Future Perspectives in the Medical Treatment of Endometriosis

Estetrol Increases Progesterone Genetic Response without Triggering Common Estrogenic Effects in Endometriotic Cell Lines and Primary Cultures

Estetrol (E4), a natural estrogen produced by the human fetal liver, is actively studied for menopause and breast cancer treatment. It has low side effects and preferential estrogen receptor alpha (ERα) affinity. There are no data about its effects on endometriosis, a common gynecological disease affecting 6-10% of cycling women, generating painful pelvic lesions and infertility. Current combined hormone treatment (progestins and estrogens) is safe and efficient; nevertheless, one-third of patients develop progesterone (P4) resistance and recurrence by reducing P4 receptors (PRs) levels. We aimed to compare E4 and 17β-estradiol (E2) effects using two human endometriotic cell lines (epithelial 11Z and stromal Hs832 cells) and primary cultures from endometriotic patients. We evaluated cell growth (MTS), migration (wound assay), hormone receptors levels (Western blot), and P4 response by PCR array. Compared to E2, E4 did not affect cell growth or migration but increased estrogen receptor alpha (ERα) and PRs, and reduced ERβ. Finally, the incubation with E4 improved the P4 gene response. In conclusion, E4 increased PRs levels and genetic response without inducing cell growth or migration. These results suggest that E4 might be useful for endometriosis treatment avoiding P4 resistance; however, evaluating its response in more complex models is required.

A Systematic Review of Systematic Reviews on the Use of Aromatase Inhibitors for the Treatment of Endometriosis: The Evidence to Date

Endometriosis is a chronic gynecologic condition that affects around 6-10% of reproductive age women. This clinical entity is characterized with pelvic pain, dysmenorrhea, dyspareunia, and infertility which are the most often presenting symptoms. Aromatase P450 is the key enzyme for ovarian estrogen biosynthesis and there is evidence that endometriotic lesions express aromatase and are able to synthesize their own estrogens. Aromatase inhibitors (AIs) are potent drugs that suppress the estrogen synthesis via suppression of aromatase. We performed a systematic review of systematic reviews and narrative reviews on the use of aromatase inhibitors in the medical management of endometriosis. We searched: PubMed (1950-2022), Google Scholar (2004-2022), Cochrane Library (2010-2022) and Researchgate (2010-2022). The search included the following medical subject headings (MeSH) or keywords: "Aromatase Inhibitors" AND "Endometriosis" AND "Systematic reviews" OR "Systematic review" AND "Reviews" OR "Reviews" AND "Endometriosis". The electronic database search yielded initially 12,106 studies from the different databases. Further assessment of the studies resulted in exclusion of (n = 12,015) studies due to duplicates and irrelevance; Finally, 24 studies were selected for inclusion, 5 were Systematic reviews and 19 were Narrative reviews. The 5 systematic reviews were assessed by AMSTAR-2 criteria and were found to have low quality. Narrative reviews were assessed with SANRA criteria and were found to have high-quality aromatase inhibitors are potent drugs that can manage the endometriosis-related symptoms in cases where initial medical management has failed to show positive results. However, their use is limited by the adverse effects that are linked with menopausal symptoms. aromatase inhibitors can be administered as an alternative treatment in patients. Future studies with randomized design are required to reach safer conclusions and further investigation. These studies should define the therapeutic dose, new add-back therapy modalities. Future directions should examine the most-appropriate way of administration and the duration of therapy.

Antilipidemic ezetimibe induces regression of endometriotic explants in a rat model of endometriosis with its anti-inflammatory and anti-angiogenic effects

To assess the potential therapeutic role of antilipidemic ezetimibe on endometriosis in an experimental rat model. A standard experimental endometriosis model was created with 18 Whistar-Albino rats, and after 1 month, the sizes of the endometriotic explants were measured. The rats were randomized as study and control groups. A total of 1 mg/kg/day ezetimibe and 1 ml/kg/day saline were administered orally to the study and control groups respectively for 28 days. At the end of 28 days, the explants were measured again, excised, and sent for histopathologic assessment for expression of tumor necrosis factor-alpha (TNF-α) and vascular endothelial growth factor (VEGF) and number of mast cells. At the end of the study period, the size of the endometriotic explants decreased significantly in the study group; but not in the control group (from 145.3 ± 120.5 to 89.8 ± 60.1 vs 174.72 ± 88.3 to 87.65 ± 27.1 cm3 respectively); however, the amount of post- and pretreatment differences in explant sizes was similar in the groups. The median TNF-α and VEGF levels were significantly lower in the ezetimibe group when compared to the control group (4 [3-4] vs 2 [1-3], p 0.029; 4 [3-4] vs 2 [2-3], p 0.002; respectively). And numbers of mast cells in all uterine layers were also lower in the ezetimibe group. Ezetimibe decreased the size of the endometriotic explants with its anti-inflammatory and anti-angiogenic properties. This agent alone or with combination of other agents may have a potential role in the treatment of endometriosis.

Genetics and Inflammation in Endometriosis: Improving Knowledge for Development of New Pharmacological Strategies

According to a rich body of literature, immune cell dysfunctions, both locally and systemically, and an inflammatory environment characterize all forms of endometriosis. Alterations in transcripts and proteins involved in the recruitment of immune cells, in the interaction between cytokines and their receptors, cellular adhesion and apoptosis have been demonstrated in endometriotic lesions. The objective of this narrative review is to provide an overview of the components and mechanisms at the intersection between inflammation and genetics that may constitute vanguard therapeutic approaches in endometriosis. The GWAS technology and pathway-based analysis highlighted the role of the MAPK and the WNT/β-catenin cascades in the pathogenesis of endometriosis. These signaling pathways have been suggested to interfere with the disease establishment via several mechanisms, including apoptosis, migration and angiogenesis. Extracellular vesicle-associated molecules may be not only interesting to explain some aspects of endometriosis progression, but they may also serve as therapeutic regimens per se. Immune/inflammatory dysfunctions have always represented attractive therapeutic targets in endometriosis. These would be even more interesting if genetic evidence supported the involvement of functional pathways at the basis of these alterations. Targeting these dysfunctions through next-generation inhibitors can constitute a therapeutic alternative for endometriosis.

Novel drug delivery methods for improving efficacy of endometriosis treatments

INTRODUCTION

Pharmacotherapy has a key role in the management of endometriosis. However, a significant proportion of patients gains only intermittent or limited benefits. In this regard, alternative and novel drug delivery methods are of paramount importance to improve efficacy and compliance of available treatments and develop alternative medical approaches.

AREAS COVERED

This review aims to provide the reader with a complete overview of available evidence about alternative and novel drug delivery methods for endometriosis pharmacotherapy and highlight new research lines.

EXPERT OPINION

Progestins and estroprogestins, which represent the first-line therapy, are already available in different formulations, being employed for contraception. Nevertheless, evidence on their adoption is still limited for some drug delivery methods, such as vaginal rings, patches, and subcutaneous implants. Further research is needed to define better their clinical utility in patients with endometriosis. Nanotechnologies have been investigated as novel drug delivery methods able to target the drug at the disease level. However, data are very limited and preliminary, and further research is needed to consider a possible clinical application in endometriosis.

Bowel Endometriosis: Current Perspectives on Diagnosis and Treatment

Endometriosis is a chronic condition primarily affecting young women of reproductive age. Although some women with bowel endometriosis may be asymptomatic patients typically report a myriad of symptoms such as alteration in bowel habits (constipation/diarrhoea) dyschezia, dysmenorrhoea and dyspareunia in addition to infertility. To date, there are no clear guidelines on the evaluation of patients with suspected bowel endometriosis. Several techniques have been proposed including transvaginal and/or transrectal ultrasonography, magnetic resonance imaging, and double-contrast barium enema. These different imaging modalities provide greater information regarding presence, location and extent of endometriosis ensuring patients are adequately informed whilst also optimizing preoperative planning. In cases where surgical management is indicated, surgery should be performed by experienced surgeons, in centres with access to multidisciplinary care. Treatment should be tailored according to patient symptoms and wishes with a view to excising as much disease as possible, whilst at the same time preserving organ function. In this review article current perspectives on diagnosis and management of bowel endometriosis are discussed.

Investigational drugs for the treatment of endometriosis, an update on recent developments

INTRODUCTION

Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis.

AREAS COVERED

This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents.

EXPERT OPINION

Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human.

Effect of simvastatin on monocyte chemoattractant protein-1 expression in endometriosis patients: a randomized controlled trial

Background

Simvastatin is a promising new drug for the treatment of endometriosis. It is a cholesterol-lowering drug that acts by inhibiting HMG-CoA reductase, resulting in a decrease in mevalonate, a precursor of cholesterol and monocyte chemoattractant protein-1 (MCP-1). This study investigated the effect of pre-operative oral simvastatin administration on MCP-1 gene expression and serum MCP-1 protein levels in patients with endometriosis.

Methods

A prospective, randomized, controlled study was conducted at the Reproductive Endocrinology Unit of the Department of Obstetrics and Gynecology at the Faculty of Medicine Ramathibodi Hospital. Forty women (mean age: 18–45 years) scheduled for laparoscopic surgery who had been diagnosed with endometriosis were recruited and randomly assigned to either a treatment group (20 mg/d of orally administered simvastatin for 2 weeks before surgery) or an untreated control group. Serum was collected before and after treatment and protein levels of MCP-1 were determined. MCP-1 and CD68 transcript levels were also quantified using real-time PCR on endometriotic cyst tissues.

Results

MCP-1 gene expression on endometriotic cyst was not significantly different between the simvastatin-treated and untreated groups (P = 0.99). CD68 expression was higher in the treatment group compared to the control group, but this was not statistically significant (P = 0.055). Serum MCP-1 levels following simvastatin treatment were higher than in samples obtained before treatment (297.89 ± 70.77 and 255.51 ± 63.79 pg/ml, respectively) (P = 0.01).

Conclusions

Treatment with 20 mg/d of simvastatin for 2 weeks did not reduce the expression of either the chemokine MCP-1 gene or macrophage-specific genes. Cumulatively, this suggests that simvastatin is not ideal for treating endometriosis because a higher dose of simvastatin (40–100 mg/d) would be needed to achieve the target outcome, which would significantly increase the risk of myopathy in patients.

Trial registration

Thai Clinical Trials Registry TCTR20130627003 Registered: June 27, 2013.

How to Manage Bowel Endometriosis: The ETIC Approach

A panel of experts in the field of endometriosis expressed their opinions on management options in a 35-year-old patient desiring pregnancy with a history of previous surgery for endometrioma and bowel obstruction symptoms. Many questions that this paradigmatic patient may pose to the clinician are addressed, and various clinical scenarios are discussed. A decision algorithm derived from this discussion is proposed as well.

Antiangiogenesis therapy of endometriosis using PAMAM as a gene vector in a noninvasive animal model

OBJECTIVE

To evaluate the characteristics and antiangiogenic effects of endostatin-loaded PAMAM on endometriosis in a noninvasive animal model.

MATERIALS AND METHODS

A noninvasive animal model was established by injecting adenovirus-GFP transfected endometrial stromal and glandular epithelial cells subcutaneously into nude mice. Endostatin-loaded PAMAM was prepared and identified by transmission electron microscopy. For in vitro studies, the DNA protection and cytotoxicity of PAMAM were investigated and compared with Lipofectamine 2000. For in vivo study, endostatin-loaded PAMAM was injected into the noninvasive model and evaluated by continuously observing the fluorescent lesion, lesion weight, microvessel density and VEGF immunostaining.

RESULTS

Compared with Lipofectamine 2000, PAMAM and HC PAMAM-ES group, MC PAMAM-ES group and LC PAMAM-ES group demonstrated a better stromal cells protective such that MC PAMAM-ES group of CCK8 was 0.617 ± 0.122 at 24 hr and 0.668 ± 0.143 at 48 hr and LC PAMAM-ES group of CCK8 was 0.499 ± 0.103 at 24 hr and 0.610 ± 0.080 at 48 hr in stromal cells (P < 0.05) but similar cytotoxicity in glandular epithelial cells in vitro. After 16 hrs of digestion, DNA decreased slightly under the protection of PAMAM. Endostatin-loaded PAMAM of HD PAMAM-ES group and LD PAMAM-ES group inhibited the growth of the endometriotic lesion in vivo at days 15, 20, 25 and 30 detected by noninvasive observation after injecting one dose endostatin of various medicines into the endometrial lesion in each mouse on day 10 (P < 0.05) and confirmed by lesion weight at day 30 with HD PAMAM-ES group being 0.0104 ± 0.0077 g and LD PAMAM-ES group being 0.0140 ± 0.0097 g (P < 0.05). Immunohistochemistry results showed that endostatin-loaded PAMAM reduced the microvessel density 3.8 ± 2.4 especially in HD PAMAM-ES group in the lesion (P < 0.05).

CONCLUSION

Endostatin-loaded PAMAM inhibits the development of endometriosis through an antiangiogenic mechanism and can be observed through the noninvasive endometriosis model.

Progestin effects on expression of AKR1C1-AKR1C3, SRD5A1 and PGR in the Z-12 endometriotic epithelial cell line

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity. This disease is associated with diminished protective effects of progesterone, which are usually explained by inadequate activation of progesterone receptors and also enhanced pre-receptor metabolism of progesterone. Endometriosis is often treated with progestins, which act as progesterone receptor agonists, although their exact mechanisms of action are not completely understood. The aim of the present study was to investigate how the progestins medroxyprogesterone acetate, dydrogesterone and dienogest, as well as progesterone, impact on the expression of genes of pre-receptor progesterone metabolism in Z-12 epithelial cell line, a model system of peritoneal endometriosis. Our data demonstrate that these progestins affect local pre-receptor metabolism to a different extent. The most favorable effects were seen for dydrogesterone and dienogest, where the first, dydrogesterone, significantly reduced SRD5A1, AKR1C2 and AKR1C3 expression, and additionally had a nonsignificant impact on progesterone receptor B (PR-B) protein levels. This might slow down the first step of pre-receptor metabolism, the conversion of progesterone to 5α-dihydroprogestrone by SRD5A1, and it might also affect further reduction of 3-keto and 20-keto groups catalyzed by AKR1C2 and AKR1C3. Similarly favorable effects were seen for dienogest, which promoted significant reduction of AKR1C1 and AKR1C2 expression and also showed no effect on PR-B protein levels. Different effects were seen for progesterone, which significantly decreased SRD5A1, PR-B and HSD17B2 protein levels. In contrast, treatment with medroxyprogesterone acetate resulted in increased AKR1C1 expression and decreased levels of PR-B, which might lead to enhanced progesterone metabolism and reduced signaling through progesterone receptors. Altogether, our data in this Z-12 cell model suggest that the beneficial effects of treatment with progestin observed in endometriosis patients might arise from decreased pre-receptor metabolism of the protective progesterone by the SRD5A1 and AKR1C enzymes.

Effects of progestins on local estradiol biosynthesis and action in the Z-12 endometriotic epithelial cell line

Endometriosis is a common estrogen-dependent gynecological disease. In patients with endometriosis estradiol can be synthesized locally in the endometriotic lesions from inactive precursors of adrenal or ovarian origin, via the aromatase pathway. These increased estradiol levels stimulate proliferation of endometriotic tissue. The progestins have been used in the therapy of endometriosis for more than 40 years but their pharmacological action is still not understood in detail. In the present study we therefore aimed to evaluate the effects of three progestins most commonly used in the therapy of endometriosis; medroxyprogesterone acetate, dydrogesterone and dienogest on expression of all genes encoding enzymes of the aromatase pathway and estrogen receptors in the Z-12 model epithelial cell line of peritoneal endometriosis, by qPCR and Western blotting. Our results show that application of medroxyprogestrone acetate, dydrogesterone and dienogest significantly decreases HSD17B1 and CYP19A1 expression and significantly increases HSD17B2 expression. Dydrogesterone and dienogest also significantly suppress ESR1 and ESR2 transcription, whereas medroxyprogestrone acetate and dydrogesterone significantly reduce mRNA levels of GPER. Our results thus suggest that in peritoneal endometriosis the beneficial effects of these progestins can be explained by lower HSD17B1 and higher HSD17B2 mRNA and protein levels, which lead to reduced local E2 biosynthesis. Although progestins significantly decrease CYP19A1 mRNA levels, the protein itself was not detectable by Western blotting. As progestins down-regulate expression of ESR1, ESR2 and GPER, they might also prevent E2-mediated proliferation.

Endostatin Gene Therapy for Endometriosis in Rats

Objective:

Endostatin gene therapy for endometriosis was studied in an experimental autotransplantation model in rats.

Methods:

Endometriotic lesions were transfected by intralesional injection of the plasmid lipofectamine-endostatinpBud (group 1), lipofectamine-pBud (empty vector; group 2) or phosphatebuffered saline (group 3). Endostatin mRNA and protein levels in lesions were evaluated by quantitative real-time reverse transcription-polymerase chain reaction and Western blot analysis. Endostatin and vascular endothelial growth factor (VEGF) protein levels in serum, and microvessel density (MVD) and matrix metalloproteinase (MMP)-2 protein levels in endometriotic lesions, were also determined.

Results:

Lipofectamine- endostatin-pBud injection increased endostatin mRNA and protein levels in lesions. Lesions were significantly smaller, and serum VEGF levels significantly lower, in group 1 versus controls. Serum VEGF was significantly and negatively correlated with serum endostatin. In group 1, MMP-2 levels and MVD were significantly lower versus controls. MMP-2 level was negatively correlated with endostatin.

Conclusions:

Gene therapy with endostatin appears to be an effective treatment for endometriosis. Restoration of endostatin gene expression by gene transfer in vivo might be a potential gene therapy approach for human endometriosis.

Treatment of Endometriosis and Chronic Pelvic Pain with Letrozole and Norethindrone Acetate

BACKGROUND

Endometriosis is encountered in 7-10% of actively menstruating women, with a suspected prevalence as high as 22% in asymptomatic women. It is an important cause of chronic pelvic pain. The aim of this study was to evaluate the efficacy and safety of letrozole in combination with norethindrone acetate and calcium in the management of endometriosis associated pelvic pain.

METHODS

Prospective non-randomized open label study was carried out including 20 patients with endometriosis related pelvic pain that was refractory to previous treatments.

RESULT

In all 14 patients completed the study. All patients showed significant improvement of pain scores and revealed significant improvement of features of endometriosis on being given letrozole in combination with norethindrone acetate and calcium.

CONCLUSION

Letrozole is an effective drug for treatment of endometriosis.

Use of aromatase inhibitors to treat endometriosis-related pain symptoms: a systematic review

This systematic review aims to assess the efficacy of aromatase inhibitors (AIs) in treating pain symptoms caused by endometriosis. A comprehensive literature search was conducted to identify all the published studies evaluating the efficacy of type II nonsteroidal aromatase inhibitors (anastrozole and letrozole) in treating endometriosis-related pain symptoms. The MEDLINE, EMBASE, PubMed, and SCOPUS databases and the Cochrane System Reviews were searched up to October 2010. This review comprises of the results of 10 publications fitting the inclusion criteria; these studies included a total of 251 women. Five studies were prospective non-comparative, four were randomized controlled trials (RCTs) and one was a prospective patient preference trial. Seven studies examined the efficacy of AIs in improving endometriosis-related pain symptoms, whilst three RCTs investigated the use of AIs as post-operative therapy in preventing the recurrence of pain symptoms after surgery for endometriosis. All the observational studies demonstrated that AIs combined with either progestogens or oral contraceptive pill reduce the severity of pain symptoms and improve quality of life. One patient preference study demonstrated that letrozole combined with norethisterone acetate is more effective in reducing pain and deep dyspareunia than norethisterone acetate alone. However, letrozole causes a higher incidence of adverse effects and does not improve patients' satisfaction or influence recurrence of symptoms after discontinuation of treatment. A RCT showed that combining letrozole with norethisterone acetate causes a lower incidence of adverse effects and lower discontinuation rate than combining letrozole with triptorelin. Two RCTs demonstrated that, after surgical treatment of endometriosis, the administration of AIs combined with gonadotropin releasing hormone analogue for 6 months reduces the risk of endometriosis recurrence when compared with gonadotropin releasing hormone analogue alone. In conclusion, AIs effectively reduce the severity of endometriosis-related pain symptoms. Since endometriosis is a chronic disease, future investigations should clarify whether the long-term administration of AIs is superior to currently available endocrine therapies in terms of improvement of pain, adverse effects and patient satisfaction.

Current pharmacotherapy for endometriosis

IMPORTANCE OF THE FIELD

Medical therapy is the most commonly used treatment for endometriosis. In particular, the administration of hormonal therapies aims to improve symptoms with minimal adverse effects.

AREAS COVERED IN THIS REVIEW

Observational and randomized studies evaluating the efficacy of medical therapy on symptoms associated with endometriosis were reviewed. We searched Medline, Embase and the Cochrane Library up to December 2009.

WHAT THE READER WILL GAIN

The reader will obtain information on the available medical therapies used to treat endometriosis-related symptoms either after surgery or as an alternative to the surgical excision of endometriosis. The effectiveness of therapies, the dose of drugs, the length of treatment and the adverse effects are examined.

TAKE HOME MESSAGE

Medical therapies can efficaciously reduce the severity of pain symptoms caused by endometriosis. Recurrence of symptoms is common after discontinuation of medical therapies; therefore, the choice of the therapy should be based not only on the improvements of symptoms but also on the potential adverse effects and patients' satisfaction.

Pharmacological treatment of endometriosis: experience with aromatase inhibitors

Current treatment of endometriosis is mainly based on surgery and ovarian suppressive agents. In the last 10 years, it has been demonstrated that aromatase P450, a key enzyme for estrogen biosynthesis, may have a pathogenic role in endometriosis because it is aberrantly expressed in endometriotic implants and in eutopic endometrium of women with endometriosis. Therefore, inhibition of aromatase activity may represent a new therapeutic option for endometriosis. Case reports and observational studies have shown that pain symptoms caused by endometriosis quickly improve after administration of aromatase inhibitors. Limited data are available on the long-term course of pain symptoms after completion of treatment with aromatase inhibitors; however, some recent studies suggest that symptoms may recur at short-term follow-up. A range of results are reported on the effects of aromatase inhibitors on endometriotic lesions, with some authors describing improvements and other authors reporting persistence of pelvic lesions at second-look laparoscopy after treatment. No severe adverse effect has been reported during treatment with aromatase inhibitors both in pre- and postmenopausal women. On the basis of the available data, administration of aromatase inhibitors should now be offered only to the small number of women who have severe pain despite previous surgical and hormonal therapies. Further research in the form of randomized controlled trials will be required before recommending the routine use of these agents.

Endometriosis-associated nerve fibers and pain

The assessment and diagnosis of endometriosis remain elusive targets. Patient and medical-related factors add to delays in the detection and treatment. Recently, investigators have revealed specific nerve fibers present in endometriotic tissue, with existing parallels between density and pain severity. The aim of this review is to compile a comprehensive review of existing literature on endometriosis-related nerve fiber detection, and the effects of medical therapy on these neural fibers. We performed a systematic literature-based review using Medline and PubMed of nerve fibers detected in eutopic endometrium, endometriotic lesions, and the peritoneum. Various arrangements of significant medical terms and phrases consisting of endometriosis, pelvic pain, nerve fiber detection/density in endometriosis, and diagnoses methodology, including treatment and detection were applied in the search. Subsequent references used were cross-matched with existing sources to compile all additional similar reports. Similar nerve fibers were detected within lesions, endometrium, and myometrium, though at varying degrees of density. Hormonal therapy is widely used to treat endometriosis and was shown to be related to a reduction in fiber density. A direct result of specific nerve fiber detection within eutopic endometrial layers points to the use of a minimally invasive endometrial biopsy technique in reducing delay in diagnosis and subsequent possible preservation of fertility.

Endometriosis: current therapies and new pharmacological developments

Endometriosis is a chronic inflammatory condition that is responsive to management with steroids. The establishment of a steady hormonal environment and inhibition of ovulation can temporarily suppress ectopic implants and reduce inflammation as well as associated pain symptoms. In terms of pharmacological management, the currently available agents are not curative, and treatment often needs to be continued for years or until pregnancy is desired. Similar efficacy has been observed from the various therapies that have been investigated for endometriosis. Accordingly, combined oral contraceptives and progestins, based on their favourable safety profile, tolerability and cost, should be considered as first-line options, as an alternative to surgery and for post-operative adjuvant use. In situations where progestins and oral contraceptives prove ineffective, are poorly tolerated or are contraindicated, gonadotrophin-releasing hormone analogues, danazol or gestrinone may be used. Future therapeutic options for managing endometriosis must compare favourably against existing agents before they can be considered for inclusion into current practice. Finally, as reproductive prognosis is not ameliorated by medical treatment, it is not indicated for women seeking conception.

Gene therapy of benign gynecological diseases

Gene therapy is the introduction of genetic material into patient's cells to achieve therapeutic benefit. Advances in molecular biology techniques and better understanding of disease pathogenesis have validated the use of a variety of genes as potential molecular targets for gene therapy based approaches. Gene therapy strategies include: mutation compensation of dysregulated genes; replacement of defective tumor-suppressor genes; inactivation of oncogenes; introduction of suicide genes; immunogenic therapy and antiangiogenesis based approaches. Preclinical studies of gene therapy for various gynecological disorders have not only shown to be feasible, but also showed promising results in diseases such as uterine leiomyomas and endometriosis. In recent years, significant improvement in gene transfer technology has led to the development of targetable vectors, which have fewer side-effects without compromising their efficacy. This review provides an update on developing gene therapy approaches to treat common gynecological diseases such as uterine leiomyoma and endometriosis.

Proteomics technologies in endometriosis

Endometriosis is a common disorder that is associated with infertility and pelvic pain. Diagnosis is based on the visualization of endometriotic lesions during surgery as no reliable serum marker is currently available. The etiology of endometriosis is largely unknown. Over the last 20 years, several proteomics technologies have been used to research novel proteins with a potential etiological role in endometriosis, and to identify candidate serum markers for this condition. While some molecules identified by proteomics technologies may have a relevant role in the pathogenesis of endometriosis, the research of potential serum markers for this condition is still far from any clinical application. This review summarizes the state of the art and potential applications of proteomics in endometriosis research.

Toward gene therapy of endometriosis: transductional and transcriptional targeting of adenoviral vectors to endometriosis cells

OBJECTIVE

The purpose of this study was to screen a panel of targeted adenoviruses as vectors for endometriosis gene therapy.

STUDY DESIGN

Endometriotic cells were obtained from subjects with ovarian endometriomas. Liver tissues were taken from donors during hepatic transplantation surgery. Human endometriotic cells and liver tissues were transfected by targeted adenoviruses expressing luciferase reporter gene. Luciferase activity that was mediated by each virus was expressed as a percentage of adenovirus serotype 5 (Ad5-CMV-luc) activity. The 2-tailed Studentt test was used to compare the adenovirus data.

RESULTS

In endometriotic cells, the adenovirus-RGD (Ad-RGD-luc), adenovirus under secretory leukocyte protease inhibitor promoter (Ad-SLPI-luc), and adenovirus under heparanase promoter (Ad-heparanase-luc) showed significantly higher activity, compared with the adenovirus serotype 5. In liver tissues, adenovirus-survivin (Ad-survivin-luc) and Ad-heparanase-luc had significantly lower activity, compared with adenovirus serotype 5.

CONCLUSION

Ad-heparanase-luc showed "endometriosis on, liver off" phenotype and is a promising vector for endometriosis gene therapy.

Peritoneal fluid macrophages in endometriosis: correlation between the expression of estrogen receptors and inflammation

OBJECTIVE

To investigate the expression of estrogen receptors (ERs) and inflammatory cytokines in macrophages obtained from peritoneal fluid (PF) of women with endometriosis.

DESIGN

Comparative immunocytochemical study.

SETTING

University hospital.

PATIENT(S)

Thirty women with endometriosis and 22 controls.

INTERVENTION(S)

The PF samples were collected at laparoscopy.

MAIN OUTCOME MEASURE(S)

The expression of ERalpha, ERbeta, differentiation markers (CD68, NCL-MACRO, HAM56), and inflammatory cytokines (interleukin [IL]-1beta, tumor necrosis factor-alpha [TNF-alpha], IL-6) in PF macrophages was determined.

RESULT(S)

The expression of CD68, NCL-MACRO, HAM56, TNFalpha, IL-6, and IL-1beta was significantly higher in PF macrophages obtained from women with endometriosis than in controls. The ERalpha and ERbeta had significantly higher expression in macrophages of women with endometriosis than in controls. A positive correlation was observed between the expression of ERalpha and ERbeta both in women with and without endometriosis. The ERalpha expression was positively correlated with the expression of inflammatory cytokines in women with endometriosis but not in controls; ERbeta expression was correlated to the expression of inflammatory cytokines in the both groups.

CONCLUSION(S)

There is a correlation between the expression of ERbeta and proinflammatory cytokines both in women with and without endometriosis. The expression of ERalpha correlates with cytokine production selectively in women with endometriosis but not in controls.

Persistent bilateral ureteral obstruction secondary to endometriosis despite treatment with an aromatase inhibitor

OBJECTIVE

To present a case demonstrating lack of efficacy of an aromatase inhibitor in treating ureteral endometriosis.

DESIGN

Case report.

SETTING

A tertiary-care hospital.

PATIENT(S)

A 47-year-old woman with severe ureteral endometriosis.

INTERVENTION(S)

Anastrozole 1 mg daily for 15 months.

MAIN OUTCOME MEASURE(S)

Renal function.

RESULT(S)

Despite medical management with anastrozole, our patient continued to have worsening renal function and subsequently required surgical intervention.

CONCLUSION(S)

Anastrozole was ineffective at preventing deterioration of renal function in this patient.

Treatment strategies for endometriosis

BACKGROUND

Endometriosis is a common chronic disease that causes symptoms of pain and infertility. The pain syndrome can be quite incapacitating. The pain symptoms usually originate in the reproductive organs but can also involve the urinary or intestinal tracts if endometriosis implantation has occurred there. The presentation and physical appearance of endometriosis is extremely variable and can be characterized by a chronic intraperitoneal inflammatory process and adhesions. The only definitive diagnostic technique is laparoscopy.

OBJECTIVE

To review current literature on the treatment strategies for endometriosis.

METHODS

Review of Pubmed, Cochrane database and Medline for current review articles and studies regarding the current treatment strategies for endometriosis.

RESULTS

Initial treatment is surgical or medical. Medical therapy is often used as a first-line therapy and can also be used in conjunction with those patients who undergo surgical therapy for pain. No medical therapy has proven effective for infertility. Medical therapy consists mostly of hormonal suppressive therapy in which the medication causes a downregulation of the hypothalamus-pituitary-ovarian pathway. Non-steroidal anti-inflammatory drugs and oral contraceptives are often used as an initial approach even without a definitive diagnosis. Progestins, such as oral norethindrone and depot medroxyprogesterone, are effective while using them but have a high recurrence rate. The norgestrol intrauterine device is also quite effective at relieving pain associated with endometriosis, especially pain arising during menses as well as from lesions in the rectovaginal tissue. Gonadotropin-releasing hormone agonists induce a pseudomenopausal state and have significant side effects, such as hot flashes and genital atrophy. 'Add-back' therapy with a progestin has been shown to relieve most of these drug related symptoms. Gonadotropin-releasing hormone agonists are also very effective at relieving symptoms of pain during treatment but are also associated with a high recurrence rate. New drug therapies that are under investigation are aromatase inhibitors and immunomodulators. Furthermore, new delivery systems are being investigated that may also improve the patient response.

Suppression of IL-1β-induced COX-2 expression by trichostatin A (TSA) in human endometrial stromal cells

OBJECTIVE

Over-production of cyclooxygenase-2 (COX-2) plays an important role in the positive feedback loop that leads to proliferation and inflammation in endometriosis. Following our observation that histone deacetylase inhibitors (HDACIs) trichostatin A (TSA) and valproic acid (VPA) can suppress proliferation of endometrial stromal cells, we sought to determine whether TSA suppresses IL-1beta-induced COX-2 expression in endometrial stromal cells.

STUDY DESIGN

In vitro study using a recently established immortalized endometrial stromal cell line. The stromal cells were pretreated with TSA before stimulation with IL-1beta, and COX-2 gene and protein expression was measured by real-time quantitative RT-PCR and Western blot analysis, respectively.

RESULTS

IL-1beta stimulated COX-2 expression in a concentration-dependent manner in endometrial stromal cells. The induced COX-2 gene and protein expression were suppressed by TSA pretreatment.

CONCLUSIONS

TSA suppresses IL-1beta-induced COX-2 gene and protein expression in endometrial stromal cells. This finding, coupled with the findings that TSA and another HDACI, valproic acid, suppress proliferation and induce cell cycle arrest, suggests that HDACIs are a promising class of compound that has therapeutic potential for endometriosis.

Future of endometriosis research

In women of reproductive age, health economic costs are estimated to be considerably higher for endometriosis than for conditions such as Crohn's disease, migraine and hypertension, and similar to the cost of diabetes. However, more awareness of endometriosis among patients and politicians is needed to create a better climate for research funding in the area of endometriosis in particular, and women's health in general. Recent collaboration between patients, physicians and politicians in the EU has shown that such efforts can be successful. Many arguments exist to organize the clinical care for women with advanced endometriosis in centers of excellence, but continuing education of primary-care physicians also remains a priority. New molecular techniques are resulting in new hormonal and nonhormonal targets for the noninvasive diagnosis and treatment of endometriosis. A future diagnostic serum assay might contain various elements from inflammatory serum markers to genetic/microarray/proteomics markers, owing to the multifactorial features of endometriosis.

[Intestinal endometriosis. Current status]

Endometriosis affects a wide spectrum of premenopausal women. Intestinal involvement, affecting mainly the large bowel and sometimes the small bowel, is much less frequent. Diagnosis is relatively straightforward in women with long standing pelvic endometriosis but is difficult in acute intestinal obstruction, since a diagnosis of endometriosis is not often considered in this entity. We performed an exhaustive review of the medical literature, including the option of medical treatment, which is rarely effective in intestinal endometriosis. In most patients with intestinal symptoms, the disease is so severe that surgical treatment is required. Recent studies indicate that the most effective approach is laparoscopic. We analyze the most important classical and recent series of patients and discuss treatment results.

Genistein causes regression of endometriotic implants in the rat model

OBJECTIVE

To determine the effects of raloxifene and genistein on experimentally induced endometriosis in a rat model.

DESIGN

Prospective, randomized animal study.

SETTING

Animal surgery laboratory in a university hospital.

ANIMAL(S)

Thirty-three adult, mature female Wistar-Albino rats in which endometriotic implants were induced by transplanting autologous uterine tissue to ectopic sites on the peritoneum.

INTERVENTION(S)

After the endometriotic implants were formed surgically, the 33 rats were randomly divided into three groups. Group 1 (genistein group, 10 rats) were given 500 mg/kg per day of oral genistein. Group 2 (raloxifene group, 10 rats) were given 10 mg/kg per day of oral raloxifene. Group 3 were given no medication and served as controls (13 rats). All the rats continued to receive treatment for 21 days, and then were killed to assess the implants' size and for histologic examination.

MAIN OUTCOME MEASURE(S)

The surface area of the endometriotic implants and the score of histologic analysis.

RESULT(S)

At the beginning of the medical treatment, the mean surface areas of the endometriotic implants were comparable in all three groups. At the end of the medical treatment, the mean surface area of implants in groups 1 and 2 was smaller than that of implants in the control group. The decrease in the surface area of the endometriotic implants was greater in group 1 and group 2 than found in the control group. The histologic assessment revealed that the mean of the histopathologic score of the implants at the end of the treatment was lower in groups 1 and 2 when compared with the control group.

CONCLUSION(S)

Genistein caused a statistically significant regression of endometriotic implants.

Letrozole and desogestrel-only contraceptive pill for the treatment of stage IV endometriosis

BACKGROUND

It has recently been suggested that aromatase inhibitors may effectively reduce pain symptoms related to the presence of endometriosis both in postmenopausal women and in subjects of reproductive age.

AIMS

This study aims to evaluate the effectiveness of a combination of letrozole and desogestrel in the treatment of pain symptoms related to the presence of endometriosis.

METHODS

This open-label prospective study included 12 women with endometriosis-related pain symptoms that were refractory to previous medical and surgical treatments. All women had previous laparoscopy documenting stage IV endometriosis. The treatment protocol included the daily oral administration of letrozole 2.5 mg (Femara), desogestrel 75 microg (Cerazette), elemental calcium 1000 mg and vitamin D 880 I.U. The scheduled treatment period was six months.

RESULTS

None of the women included in the study completed the six-month treatment because all patients developed ovarian cysts; the median length of treatment was 84 days (range, 56-112). At interruption of treatment, all women reported significant improvements in dysmenorrhoea and dyspareunia. Pain symptoms quickly recurred at three-month follow up. There were no severe adverse effects of treatment; no significant change in the mineral bone density was observed during treatment.

CONCLUSIONS

The combination of letrozole and desogestrel induces a relief of pain symptoms in women with endometriosis but it causes the development of ovarian cysts. Pain symptoms quickly recur after the completion of treatment.

Effect of GnRH analogues on apoptosis and expression of Bcl-2, Bax, Fas and FasL proteins in endometrial epithelial cell cultures from patients with endometriosis and controls

BACKGROUND

Our purpose was to evaluate the effect of the GnRH agonist (GnRHa), leuprolide acetate (LA), and the GnRH antagonist (GnRHant), Antide, on apoptosis and expression of apoptosis-related proteins in endometrial epithelial cell (EEC) cultures from patients with endometriosis and controls (infertile women without endometriosis).

METHODS

Biopsy specimens of eutopic endometrium were obtained from 22 patients with endometriosis and from 14 women that served as controls. Apoptosis was examined in EEC after incubation with LA and Antide. Bax, Bcl-2, Fas and FasL expression was evaluated after exposure to LA, Antide or a combination of both. The percentage of apoptotic cells (%ApC) was assessed by the acridine orange-ethidium bromide technique, and protein expression was evaluated by western blot and immunocytochemistry.

RESULTS

LA 100 and 1000 ng/ml increased the %ApC in EEC from patients with endometriosis (both P < 0.05) and controls (p < 0.05 and P < 0.01, respectively). Antide 10(-5) M increased the %ApC in EEC from patients with endometriosis and controls (P < 0.01). In EEC from women with endometriosis, Bax expression increased after treatment with LA, Antide and LA + Antide (P < 0.05, P < 0.001 and P < 0.001), whereas Bcl-2 expression decreased after exposure to LA and Antide (P < 0.001 and P < 0.01). FasL expression increased after LA, Antide and LA + Antide treatments (P < 0.01, P < 0.001 and P < 0.01). No significant changes were observed on Fas expression.

CONCLUSIONS

GnRH analogues enhanced apoptosis in EEC, and this was accompanied by an increase in expression of the pro-apoptotic proteins Bax and FasL and a decrease in expression of the anti-apoptotic protein Bcl-2.

Antiangiogenic therapies in endometriosis

Oral contraceptives, androgenic agents, progestins and gonadotropin-releasing hormone analogues have all been successfully used in the treatment of endometriosis. However, none of these drugs can eradicate the disease. It is widely accepted that the growth of newly formed blood vessels is essential for the establishment and growth of endometriotic lesions; therefore, inhibition of angiogenesis may offer a new option for treatment of this disorder. In this paper, we reviewed anti-vascular endothelial growth factor agents and other angiostatic drugs (i.e., TNP470, endostatin, anginex, rapamycin) that have been studied in laboratory and animal models of endometriosis. Although preliminary results are interesting, further investigations are required before clinical trials can be planned in humans.