Leiomyoma fibrosis inhibited by liarozole, a retinoic acid metabolic blocking agent

Retinoids as Chemo-Preventive and Molecular-Targeted Anti-Cancer Therapies

Retinoic acid (RA) agents possess anti-tumor activity through their ability to induce cellular differentiation. However, retinoids have not yet been translated into effective systemic treatments for most solid tumors. RA signaling is mediated by the following two nuclear retinoic receptor subtypes: the retinoic acid receptor (RAR) and the retinoic X receptor (RXR), and their isoforms. The identification of mutations in retinoid receptors and other RA signaling pathway genes in human cancers offers opportunities for target discovery, drug design, and personalized medicine for distinct molecular retinoid subtypes. For example, chromosomal translocation involving RARA occurs in acute promyelocytic leukemia (APL), and all-trans retinoic acid (ATRA) is a highly effective and even curative therapeutic for APL patients. Thus, retinoid-based target discovery presents an important line of attack toward designing new, more effective strategies for treating other cancer types. Here, we review retinoid signaling, provide an update on retinoid agents and the current clinical research on retinoids in cancer, and discuss how the retinoid pathway genotype affects the ability of retinoid agents to inhibit the growth of colorectal cancer (CRC) cells. We also deliberate on why retinoid agents have not shown clinical efficacy against solid tumors and discuss alternative strategies that could overcome the lack of efficacy.

Non-hormonal mediators of uterine fibroid growth

PURPOSE OF REVIEW

Uterine fibroids are the most common benign neoplasms of the female reproductive tract and one of the major public health concerns. Although most women with uterine fibroids are asymptomatic, over 30% of them will present with varying symptoms. This review focuses on the role of non-hormonal mediators and pathways in uterine fibroid biology. Furthermore, it provides data regarding the most recent findings in the field of compounds, which use those non-hormonal pathways in the medical therapy of uterine fibroids.

RECENT FINDINGS

Complex signaling pathway alterations are crucial for uterine fibroid development. The topic of the pathophysiology of uterine fibroids focuses mostly on steroids and other hormones. However, other very important pathways exist, and some of them are independent of hormones. Some of the most important pathways, which are non-hormonal, but in some cases still hormone-depended, include growth factors, cytokines and inflammation, Smad proteins, wingless type/β-catenin and others.

SUMMARY

Much more is known about hormonal than about non-hormonal signaling in uterine fibroids. Growth factors, early life exposure and inflammation are key factors in uterine fibroid biology. Numerous agents depend on those pathways and may find their place in the current and future therapy of uterine fibroids.

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.

NAMS 2018 Utian Translational Science Symposium, October 2018, San Diego, California New therapies for leiomyomas: when surgery may not be the best option

The North American Menopause Society (NAMS) held the 2018 Utian Translational Science Symposium on October 2, 2018, in San Diego, California, to discuss new therapeutic approaches to uterine leiomyomas when surgery is not the optimal choice.Uterine leiomyomas arise from a single clonal cell and are the most common gynecologic disorder affecting reproductive and perimenopausal women worldwide. The prevalence of this disorder is approximately 40% to 70% in white women and 60% to 80% in black women. Recent research suggests that both estrogen and progesterone modulate the growth of leiomyomas, with progesterone being a major stimulator of leiomyoma growth.Women with symptomatic uterine leiomyomas experience heavy uterine bleeding, bulk symptoms, miscarriages, and pregnancy complications. Surgical therapies such as myomectomy or hysterectomy are highly effective; however, medical therapy with progestin-predominant contraceptives or gonadotropin-releasing hormone (GnRH) agonists are in many ways inadequate to address the unmet need for better, noninvasive, and cost-effective treatments.Recent advances in medical treatment, such as selective progesterone receptor modulators, new oral GnRH analogs, and clinical trials that provide new therapeutic approaches, were presented by speakers at the symposium. Research on why there is a prevalence of leiomyomas in black women, the racial and genetic effects on leiomyoma growth, and potential molecular mechanisms also were discussed.

Ulipristal Acetate Mediates Decreased Proteoglycan Expression Through Regulation of Nuclear Factor of Activated T-Cells (NFAT5)

Nuclear factor of activated T-cells (NFAT5) is a tissue specific, osmoadaptive transcription factor essential for the control of hydration homeostasis in mammalian cells. Nuclear factor of activated T-cells regulates osmolyte transporters aldo-keto reductase family 1 member B1 (AKR1B1) and solute carrier family 5 member 3 (SLC5A3) to maintain fluid equilibrium in cells. The osmotic potential of the extracellular matrix of leiomyomas is attributed to the role of proteoglycans. In leiomyoma cells, NFAT5 is overexpressed compared to myometrial cells. The selective progesterone receptor modulator, ulipristal acetate, has been reported to decrease the size of leiomyomas in clinical trials. When treated with ulipristal acetate, both patient leiomyoma tissue and leiomyoma cells grown in 3-dimensional cultures show a decrease in the expression of NFAT5 protein, solute transporters AKR1B1 and SLC5A3, and results in an associated decline in the expression of proteoglycans, versican, aggrecan, and brevican. In summary, ulipristal acetate induces changes in leiomyoma cell osmoregulation which result in a decrease in proteoglycan expression.

Global metabolomic profiling of uterine leiomyomas

BACKGROUND

Uterine leiomyomas can be classified into molecularly distinct subtypes according to their genetic triggers: MED12 mutations, HMGA2 upregulation, or inactivation of FH. The aim of this study was to identify metabolites and metabolic pathways that are dysregulated in different subtypes of leiomyomas.

METHODS

We performed global metabolomic profiling of 25 uterine leiomyomas and 17 corresponding myometrium specimens using liquid chromatography-tandem mass spectroscopy.

RESULTS

A total of 641 metabolites were detected. All leiomyomas displayed reduced homocarnosine and haeme metabolite levels. We identified a clearly distinct metabolomic profile for leiomyomas of the FH subtype, characterised by metabolic alterations in the tricarboxylic acid cycle and pentose phosphate pathways, and increased levels of multiple lipids and amino acids. Several metabolites were uniquely elevated in leiomyomas of the FH subtype, including N6-succinyladenosine and argininosuccinate, serving as potential biomarkers for FH deficiency. In contrast, leiomyomas of the MED12 subtype displayed reduced levels of vitamin A, multiple membrane lipids and amino acids, and dysregulation of vitamin C metabolism, a finding which was also compatible with gene expression data.

CONCLUSIONS

The study reveals the metabolomic heterogeneity of leiomyomas and provides the requisite framework for strategies designed to target metabolic alterations promoting the growth of these prevalent tumours.

Combining affinity propagation clustering and mutual information network to investigate key genes in fibroid

The aim of the present study was to investigate key genes in fibroids based on the multiple affinity propogation-Krzanowski and Lai (mAP-KL) method, which included the maxT multiple hypothesis, Krzanowski and Lai (KL) cluster quality index, affinity propagation (AP) clustering algorithm and mutual information network (MIN) constructed by the context likelihood of relatedness (CLR) algorithm. In order to achieve this goal, mAP-KL was initially implemented to investigate exemplars in fibroid, and the maxT function was employed to rank the genes of training and test sets, and the top 200 genes were obtained for further study. In addition, the KL cluster index was applied to determine the quantity of clusters and the AP clustering algorithm was conducted to identify the clusters and their exemplars. Subsequently, the support vector machine (SVM) model was selected to evaluate the classification performance of mAP-KL. Finally, topological properties (degree, closeness, betweenness and transitivity) of exemplars in MIN constructed according to the CLR algorithm were assessed to investigate key genes in fibroid. The SVM model validated that the classification between normal controls and fibroid patients by mAP-KL had a good performance. A total of 9 clusters and exemplars were identified based on mAP-KL, which were comprised of CALCOCO2, COL4A2, COPS8, SNCG, PA2G4, C17orf70, MARK3, BTNL3 and TBC1D13. By accessing the topological analysis for exemplars in MIN, SNCG and COL4A2 were identified as the two most significant genes of four types of methods, and they were denoted as key genes in the progress of fibroid. In conclusion, two key genes (SNCG and COL4A2) and 9 exemplars were successfully investigated, and these may be potential biomarkers for the detection and treatment of fibroid.

Endocrine-disrupting chemicals and uterine fibroids

Uterine fibroids are the most frequent gynecologic tumor, affecting 70% to 80% of women over their lifetime. Although these tumors are benign, they can cause significant morbidity and may require invasive treatments such as myomectomy and hysterectomy. Many risk factors for these tumors have been identified, including environmental exposures to endocrine-disrupting chemicals (EDCs) such as genistein and diethylstilbestrol. Uterine development may be a particularly sensitive window to environmental exposures, as some perinatal EDC exposures have been shown to increase tumorigenesis in both rodent models and human epidemiologic studies. The mechanisms by which EDC exposures may increase tumorigenesis are still being elucidated, but epigenetic reprogramming of the developing uterus is an emerging hypothesis. Given the remarkably high incidence of uterine fibroids and their significant impact on women's health, understanding more about how prenatal exposures to EDCs (and other environmental agents) may increase fibroid risk could be key to developing prevention and treatment strategies in the future.

Dietary components and uterine leiomyomas: a review of published data

Some studies have considered the association between diet and uterine fibroid risk, but the issue is largely unsettled. To identify potential modifiable risk factors for fibroid development, we have herein systematically reviewed prior publications dealing with this aspect. Comprehensive searches in electronic databases were conducted to collect studies published on association between uterine leiomyomas and both nutrients and food groups. We identified 13 publications deriving from 4 case-control, 3 cross-sectional, and 4 cohort studies. A protective effect has been demonstrated for consumption of fruits and green vegetables in both case-control and cohort studies. Moreover, very recent cross-sectional and case-control studies evaluating serum levels of 25-hydroxyvitamin-D3 tend to indicate that vitamin D insufficiency, which may in part be due to the diet intake, may play an important role in the development of uterine fibroids. No association was found with the intake of fibers, vitamin C and E, phytoestrogens and carotenoids, whereas association was controversial for the consumption of meat, fish, dairy products, and vitamin A. Most data have also been discussed herein in light of the available experimental and animal model results. These findings may be useful in devising nutritional strategies to reduce leiomyoma risk in humans.

Matrix production and remodeling as therapeutic targets for uterine leiomyoma

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

Liarozole inhibits transforming growth factor-β3--mediated extracellular matrix formation in human three-dimensional leiomyoma cultures

OBJECTIVE

To investigate the impact of liarozole on transforming growth factor-β3 (TGF-β3) expression, TGF-β3 controlled profibrotic cytokines, and extracellular matrix formation in a three-dimensional (3D) leiomyoma model system.

DESIGN

Molecular and immunohistochemical analysis in a cell line evaluated in a three-dimensional culture.

SETTING

Laboratory study.

PATIENT(S)

None.

INTERVENTION(S)

Treatment of leiomyoma and myometrial cells with liarozole and TGF-β3 in a three-dimensional culture system.

MAIN OUTCOME MEASURE(S)

Quantitative real-time reverse-transcriptase polymerase chain reaction and Western blotting to assess fold gene and protein expression of TGF-β3 and TGF-β3 regulated fibrotic cytokines: collagen 1A1 (COL1A1), fibronectin, and versican before and after treatment with liarozole, and confirmatory immunohistochemical stains of treated three-dimensional cultures.

RESULT(S)

Both TGF-β3 gene and protein expression were elevated in leiomyoma cells compared with myometrium in two-dimensional and 3D cultures. Treatment with liarozole decreased TGF-β3 gene and protein expression. Extracellular matrix components versican, COL1A1, and fibronectin were also decreased by liarozole treatment in 3D cultures. Treatment of 3D cultures with TGF-β3 increased gene expression and protein production of COL1A1, fibronectin, and versican.

CONCLUSION(S)

Liarozole decreased TGF-β3 and TGF-β3-mediated extracellular matrix expression in a 3D uterine leiomyoma culture system.

Proceedings from the Third National Institutes of Health International Congress on Advances in Uterine Leiomyoma Research: comprehensive review, conference summary and future recommendations

BACKGROUND Uterine fibroids are the most common gynecologic tumors in women of reproductive age yet the etiology and pathogenesis of these lesions remain poorly understood. Age, African ancestry, nulliparity and obesity have been identified as predisposing factors for uterine fibroids. Symptomatic tumors can cause excessive uterine bleeding, bladder dysfunction and pelvic pain, as well as associated reproductive disorders such as infertility, miscarriage and other adverse pregnancy outcomes. Currently, there are limited noninvasive therapies for fibroids and no early intervention or prevention strategies are readily available. This review summarizes the advances in basic, applied and translational uterine fibroid research, in addition to current and proposed approaches to clinical management as presented at the 'Advances in Uterine Leiomyoma Research: 3rd NIH International Congress'. Congress recommendations and a review of the fibroid literature are also reported. METHODS This review is a report of meeting proceedings, the resulting recommendations and a literature review of the subject. RESULTS The research data presented highlights the complexity of uterine fibroids and the convergence of ethnicity, race, genetics, epigenetics and environmental factors, including lifestyle and possible socioeconomic parameters on disease manifestation. The data presented suggest it is likely that the majority of women with uterine fibroids will have normal pregnancy outcomes; however, additional research is warranted. As an alternative to surgery, an effective long-term medical treatment for uterine fibroids should reduce heavy uterine bleeding and fibroid/uterine volume without excessive side effects. This goal has not been achieved and current treatments reduce symptoms only temporarily; however, a multi-disciplined approach to understanding the molecular origins and pathogenesis of uterine fibroids, as presented in this report, makes our quest for identifying novel targets for noninvasive, possibly nonsystemic and effective long-term treatment very promising. CONCLUSIONS The Congress facilitated the exchange of scientific information among members of the uterine leiomyoma research and health-care communities. While advances in research have deepened our knowledge of the pathobiology of fibroids, their etiology still remains incompletely understood. Further needs exist for determination of risk factors and initiation of preventive measures for fibroids, in addition to continued development of new medical and minimally invasive options for treatment.

Racial and ethnic differences in the pathogenesis and clinical manifestations of uterine leiomyoma

Uterine leiomyomas are the most common benign gynecologic condition. The prevalence is three times more common among women of African ethnicity. Disparity in this disease is evidenced by earlier age of onset, greater severity of symptoms, and different response to treatment. Although the pathogenesis of disease development is not completely known, growing evidence focuses on investigating the molecular mechanisms in disease development and the influence of ethnicity. Variation in the expression levels or function of estrogen and progesterone receptors, polymorphism of genes involved in estrogen synthesis and/or metabolism (COMT, CYP17), retinoic acid nuclear receptors (retinoid acid receptor-α, retinoid X receptor-α), and aberrant expression of micro-RNAs (miRNAs) are some of the molecular mechanisms that may be involved. Nutritional factors, such as vitamin D deficiency, might also contribute to the higher incidence in dark skinned populations who are also commonly suffer from hypovitaminosis D. Culture and environmental difference might have a role in disease development. Further analysis and better understanding of these mechanisms will provide insight into the molecular basis of racial disparities in leiomyoma formation and will help to develop new innovations in leiomyoma treatment.

Genome-wide DNA methylation analysis reveals a potential mechanism for the pathogenesis and development of uterine leiomyomas

Background

The pathogenesis of uterine leiomyomas, the most common benign tumor in women, remains unclear. Since acquired factors such as obesity, hypertension and early menarche place women at greater risk for uterine leiomyomas, uterine leiomyomas may be associated with epigenetic abnormalities that are caused by unfavorable environmental exposures.

Principal Findings

Profiles of genome-wide DNA methylation and mRNA expression were investigated in leiomyomas and in myometrium with and without leiomyomas. Profiles of DNA methylation and mRNA expression in the myometrium with and without leiomyomas were quite similar while those in leiomyomas were distinct. We identified 120 genes whose DNA methylation and mRNA expression patterns differed between leiomyomas and the adjacent myometrium. The biological relevance of the aberrantly methylated and expressed genes was cancer process, including IRS1 that is related to transformation, and collagen-related genes such as COL4A1, COL4A2 and COL6A3. We also detected 22 target genes of estrogen receptor (ER) alpha, including apoptosis-related genes, that have aberrant DNA methylation in the promoter, suggesting that the aberrant epigenetic regulation of ER alpha-target genes contributes to the aberrant response to estrogen.

Conclusions

Aberrant DNA methylation and its related transcriptional aberration were associated with cancer processes, which may represent a critical initial mechanism that triggers transformation of a single tumor stem cell that will eventually develop into a monoclonal leiomyoma tumor. The aberrant epigenetic regulation of ER alpha-target genes also may contribute to the aberrant response to estrogen, which is involved in the development of uterine leiomyomas after menarche.