uterine leiomyoma and breast cancer: A genome-wide cross-trait analysis

Little is known regarding the shared genetic architecture or causality underlying the phenotypic association observed for uterine leiomyoma (UL) and breast cancer (BC). Leveraging summary statistics from the hitherto largest genome-wide association study (GWAS) conducted in each trait, we investigated the genetic overlap and causal associations of UL with BC overall, as well as with its subtypes defined by the status of estrogen receptor (ER). We observed a positive genetic correlation between UL and BC overall (rg = 0.09, p = 6.00 × 10-3), which was consistent in ER+ subtype (rg = 0.06, p = 0.01) but not in ER- subtype (rg = 0.06, p = 0.08). Partitioning the whole genome into 1,703 independent regions, local genetic correlation was identified at 22q13.1 for UL with BC overall and with ER+ subtype. Significant genetic correlation was further discovered in 9 out of 14 functional categories, with the highest estimates observed in coding, H3K9ac, and repressed regions. Cross-trait meta-analysis identified 9 novel loci shared between UL and BC. Mendelian randomization demonstrated a significantly increased risk of BC overall (OR = 1.09, 95% CI = 1.01-1.18) and ER+ subtype (OR = 1.09, 95% CI = 1.01-1.17) for genetic liability to UL. No reverse causality was found. Our comprehensive genome-wide cross-trait analysis demonstrates a shared genetic basis, pleiotropic loci, as well as a putative causal relationship between UL and BC, highlighting an intrinsic link underlying these two complex female diseases.

MicroRNAs as potential indicators of the development and progression of uterine leiomyoma

Recent studies demonstrated a significant role of several microRNAs (miRs) in the development of leiomyoma. Here, we investigated miR expression profiles using microarray and found a significantly higher expression of miRs in leiomyoma than in adjacent myometrium. We also confirmed the upregulation of five selected miRs including miR-181a-5p, 127-3p, 28-3p, 30b-5p and let-7c-5p in cellular proliferation, extracellular matrix turnover, and angiogenesis by RT-qPCR. Interestingly, the miRs showed a higher expression in cases of large leiomyoma or in patients with a history of transfusion due to anemia. We then analyzed the expression of the miR target molecules including Transforming Growth Factor Beta Receptor 2 (TGFBR2) and Insulin-like Growth Factor 2 mRNA Binding Protein 1 (IGF2BP1) via immunohistochemistry. TGFBR2 and IGF2BP1 were positively stained in 81% and 62.5% of leiomyoma tissues but not in adjacent myometrium. Both were more frequently positive in patients with ≥ 6 cm leiomyoma and mass effect. The mean expression levels of miR-181a-5p, 127-3p, 28-3p, 30b-5p and let-7c-5p were higher in cases with TGFBR2 and IGF2BP1 positive leiomyoma. We observed several miRs were overexpressed in leiomyoma tissues, and these results provide insight into the role of miRs in the development and progression of leiomyoma and underscore the need to validate their utility as diagnostic or therapeutic targets.

FKBP51 Contributes to Uterine Leiomyoma Pathogenesis by Inducing Cell Proliferation and Extracellular Matrix Deposition

The FK506-binding protein 51 (FKBP51) binds progesterone receptor (PR), glucocorticoid receptor (GR), and androgen receptor (AR) to coregulate their transcriptional activity. We evaluated FKBP51 expression and function in human leiomyoma vs. myometrial tissues and primary cultures to discover FKBP51 role(s) in the pathogenesis of leiomyomas. Quantification of in situ FKBP51 mRNA and protein levels inpaired myometrial vs. leiomyoma tissues from proliferative and secretory phases were analyzed by qPCR (n = 14), immunoblotting (n = 20), and immunohistochemistry (n = 12). Control (scramble) vs. FKBP5 siRNA-transfected leiomyoma cell cultures were assessed for proliferation, apoptosis, and mRNA levels of genes involved in cell survival and extracellular matrix (ECM) formation. Significantly higher FKBP5 mRNA levels were detected in leiomyoma vs. paired myometrium (P < 0.001). Immunoblot (P = 0.001) and immunostaining (P ≤ 0.001) confirmed increased FKBP51 levels in leiomyoma vs. paired myometrium. Compared to control siRNA transfection, FKBP5-silenced leiomyoma cell cultures displayed significantly decreased cell survival factors and reduced proliferation (P < 0.05). Moreover, qPCR analysis revealed significantly lower mRNA levels of ECM, TIPM1, and TIPM3 proteins in FKBP5-silenced leiomyoma cell cultures (P < 0.05). Increased FKBP51 expression in leiomyoma likely involves dysregulation of steroid signaling by blocking GR and PR action and promoting proliferation and ECM production. Evaluating the effect of FKBP51 inhibition in preclinical studies will clarify its significance as a potential therapeutic approach against leiomyoma.

Hsa_circ_0056686, derived from cancer-associated fibroblasts, promotes cell proliferation and suppresses apoptosis in uterine leiomyoma through inhibiting endoplasmic reticulum stress

Abnormal expression of circular RNAs (circRNAs) in cancer-associated fibroblasts (CAFs) is involved in the tumor-promoting ability of CAFs. Hsa_ circ_ 0056686 has been reported to affect leiomyoma size. The purpose of this study is to investigate the regulatory role of hsa_circ_0056686 in CAFs on uterine leiomyoma (ULM). The primary CAFs and corresponding normal fibroblasts (NFs) were isolated from the tumor zones of ULM tissues and adjacent, respectively. Hsa_circ_0056686 level was higher in CAFs than NFs, and also higher in ULM tissues than in adjacent tissues. CAFs-CM significantly increased the proliferation and migration and inhibited apoptosis of ULM cells, as confirmed by CCK-8, transwell, and flow cytometry assays. Moreover, conditioned medium (CM) from CAFs transfected with hsa_circ_0056686 shRNA (CAFssh-circ_0056686-CM) abolished CAFs-mediated proliferation, migration and apoptosis of ULM cells. CAFs-CM suppressed the expression of endoplasmic reticulum stress (ERS) marker proteins and induced the expression of extracellular matrix (ECM) marker proteins, thus suppressing ERS and increasing ECM accumulation, which could be declined by CAFssh-circ_0056686-CM. Meanwhile, knockdown of hsa_circ_0056686 reversed the inhibitory effects of CAFs-CM on brefeldin A-induced cell apoptosis. Luciferase gene reporter and RNA pull-down assays indicated that miR-515-5p directly bound with hsa_circ_0056686. MiR-515-5p overexpression restored the hsa_circ_0056686-shRNA-mediated malignant biological behaviors of ULM cells. Hsa_circ_0056686 contributed to tumor-promoting effects of CAFs in ULM, manifested by promoting ULM cell proliferation and migration and reducing ERS-induced apoptosis through sponging miR-515-5p.

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.

Integrative Genomic and Transcriptomic Profiling Reveals a Differential Molecular Signature in Uterine Leiomyoma versus Leiomyosarcoma

The absence of standardized molecular profiling to differentiate uterine leiomyosarcomas versus leiomyomas represents a current diagnostic challenge. In this study, we aimed to search for a differential molecular signature for these myometrial tumors based on artificial intelligence. For this purpose, differential exome and transcriptome-wide research was performed on histologically confirmed leiomyomas (n = 52) and leiomyosarcomas (n = 44) to elucidate differences between and within these two entities. We identified a significantly higher tumor mutation burden in leiomyosarcomas vs. leiomyomas in terms of somatic single-nucleotide variants (171,863 vs. 81,152), indels (9491 vs. 4098), and copy number variants (8390 vs. 5376). Further, we discovered alterations in specific copy number variant regions that affect the expression of some tumor suppressor genes. A transcriptomic analysis revealed 489 differentially expressed genes between these two conditions, as well as structural rearrangements targeting ATRX and RAD51B. These results allowed us to develop a machine learning approach based on 19 differentially expressed genes that differentiate both tumor types with high sensitivity and specificity. Our findings provide a novel molecular signature for the diagnosis of leiomyoma and leiomyosarcoma, which could be helpful to complement the current morphological and immunohistochemical diagnosis and may lay the foundation for the future evaluation of malignancy risk.

Obesity and risk of female reproductive conditions: A Mendelian randomisation study

BACKGROUND

Obesity is observationally associated with altered risk of many female reproductive conditions. These include polycystic ovary syndrome (PCOS), abnormal uterine bleeding, endometriosis, infertility, and pregnancy-related disorders. However, the roles and mechanisms of obesity in the aetiology of reproductive disorders remain unclear. Thus, we aimed to estimate observational and genetically predicted causal associations between obesity, metabolic hormones, and female reproductive disorders.

METHODS AND FINDINGS

Logistic regression, generalised additive models, and Mendelian randomisation (MR) (2-sample, non-linear, and multivariable) were applied to obesity and reproductive disease data on up to 257,193 women of European ancestry in UK Biobank and publicly available genome-wide association studies (GWASs). Body mass index (BMI), waist-to-hip ratio (WHR), and WHR adjusted for BMI were observationally (odds ratios [ORs] = 1.02-1.87 per 1-SD increase in obesity trait) and genetically (ORs = 1.06-2.09) associated with uterine fibroids (UF), PCOS, heavy menstrual bleeding (HMB), and pre-eclampsia. Genetically predicted visceral adipose tissue (VAT) mass was associated with the development of HMB (OR [95% CI] per 1-kg increase in predicted VAT mass = 1.32 [1.06-1.64], P = 0.0130), PCOS (OR [95% CI] = 1.15 [1.08-1.23], P = 3.24 × 10-05), and pre-eclampsia (OR [95% CI] = 3.08 [1.98-4.79], P = 6.65 × 10-07). Increased waist circumference posed a higher genetic risk (ORs = 1.16-1.93) for the development of these disorders and UF than did increased hip circumference (ORs = 1.06-1.10). Leptin, fasting insulin, and insulin resistance each mediated between 20% and 50% of the total genetically predicted association of obesity with pre-eclampsia. Reproductive conditions clustered based on shared genetic components of their aetiological relationships with obesity. This study was limited in power by the low prevalence of female reproductive conditions among women in the UK Biobank, with little information on pre-diagnostic anthropometric traits, and by the susceptibility of MR estimates to genetic pleiotropy.

CONCLUSIONS

We found that common indices of overall and central obesity were associated with increased risks of reproductive disorders to heterogenous extents in a systematic, large-scale genetics-based analysis of the aetiological relationships between obesity and female reproductive conditions. Our results suggest the utility of exploring the mechanisms mediating the causal associations of overweight and obesity with gynaecological health to identify targets for disease prevention and treatment.