Effect of danazol in vitro and in vivo on monocyte-mediated enhancement of endometrial cell proliferation in women with endometriosis *†*Supported by Public Health Service grant 58922, Bethesda, Maryland, and a grant from Sterling International, New York, New York.†Presented at the 47th Annual Meeting of The American Fertility Society, Orlando, Florida, October 20 to 23, 1991

Emerging hallmarks of endometriosis metabolism: A promising target for the treatment of endometriosis

Endometriosis, characterized by ectopic endometrium growth in the extrauterine environment, is one of the most notable diseases of the female reproductive system. Worldwide, endometriosis affects nearly 10 % of women in their reproductive years and causes a significant decline in quality of life. Despite extensive investigations of endometriosis over the past years, the mechanisms of endometriosis pathogenesis remain unclear. In recent years, metabolic factors have increasingly been considered factors in endometriosis. There is compelling evidence regarding the progress of endometriosis in the context of severe metabolic dysfunction. Hence, the curative strategies and ongoing attempts to conquer endometriosis might start with metabolic pathways. This review focuses on metabolic mechanisms and summarizes current research progress. These findings provide valuable information for the non-intrusive diagnosis of the disease and may contribute to the understanding of the pathogenesis of endometriosis.

Progesterone receptor ligands for the treatment of endometriosis: the mechanisms behind therapeutic success and failure

BACKGROUND

Despite intense research, it remains intriguing why hormonal therapies in general and progestins in particular sometimes fail in endometriosis.

OBJECTIVE AND RATIONALE

We review here the action mechanisms of progesterone receptor ligands in endometriosis, identify critical differences between the effects of progestins on normal endometrium and endometriosis and envisage pathways to escape drug resistance and improve the therapeutic response of endometriotic lesions to such treatments.

SEARCH METHODS

We performed a systematic Pubmed search covering articles published since 1958 about the use of progestins, estro-progestins and selective progesterone receptor modulators, to treat endometriosis and its related symptoms. Two reviewers screened the titles and abstracts to select articles for full-text assessment.

OUTCOMES

Progesterone receptor signalling leads to down-regulation of estrogen receptors and restrains local estradiol production through interference with aromatase and 17 beta-hydroxysteroid dehydrogenase type 1. Progestins inhibit cell proliferation, inflammation, neovascularisation and neurogenesis in endometriosis. However, progesterone receptor expression is reduced and disrupted in endometriotic lesions, with predominance of the less active isoform (PRA) over the full-length, active isoform (PRB), due to epigenetic abnormalities affecting the PGR gene transcription. Oxidative stress is another mechanism involved in progesterone resistance in endometriosis. Among the molecular targets of progesterone in the normal endometrium that resist progestin action in endometriotic cells are the nuclear transcription factor FOXO1, matrix metalloproteinases, the transmembrane gap junction protein connexin 43 and paracrine regulators of estradiol metabolism. Compared to other phenotypes, deep endometriosis appears to be more resistant to size regression upon medical treatments. Individual genetic characteristics can affect the bioavailability and pharmacodynamics of hormonal drugs used to treat endometriosis and, hence, explain part of the variability in the therapeutic response.

WIDER IMPLICATIONS

Medical treatment of endometriosis needs urgent innovation, which should start by deeper understanding of the disease core features and diverse phenotypes and idiosyncrasies, while moving from pure hormonal treatments to drug combinations or novel molecules capable of restoring the various homeostatic mechanisms disrupted by endometriotic lesions.

Role of medical therapy in the management of uterine adenomyosis

Adenomyosis is a benign uterine condition affecting women at various ages with different symptoms. The management of these patients is still controversial. Few clinical studies focusing on medical or surgical treatment for adenomyosis have been performed. No drug is currently labelled for adenomyosis and there are no specific guidelines to follow for the best management. Anyhow, medical treatments are effective in improving symptoms (pain, abnormal uterine bleeding and infertility). The rationale for using medical treatment is based on the pathogenetic mechanisms of adenomyosis: sex steroid hormones aberrations, impaired apoptosis, and increased inflammation. Several nonhormonal (i.e., nonsteroidal anti-inflammatory drugs) and hormonal treatments (i.e., progestins, oral contraceptives, gonadotropin-releasing hormone analogues) are currently used off-label to control pain symptoms and abnormal uterine bleeding in adenomyosis. Gonadotropin-releasing hormone analogues are indicated before fertility treatments to improve the chances of pregnancy in infertile women with adenomyosis. An antiproliferative and anti-inflammatory effect of progestins, such as dienogest, danazol and norethindrone acetate, suggests their use in medical management of adenomyosis mainly to control pain symptoms. On the other hand, the intrauterine device releasing levonorgestrel resulted is extremely effective in resolving abnormal uterine bleeding and reducing uterine volume in a long-term management plan. Based on new findings on pathogenetic mechanisms, new drugs are under development for the treatment of adenomyosis, such as selective progesterone receptor modulators, aromatase inhibitors, valproic acid, and anti-platelets therapy.

Current and Future Medical Treatment of Adenomyosis

Adenomyosis is a benign gynecological disorder associated with abnormal uterine bleeding, dysmenorrhea, dyspareunia and infertility, requiring a life-long management plan through medical or surgical treatment. The choice depends on woman's age, reproductive status and clinical symptoms. However, until now no drug labelled for adenomyosis is available; thus, the present review will focus on medical treatments currently used for adenomyosis and those in development.

Adenomyosis may be considered a sex steroid hormone-related disorder associated with an intense inflammatory process. The use of gonadotropin-releasing hormone agonists (GnRH-a) for treating adenomyosis is described blocking the hypothalamic-pituitary-gonadal axis; however, it has long been associated with frequent and intolerable hypoestrogenic side effects. An antiproliferative effect of progestins suggests their use for treating adenomyosis, reducing bleeding and pain. Continuous oral norethisterone acetate or medroxyprogesterone acetate may help to inducing regression of adenomyosis, relief pain and reduce bleeding. The use of vaginal danazol has therapeutic effect on adenomyosis combining progestogenic and anti-inflammatory activity. The intrauterine device releasing levonorgestrel (Lng-IUD) is widely assessed in menorrhagia, and has been shown to be extremely effective in resolving pain and bleeding symptoms associated with adenomyosis. Recent data show a therapeutic effect of dienogest on adenomyosis symptoms.

New drugs are under development for the treatment of adenomyosis, such as aromatase inhibitors (AIs) and selective estrogen receptor modulators (SERMs), that produce a hypoestrogenic environment reducing pain, but are correlated with some adverse effects and a recurrence of symptoms after discontinuation of treatment. Selective progesterone receptor modulators (SPRMs) may reduce adenomyosis-associated pelvic pain, by inhibiting endometrial proliferation and suppressing adenomyotic lesion growth, as shown in animal models; however, the long-term effect with SPRMs needs further determination.

Aberrant expression of apoptosis-related molecules in endometriosis: a possible mechanism underlying the pathogenesis of endometriosis

Endometriosis, a disease affecting 3% to 10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue under the influence of estrogen. It is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a "death" signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of antiapoptotic factors and decreased expression of preapoptotic factors. Further investigations may elucidate the role of apoptosis-associated molecules in the pathogenesis of endometriosis. Medical treatment with apoptosis-inducing agents may be novel and promising therapeutic strategy for endometriosis.

Is aromatase expression in the endometrium the cause of endometriosis and related infertility?

Aromatase expression in the endometrium seems to play a pivotal role in the development of endometriotic lesions. Because inflammatory mediators such as prostaglandin E2 appear to activate aromatase in the cells of the endometrial stroma, it was hypothesised that the ensuing inflammation caused by the arrival of aromatase-positive cells in the peritoneal cavity would stimulate local estrogen production, which would in turn facilitate the development of endometriotic lesions by suppressing macrophage phagocytosis. Aromatase expression in the eutopic endometrium will also hamper ovum nidation, thus causing infertility. Progestins, such as gestodene and danazol, are potent inhibitors of aromatase expression in the endometrium, and the use of vaginal rings with danazol in doses that do not block ovulation is associated with the occurrence of pregnancy in patients with severe endometriosis without the need for surgery. A local effect on the endometrium suppressing aromatase expression has been suggested as a possible mechanism of action for the danazol ring.

Evaluation of the efficacy of a danazol-loaded intrauterine contraceptive device on adenomyosis in an ICR mouse model

BACKGROUND

Danazol, a synthetic steroid with antigonadotrophic properties, has been widely used for the treatment of endometriosis and adenomyosis. However, the local application of danazol to the uterus to treat adenomyosis is controversial. The objective of this study is to develop an effective treatment for adenomyosis using danazol via intrauterine contraceptive device (IUCD) delivery.

METHODS

An adenomyosis animal model was established using Institute for Cancer Research, Swiss-derived (ICR) mice, grafted with a single pituitary gland (n = 30). Four months after grafting, IUCDs with three different quantities of danazol were prepared and used to treat the ICR mice with adenomyosis. After 2 months of treatment with a danazol-loaded IUCD, the number of adenomyosis nodules and the hematoxylin-eosin staining scores were measured and compared with mice given daily oral danazol and controls (no adenomyosis).

RESULTS

As the danazol dose increased, the nodule number decreased reaching significance at a dose of 2.0 mg per 20 g body weight (P = 0.002). When compared with oral administration, the plasma danazol concentrations with IUCD delivery were low and stable.

CONCLUSIONS

These results suggest that an IUCD loaded with an appropriate dose of danazol may be an effective treatment for adenomyosis and that human trials are warranted.

Effects of danazol on endothelial cell function and angiogenesis

OBJECTIVE

To determine the effects of the androgen-like synthetic steroid, danazol, on endothelial cell function and angiogenesis.

DESIGN

In vitro cell culture models were designed to investigate three critical steps involved in angiogenesis: endothelial cell proliferation, invasion, and tube formation.

SETTING

Research laboratory at a level one trauma center.

PATIENT(S)

Commercially available human umbilical vein endothelial cells (HUVEC) were purchased from a pooled patient source.

INTERVENTION(S)

The HUVEC cells were treated with danazol at concentrations ranging from 1 to 100 microM and evaluated using a series of angiogenesis assays.

MAIN OUTCOME MEASURE(S)

Absolute cells numbers were quantified using colorimetric methods and fluorescent dyes for cells exposed to danazol in both proliferation assays and invasion chambers. AngiQuant vl.33 software was used to evaluate the formation of capillary-like structures on extracellular matrix gels in the presence of danazol.

RESULT(S)

Endothelial cells scrutinized by our in vitro models exhibited decreased proliferation (up to 86%) and tube length (up to 115%) in the presence danazol. Cellular invasion through extracellular matrix, however, was not apparently affected by danazol under the conditions used.

CONCLUSION(S)

Danazol interfered with two of the three steps of angiogenesis studied in vitro. This data may help elucidate the mode of action for danazol in vivo.

Inhibition of proliferation of endometrial stromal cells by trichostatin A, RU486, CDB-2914, N-acetylcysteine, and ICI 182780

BACKGROUND

All current major medications in treating endometriosis are effective in treating pain, most likely through suppression of proliferation of the implants, yet their effectiveness is relatively short term and they all have many undesirable, and sometimes severe, side effects. There is pressing need for novel, more effective medications in treating endometriosis with less and/or milder side effects.

METHODS

Using a recently established immortalized endometrial stromal cell line, we carried out cell proliferation assays for cells treated with trichostatin A (TSA), RU486, CDB-2914, and N-acetylcysteine, and ICI 182780. Gene expression levels for PR-A, PR-B, AR, Fas and FasL were measured. Protein expression levels for ERalpha, ERbeta, and AR were also measured.

RESULTS

Cell proliferation assay results for NAC, H2O2, CDB, and RU486 were nearly identical or similar to what have been reported based on primary cell cultures or in vivo studies. TSA, CDB, RU486 and NAC all had various antiproliferative effects. TSA had a more potent and longer lasting antiproliferative effect than CDB and NAC, even in the presence of an oxidant, H2O2. Its antiproliferative effect was concentration-dependent. ICI did not have a significant antiproliferative effect. PR-A, PR-B, AR, and FasL expression were all increased as compared with untreated cells.

CONCLUSIONS

The cell line appears to be an adequate model for stromal components of endometriotic implants. That ICI has no inhibitory effect on endometrial proliferation may explain why a phase II clinical trial on its use to treat endometriosis did not advance to later stages. The upregulation of PR-B and AR may be responsible for antiproliferative effects induced by TSA, a histone deacetylase inhibitor (HDACI). HDACIs may be promising therapeutics in treating endometriosis due to their antiproliferative effects as well as the potential to restore gene dysregulation through chromatin remodeling.

Elevated levels of macrophage migration inhibitory factor in the peripheral blood of women with endometriosis

OBJECTIVE

To evaluate the concentrations of macrophage migration inhibitory factor (MIF) in the peripheral blood of normal women and patients with endometriosis.

DESIGN

Retrospective study using ELISA to measure peripheral blood MIF.

SETTING

Gynecology clinic and human reproduction research laboratory.

PATIENT(S)

Thirty-eight normal women and 55 women with endometriosis.

INTERVENTION(S)

Peripheral blood samples were obtained a few days before laparoscopy.

MAIN OUTCOME MEASURE(S)

The MIF concentrations in blood serum.

RESULT(S)

This current study showed a 364% increase in MIF concentrations in women with endometriosis as compared to normal women. A significant increase was seen in endometriosis stages I-II, but a more marked increase was observed in the more advanced stages of the disease (III-IV). Both fertile and infertile women with endometriosis had higher levels of MIF than normal controls, but the difference was more significant in infertile women with endometriosis. Women with endometriosis with no pelvic pain had higher levels of MIF than normal controls, but a more significant increase in MIF levels was observed in women with endometriosis reporting pelvic pain.

CONCLUSION(S)

This study showed a marked increase in MIF concentrations in the peripheral blood of women with endometriosis and a relationship with disease progress, and suggests that MIF may be involved in endometriosis-related pain and infertility.

Immunology of endometriosis

Endometriosis is a benign gynecologic disorder characterized by the ectopic growth of misplaced endometrial cells. A unifying hypothesis to explain endometriosis has not been elucidated as yet but numerous investigations have implicated disturbances in the immune response as fundamental to its etiology and pathogenesis. Clearly, the immune system is involved in endometriosis. It is not clear, however, whether and to what extent this involvement is a primary response leading to the initiation, promotion, and progression of the disease or a secondary response to the ectopic endometrial growth in an attempt to restore homeostasis. Thus, although numerous studies have shown alterations in cell-mediated and humoral immunity in subjects with endometriosis, the importance of these changes remains obscure. This review considers the past two decades of investigation of immune function changes in women with endometriosis with the expectation that this information will ultimately provide the basis for developing new approaches to patient management.

Gonadotropin-releasing hormone agonist and danazol normalize aromatase cytochrome P450 expression in eutopic endometrium from women with endometriosis, adenomyosis, or leiomyomas

OBJECTIVE

To investigate whether GnRH agonists or danazol therapy normalizes estrogen metabolism in the eutopic endometrium of women with endometriosis, adenomyosis, or leiomyomas.

DESIGN

Prospective clinical study.

SETTING

University hospital.

PATIENT(S)

Fifty-three women with endometriosis, adenomyosis, or leiomyomas.

INTERVENTION(S)

Patients received GnRH agonist or danazol. Biopsy samples of the endometrium were obtained before and after endocrine therapy. Nontreated endometrial explants were cultured in the presence of either drug.

MAIN OUTCOME MEASURE(S)

Reverse transcription polymerase chain reaction-Southern blot and immunohistochemical analyses of the endometrial expression of aromatase cytochrome P450, estrogen receptor, progesterone receptor, and Ki-67. Nontreated endometrial explants were cultured in the presence of either drug.

RESULT(S)

Messenger RNA and protein of aromatase cytochrome P450 were greatly reduced in the eutopic endometrium of patients treated with GnRH agonist for 2 months or more or with danazol for 1 month or more. Culture of endometrial explants with GnRH agonist (10(-9)-10(-7) M) did not change the amount of aromatase cytochrome P450, whereas danazol (10(-7)-10(-6) M) efficiently reduced aromatase cytochrome P450 expression.

CONCLUSION(S)

Therapy with GnRH agonist or danazol decreases expression of aromatase cytochrome P450 in diseased eutopic endometrium. Endocrine therapy normalized in part the impaired hormonal expression of the eutopic endometrium. GnRH agonist reduced aromatase cytochrome P450 expression mainly by promoting a hypoestrogenic state, whereas danazol reduced aromatase cytochrome P450 in part by direct action on the eutopic endometrium.

Effect of hormonal agents on monocyte chemotactic protein-1 expression by endometrial epithelial cells of women with endometriosis

OBJECTIVE

To assess whether hormonal agents used in the medical treatment of endometriosis, such as danazol and GnRH agonist, exert direct regulatory action on monocyte chemotactic protein-1 (MCP-1) expression by endometrial epithelial cells.

DESIGN

Primary cultures of epithelial cells isolated from human endometrium were exposed to different concentrations of cytokines and steroid hormone analogs. Expression of MCP-1 was analyzed at the levels of protein and messenger RNA.

SETTING

Gynecology clinic and laboratory of endocrinology of reproduction.

PATIENT(S)

Women presenting for infertility or pelvic pain in whom endometriosis was diagnosed by using laparoscopy.

INTERVENTION(S)

Endometrial tissue biopsy performed at laparoscopy.

MAIN OUTCOME MEASURE(S)

Secretion of MCP-1 protein was measured by using enzyme-linked immunosorbent assay, and mRNA steady-state levels were measured by performing Northern blot analysis.

RESULT(S)

Buserelin acetate, a GnRH agonist (0.1-10 ng/mL), had no significant effect on MCP-1 expression, whereas danazol (10(-7)-10(-5) M), a testosterone analog, and dexamethasone, an anti-inflammatory glucocorticoid hormone (10(-12)-10(-6)M), showed a direct and a dose-dependent inhibitory effect on MCP-1 expression. This effect occurred at the level of protein and mRNA.

CONCLUSION(S)

The findings of the study may affect understanding of the mechanisms by which hormonal treatments act on endometriosis and influence its clinical manifestations.

The role of estradiol, progesterone, and transforming growth factor on human endometrioma cell culture

The present study demonstrates several aspects of endometrioma cells in culture, namely, 1) cell growth, proliferation, and morphology, 2) effect of cell culture on estrogen and progesterone receptor concentration, 3) effect of estradiol, progesterone, and transforming growth factor. The tissue sample was obtained from ovarian endometriomas that were removed via laparotomy or laparoscopy. The tissue sample was digested with collagenase. After washing, the tissue was cultured in endothelial cell culture medium. Cell count was done by flow cytometry. Receptor study was done by immunohistochemistry. The results demonstrated the growth and proliferation of endometrioma cell in culture medium. Electron microscopy showed stroma-like cells. The cells lost their estrogen and progesterone receptors. Estradiol and progesterone added to these cultures did not affect the rate of growth and proliferation of the cells. Transforming growth factor significantly increased the rate of growth and proliferation of these cells.

Effect of danazol on the immunocompetent cells in the eutopic endometrium in patients with endometriosis: a multicenter cooperative study

OBJECTIVE

To assess the effects of danazol on immunocompetent cells, human leukocyte antigen (HLA) expression, and adhesion molecules in the eutopic endometrium of patients with endometriosis.

DESIGN

Antigens were localized immunohistochemically in the endometria, before treatment and during treatment (2 months later).

PARTICIPANTS

Ten patients with laparoscopically proven endometriosis who consented to participate in this study were treated with 400 mg/d of danazol for 4 months. Forty-two infertile patients without endometriosis or adenomyosis served as controls.

RESULTS

Immunohistochemical analysis revealed significantly increased expression of the T cell subsets, macrophages, adhesion molecules, and HLA antigens in eutopic endometrium in patients with endometriosis compared with the infertile group. Treatment with danazol reduced the number of cells in T cell subsets, adhesion molecules, or HLA antigen expression, especially of gamma delta T cells, to 39.5% of the pretreatment value in patients with endometriosis.

CONCLUSIONS

Danazol had an immunomodulatory effect on the autoimmune response in endometrium associated with endometriosis.

PGE2 and PGF2 alpha release by human peritoneal macrophages in endometriosis

OBJECTIVE

To test for differences in the amount and activity of peritoneal macrophages present in the peritoneal fluid of women with, and without endometriosis using prostaglandin release by macrophages in culture as a marker.

PATIENTS

Women of reproductive age undergoing laparoscopy for infertility or chronic pelvic pain with postoperative diagnosis of endometriosis and women undergoing laparoscopy for sterilization.

METHODS

Peritoneal fluid was aspirated during laparascopy, volume was recorded, macrophages were isolated via a Ficoll Paque gradient and kept in primary culture. PGE2 and PGF2 alpha release of the cells were measured before and after stimulation with zymosan.

RESULTS

Women with endometriosis had significantly more peritoneal macrophages than controls. Peritoneal macrophages of women with endometriosis released significantly more PGE2 than those of the control group: 8.4 +/- 2.0 versus 1.4 +/- 0.4 ng/ml/10(6) cells (mean +/- SEM, p = 0.0005) and PGF2 alpha: 10 +/- 4.3 (endometriosis) versus 1.8 +/- 0.4 (control) ng/ml/10(6) cells (mean +/- SEM, p = 0.045).

CONCLUSION

There is a significant increase in the amount of prostaglandins released by peritoneal macrophages from women with endometriosis. These prostaglandins might alter uterine and tubal contractility, thereby affecting fertility.