Polymorphism of catechol-o-methyltransferase and uterine leiomyoma

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.

Analysis of estrogen and progesterone receptor gene polymorphisms in leiomyoma

BACKGROUND

Leiomyoma, one of the most common benign tumors, causes morbidity during the reproductive years in women. The molecular pathogenesis of the disease is not clear. Leiomyomas are hormone-sensitive tumors affecting around 20%-25% of women. Gene polymorphism studies could be important and explaining in the evaluation of multifactorial diseases such as leiomyoma. Polymorphisms involving genes responsible for the synthesis and signalization of steroid hormones could be used as genetic markers for hormone-related conditions. The purpose of this study was to analyze the effect of ERα-351 XbaI A/G, ERα-397 PvuII T/C, and progesterone receptor (PGR) PROGINS polymorphisms on the development of leiomyomas.

MATERIAL AND METHODS

In this study, 213 samples (103 leiomyoma patients and 110 healthy controls) participated. The ERα-351 XbaI A/G and ERα-397 PvuII T/C gene polymorphisms were analyzed using PCR-RFLP method. PGR PROGINS polymorphism was analyzed by PCR method with specific primers.

RESULTS

The genotype distribution and allele frequency of the ERα-351 XbaI A/G, ERα-397 PvuII T/C, and PGR PROGINS polymorphisms were not statistically different between leiomyoma patient and control groups (p > 0.05).

CONCLUSION

This study reflects that ERα and PGR PROGINS polymorphisms may not be one of the many genetic factors for leiomyoma susceptibility.

G-protein-coupled estrogen receptor-30 gene polymorphisms are associated with uterine leiomyoma risk

The G-protein-coupled estrogen receptor (GPR30, GPER-1) is a member of the G-protein-coupled receptor 1 family and is expressed significantly in uterine leiomyomas. To understand the relationship between GPR30 single nucleotide polymorphisms and the risk of leiomyoma, we measured the follicle-stimulating hormone (FSH) and estradiol (E2) levels of 78 perimenopausal healthy women and 111 perimenopausal women with leiomyomas. The participants' leiomyoma number and volume were recorded. DNA was extracted from whole blood with a GeneJET Genomic DNA Purification Kit. An amplification-refractory mutation system polymerase chain reaction approach was used for genotyping of the GPR30 gene (rs3808350, rs3808351, and rs11544331). The differences in genotype and allele frequencies between the leiomyoma and control groups were calculated using the chi-square (χ2) and Fischer's exact test. The median FSH level was higher in controls (63 vs. 10 IU/L, p=0.000), whereas the median E2 level was higher in the leiomyoma group (84 vs. 9.1 pg/mL, p=0.000). The G allele of rs3808351 and the GG genotype of both the rs3808350 and rs3808351 polymorphisms and the GGC haplotype increased the risk of developing leiomyoma. There was no significant difference in genotype frequencies or leiomyoma volume. However, the GG genotype of the GPR30 rs3808351 polymorphism and G allele of the GPR30 rs3808351 polymorphism were associated with the risk of having a single leiomyoma. Our results suggest that the presence of the GG genotype of the GPR30 rs3808351 polymorphism and the G allele of the GPR30 rs3808351 polymorphism affect the characteristics and development of leiomyomas in the Turkish population.

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.