Cytogenetic aberrations and the development of uterine leiomyomata

Molecular and Cellular Insights into the Development of Uterine Fibroids

Uterine leiomyomas represent the most common benign gynecologic tumor. These hormone-dependent smooth-muscle formations occur with an estimated prevalence of ~70% among women of reproductive age and cause symptoms including pain, abnormal uterine bleeding, infertility, and recurrent abortion. Despite the prevalence and public health impact of uterine leiomyomas, available treatments remain limited. Among the potential causes of leiomyomas, early hormonal exposure during periods of development may result in developmental reprogramming via epigenetic changes that persist in adulthood, leading to disease onset or progression. Recent developments in unbiased high-throughput sequencing technology enable powerful approaches to detect driver mutations, yielding new insights into the genomic instability of leiomyomas. Current data also suggest that each leiomyoma originates from the clonal expansion of a single transformed somatic stem cell of the myometrium. In this review, we propose an integrated cellular and molecular view of the origins of leiomyomas, as well as paradigm-shifting studies that will lead to better understanding and the future development of non-surgical treatments for these highly frequent tumors.

Macrophages and Immune Responses in Uterine Fibroids

Uterine fibroids represent the most common benign tumors of the uterus. They are considered a typical fibrotic disorder. In fact, the extracellular matrix (ECM) proteins—above all, collagen 1A1, fibronectin and versican—are upregulated in this pathology. The uterine fibroids etiology has not yet been clarified, and this represents an important matter about their resolution. A model has been proposed according to which the formation of an altered ECM could be the result of an excessive wound healing, in turn driven by a dysregulated inflammation process. A lot of molecules act in the complex inflammatory response. Macrophages have a great flexibility since they can assume different phenotypes leading to the tissue repair process. The dysregulation of macrophage proliferation, accumulation and infiltration could lead to an uncontrolled tissue repair and to the consequent pathological fibrosis. In addition, molecules such as monocyte chemoattractant protein-1 (MCP-1), granulocyte macrophage-colony-stimulating factor (GM-CSF), transforming growth factor-beta (TGF-β), activin A and tumor necrosis factor-alfa (TNF-α) were demonstrated to play an important role in the macrophage action within the uncontrolled tissue repair that contributes to the pathological fibrosis that represents a typical feature of the uterine fibroids.

Deoxyelephantopin, a novel naturally occurring phytochemical impairs growth, induces G2/M arrest, ROS-mediated apoptosis and modulates lncRNA expression against uterine leiomyoma

Deoxyelephantopin (DOE), a phytochemical, extracted and purified from Elephantopus scaber, has been shown to exhibit antitumor activities. Objective of the present study was to investigate anti-tumor and apoptosis-inducing properties of DOE against uterine leiomyoma (UL) and to explore their molecular mechanisms. Primary cell cultures from fresh UL tissue were established and maintained up to 12 passages. The cells exhibited continuous proliferation with 24 -h doubling time until 12 passages and was then subjected to molecular characterization. The growth inhibitory effect of DOE on UL cells was confirmed by colony formation, cellular senescence, AO/PI and DAPI staining. Fluorescent-activated cell sorting (FACS) assay for apoptosis and cell cycle arrest analysis revealed that DOE significantly (p < 0.05) inhibited the UL cell proliferation via cell cycle arrest at G2/M phase and induced apoptosis via ROS production by lowering mitochondrial membrane potential. Subsequently, the DOE induced ROS was markedly attenuated by co-treatment of N-Acetyl-Cysteine (NAC). Our quantitative RT-PCR and western blot results showed up-regulation of Bax, Caspase-3 and down-regulation of Bcl₂, P⁵³, αSMA, COL4A2, VEGF, PCNA, Cyclin B1 and oncogenic lncRNAs (H19, HOTAIR, BANCR and ROR) in DOE treated UL cells which further strengthen our findings. In conclusion, DOE inhibits growth of UL cells via cell cycle arrest at G2/M phase, induces ROS-dependent caspase-3-mediated mitochondrial intrinsic apoptotic pathway and down-regulation of oncogenic lncRNA in UL cells. Our findings suggest that DOE deserves for further systematic investigation in the uterine leiomyoma animal model as a novel apoptosis inducer for potential applications in the prevention or treatment of uterine leiomyoma.

Vitamins and Uterine Fibroids: Current Data on Pathophysiology and Possible Clinical Relevance

Uterine fibroid (UF) is the most common benign tumor pathology of the female reproductive organs. UFs constitute the main reason for a hysterectomy and hospitalization due to gynecological conditions. UFs consist of uterine smooth muscle immersed in a large amount of extracellular matrix (ECM). Genetic studies have demonstrated that UFs are monoclonal tumors originating from the myometrial stem cells that have underwent specific molecular changes to tumor initiating stem cells which proliferate and differentiate later under the influence of steroid hormones. There is growing interest in the role of micronutrients, for example, vitamins, in UFs. This article is a comprehensive review of publications regarding the available data concerning the role of vitamins in the biology and management of UFs. In summary, the results showed that some vitamins are important in the biology and pathophysiology of UFs. For example, vitamins A and D deserve particular attention following studies of their influence on the treatment of UF tumors. Vitamins B3, C, and E have not been as widely studied as the abovementioned vitamins. However, more research could reveal their potential role in UF biology.

A Trans-Ethnic Genome-Wide Association Study of Uterine Fibroids

Uterine fibroids affect up to 77% of women by menopause and account for up to $34 billion in healthcare costs each year. Although fibroid risk is heritable, genetic risk for fibroids is not well understood. We conducted a two-stage case-control meta-analysis of genetic variants in European and African ancestry women with and without fibroids classified by a previously published algorithm requiring pelvic imaging or confirmed diagnosis. Women from seven electronic Medical Records and Genomics (eMERGE) network sites (3,704 imaging-confirmed cases and 5,591 imaging-confirmed controls) and women of African and European ancestry from UK Biobank (UKB, 5,772 cases and 61,457 controls) were included in the discovery genome-wide association study (GWAS) meta-analysis. Variants showing evidence of association in Stage I GWAS (P < 1 × 10^-5) were targeted in an independent replication sample of African and European ancestry individuals from the UKB (Stage II) (12,358 cases and 138,477 controls). Logistic regression models were fit with genetic markers imputed to a 1000 Genomes reference and adjusted for principal components for each race- and site-specific dataset, followed by fixed-effects meta-analysis. Final analysis with 21,804 cases and 205,525 controls identified 326 genome-wide significant variants in 11 loci, with three novel loci at chromosome 1q24 (sentinel-SNP rs14361789; P = 4.7 × 10^-8), chromosome 16q12.1 (sentinel-SNP rs4785384; P = 1.5 × 10^-9) and chromosome 20q13.1 (sentinel-SNP rs6094982; P = 2.6 × 10^-8). Our statistically significant findings further support previously reported loci including SNPs near WT1, TNRC6B, SYNE1, BET1L, and CDC42/WNT4. We report evidence of ancestry-specific findings for sentinel-SNP rs10917151 in the CDC42/WNT4 locus (P = 1.76 × 10^-24). Ancestry-specific effect-estimates for rs10917151 were in opposite directions (P-Het-between-groups = 0.04) for predominantly African (OR = 0.84) and predominantly European women (OR = 1.16). Genetically-predicted gene expression of several genes including LUZP1 in vagina (P = 4.6 × 10^-8), OBFC1 in esophageal mucosa (P = 8.7 × 10^-8), NUDT13 in multiple tissues including subcutaneous adipose tissue (P = 3.3 × 10^-6), and HEATR3 in skeletal muscle tissue (P = 5.8 × 10^-6) were associated with fibroids. The finding for HEATR3 was supported by SNP-based summary Mendelian randomization analysis. Our study suggests that fibroid risk variants act through regulatory mechanisms affecting gene expression and are comprised of alleles that are both ancestry-specific and shared across continental ancestries.

Role of Transforming Growth Factor β in Uterine Fibroid Biology

Uterine fibroids (UFs) are benign tumors of the female genital tract made of the smooth muscle of the uterus. UF growth depends mostly on the influence of the steroid hormones and selected growth factors. Transforming growth factor β (TGF-βs) is a polypeptide that consists of three isoforms: TGF-β1, TGF-β2, and TGF-β3. At present, TGF-β is considered to be one of the key factors in the pathophysiology of UFs. It plays a major role in cellular migration within the tumor, stimulates tumor growth, and enhances tumor metabolism. As a consequence of various dependencies, the synthesis and release of TGF-β in a UF tumor is increased, which results in excessive extracellular matrix production and storage. High concentrations or overexpression of TGF-β mediators may be responsible for clinically symptomatic UFs. The aim of this review was to check the available evidence for the influence of the TGF-β family on UF biology. We conducted their search in PubMed of the National Library of Medicine with the use of the following selected keywords: “uterine fibroid”, “leiomyoma”, and “transforming growth factor β”. After reviewing the titles and abstracts, more than 115 full articles were evaluated. We focused on the TGF-β-related molecular aspects and their influence on the most common symptoms that are associated with UFs. Also, we described how the available data might implicate the current medical management of UFs.

Glipizide suppresses prostate cancer progression in the TRAMP model by inhibiting angiogenesis

Drug repurposing of non-cancer drugs represents an attractive approach to develop new cancer therapy. Using the TRAMP transgenic mouse model, glipizide, a widely used drug for type 2 diabetes mellitus, has been identified to suppress prostate cancer (PC) growth and metastasis. Angiogenesis is intimately associated with various human cancer developments. Intriguingly, glipizide significantly reduces microvessel density in PC tumor tissues, while not inhibiting prostate cancer cell proliferation from the MTT assay and flow cytometry investigation. Moreover, glipizide inhibits the tubular structure formation of human umbilical vein endothelial cells by regulating the HMGIY/Angiopoietin-1 signaling pathway. Taken together, these results demonstrate that glipizide has the potential to be repurposed as an effective therapeutic for the treatment of PC by targeting tumor-induced angiogenesis.

Systematic analysis of gene expression pattern in has-miR-197 over-expressed human uterine leiomyoma cells

INTRODUCTION

Our previous study showed that the expression of miR-197 in leiomyoma was down-regulated compared with myometrium. Further, miR-197 has been identified to affect uterine leiomyoma cell proliferation, apoptosis, and metastasis ability, though the responsible molecular mechanism has not been well elucidated. In this study, we sought to determine the expression patterns of miR-197 targeted genes and to explore their potential functions, participating Pathways and the networks that are involved in the biological behavior of human uterine leiomyoma.

METHODS

After transfection of human uterine leiomyoma cells with miR-197, we confirmed the expression level of miR-197 using quantitative real-time PCR (qRT-PCR), and we detected the gene expression profiles after miR-197 over-expression through DNA microarray analysis. Further, we performed GO and Pathway analysis. The dominantly dys-regulated genes, which were up- or down-regulated by more than 10-fold, compared with parental cells, were confirmed using qRT-PCR technology.

RESULT

Compared with the control group, miR-197 was up-regulated by 30-fold after miR-197 lentiviral transfection. The microarray data showed that 872 genes were dys-regulated by more than 2-fold in human uterine leiomyoma cells after miR-197 overexpression, including 537 up-regulated and 335 down-regulated genes. The GO analysis indicated that the dys-regulated genes were primarily involved in response to stimuli, multicellular organ processes, and the signaling of biological progression. Further, Pathway analysis data showed that these genes participated in regulating several signaling Pathways, including the JAK/STAT signaling Pathway, the Toll-like receptor signaling Pathway, and cytokine-cytokine receptor interaction. The qRT-PCR results confirmed that 17 of the 66 selected genes, which were up- or down-regulated more than 10-fold by miR-197, were consistent with the microarray results, including tumorigenesis-related genes, such as DRT7, SLC549, SFMBT2, FLJ37956, FBLN2, C10orf35, HOXD12, CACNG7, and LOC100134279.

CONCLUSION

Our study explored gene expression patterns after miR-197 overexpression and confirmed 17 dominantly dys-regulated genes, which could expand the insights into the function of miR-197 and the molecular mechanisms during the development and progression of uterine leiomyomas. This study might afford new clues for understanding the pathogenesis of uterine leiomyomas, and it could likely provide a unique method for diagnosing or predicting prognosis in the clinical treatment of leiomyoma.

Clonally related uterine leiomyomas are common and display branched tumor evolution

Uterine leiomyomas are extremely frequent benign smooth muscle tumors often presenting as multiple concurrent lesions and causing symptoms such as abnormal menstrual bleeding, abdominal pain and infertility. While most leiomyomas are believed to arise independently, a few studies have encountered separate lesions harboring identical genetic changes, suggesting a common clonal origin. To investigate the frequency of clonally related leiomyomas, genome-wide tools need to be utilized, and thus little is known about this phenomenon. Using MED12 sequencing and SNP arrays, we searched for clonally related uterine leiomyomas in a set of 103 tumors from 14 consecutive patients who entered hysterectomy owing to symptomatic lesions. Whole-genome sequencing was also utilized to study the genomic architecture of clonally related tumors. This revealed four patients to have two or more tumors that were clonally related, all of which lacked MED12 mutations. Furthermore, some tumors were composed of genetically distinct subclones, indicating a nonlinear, branched model of tumor evolution. DEPDC5 was discovered as a novel tumor suppressor gene playing a role in the progression of uterine leiomyomas. Perhaps counterintuitively—considering Knudson's two-hit hypothesis—a large shared deletion was followed by different truncating DEPDC5 mutations in four clonally related leiomyomas. This study provides insight into the intratumor heterogeneity of these tumors and suggests that a shared clonal origin is a common feature of leiomyomas that do not carry an MED12 mutation. These observations also offer one explanation to the common occurrence of multiple concurrent lesions.

BET1L and TNRC6B associate with uterine fibroid risk among European Americans

Uterine fibroid (UFs) affect 77 % of women by menopause and account for $9.4 billion in healthcare costs each year. Although UFs are heritable, genetic risk is poorly understood. The first genome-wide association study (GWAS) of UFs was recently performed in a Japanese population, with reported genome-wide significance for single nucleotide polymorphisms (SNPs) across three chromosomal regions. We tested these SNPs for association with UFs in US cohorts. Women were enrolled in the Right from the Start (RFTS) cohort and the BioVU DNA repository. UF status in both cohorts was determined by pelvic imaging. We tested 65 candidate and haplotype-tagging SNPs for association with UFs presence using logistic regression in RFTS and the top three GWAS-associated SNPs in BioVU. We also combined association results from both cohorts using meta-analysis. 1,086 European American (EA) cases and 1,549 controls were examined. Two SNP associations replicated [blocked early in transport 1 homolog (BET1L) rs2280543, RFTS-BioVU meta-odds ratio (OR) = 0.67 95 % confidence interval (CI) 0.38-0.96, Q = 0.70, I = 0, p = 6.9 × 10⁻³; trinucleotide repeat containing 6B (TNRC6B) rs12484776, RFTS-BioVU meta-OR = 1.21, 95 % CI 1.07-1.35, Q = 0.24, I = 28.37, p = 8.7 × 10⁻³). Meta-analyses combining evidence from RFTS, BioVU, and prior GWAS showed little heterogeneity in effect sizes across studies, with meta-p values between 7.45 × 10⁻⁸ and 3.89 × 10⁻⁹, which were stronger than prior GWAS and supported associations observed for all previously identified loci. These data suggest common variants increase risk for UF in both EA and Japanese populations. However, further research is needed to assess the role of these genes across other racial groups.

Variants in BET1L and TNRC6B associate with increasing fibroid volume and fibroid type among European Americans

Uterine fibroids (UFs) affect 77 % of women by menopause and account for $9.4 billion in yearly healthcare costs. We recently replicated findings from the first UF genome-wide association study (GWAS), conducted in the Japanese. Here we tested these GWAS-discovered SNPs for association with UF characteristics to further assess whether risk varies by sub-phenotypes of UFs. Women were enrolled in Right from the Start (RFTS) and the BioVU DNA repository (BioVU). UF status was determined by pelvic imaging. We tested the top GWAS-associated SNPs for association with UF characteristics (RFTS: type, number, volume; BioVU: type) using covariate adjusted logistic and linear regression. We also combined association results of UF type using meta-analysis. 456 European American (EA) cases and 1,549 controls were examined. Trinucleotide repeat containing 6B (TNRC6B) rs12484776 associated with volume in RFTS (β = 0.40, 95 % CI 0.05-0.75, p = 0.024). RFTS analyses evaluating stratified quartiles of volume showed the strongest OR at rs12484776 for the largest volume (16.6-179.1 cc, odds ratio (OR) = 2.19, 95 % confidence interval (CI) 1.07-4.46, p = 0.031). Meta-analysis showed a strong association at blocked early in transport 1 homolog (BET1L) rs2280543 for intramural UFs (meta-OR = 0.51, standard error (SE) = 0.14, Q = 0.590, I = 0, p = 2.48 × 10(-6)), which is stronger than the overall association with UF risk. This study is the first to evaluate these SNPs for association with UF characteristics and suggests these genes associate with increasing UF volume and protection from intramural UF in EAs.

An integrative genomic and transcriptomic analysis reveals potential targets associated with cell proliferation in uterine leiomyomas

Background

Uterine Leiomyomas (ULs) are the most common benign tumours affecting women of reproductive age. ULs represent a major problem in public health, as they are the main indication for hysterectomy. Approximately 40–50% of ULs have non-random cytogenetic abnormalities, and half of ULs may have copy number alterations (CNAs). Gene expression microarrays studies have demonstrated that cell proliferation genes act in response to growth factors and steroids. However, only a few genes mapping to CNAs regions were found to be associated with ULs.

Methodology

We applied an integrative analysis using genomic and transcriptomic data to identify the pathways and molecular markers associated with ULs. Fifty-one fresh frozen specimens were evaluated by array CGH (JISTIC) and gene expression microarrays (SAM). The CONEXIC algorithm was applied to integrate the data.

Principal Findings

The integrated analysis identified the top 30 significant genes (P<0.01), which comprised genes associated with cancer, whereas the protein-protein interaction analysis indicated a strong association between FANCA and BRCA1. Functional in silico analysis revealed target molecules for drugs involved in cell proliferation, including FGFR1 and IGFBP5. Transcriptional and protein analyses showed that FGFR1 (P = 0.006 and P<0.01, respectively) and IGFBP5 (P = 0.0002 and P = 0.006, respectively) were up-regulated in the tumours when compared with the adjacent normal myometrium.

Conclusions

The integrative genomic and transcriptomic approach indicated that FGFR1 and IGFBP5 amplification, as well as the consequent up-regulation of the protein products, plays an important role in the aetiology of ULs and thus provides data for potential drug therapies development to target genes associated with cellular proliferation in ULs.

Uterine leiomyoma: available medical treatments and new possible therapeutic options

CONTEXT

Uterine leiomyomas (fibroids or myomas) are benign tumors of the uterus and are clinically apparent in up to 25% of reproductive-age women. Heavy or abnormal uterine bleeding, pelvic pain or pressure, infertility, and recurrent pregnancy loss are generally associated with leiomyoma. Although surgical and radiological therapies are frequently used for the management of this tumor, medical therapies are considered the first-line treatment of leiomyoma.

EVIDENCE ACQUISITION AND SYNTHESIS

A review was conducted of electronic and print data comprising both original and review articles on pathophysiology and medical treatments of uterine leiomyoma retrieved from the PubMed or Google Scholar database up to June 2012. These resources were integrated with the authors' knowledge of the field.

CONCLUSION

To date, several pathogenetic factors such as genetic factors, epigenetic factors, estrogens, progesterone, growth factors, cytokines, chemokines, and extracellular matrix components have been implicated in leiomyoma development and growth. On the basis of current hypotheses, several medical therapies have been investigated. GnRH agonist has been approved by US Food and Drug Administration for reducing fibroid volume and related symptoms. In addition, the FDA also approved an intrauterine device, levonorgestrel-releasing intrauterine system (Mirena), for additional use to treat heavy menstrual bleeding in intrauterine device users only. Currently, mifepristone, asoprisnil, ulipristal acetate, and epigallocatechin gallate have been shown to be effective for fibroid regression and symptomatic improvement which are all in clinical trial. In addition, some synthetic and natural compounds as well as growth factor inhibitors are now under laboratory investigation, and they could serve as future therapeutic options.

A genome-wide association study identifies three loci associated with susceptibility to uterine fibroids

Uterine fibroids are a common benign tumor of the female genital tract. We conducted a genome-wide association study in which 457,044 SNPs were analyzed in 1,607 individuals with clinically diagnosed uterine fibroids and 1,428 female controls. SNPs showing suggestive associations (P < 5 × 10(-5)) were further genotyped in 3,466 additional cases and 3,245 female controls. Three loci on chromosomes 10q24.33, 22q13.1 and 11p15.5 revealed genome-wide significant associations with uterine fibroids. The SNPs showing the most significant association in a combination analysis at each of these loci were rs7913069 (P = 8.65 × 10(-14), odds ratio (OR) = 1.47), rs12484776 (P = 2.79 × 10(-12), OR = 1.23) and rs2280543 (P = 3.82 × 10(-12), OR = 1.39), respectively. Subsequent fine mapping of these regions will be necessary to pinpoint the causal variants. Our findings should shed light on the pathogenesis of uterine fibroids.