Screening of a panel of steroid-related genes showed polymorphisms of aromatase genes confer susceptibility to advanced stage endometriosis in the Taiwanese Han population

ObjectiveTo establish a multilocus model for studying the effect of steroid-related genes on advanced stage endometriosis.Materials and methodsA total of 121 patients with advanced stage endometriosis and 171 control women were included. Eighteen single-nucleotide polymorphisms (SNPs) from nine genes (HSD17B1, HSD17B2, HSD17B5, HSD17B6, CYP17, CYP19, ERα, ERβ, and PGR) were genotyped using the TaqMan assays. Logistic regression models were used to evaluate the genetic effects, with adjustment for other covariates.ResultsOnly the presence of the mutant CYP19 (aromatase gene) was associated with a significantly increased risk of endometriosis after adjusting for age, BMI, and parity (p = 0.002, OR = 2.69; 95% CI = 1.44–5.02). No association was ascertained between the other investigated SNPs and endometriosis.ConclusionPolymorphisms of the aromatase gene confer susceptibility to advanced stage endometriosis in the Taiwanese Han population.     

Endometriosis: the ultimate hormonal disease

Estrogen is an extremely potent mitogen for endometrium and endometriosis. Progesterone, on the other hand, inhibits the mitogenic action of estrogen on endometrium and enhances differentiation. These antiproliferative and differentiative effects of progesterone are less pronounced on endometriosis tissue compared with endometrium. Thus, endometriosis is, at least in part, resistant to progesterone action. The product of a single gene named aromatase synthesizes estrogen. The potent estrogen estradiol is metabolized and thus inactivated by an enzyme termed 17beta-hydroxysteroid dehydrogenase (HSD) type 2 that is normally induced by progesterone in endometrium. Progesterone action is mediated by its receptor subtypes progesterone receptor (PR)-A and PR-B. We found a number of abnormalities in the expression of aromatase, 17beta-HSD type 2, and the PR-B/PR-A ratio in endometriosis tissue. These abnormalities and their functional consequences are discussed in this review article.     

CYP2C19 polymorphism increases the risk of endometriosis

PurposeEstrogen metabolizing gene mutations can be associated with defective hormonal signaling leading to disease processes. Endometriosis is an estrogen dependent that can be influenced by defective signaling in the estrogen pathway.ObjectivesTo evaluate the association of A/G 85952 CYP2C19 and A/G 937 HSD17B1 gene polymorphisms with endometriosis through the investigation of a large Brazilian sample of women with endometriosis and a fertile control group.MethodsFive hundred women with endometriosis and 500 women without endometriosis were tested for CYP2C19 and HSD17B1 polymorphisms, by TaqMan Real Time PCR. The results were statistically analyzed by chi-square, logistic regression and tested for Hardy-Weinberg equilibrium.ResultsThe comparison of genotype and allelic frequency of CYP2C19 polymorphism (rs11592737) in patients with endometriosis and control group showed a statistically significant difference (p = 0.0203) and for the HSD17B1 polymorphism (rs605059) differences were not significant (p = 0.0687). Comparing the stages I/II and III/IV endometriosis with the control group for the CYP2C19 we observed p = 0.0133 and p = 0.0564, respectively, and for HSD17B1 the values for p = 0.4319 and p = 0.0667.ConclusionWe observed that CYP2C19 polymorphism is associated with endometrisis in Brazilian women and can be considered a potential biomarker of the disease.     

Association of endometriosis risk and genetic polymorphisms involving biosynthesis of sex steroids and their receptors: an updating meta-analysis

The objective of our study is to assess the association of endometriosis risk and genetic polymorphisms involving biosynthesis of sex steroids and their receptors. A systematic search of three databases was conducted. Twenty-seven studies on the association of the cytochrome P450 subfamily 17 (CYP17), estrogen receptor gene (ER), progesterone receptor gene (PR), 17-beta-hydroxysteroid dehydrogenase type 1 gene (HSD17B1), and cytochrome P450 subfamily 19 (CYP19) polymorphisms with endometriosis risk were identified. When all groups were pooled, we found an association between HSD17B1 (A variant allele vs. G wild allele: odds ratio (OR)=1.42, 95% confidence interval (CI)=1.10-1.84, P=0.007) and PR (P2 variant allele vs. P1 wild allele, OR=1.43, 95% CI=0.99-2.08, P=0.058) polymorphisms and endometriosis risk, while failing to detect links with CYP17, ER, and CYP19 polymorphisms examined. In the subgroup analysis, a significant association of CYP17 and ERα-PvuII polymorphisms with endometriosis was found neither in a Caucasian population nor in an Asian population. The findings of our study suggest that HSD17B1 and PR polymorphisms are associated with an increased risk of endometriosis. Further investigation into the association between CYP17, ER, PR, HSD17B1, and CYP19 polymorphisms and endometriosis risk is warranted and should include larger sample sizes.     

Aromatase und Cyclooxygenase-2 – neue Ansätze in der Endometriosetherapie?

Therapeutic management of endometriosis-associated pain or recurrent disease is primarily aimed at downregulating the ovarian function or at antagonizing the effect of estrogen in ectopic endometrial implants. Recently, aromatase overexpression has been detected in endometriotic tissue. Aromatase (p450arom) is responsible for conversion of C19 androgens to estrogen in several human tissues. Aromatase activity gives rise to local estrogen biosynthesis, which stimulates prostaglandin E₂ production by upregulation of cyclooxygenase-2 (COX-2). Another abnormality in endometriosis, i. e. the deficiency in 17β-hydroxysteroiddehydrogenase type 2 (17β-HSD Type 2) expression, impairs the inactivation of estradiol to estrone. These molecular aberrations favour the accumulation of local estradiol and prostaglandin E₂ in endometriosis. In several human cell lines, elevated prostaglandin and estrogen concentrations are associated with proliferation, migration, angiogenesis, apoptosis resistance, and invasiveness. Consequentely, aromatase and COX-2 might be promising new therapeutic targets.     

Polymorphisms in ESR1, ESR2 and HSD17B1 genes are associated with fertility status in endometriosis

Objective.?To investigate whether polymorphisms in genes involved in biosynthesis and signalling of sex steroids influence susceptibility to endometriosis and to infertility associated with it.

Materials and methods.?Patients with endometriosis (n?=?150) and fertile controls (n?=?199) were genotyped for polymorphisms in oestrogen receptor genes ESR1 (rs2234693 – T/C single nucleotide polymorphism (SNP), dinucleotide (TA)_n repeat) and ESR2 (dinucleotide (CA)_n repeat), progesterone receptor gene PGR (rs10895068 – G/A SNP, 306-bp Alu-insertion), 17β-hydroxysteroid dehydrogenase type 1 gene HSD17B1 (rs605059 – A/G SNP), and aromatase gene CYP19A1 (rs10046 – C/T SNP, (TTTA)_n tetranucleotide repeat, 3-bp TCT insertion/deletion polymorphism).

Results.?The HSD17B1 A/G SNP A allele increased overall endometriosis risk and the risk of stage I–II disease, while ESR1 longer (TA)_n repeats only correlated with susceptibility to stage I–II endometriosis. When considering patients' fertility status, HSD17B1 A/G SNP A allele and ESR1 longer (TA)_n repeats were associated with endometriosis accompanied by infertility, while ESR2 shorter (CA)_n repeats were linked with endometriosis without infertility. Other polymorphisms were distributed similarly among patients and controls.

Conclusions.?Genetic variants in ESR1, ESR2, and HSD17B1 genes could modify susceptibility to endometriosis and might influence the fertility status in endometriosis patients.     

Role of estrogen receptor-β in endometriosis

Endometriosis is an estrogen-dependent disease. The biologically active estrogen, estradiol, aggravates the pathological processes (e.g., inflammation and growth) and the symptoms (e.g., pain) associated with endometriosis. Abundant quantities of estradiol are available for endometriotic tissue via several mechanisms including local aromatase expression. The question remains, then, what mediates estradiol action. Because estrogen receptor (ER)β levels in endometriosis are >100 times higher than those in endometrial tissue, this review focuses on this nuclear receptor. Deficient methylation of the ERβ promoter results in pathological overexpression of ERβ in endometriotic stromal cells. High levels of ERβ suppress ERα expression. A severely high ERβ-to-ERα ratio in endometriotic stromal cells is associated with suppressed progesterone receptor and increased cyclo-oxygenase-2 levels contributing to progesterone resistance and inflammation. ERβ-selective estradiol antagonists may serve as novel therapeutics of endometriosis in the future.     

Induction of estrogen receptor-α and -β activities by synthetic progestins

The cellular action of steroid hormones is mediated by specific receptors. Recently, two different estrogen receptors (ER), α and β, have been cloned with a specific tissue distribution. Active estrogen as well as active progestin are compounds of oral hormonal contraceptives and hormone replacement therapy.

To examinate the regulation of ER-α and -β activities after treatment with synthetic progestins and synthetic and natural estrogens, COS 7 cells were transfected with the vector expressing ER-α and -β in combination with a luciferase reporter vector. ER-α activity was upregulated in the presence of synthetic progestins in a dose-dependent manner. Norethisterone, norethynodrel and desogestrel proved to be the most potent stimulatory agents of ER-α expression. On the other hand, not all progestins exhibited a stimulatory action on ER-β activity. Only norgestrel, levonorgestrel, norethynodrel and norethisterone induced ER-β-activating functions in a dose-dependent manner. Luciferase activity due to estrogen stimulation served as a positive control.

Our results indicate that progestins have different effects on the activities of ER-α and -β.     

Immunomodulators and aromatase inhibitors: are they the next generation of treatment for endometriosis?

PURPOSE OF REVIEW: This article will present an overview of current and new hormonal and non-hormonal medical treatment in the management of endometriosis, with special emphasis on immunomodulators and aromatase inhibitors. RECENT FINDINGS: Recent research shows a very promising role for new hormonal medication (aromatase inhibitors, estrogen and progesterone receptor modulators) and anti-inflammatory drugs (tumor necrosis factor-alpha inhibitors, matrix metalloproteinase inhibitors, cyclooxygenase-2 inhibitors) in the management of endometriosis. SUMMARY: The ideal drug in the treatment of endometriosis alleviates pain and cures sub-fertility without inhibition of ovulation or menstruation and without significant side effects or teratological effects. Such a drug would allow conception during treatment and would fundamentally change the management of endometriosis from a surgical approach to medical management. Although such a drug does not yet exist, promising research using tumor necrosis factor inhibitors indicates that this could become possible in the not too distant future. We strongly recommend testing new medication for the prevention or treatment of endometriosis in the baboon model, an established research model for fundamental and preclinical research in endometriosis.     

Surgery for Endometriosis Improves Major Domains of Quality of Life: A Systematic Review and Meta-Analysis

Because surgery for endometriosis can involve severe complications, it is important to determine if the patient's quality of life (QOL) is indeed improved after surgery. A systematic review and meta-analysis, when appropriate, was conducted and included 38 studies that assessed the QOL using validated questionnaires administered before and after surgery. Results were grouped according to the type of endometriosis reported: all types endometriosis, deep infiltrative endometriosis (DIE), and bowel endometriosis. Quantitative analysis was performed on 17 homogeneous studies. Pooled response mean differences between the 36-Item and 12-Item Short Form Survey (SF-36 and SF-12) showed significant improvement in Mental Component Score (MCS) after surgery for all types of endometriosis (.21; 95% confidence interval [CI], .04–.38); significant improvement after surgical treatment for DIE in Vitality (.67; 95% CI, .41–.94), Social Functioning (.59; 95% CI, .18–.99), Role Emotional .49; 95% CI, .02–.97), Mental Health (.39; 95% CI, .03–.74), Physical Functioning (.93; 95% CI, .49–1.38), Bodily Pain (1.23; 95% CI, .47–1.99), General Health (.57; 95% CI, .02–1.12), MCS (.55; 95% CI, .10–1.00), and Physical Component Score (PCS; .73; 95% CI, .27–1.18); and significant improvement after surgery for bowel endometriosis for all 8 domains (Vitality [1.00; 95% CI, .56–1.43], Social Functioning [.97; 95% CI, .57–1.37], Role Emotional [1.17; 95% CI, .7–1.63], Mental Health [.94; 95% CI, .5–1.38], Physical Functioning [.74; 95% CI, .3–1.18], Role Physical [1.25; 95% CI, .75–1.76], Bodily Pain [1.39; 95% CI, .79–1.98], General Health [.84; 95% CI, 1.46–1.22]), MCS (.93; 95% CI, .47–1.40), PCS (.82; 95% CI, .40–1.23), and total score (1.15; 95% CI, .48–1.83). Only 1 study assessed patients with minimal disease and showed significant improvement in PCS (p?=?.002) and MCS (p <.001). This systematic review reveals that surgery for endometriosis resulted in overall improvement in most health domains of health-related QOL, with the greatest improvement found in the Bodily Pain domain.     

Biochemical Analysis of Four Missense Mutations in the HSD17B3 Gene Associated With 46,XY Disorders of Sex Development in Egyptian Patients

BackgroundMutations in the HSD17B3 gene are associated with a 46,XY disorder of sexual development (46,XY DSD) as a result of low testosterone production during embryogenesis.AimTo elucidate the molecular basis of the disorder by chemically analyzing four missense mutations in HSD17B3 (T54A, M164T, L194P, G289S) from Egyptian patients with 46,XY DSD.MethodsExpression plasmids for wild-type 17β-hydroxysteroid hydrogenase type 3 (17β-HSD3) and mutant enzymes generated by site-directed mutagenesis were transiently transfected into human HEK-293 cells. Protein expression was verified by western blotting and activity was determined by measuring the conversion of radiolabeled Δ⁴-androstene-3,17-dione to testosterone. Application of a homology model provided an explanation for the observed effects of the mutations.OutcomesTestosterone formation by wild-type and mutant 17β-HSD3 enzymes was compared.ResultsMutations T54A and L194P, despite normal protein expression, completely abolished 17β-HSD3 activity, explaining their severe 46,XY DSD phenotype. Mutant M164T could still produce testosterone, albeit with significantly lower activity compared with wild-type 17β-HSD3, resulting in ambiguous genitalia or a microphallus at birth. The substitution G289S represented a polymorphism exhibiting comparable activity to wild-type 17β-HSD3. Sequencing of the SRD5A2 gene in three siblings bearing the HSD17B3 G289S polymorphism disclosed the homozygous Y91H mutation in the former gene, thus explaining the 46,XY DSD presentations. Molecular modeling analyses supported the biochemical observations and predicted a disruption of cofactor binding by mutations T54A and M164T and of substrate binding by L196P, resulting in the loss of enzyme activity. In contrast, the G289S substitution was predicted to disturb neither the three-dimensional structure nor enzyme activity.Clinical TranslationBiochemical analysis of mutant 17β-HSD3 enzymes is necessary to understand genotype-phenotype relationships.Strengths and LimitationsBiochemical analysis combined with molecular modeling provides insight into disease mechanism. However, the stability of mutant proteins in vivo cannot be predicted by this approach.ConclusionThe 17β-HSD3 G289S substitution, previously reported in other patients with 46,XY DSD, is a polymorphism that does not cause the disorder; thus, further sequence analysis was required and disclosed a mutation in SRD5A2, explaining the cause of 46,XY DSD in these patients.Engeli RT, Tsachaki M, Hassan HA, et al. Biochemical Analysis of Four Missense Mutations in the HSD17B3 Gene Associated With 46,XY Disorders of Sex Development in Egyptian Patients. J Sex Med 2017;14:1165–1174.     

Aromatase and endometriosis

Aromatase p450 (p450arom) is the key enzyme for biosynthesis of estrogen, which is an essential hormone for the establishment and growth of endometriosis. There is no detectable aromatase enzyme activity in normal endometrium; therefore, estrogen is not locally produced in endometrium. Endometriosis tissue, however, contains very high levels of aromatase enzyme, which leads to production of significant quantities of estrogen. Moreover, one of the best-known mediators of inflammation and pain, prostaglandin E (2), strikingly induces aromatase enzyme activity and formation of local estrogen in this tissue. Additionally, estrogen itself stimulates cyclo-oxygenase-2 and therefore increases the formation of prostaglandin E (2) in endometriosis. We were able to target this positive feedback cycle in endometriosis using aromatase inhibitors. In fact, pilot trials showed that aromatase inhibitors could decrease pelvic pain associated with endometriosis.     

Genetic Polymorphisms of 17β-Hydroxysteroid Dehydrogenase 3 and the Risk of Hypospadias

IntroductionHypospadias is a common congenital anomaly caused by incomplete fusion of urethral folds. Development of the urethra and external genital system in the male fetus is an androgen-dependent process. In this regard, enzymes 17β-hydroxysteroid dehydrogenase type 3 (17βHSD3, encoded by HSD17B3) and steroid 5α-reductase type 2 (encoded by SRD5A2) play crucial roles.AimTo investigate the possible associations between common polymorphisms in HSD17B3 as well as well-known V89L polymorphism in SRD5A2 and risk of hypospadias.MethodsA case-control study was performed between 1999 and 2005. There were 89 Japanese boys with hypospadias and 291 newborn controls. We genotyped HSD17B3?1999T>C, +10A>G, +20A>G, +139G>A (V31I), +913G>A (G289S), and SRD5A2+336G>C (V89L) polymorphisms by allelic discrimination assay. We measured mRNA expression of the wildtype G289 allele and the mutant S289 allele of the HSD17B3 gene in the transfected human fetal kidney HEK293 cells.Main Outcome MeasuresAssessment of hypospadias including its severity and HSD17B3 and SRD5A2 genes using DNA blood samples: allele and genotype distribution of single nucleotide polymorphisms in these two genes in cases and controls.ResultsIn our study, the risk of hypospadias was significantly higher in subjects carrying homozygous HSD17B3+913A (289S) alleles (odds ratio [OR]: 3.06; 95% confidence interval [CI]: 1.38–6.76). The risk of severe hypospadias was much higher in these subjects (OR: 3.93; 95% CI: 1.34–11.49). The mRNA expression levels of HSD17B3 G289 were higher than those of HSD17B3 S289 mutant (P < 0.001). In addition, the risk of severe hypospadias increased in boys carrying the SRD5A2+336C (89L) allele (OR: 3.19; 95% CI: 1.09–9.36).ConclusionsThese results suggest that the HSD17B3 G289S polymorphism may be a potential risk modifier for hypospadias. Our findings provide evidence that a certain genotype related to androgen production may potentiate risk of hypospadias. Sata F, Kurahashi N, Ban S, Moriya K, Tanaka KD, Ishizuka M, Nakao H, Yahata Y, Imai H, Kakizaki H, Nonomura K, and Kishi R. Genetic polymorphisms of 17β-hydroxysteroid dehydrogenase 3 and the risk of hypospadias.     

Mechanisms of excessive estrogen formation in endometriosis

Estrogen is produced in a number of human tissues including the ovary, placenta and extraglandular sites such as adipose tissue, skin and the brain. Aromatase is the key enzyme that regulates estrogen formation in these tissues. Aromatase activity is not detectable in normal endometrium. In contrast, aromatase is expressed aberrantly in endometriosis and is stimulated by PGE(2). This results in local production of estrogen, which induces PGE(2) formation and establishes a positive feedback cycle. Another abnormality in endometriosis, i.e. deficient 17beta-hydroxysteroid dehydrogenase (17beta-HSD) type 2 expression, impairs the inactivation of estradiol to estrone. These molecular aberrations collectively favor accumulation of increasing quantities of estradiol and PGE(2) in endometriosis. The clinical relevance of these findings was exemplified by the successful treatment of an unusually aggressive case of postmenopausal endometriosis using an aromatase inhibitor.     

Aromataseinhibitoren bei Endometriose?

Aromatase overexpression has been detected in endometriotic tissue. Aromatase activity gives rise to local estrogen biosynthesis, which in turn stimulates prostaglandin E₂ production by upregulation of cyclooxygenase-2 (COX-2), thus establishing a positive feedback cycle. Another abnormality in endometriosis, i.e., the deficiency in 17ß-hydroxysteroid dehydrogenase type II (17ß-HSD type II) expression, impairs the inactivation of estradiol to estrone. These molecular aberrations collectively favor accumulation of increasing amounts of local estradiol and prostaglandin E₂ in endometriosis. In several human cell lines, prostaglandin and estrogen concentrations are associated with proliferation, migration, angiogenesis, apoptosis resistance, and even invasiveness. Consequently, aromatase and COX-2 are promising new therapeutic targets. Specific aromatase inhibitors or selective COX-2 inhibitors are of great interest to be studied in clinical trials in premenopausal woman with endometriosis to extend the spectrum of currently available treatment options.     

Aromatase inhibitors--theoretical concept and present experiences in the treatment of endometriosis

The medical treatment of endometriosis needs to be optimized. Therapeutic management strategies of endometriosis-associated pain or recurrent disease is primarily aimed at downregulating the ovarian function or at antagonizing the effect of estrogen in ectopic endometrial implants. In this context, basic research is delivering powerful tools for the possible development of new, specific treatment modalities. Recently, aromatase overexpression has been detected in endometriotic tissue. Aromatase (p450arom) is responsible for conversion of C19 androgens to estrogen in several human tissues. Aromatase activity gives rise to local estrogen biosynthesis, which, in turn, stimulates prostaglandin E(2) production by upregulation of cyclooxygenase-2 (COX-2), thus establishing a positive feedback cycle. Another abnormality in endometriosis, i. e. the deficiency in 17 beta-hydroxysteroiddehydrogenase type-II (17 beta-HSD-Type-II) expression, impairs the inactivation of estradiol to estrone. In contrast to the eutopic endometrium, these molecular aberrations collectively favour accumulation of increasing amounts of local estradiol and prostaglandin E(2) in endometriosis. In several human cell lines, prostaglandin and estrogen concentrations are associated with proliferation, migration, angiogenesis, apoptosis resistance, and even invasiveness. Consequently, aromatase and COX-2 are promising new therapeutic targets. In summary, specific aromatase inhibitors (such as Letrozole, Anastrozol or Exemestan) or selective COX-2 inhibitors (e.g. Celecoxib, Rofecoxib) are of great interest to be studied in clinical trials in premenopausal woman with endometriosis to extend the spectrum of currently available treatment options.     

Involvement of <Emphasis Type="Italic">17β-hydroxysteroid dehydrogenase type</Emphasis> gene <Emphasis Type="Italic">1</Emphasis> 937 A&gt;G polymorphism in infertility in Polish Caucasian women with endometriosis

Purpose

Endometriosis is considered to be an estrogen-related chronic inflammatory disease. The 17β-hydroxysteroid dehydrogenase 1 (HSD17B1) converts estrone to 17β estradiol. The role of HSD17B1 937 A>G (rs605059) single nucleotide polymorphism (SNP) in development of endometriosis is still disputable. This study evaluated the association of the HSD17B1 937 A>G (rs605059) SNP with infertile women affected by endometriosis from Polish Caucasian population.

Methods

The genotyping of cases (n = 290) and fertile women (n = 410) was conducted by high-resolution melting curve analysis.

Results

Statistical analysis demonstrated that the HSD17B1 937 A>G SNP is associated with endometriosis in stages I and II. The p _trend and p _allelic values calculated for the HSD17B1 937 A>G polymorphism were statistically significant and were equal to 0.001 and 0.0009, respectively. There was a significant association for the dominant model: (AG + GG vs AA) OR = 1.973 (95% CI = 1.178–3.304), p = 0.009, and for the recessive model: (GG vs AG + AA) OR = 1.806 (95% CI = 1.178–2.770), p = 0.006. However, we did not find statistical association of HSD17B1 937 A>G polymorphism with all infertile women with endometriosis or infertile women with endometriosis in stages III and IV.

Conclusion

Our genetic study demonstrated HSD17B1 937 G variant as a risk factor for infertility in women with stage I and II endometriosis in Polish Caucasian patients.