CYP17A1 rs743572 polymorphism might contribute to endometriosis susceptibility: evidences from a case-control study

Investigation of biomarkers in Endometriosis-associated infertility: Systematic Review

The relationship between endometriosis and infertility is still unknown, but it is possible that genetic polymorphisms influence these two variables. This study aims to identify, in the literature, which polymorphisms are related to infertility in women with endometriosis. A search was performed in databases using the descriptors: polymorphisms genetics and infertility and endometriosis. 386 articles were identified, and after applying the inclusion and exclusion criteria, 33 case-control studies were included. Genes and their respective polymorphisms, which exhibited statistically significant values, were classified into three categories: related to metabolic/cellular processes, steroidogenesis and sex hormone receptors, inflammation and immune response. In summary, the results of these studies suggest that the polymorphisms rs882605 of MUC4 gene, rs16826658 of WNT4 gene, rs10953316 of MUC17 gene, rs10928050 of KAZN gene, rs1799889 of PAI-1 gene, (TA)n repeats of ESR1 gene, (CA)n repeats of ESR2 gene, rs605059 of HSD17B1 gene, rs743572 of CYP17A1 gene, insLQ of LHR gene, p.Ile49Ser of AMH gene, rs12700667 of NPVF/NFE2L3 gene, G1502A of LHβ gene, G + 1730A of ERβ gene, rs7528684 of FCRL3 gene, rs3761549 of FOXP3 gene and rs28362491 of NFKβ1 gene are implicated in the etiology of infertility in women with endometriosis.

CYP17 T/C (rs74357) gene polymorphism contributes to polycystic ovary syndrome susceptibility: evidence from a meta-analysis

The cytochrome P450 family 17 (CYP17) is associated with hyperandrogenism in women, and the association between CYP17 gene polymorphism and the risk of polycystic ovary syndrome (PCOS) is not definitive. In order to determine whether the CYP17 T/C (rs74357) gene polymorphism is an exposure risk for PCOS, a comprehensive meta-analysis summarizing 19 studies was performed. The pooled odds ratio (OR) and the corresponding 95% CI were measured under five genetic models, and the stratified analyses by ethnicity, Hardy-Weinberg equilibrium, testosterone levels and BMI in controls were carried out to identify the causes of substantial heterogeneity. The overall results validated that the CYP17 T/C (rs74357) gene polymorphism was significantly associated with PCOS risk in four genetic models. Moreover, the outcomes of subgroup analysis by ethnicity indicated that the frequencies of the C allele of CYP17 T/C (rs74357) polymorphism were markedly higher in women from Asia than in Caucasians (T vs C: OR 0.85, 95% CI = 0.74-0.99, P < 0.05). Therefore, these findings suggested that the CYP17 T/C (rs74357) gene polymorphism played an indispensable part in increasing the susceptibility of PCOS when carrying the C allele, which proposed that the polymorphism of the CYP17 gene may be a predictive factor for the risk of PCOS or an important pathway in PCOS-associated metabolic and hormonal dysregulation.

Polymorphisms in the 3 ′ UTR Region of ESR2 and CYP19A1 Genes and Its Influence on Allele-Specific Gene Expression in Endometriosis

Objectives. Endometriosis is supported by hormonal, immunological, and environmental factors. No specific marker for endometriosis has yet been identified. ESR2 and CYP19A1 genes play a major role in the hormonal control of endometriosis women, the development of which largely depends on steroid hormones. Aim. An analysis of ESR2 and CYP19A1 allele-specific gene expressions in the context of the risk for endometriosis occurrence. Methods. The study material included paraffin-embedded tissue specimens, collected from patients ( $n=100$ ) with endometriosis. Blood samples from age-matched, endometriosis-free women ( $n=100$ ) served as a control. the RT-PCR technique was performed to observe the expression of ESR2 and CYP19A1 genes. Moreover, Sanger’s sequencing method was applied for polymorphism analysis. Results. A set of 4 single-nucleotide polymorphisms (SNPs) was determined; all of them most significantly associated with endometriosis: rs4986938 (G>A)(chromosome 14), rs928554 (A>G) (chromosome 14), rs10046 (C>T) (chromosome 15), and rs4646 (C>A) (chromosome 15). There were no differences in the distribution of genotypes and alleles in the studied groups, taking into account ESR2 and CYP19A1 gene expressions. Conclusion. The ESR2 and CYP19A1 polymorphisms may not be correlated with endometriosis susceptibility. Further analysis is needed to specify the role of these polymorphisms in the pathogenesis of endometriosis.

Polymorphisms in the 3'UTR Region of ESR2 and CYP19A1 Genes in Women With Endometriosis

OBJECTIVE

ESR2 and CYP19A1 genes play a major role in the hormonal control of women with endometriosis. The aim of the study was to analyze single nucleotide polymorphisms (SNPs) in the 3'UTR region of ESR2 and CYP19A1 genes. The study aimed at localisation of new polymorphisms, the nucleotide variants of which determine the level of susceptibility to endometriosis.

STUDY DESIGN

The study included n = 200 patients: 100 with endometriosis and 100 healthy controls. The Sanger's sequencing method was applied for polymorphism analysis.

RESULTS

Statistically significant correlations were identified between new, not previously described, two SNPs of ESR2 gene and endometriosis: rs4986938 (G>A) and rs928554 (A>G). In the case of rs4986938 polymorphism, the genotype AA was found to decrease the risk of endometriosis (OR = 0.24 95 % PU 0.05-1.22, p = 0.04). Analysis of the rs928554 polymorphism revealed that the occurrence of the AG genotype reduced the risk of endometriosis (OR = 0.38 95 % PU 0.21-0.71, p = 0.002). There were no differences in the distribution of genotypes of the polymorphisms rs10046 (C>T) and rs4646 (C>A) of CYP19A1 gene between patients and control.

CONCLUSIONS

Further studies are necessary in groups with higher numbers of patients to explain whether the above-mentioned polymorphisms may be the risk factors for endometriosis.

Cross-disorder analysis of endometriosis and its comorbid diseases reveals shared genes and molecular pathways and proposes putative biomarkers of endometriosis

RESEARCH QUESTION

Women with endometriosis are considered to be at higher risk of several chronic diseases, such as autoimmune disorders, gynaecological cancers, asthma/atopic diseases and cardiovascular and inflammatory bowel diseases. Could the study of endometriosis-associated comorbidities help to identify potential biomarkers and target pathways of endometriosis?

DESIGN

A systematic review was performed to identify all possible endometriosis-associated comorbid conditions. Next, this list of disorders was coded into MeSH terms, and the gene expression profiles were downloaded from the Phenopedia database and subsequently analysed following a systems biology approach.

RESULTS

The results identified a group of 127 candidate genes that were recurrently expressed in endometriosis and its closest comorbidities and that were defined as 'endometriosis sibling disorders' (ESD). The enrichment analysis showed that these candidate genes are principally involved in immune and drug responses, hormone metabolism and cell proliferation, which are well-known hallmarks of endometriosis. The expression of ESD genes was then validated on independent sample cohorts (n = 207 samples), in which the involvement of 16 genes (AGTR1, BDNF, C3, CCL2, CD40, CYP17A1, ESR1, IGF1, IGF2, IL10, MMP1, MMP7, MMP9, PGR, SERPINE1 and TIMP2) in endometriosis was confirmed. Several of these genes harbour polymorphisms that associate to either endometriosis or its comorbid conditions.

CONCLUSIONS

The study results highlight the molecular processes underlying the aetiopathogenesis of endometriosis and its comorbid conditions, and identify putative endometriosis biomarkers.

Defining the genetic profile of endometriosis

Endometriosis is a pathological condition which has been extensively studied, since its pathophysiology stems from a broad spectrum of environmental influences and genetic factors. Familial studies aim at defining inheritance trends, while linkage analysis studies focus on the identification of genetic sites related to endometriosis susceptibility. Genetic association studies take into account candidate genes and single nucleotide polymorphisms, and hence target at unraveling the association between disease severity and genetic variation. The common goal of various types of studies is, through genetic mapping methods, the timely identification of therapeutic strategies for disease symptoms, including pelvic pain and infertility, as well as efficient counselling. While genome-wide association studies (GWAS) play a primary role in depicting genetic contributions to disease development, they entail a certain bias as regards the case-control nature of their design and the reproducibility of the results. Nevertheless, genetic-oriented studies and the implementation of the results through clinical tests, hold a considerable advantage in proper disease management. In this review article, we present information about gene-gene and gene-environment interactions involved in endometriosis and discuss the effectiveness of GWAS in identitying novel potential therapeutic targets in an attempt to develop novel therapeutic strategies for a better management and treatment of patients with endometriosis.