The associations between the polymorphisms of the ER-α gene and the risk of uterine leiomyoma (ULM)

The AGT Haplotype of the ESR2 Gene Containing the Polymorphisms rs2077647A, rs4986938G, and rs1256049T Increases the Susceptibility of Unexplained Recurrent Spontaneous Abortion in Women in the Chinese Hui Population

Background

Estrogen has an important role in unexplained recurrent spontaneous abortion (URSA). Polymorphisms of the ESR1 gene and the ESR2 gene have been identified as risk factors for URSA, but with varied associations in Chinese populations. This study aimed to compare the role of gene polymorphisms of ESR1 and ESR2 and the risk of URSA in the Chinese Hui and Chinese Han populations.

Material/Methods

Chinese Hui women (n=171) and Chinese Han women (n=234) with URSA were compared with healthy controls (n=417) matched by ethnicity and age. Genotyping was performed using direct sequencing and identified three polymorphisms of the ESR1 gene (rs9340799, rs2234693, and rs3798759) and three polymorphisms of the ESR2 gene (rs207764, rs4986938, and rs1256049). The association between ESR1 and ESR2 gene polymorphisms and the risk of URSA was evaluated statistically using the odds ratio (OR) and 95% confidence interval (CI).

Results

No association was detected between the allelic, dominant, and recessive models of ESR1 and ESR2 gene polymorphisms and the risk of URSA in Chinese Han and Hui populations (p>0.05). The distribution of the AGT haplotype containing ESR2 gene polymorphisms rs2077647A, rs4986938G, and rs1256049T was significantly reduced in patients with URSA compared with controls in the Chinese Hui population (OR, 0.29; 95% CI, 0.14–0.62; p=0.0009; p_adj=0.005).

Conclusions

The AGT haplotype of the ESR2 gene containing the polymorphism rs2077647A, rs4986938G, and rs1256049T (ESR2 hap_AGT) was a protective factor for URSA in women in the Chinese Hui population when compared with the Chinese Han population.

Oestrogen receptor alpha PvuII polymorphism and uterine fibroid incidence in Caucasian women

Introduction

Uterine fibroids (UFs) are benign, monoclonal tumours of the female genital tract that originate from the myometrium. They may be diagnosed in as many as 80% of women depending on the selected population. UFs depend mostly on steroid hormones. Elevated levels of oestrogens and progesterone are believed to be among the most important factors inducing their formation and growth. These facts suggest that oestrogen (ESR) and progesterone receptors are crucial in UF pathophysiology as well. Previous studies have shown that, in some populations, polymorphisms in ESR genes (e.g. PvuII) constitute an important risk factor for UFs.

Material and methods

The aim of our study was to investigate whether ESRα PvuII polymorphism is associated with an increased risk of UFs in Caucasian women of Polish origin. A total of 197 patients (114 UF-positive and 83 controls) were included in this retrospective cohort study. ESRα gene polymorphism PvuII (rs2234693) was assayed with PCR and restriction fragment length polymorphism (RFLP).

Results

Our study found no significant difference in the occurrence of ESR PvuII polymorphism between women with UFs and UF-free controls in the selected population.

Conclusions

Our results did not indicate a significant association between ESRα gene PvuII polymorphism and the risk of UFs in Caucasian women of Polish origin. More studies and comparisons between races are necessary to clarify the role of ESRα in the development and progression of UFs.

Combination effect of cytochrome P450 1A1 gene polymorphisms on uterine leiomyoma: A case-control study

Uterine leiomyoma (UL) is an estrogen-dependent neoplasm of the uterus, and estrogen metabolizing enzymes affect its progression. This study aimed to evaluate the association between two single-nucleotide polymorphisms of cytochrome P450 1A1 (CYP1A1) gene and UL risk. The study consisted of 105 patients with UL and 112 healthy women as controls. Ile462Val (A/G) and Asp449Asp (T/C) polymorphisms of CYP1A1 gene were analyzed by DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism methods, respectively. The findings indicated no association between Ile462Val (A/G) and Asp449Asp (T/C) polymorphisms of CYP1A1 gene and UL (p < 0.05). However, the combination effect of TT/AG genotypes of the Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms was associated with 4.3-fold higher risk of UL. In addition, haplotype analysis revealed that TG haplotype of the Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms could increase the UL risk nearly 4.9-fold. Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms of CYP1A1 gene were not associated with UL susceptibility; however, the combination of the TT/AG genotypes and TG haplotype could increase the UL risk.

Gene Polymorphisms of Toll-Like Receptor 9 -1486T/C and 2848G/A in Cervical Cancer Risk

OBJECTIVE

This work aims to explore whether Toll-like receptor 9 (TLR9) -1486T/C and 2848G/A polymorphisms are associated with cervical cancer risk.

METHODS

A comprehensive electronic search of studies published from January 1999 to October 2014 was conducted in Medline (Ovid), Embase, PubMed, Wanfang, Weipu, and CNKI. The algorithm included "TLR," "Toll-like receptor," "polymorphism," "variant," "mutation," and "cervical cancer." Seven articles, including 9 studies, were pooled using Revman 5.2 (Cochrane Collaboration, Copenhagen, Denmark). Odds ratio (OR) was used to explore the involvement of minor allele C (C vs T and CC + CT vs TT) of TLR9 (-1486T/C, rs187084) and minor allele A (A vs G and AA + AG vs GG) of TLR9 (2848G/A, rs352140) in cervical cancer risk.

RESULTS

Toll-like receptor 9 (-1486T/C, rs187084) polymorphisms were associated with an elevated risk of cervical cancer (C vs T: OR, 1.15; 95% confidence interval [CI], 1.03-1.29; CC + CT vs TT: OR, 1.30; 95% CI, 1.11-1.53). We found no significant association between TLR9 (2848G/A, rs352140) polymorphisms and cervical cancer risk (A vs G: OR, 1.15; 95% CI, 0.87-1.54; AA + AG vs GG: OR, 1.27; 95% CI, 0.75-2.17).

CONCLUSIONS

This meta-analysis indicates that TLR9 (-1486T/C, rs187084)-but not TLR9 (2848G/A, rs352140)-may be a risk factor for cervical cancer.

Endocrinology of uterine fibroids: steroid hormones, stem cells, and genetic contribution

PURPOSE OF REVIEW

Uterine fibroids are extremely common, and can cause significant morbidity, yet the exact cause of these tumors remains elusive and there are currently no long-term treatments available. In this review, we aim to provide an overview of steroid hormones, genetic abnormalities, and stem cells in the pathogenesis of uterine fibroids.

RECENT FINDINGS

A universal feature of fibroids is responsiveness to estrogen and progesterone, and most of the currently available therapies exploit this characteristic. Ulipristal acetate has recently shown particular promise for providing long-term relief from uterine fibroids. Additionally, fibroid stem cells were isolated and appear to be necessary for growth. The recent discovery of somatic mutations involving mediator subunit complex 12 (MED12) or high-mobility group AT-hook 2 (HMGA2) in the majority of fibroids and the links to their pathophysiology were also significant advances.

SUMMARY

The recent shift in focus from hormones to fibroid stem cells and genetic aberrations should lead not only to a deeper understanding of the specific cause of fibroids, but also to the discovery of new therapeutic targets. Targeting the products of genetic mutations or fibroid stem cells has the potential to achieve both better control of current tumors and the prevention of new fibroids.

Ovarian steroids, stem cells and uterine leiomyoma: therapeutic implications

BACKGROUND

Uterine leiomyoma is the most common benign tumor in women and is thought to arise from the clonal expansion of a single myometrial smooth muscle cell transformed by a cellular insult. Leiomyomas cause a variety of symptoms, including abnormal uterine bleeding, pelvic pain, bladder or bowel dysfunction, and recurrent pregnancy loss, and are the most common indication for hysterectomy in the USA. A slow rate of cell proliferation, combined with the production of copious amounts of extracellular matrix, accounts for tumor expansion. A common salient feature of leiomyomas is their responsiveness to steroid hormones, thus providing an opportunity for intervention.

METHODS

A comprehensive search of PUBMED was conducted to identify peer-reviewed literature published since 1980 pertinent to the roles of steroid hormones and somatic stem cells in leiomyoma, including literature on therapeutics that target steroid hormone action in leiomyoma. Reviewed articles were restricted to English language only. Studies in both animals and humans were reviewed for the manuscript.

RESULTS

Estrogen stimulates the growth of leiomyomas, which are exposed to this hormone not only through ovarian steroidogenesis, but also through local conversion of androgens by aromatase within the tumors themselves. The primary action of estrogen, together with its receptor estrogen receptor α (ERα), is likely mediated via induction of progesterone receptor (PR) expression, thereby allowing leiomyoma responsiveness to progesterone. Progesterone has been shown to stimulate the growth of leiomyoma through a set of key genes that regulate both apoptosis and proliferation. Given these findings, aromatase inhibitors and antiprogestins have been developed for the treatment of leiomyoma, but neither treatment results in complete regression of leiomyoma, and tumors recur after treatment is stopped. Recently, distinct cell populations were discovered in leiomyomas; a small population showed stem-progenitor cell properties, and was found to be essential for ovarian steroid-dependent growth of leiomyomas. Interestingly, these stem-progenitor cells were deficient in ERα and PR and instead relied on the strikingly higher levels of these receptors in surrounding differentiated cells to mediate estrogen and progesterone action via paracrine signaling.

CONCLUSIONS

It has been well established that estrogen and progesterone are involved in the proliferation and maintenance of uterine leiomyoma, and the majority of medical treatments currently available for leiomyoma work by inhibiting steroid hormone production or action. A pitfall of these therapeutics is that they decrease leiomyoma size, but do not completely eradicate them, and tumors tend to regrow once treatment is stopped. The recent discovery of stem cells and their paracrine interactions with more differentiated cell populations within leiomyoma has the potential to provide the missing link between developing therapeutics that temper leiomyoma growth and those that eradicate them.

Association of PvuII and XbaI polymorphisms in estrogen receptor alpha gene with the risk of hepatitis B virus infection in the Guangxi Zhuang population

BACKGROUND AND OBJECTIVE

Available evidence has suggested that estrogen receptor alpha (ESR1) is implicated in the pathogenic process of hepatitis B infection. Therefore, we evaluated the association of PvuII (rs2234693) and XbaI (rs9340799) in ESR1 and HBV infection in Guangxi Zhuang populations.

METHODS

A total of 389 subjects were divided into four groups: 112 patients with chronic hepatitis B (CHB), 65 patients with hepatitis B virus (HBV)-related liver cirrhosis (LC), 107 patients with HBV-related hepatocellular carcinoma (HCC), and 105 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism strategy was used to detect ESR1 gene PvuII and XbaI polymorphisms.

RESULTS

Compared with healthy controls, binary logistic regression analyses show that the CC genotype of PvuII was associated with a significantly increased susceptibility to CHB compared with the TT genotype (OR=1.760, 95% CI 1.316-2.831; p=0.044). The PvuII CC genotype was also associated with significantly increased risk of HBV-related LC (OR=1.921, 95% CI 1.342-2.478; p=0.043). Similarly, the subjects bearing the homozygous CC genotype of PvuII polymorphism also had more than a 1.7-fold increased risk for development of HCC (OR=1.748, 95% CI 1.313-2.787; p=0.010) compared with those bearing the TT genotype. Furthermore, the AC haplotype was associated with a significantly increased risk of HCC with an OR of 1.456 (p=0.003). In contrast, there were no significant differences in the genotype and allele of XbaI polymorphisms in the ESR1 gene between the groups of patients and healthy controls. In addition, ESR1 polymorphisms were not significantly associated with susceptibility to HBV-related HCC when using CHB and LC patients as references.

CONCLUSION

We conclude that the CC genotype of PvuII in ESR1 is associated with an increased risk of CHB, HBV-related LC and HCC in Guangxi Zhuang populations.