The catechol-O-methyltransferase (COMT) gene polymorphism and prevalence of uterine fibroids

Evaluation of Comt2, Comt3, Cyp1b1, and Esr1 gene polymorphisms as risk factor for endometrial polyp

The aim of this study is to evaluate COMT2, COMT3, CYP1B1, and ESR1 gene polymorphisms and occurrence of endometrial polyps. In addition, we intended to evaluate the clinical and epidemiological features of patients with and without the presence of the disease, characterizing the possible risk factors. A cross-sectional study was performed, with a total of 309 women, including 236 in the group of women with endometrial polyp confirmed by hysteroscopy and anatomical pathological examination and 73 in the group of people with diagnostic hysteroscopy without abnormal findings from the macroscopic point of view. Polymorphisms of four genes were studied: COMT2 (rs4680), COMT3 (rs5031015), CYP1B1 (rs1056836), and ESR1 (rs2234693). Polymorphism genotyping was determined using real-time polymerase chain reaction. Considering the results, no differences were identified between the two groups with respect to age, body mass index, diabetes, dyslipidemia, or smoking. The group of women without endometrial polyps showed higher use of hormone therapy than the other group (16.4 percent versus 3.8 percent, p < .001). The COMT2, COMT3, CYP1B1, and ESR1 genes exhibited no significant difference for the occurrence of endometrial polyp between the two groups. The research concluded that no correlation was identified between the genetic polymorphisms evaluated and the presence of endometrial polyps.

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.

The Effect of Estrogen-Related Genetic Variants on the Development of Uterine Leiomyoma: Meta-analysis

Uterine leiomyoma is the most common benign gynecological tumor in women of reproductive age. It has been diagnosed approximately in 5 to 69% of women and was symptomatic in 30% of them. The underlying pathobiology of uterine leiomyoma is not well understood yet, but it can be defined as an estrogen-dependent tumor. Thus, this meta-analysis aimed to investigate ESR1rs9340799 (XbaI, A351G), ESR1rs2234693 (Pvull, T397C), and COMT rs4680 (Val158Met) polymorphisms, which affect estrogen functioning and metabolism, in association with UL risk. According to PRISMA protocol, systematic searching of databases resulted 24 included studies. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were used to evaluate associations of the three targeted polymorphisms with uterine leiomyoma risk in dominant model of inheritance. Meta-analysis included 4969 women diagnosed with uterine leiomyoma and 4934 controls. ESR1 (XbaI, A351G) polymorphism showed no significant association with uterine myeloma risk (OR = 1.19, 95% CI 0.98-1.45, P = 0.07). ESR1 (Pvull, T397C) was associated with a higher risk of uterine leiomyoma, but only in Asian (OR = 1.78, 95% CI 1.30-2.45, P = 0.0004) and COMT (Val158Met) according to our data is significantly associated with a lower risk of leiomyoma (OR = 0.83, 95% CI 0.71-0.97, P = 0.02). Our updated meta-analysis provided statistical evidence for the protective role of COMT (Val158Met) in association with the susceptibility to uterine leiomyoma and the possible role of ESR1 (Pvull, T397C) as a risk factor of this tumor.

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.

Catechol-O-methyltransferase Val158Met polymorphism is associated with increased risk of multiple uterine leiomyomas either positive or negative for MED12 exon 2 mutations

AIMS

To study the possible association of catechol-O-methyltransferase (COMT) Val158Met polymorphism with multiple and solitary uterine leiomyomas (ULs) and to check whether the COMT Val/Val genotype is associated with MED12 exon 2 mutations in fibroids.

METHODS

The COMT Val158Met allele and genotype frequencies were compared between age-matched women with ULs (n=104) and controls (n=59). Patients with UL were subcategorised by diagnosis of solitary (n=59) or multiple (n=45) fibroids and by the presence of somatic MED12 exon 2 mutations in at least one fibroid (n=32) or in neither fibroid (n=26). The association of COMT Val/Val genotype with the presence of any ULs, solitary/multiple ULs and ULs positive/negative for MED12 exon 2 mutations was evaluated by χ² tests using a dominant genotype model (G/G vs G/A+A/A) and expressed as ORs and 95% CIs.

RESULTS

The COMT Val/Val genotype frequency did not differ between the patients with UL and the controls (28.8% vs 18.6%, p=0.149, OR 1.77; CI 0.81 to 3.86). However, it was significantly higher in the patients who had multiple UL compared with the solitary UL (40% vs 20.3%, p=0.028, OR 2.61; CI 1.09 to 6.24) and to the controls (40% vs 18.6%, p=0.016, OR 2.91; CI 1.20 to 7.06). No association of the COMT Val/Val genotype with UL-specific MED12 exon 2 mutations was found (p=0.662, OR 0.77; CI 0.23 to 2.53).

CONCLUSIONS

Women with COMT Val/Val genotype are at high risk of developing multiple uterine fibroids either positive or negative for MED12 exon 2 mutations. These data are important to design new strategies for UL prophylaxis and treatment.

Epistatic Interaction of CYP1A1 and COMT Polymorphisms in Cervical Cancer

There is a clear association between the excessive and cumulative exposure to estrogens and the development of cancer in hormone-sensitive tissues, such as the cervix. We studied the association of CYP1A1 M1 (rs4646903) and COMT (rs4680) polymorphisms in 130 cervical cancer cases (c-cancer) and 179 controls. The CYP1A1 TT genotype was associated with a lower risk for c-cancer (OR = 0.39, p = 0.002). The allele C of CYP1A1 was a risk for c-cancer (OR = 2.29, p = 0.002). Women with COMT LL genotype had a higher risk of developing c-cancer (OR = 4.83, p < 0.001). For the interaction of the CYP1A1&COMT, we observed that TC&HL genotypes had a greater risk for c-cancer (OR = 6.07, p = 0.006) and TT&HL genotypes had a protection effect (OR = 0.24, p < 0.001). The CYP1A1 TT and COMT LL genotypes had higher estradiol levels in c-cancer (p < 0.001 and p = 0.037, resp.). C-cancer is associated with less production of 2-methoxy-estradiol resultant of functional polymorphisms of CYP1A1 and COMT, separately. CYP1A1 and COMT work in a metabolic sequence and their interaction could lead to an alternative pathway of estrogen metabolism with production of 16-OH-estrone that is more proliferative.

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

BACKGROUND

Uterine leiomyomas (fibroids) are highly prevalent benign smooth muscle tumors of the uterus. In the USA, the lifetime risk for women developing uterine leiomyomas is estimated as up to 75%. Except for hysterectomy, most therapies or treatments often provide only partial or temporary relief and are not successful in every patient. There is a clear racial disparity in the disease; African-American women are estimated to be three times more likely to develop uterine leiomyomas and generally develop more severe symptoms. There is also familial clustering between first-degree relatives and twins, and multiple inherited syndromes in which fibroid development occurs. Leiomyomas have been described as clonal and hormonally regulated, but despite the healthcare burden imposed by the disease, the etiology of uterine leiomyomas remains largely unknown. The mechanisms involved in their growth are also essentially unknown, which has contributed to the slow progress in development of effective treatment options.

METHODS

A comprehensive PubMed search for and critical assessment of articles related to the epidemiological, biological and genetic clues for uterine leiomyoma development was performed. The individual functions of some of the best candidate genes are explained to provide more insight into their biological function and to interconnect and organize genes and pathways in one overarching figure that represents the current state of knowledge about uterine leiomyoma development and growth.

RESULTS

In this review, the widely recognized roles of estrogen and progesterone in uterine leiomyoma pathobiology on the basis of clinical and experimental data are presented. This is followed by fundamental aspects and concepts including the possible cellular origin of uterine fibroids. The central themes in the subsequent parts are cytogenetic aberrations in leiomyomas and the racial/ethnic disparities in uterine fibroid biology. Then, the attributes of various in vitro and in vivo, human syndrome, rodent xenograft, naturally mutant, and genetically modified models used to study possible molecular mechanisms of leiomyoma development and growth are described. Particular emphasis is placed on known links to fibrosis, hypertrophy, and hyperplasia and genes that are potentially important in these processes.

CONCLUSIONS

Menstrual cycle-related injury and repair and coinciding hormonal cycling appears to affect myometrial stem cells that, at a certain stage of fibroid development, often obtain cytogenetic aberrations and mutations of Mediator complex subunit 12 (MED12). Mammalian target of rapamycin (mTOR), a master regulator of proliferation, is activated in many of these tumors, possibly by mechanisms that are similar to some human fibrosis syndromes and/or by mutation of upstream tumor suppressor genes. Animal models of the disease support some of these dysregulated pathways in fibroid etiology or pathogenesis, but none are definitive. All of this suggests that there are likely several key mechanisms involved in the disease that, in addition to increasing the complexity of uterine fibroid pathobiology, offer possible approaches for patient-specific therapies. A final model that incorporates many of these reported mechanisms is presented with a discussion of their implications for leiomyoma clinical practice.

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.

The associations between the Val158Met in the catechol-O-methyltransferase (COMT) gene and the risk of uterine leiomyoma (ULM)

The Val158Met polymorphism of the COMT gene has been implicated in susceptibility to uterine leiomyoma (ULM), but the reported results were inconclusive. The aim of the study was to evaluate the Val158Met polymorphism of the COMT gene and the risk of ULM by meta-analysis. A comprehensive electronic search for relevant articles was conducted in Pubmed, Embase, CNKI, Wanfang, and Weipu databases. Statistical analysis was performed by using the Revman4.2 software and Stata10.0 software. A total of 7 articles including 12 case-control studies were identified in this meta-analysis. The results showed that the polymorphism was associated with decreased risk of ULM (Met/Met+Val/Met vs. Met/Met: OR=0.84, 95% CI=0.70-0.99, Z=2.07, p=0.04). In the subgroup analyses by ethnicity, significant decreased risk was found among the black populations (OR=0.68, 95% CI=0.48-0.97, Z=2.15, p=0.03). The current meta-analysis suggested that the Val158Met polymorphism in the COMT gene was associated with decreased risk of ULM, especially in the black population. Future studies are needed to validate our conclusions.

Is fibroid heterogeneity a significant issue for clinicians and researchers?

The clinical and scientific literature overwhelmingly deals with fibroids as a single entity or disease. This convenient assumption of homogeneity may be an important oversight given that substantial evidence exists for heterogeneity between fibroids at many levels. Failure to recognize and accommodate fibroid heterogeneity can have significant ramifications for both clinical treatment decisions and research protocol design. The aim of this article is to review the current knowledge of fibroid heterogeneity and to identify key areas where fibroid heterogeneity should be taken into consideration both clinically and when designing research protocols. Uterine leiomyomata display significant and well-documented heterogeneity in symptoms, diagnostic imaging appearance, pathology, genetic background and therapeutic requirements. Additional research is needed to better understand fibroid heterogeneity as it relates to pathogenesis, molecular targets for potential new therapies, patient symptoms and, ultimately, treatment. To this list should also be added heterogeneity of genetics, lifestyle and individual clinical characteristics of the fibroid. Increasingly, an understanding of uterine leiomyoma heterogeneity will be of importance for clinicians who see patients with this common and costly disease.

Polymorphism of catechol-o-methyltransferase and uterine leiomyoma

Uterine leiomyoma (ULM) is the most common gynecological benign tumor that is affecting around 20-50 % of women over the age of 30. Although its molecular pathogenesis is still unknown, ULM has a multifactorial etiology determined by both genetics and environmental factors. The present study was designed to find out whether Val158Met polymorphism in the catechol-o-methyltransferase (COMT) gene is associated with the risk of ULM. We analyzed COMT Val158Met polymorphism in 105 ULMs patients and 105 healthy subjects using a polymerase chain reaction-based restriction fragment length polymorphism assay. We found remarkably similar frequencies in ULM compared with controls for COMT Val158Met genotypes and alleles, and no association was found between ULM and this polymorphism (p = 0.46). The COMT 158 Met allele in patients with large (≥5 cm) fibroids was higher than in patients with small (<5 cm) fibroids, and significant association was found between fibroid size and COMT 158 Met allele (p = 0.011, OR 0.50, 95 %CI 0.28-0.90). Our results reflect that COMT Val158Met polymorphism is not associated with an increased risk of ULMs, but Val158Met polymorphism may be a risk factor for development of large fibroids in Turkish patients with ULM.

The role of MSP I CYP1A1 gene polymorphism in the development of uterine fibroids

The cytochrome P-450 1A1 (CYPA1A) gene plays an important role in the metabolization of estrogen and is therefore a candidate marker for fibroids. In a case-control study, we were unable to demonstrate any association between MSP I CYP1A1 polymorphism and the risk of leiomyoma in Brazilian women.