Role of vitamin D in uterine fibroid biology

Human uterine leiomyoma contains low levels of 1, 25 dihdroxyvitamin D3, and shows dysregulated expression of vitamin D metabolizing enzymes

OBJECTIVES

To evaluate tissue concentration of 1, 25 dihydroxyvitamin D3, and gene expression level of CYP27B1 that codes for 1-α hydroxylase (vitamin D activating enzyme), and CYP24A1 that codes for 24-hydroxylase (vitamin D catabolizing enzyme) in human uterine leiomyoma (ULM), its adjacent myometrium (Myo-F), and normal myometrium (Myo-N).

STUDY DESIGN

Levels of 1, 25 dihydroxyvitamin D3 were measured using HPLC and Diode detectors whereas CYP27B1, and CYP24A1 expressions were assessed using Real-Time PCR in ULM, Myo-F, and Myo-N. Non-parametric statistics were used.

RESULTS

ULMs contained significantly less 1, 25 dihydroxy vitamin D3 compared to Myo-F (3.0, IQR: 1.0-9.0 versus 6.0, IQR: 3.0-13.0 μg/ kg, P value is 0.03). No significant difference was detected between ULM and Myo-N, or Myo-F and Myo-N. Intratumoral level of the active form of vitamin D did not differ according to the type of ULM (submucous or interstitial/subserous), or to the ULM volume. CYP27B1 was expressed in ULM (2.17, IQR: 0.65-4.9), Myo-F (4.94, IQR: 1.04-22.59), and Myo-N (0.99, IQR: 0.49-1.71) to a comparable level. CYP24A1 expression was significantly higher in ULM compared to Myo-N (2.00, IQR: 0.69-10.77 versus 0.22, IQR: 00- 0.96, respectively, P value is 0.04).

CONCLUSIONS

Human ULMs contain significantly lower 1, 25 dihydroxyvitamin D3 than its adjacent myometrium. ULM, Myo-F, and Myo-N express CYP27B1 and CYP24A1. ULMs express significantly higher level of CYP24A1 than normal myometrium indicating that over expression of 24-hydroxylase is a mechanism by which ULMs sustain a relative state of hypovitaminosis D.

Vitamin D and Uterine Fibroids-Review of the Literature and Novel Concepts

This article provides a detailed review of current knowledge on the role of vitamin D and its receptor in the biology and management of uterine fibroids (UFs). Authors present ideas for future steps in this area. A literature search was conducted in PubMed using the following key words: "uterine fibroid" and "vitamin D". The results of the available studies, published in English from January 2002 up to April 2018, have been discussed. Vitamin D is a group of steroid compounds with a powerful impact on many parts of the human body. This vitamin is believed to regulate cell proliferation and differentiation, inhibit angiogenesis, and stimulate apoptosis. Nowadays, hypovitaminosis D is believed to be a major risk factor in the development of UFs. In many studies vitamin D appears to be a powerful factor against UFs, resulting in inhibition of tumor cell division and a significant reduction in its size, however, the exact role of this compound and its receptor in the pathophysiology of UFs is not fully understood. According to available studies, vitamin D and its analogs seem to be promising, effective, and low-cost compounds in the management of UFs and their clinical symptoms, and the anti-tumor activities of vitamin D play an important role in UF biology. The synergy between vitamin D and selected anti-UF drugs is a very interesting issue which requires further research. Further studies about the biological effect of vitamin D on UF biology are essential. Vitamin D preparations (alone or as a co-drugs) could become new tools in the fight with UFs, with the additional beneficial pleiotropic effect.

Evaluating the effects of administration of 25-hydroxyvitamin D supplement on serum anti-mullerian hormone (AMH) levels in infertile women

The aim of the study was to evaluate the effects of administration of 25-hydroxyvitamin D [25(OH) D] on serum antimullerian hormone (AMH) levels in infertile women. The study was performed as a non-randomized clinical trial on 30 infertile women who had low serum level of both 25(OH) D and anti-mullerian hormone. Vitamin D was prescribed 50,000 IU weekly for up to three months for all eligible participants. Serum levels of both 25(OH) D and AMH have increased significantly after treatment with 25(OH) D. There was a significant correlation between serum levels of 25(OH) D after treatment with AMH (p = .029, OR = 2.9, CI 95% = 2.7-5.5). Mean AMH level after treatment was higher in women with sufficient 25(OH) D, than women with insufficient 25(OH) D (1.048 ± 0.644 vs. 0.513 ± 0.284 ng/ml), which shows a significant difference (p = .043). Also, after treatment, in women with mean AMH level of >0.7 ng/ml (19 women), mean level of 25(OH) D was higher than in women with mean AMH level of <0.7 ng/ml (11 women) (59.332 ± 21.751 vs. 38.881 ± 17.281 ng/ml, p = .013). This means that higher levels of 25(OH) D are accompanied with higher levels of AMH. In conclusions with administration and increasing the amount of vitamin D serum levels, the serum levels of AMH have increased.

Association between fok1 polymorphism of vitamin D receptor gene with uterine leiomyoma in Turkish populations

Objective:

The aim of this research was to determine the association between the fok1 polymorphism and uterine leiomyomas.

Material and Methods:

For genotyping the fok1 polymorphism of the vitamin D receptor, real-time polymerase chain reaction was performed on blood samples of uterine leiomyoma (n=27) and control (n=33) groups. For statistical analyses, SPSS v.23 software (SPSS Inc., Chicago, IL, USA) was used.

Results:

A statistically significant difference was observed for the frequency of the CC genotype between the uterine leiomyoma and control groups, and the frequencies of the T allele in the uterine leiomyoma groups were significantly higher than in the control group.

Conclusion:

The presence of the fok1 CC genotype may be a risk-reducing factor and the T allele may be a potential risk factor for developing uterine leiomyoma.

Alternative Oral Agents in Prophylaxis and Therapy of Uterine Fibroids-An Up-to-Date Review

Uterine fibroids (UFs) are the most common tumors of the female genital tract. The effect of UFs on the quality of life and the overall cost of treatment are significant issues worldwide. Tumor size and location are the two specific factors which influence the occurrence of symptoms, the need for, and method of, treatment (some tumors require surgery while some can be treated with selected drugs). Primary prevention and treatment of early UF disease are worthy goals that might have a great impact on health care systems. Several treatments and prophylactic methods can be used in this endeavor. This publication presents current data about lesser-known substances which may have a beneficial effect on the treatment or prophylaxis of UFs and can be administered orally, serving as an alternative to (or complement of) surgery or selective progesterone receptor modulators (SPRMs). Early prevention and treatment of UFs in women from high-risk groups should be our priority. Innovative forms of UF management are under intensive investigation and may be promising options in the near future. Many of them evaluated vitamin D, paricalcitol, epigallocatechin gallate (EGCG), elagolix, aromatase inhibitors (AIs), and cabergoline and deemed them to be safe and effective. The next step in such projects should be properly constructed randomized control trials (RCTs), carried out by successive phases.

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.

Uterine Fibroids: Burden and Unmet Medical Need

Uterine fibroids affect a wide cross-section of the population, with prevalence, symptom severity, and overall disease burden generally higher among black women, likely due to both genetic and environmental factors. Potential symptoms of uterine fibroids include painful and excessive uterine bleeding, interference with everyday life and self-image, and impaired fertility. Because of the high estimated prevalence and costs associated with treatments, the direct and indirect costs of uterine fibroids are substantial for both the health care system and the individual patient. Special patient populations—such as black women, women seeking to retain fertility, and women with asymptomatic fibroids—have particular treatment needs that require a variety of diagnostic methods and treatment options. Despite the widespread occurrence of uterine fibroids and newer treatment options, little high-quality data are available to formulate evidence-based guidelines that address these unmet patient needs. Specific areas in need of attention include improving diagnostic techniques, increasing patient access to early treatment, and identifying best practices for this diverse patient population.

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.

Oxidative stress: a key regulator of leiomyoma cell survival

OBJECTIVE

To determine the effects of attenuating oxidative stress with the use of dichloroacetate (DCA) on the expression of key redox enzymes myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) as well as on apoptosis.

DESIGN

Prospective experimental study.

SETTING

University medical center.

PATIENT(S)

Cells established from myometrium and uterine fibroid from the same patients.

INTERVENTION(S)

Cells were exposed to normal (20% O₂) or hypoxic (2% O₂) conditions for 24 hours with or without DCA (20 μg/mL), a metabolic modulator that shifts anaerobic to aerobic metabolism.

MAIN OUTCOME MEASURE(S)

Nitrate/nitrite (iNOS activity indicator), iNOS, Bcl-2/Bax ratio, MPO, and caspase-3 activities and levels were determined by means of Greiss assay, real-time reverse-transcription polymerase chain reaction, and ELISA. Data were analyzed with the use of SPSS by means of one-way analysis of variance with Tukey post hoc analysis and independent t tests.

RESULT(S)

MPO, iNOS, and nitrate/nitrite expression were higher in leiomyoma than in myometrial cells, and they were further enhanced by hypoxia in myometrial cells. Treatment with the use of DCA decreased MPO, iNOS, and nitrate/nitrite levels and negated the effect of hypoxia in both types of cells. Leiomyoma cells showed less apoptosis, as indicated by both caspase-3 activity and the Bcl-2/Bax ratio, than myometrial cells. Hypoxia further decreased apoptosis in myometrial cells with no further effect on leiomyoma cells. Treatment with DCA resulted in increased apoptosis in both types of cells, even in the presence of hypoxia.

CONCLUSION(S)

Shifting anaerobic to aerobic metabolism with the use of DCA resulted in an increase in apoptosis in leiomyoma cells and protected myometrial cells from the acquisition of the leiomyoma-like phenotype.

Tranilast Inhibits Genes Functionally Involved in Cell Proliferation, Fibrosis, and Epigenetic Regulation and Epigenetically Induces miR-29c Expression in Leiomyoma Cells

Tranilast (N-3,4-dimethoxycinnamoyl anthranilic acid) is an antiallergic agent with inhibitory effects on cell proliferation and extracellular matrix production. Here we assess the effect of tranilast on the expression of miR-29c and genes functionally involved in cell proliferation, fibrosis, and epigenetic regulation in isolated leiomyoma smooth muscle cells (LSMC). Tranilast significantly inhibited the rate of LSMC proliferation, which was associated with downregulation of cell cycle progression genes cyclin D1 (CCND1) and cyclin-dependent kinase 2 (CDK2) expression at messenger RNA and protein levels ( P < .05). Tranilast also suppressed the expression of collagen type I (COL1), collagen type III alpha 1 chain (COL3A1), the profibrotic cytokine, transforming growth factor β-3 (TGF-β3), DNA (cytosine-5)-methyltransferase 1 (DNMT1), and enhancer of zeste homolog 2 (EZH2), which regulate epigenetic status of gene promoters ( P < .05). Tranilast also significantly induced the expression of cellular and secreted miR-29c through downregulation of methylation status of miR-29c promoter ( P < .05). In addition, tranilast suppressed the activity of luciferase reporter containing 3'UTR of COL3A1 and CDK2, which are downstream targets of miR-29c ( P < .05). Knockdown of miR-29c expression attenuated the inhibitory effects of tranilast on COL3A1 and CDK2 protein expression ( P < .05). Collectively, these findings suggest that tranilast could have therapeutic potential as an inhibitory agent for leiomyoma growth and its associated symptoms.

Hypovitaminosis D and "small burden" uterine fibroids: Opportunity for a vitamin D supplementation

The aim of this study was to evaluate the effect of vitamin D supplementation in women with hypovitaminosis D and "small burden" uterine fibroids.This study focused on 208 women diagnosed with uterine fibroids and concomitant hypovitaminosis D, from January to December 2014. One hundred eight women of the initial study population were diagnosed with "small burden" uterine fibroids. Among them, those who underwent a proper vitamin D supplementation constituted the "study group" (n = 53), while women who spontaneously refused the therapy or did not perform it properly, constituted the "control group" (n = 55). The characteristics of uterine fibroids, the fibroid-related symptoms, and the vitamin D serum levels were evaluated 12 months after the initial diagnosis.In women with uterine fibroids, a negative correlation emerged between the baseline 25-hydroxy-cholecalciferol (25-OH-D3) concentration and both the volume of the largest fibroid (r = -0.18, P = 0.01) and the total volume of fibroids (r = -0.19, P = 0.01). No correlation was found between the baseline 25-OH-D3 levels and the number of fibroids per patient (r = -0.10, P = 0.16). In women of the "study group," a significant increase in the 25-OH-D3 serum level was observed after 12 months of supplementation, and a lower rate of surgical or medical treatment due to the "progression to extensive disease" was reported (13.2% vs 30.9%, P = 0.05).Supplementation therapy with 25-OH-D3 restores normal vitamin D serum levels in women with "small burden" fibroids. In these women, vitamin D supplementation seems to reduce the progression to an extensive disease, and thus the need of conventional surgical or medical therapy.

Influence of vitamin D and transforming growth factor β3 serum concentrations, obesity, and family history on the risk for uterine fibroids

OBJECTIVE

To evaluate the influence of 25-hydroxyvitamin D and transforming growth factor β3 (TGF-β3) serum concentrations, weight, and family history on the risk of developing uterine fibroids.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PATIENT(S)

A total of 188 women, including patients admitted for uterine fibroid surgery (n = 105) as the study group and healthy women of similar age (n = 83) as controls.

INTERVENTION(S)

Medical history and completion of specially designed questionnaire, transvaginal or transabdominal genital ultrasound scan, blood sampling, and measurement of vitamin D and TGF-β3 serum concentrations.

MAIN OUTCOME MEASURE(S)

Evaluation of the impact of family history, vitamin D, and TGF-β3 serum concentrations on the risk of developing uterine fibroids.

RESULT(S)

Mean 25-hydroxyvitamin D serum concentrations were 21.9 ± 8.9 ng/mL and 26.7 ± 11.9 ng/mL in patients with uterine fibroids and controls, respectively. The difference was statistically significant. The TGF-β3 serum concentrations in the fibroid-positive group ranged from 1.20 to 436.15 pg/mL (half the patients had concentrations >16.25 pg/mL). Concentrations in the control group ranged from 0.96 to 49.08 pg/mL (half the women had concentrations of >11.80 pg/mL). The differences were statistically significant. Higher body mass index (BMI) and positive family history were also found to be among the risk factors for uterine fibroids.

CONCLUSION(S)

Our study confirmed higher BMI, positive family history, and lower vitamin D and higher TGF-β3 serum concentrations as risk factors for uterine fibroids.

Cesarean myomectomy trends and controversies: an appraisal

OBJECTIVE

Although the first report on cesarean myomectomy (CM) was a century ago, the management of a myomectomy during a cesarean section (CS) remains controversial. The objective of this study is to provide the latest data on this topic regarding the techniques and complications of CM.

METHODS

The authors consulted the most important scientific databases investigating the indications and contraindications for CM, the operational techniques, benefits and complications.

RESULTS

CM provides the benefits of two surgeries in one laparotomy, avoiding the risks of repeated anesthesia and relaparotomy. Nevertheless, in some patients, CM may be associated with increased morbidity and, in such cases, an interval myomectomy might be a safer option. Myomas compromising fetal extraction and uterine incision and/or suturing should be preferably enucleated during CS. CM is generally considered relatively safe in cases of anterior wall myomas, subserous and pedunculated myomas, particularly if a myomectomy is feasible without additional hysterotomy. Multiple myomas, deep intramural, fundal and cornual myomas and posterior uterine wall myomas are associated with more surgical complications during CM.

CONCLUSIONS

With increasing reports in favor of CM, the risk-benefit ratio should be still evaluated with randomized controlled trials, in order to achieve more data on CM.

Uterine fibroids

Uterine fibroids (also known as leiomyomas or myomas) are common clonal neoplasms of the uterus. Fibroids have both smooth muscle and fibroblast components, in addition to a substantial amount of fibrous extracellular matrix, which all contribute to the pathogenetic process. Fibroids are extremely heterogeneous in their pathophysiology, size, location and clinical symptomatology. They are also a part of a range of disease in which some variants have facets of malignant behaviour but overall are benign. Risk for fibroids is associated with race; black women have a higher risk of developing fibroids earlier in life than their white counterparts and also develop more-severe forms of the disease. Clinically, fibroids account for one-third to half of all hysterectomies and are associated with substantial morbidity and health care costs for women of reproductive age. Indeed, current treatments are primarily surgical and interventional; approximately three-quarters of all fibroid treatments are hysterectomies. However, clinical innovations are emerging in the use of progesterone receptor modulators as a medical therapy. New information is rapidly accumulating about the genetic subgroups that lead to fibroid formation, which might aid further understanding of the clinical heterogeneity of this disease and lead to individualized treatments. This information is a crucial development given the current lack of high-quality evidence on which to base therapeutic decisions.

Increasing serum 25-hydroxyvitamin D is associated with reduced odds of long menstrual cycles in a cross-sectional study of African American women

OBJECTIVE

To examine the association between serum 25-hydroxyvitamin D [25(OH)D] and menstrual cycle length and regularity.

DESIGN

Community-based, cross-sectional study of serum 25(OH)D (adjusted for seasonal differences in timing of blood draw) and menstrual cycle length. Women aged 23-34 years reported their gynecologic history. Menstrual cycles were described with four independent categories (normal, short, long, irregular). We used polytomous logistic regression to estimate the association between a doubling of seasonally adjusted 25(OH)D and the odds of each cycle category.

SETTING

Not applicable.

PATIENT(S)

A total of 1,102 African American women.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Self-reported menstrual cycle length over the previous 12 months, excluding women who were using cycle-regulating medications over the entire year. Women who reported that their cycles were "too irregular to estimate" were classified as having irregular cycles. A typical cycle length of <27 days was considered "short," >34 days was "long," and 27-34 days was "normal."

RESULT(S)

The median 25(OH)D level was 14.7 ng/mL (interquartile range, 10.9-19.6 ng/mL). A doubling of 25(OH)D was associated with half the odds of having long menstrual cycles: adjusted odds ratio (aOR) 0.54, 95% confidence interval (CI) 0.32-0.89. 25-Hydroxyvitamin D was not associated with the occurrence of short (aOR 1.03, 95% CI 0.82-1.29) or irregular (aOR 1.46, 95% CI 0.88-2.41) menstrual cycles. Results were robust to several sensitivity analyses.

CONCLUSION(S)

These findings suggest that vitamin D status may influence the menstrual cycle and play a role in ovarian function. Further investigation of 25(OH)D and ovarian hormones, and prospective studies of 25(OH)D and cycle length, are needed.