Direct effects of medroxyprogesterone acetate, danazol, and leuprolide acetate on endometrial stromal cell proliferation in vitro**Supported in part by grant HD21546 from the National Institutes of Health, Bethesda, Maryland.††Presented in part as the First Prize Winning Poster at the 45th Annual Meeting of The American Fertility Society, San Francisco, California, November 11 to 16, 1989

Predictive Biomarkers May allow Precision Therapy of Endometriosis

Introduction

Endometriosis is a chronic inflammatory gynecological disorder that causes pelvic pain. Due to the heterogeneity of the disease, response to any treatment in an individual is variable. We aimed to develop in vitro testing that could be adapted for use in precision therapy for endometriosis. We piloted a personalized medicine approach by identifying predictive biomarkers while determining the effect of bazedoxifene (BZA) and medroxyprogesterone acetate (MPA) on the gene expression of a progesterone receptor (PR), an estrogen receptor (ER), and an aromatase (CYP19A1) enzyme in cells cultured from biopsies of endometriosis patients. The differential expression of the most common molecular targets in endometriosis therapy correlated with cellular response.

Methods

Primary eutopic endometrial stromal cells were cultured from endometrial biopsies obtained in secretory phase from women between 24 and 42 years old with moderate-to-severe endometriosis (stages III and IV). Exclusion criteria included use of hormonal treatments and intrauterine contraception in the 6 months prior to surgery. Cells were treated either with BZA, MPA, or vehicle control. Total RNA was extracted from the treated and untreated cells. Differential expression of genes that are involved in the pathogenesis of endometriosis was determined by quantitative reverse transcriptase-polymerase chain reaction analysis.

Results

After determining the baseline expression levels of PRA/B, ERα and CYP19A1, response to treatment was monitored using Ki-67 as a marker of cell proliferation. MPA was effective in blocking proliferation in the group expressing high levels of PRA/B. Endometrium expressing high levels of CYP19A1 preferentially responded to BZA, a selective estrogen receptor modulator known to block estrogen action in endometrium.

Conclusions

PR expression may predict progestin resistance in endometriosis while CYP19A1 expression may indicate the need to block estrogen signaling.

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.

Trichostatin A, a histone deacetylase inhibitor, attenuates invasiveness and reactivates E-cadherin expression in immortalized endometriotic cells

The objective of this study is to determine whether trichostatin A (TSA) can suppress the invasiveness of 2 endometriotic cell lines known to be invasive and E-cadherin negative. The membrane invasion culture system was used to assess cell invasion using invasive and a noninvasive bladder cancer cell lines as positive and negative controls, respectively. The E-cadherin mRNA levels and protein expression were evaluated by real-time reverse transcriptase polymerase chain reaction and Western blot analysis, respectively. The authors found that TSA attenuates the invasiveness of 2 cell lines in the presence or absence of tumor necrosis factor alpha (TNFalpha) stimulation. In addition, TSA treatment reactivates E-cadherin gene and protein expression in these cell lines. These results, along with recent findings that TSA suppresses proliferation, interleukin-1 beta-induced cyclo-oxygenase 2 expression, and constitutive or TNFalpha-stimulated nuclear factor kappa B activation in endometrial and endometriotic cells, makes histone deacetylase inhibitors a promising class of compounds for novel and more effective medical treatment of endometriosis, especially given the mounting evidence that endometrios be an epigenetic disease.

Dienogest inhibits BrdU uptake with G0/G1 arrest in cultured endometriotic stromal cells

OBJECTIVE

To investigate the effect of dienogest on the proliferation of endometriotic stromal cells.

DESIGN

Comparative and laboratory study.

SETTING

University of Tokyo Hospital.

PATIENT(S)

Endometriotic stromal cells were isolated and cultured from ovarian endometriomas of patients undergoing surgery.

INTERVENTION(S)

Dienogest was added to the cultured endometriotic stromal cells.

MAIN OUTCOME MEASURE(S)

5-Bromo-2'-deoxyuridine (BrdU) incorporation into DNA of the endometriotic stromal cells was measured by ELISA. Cell cycle analysis of the cultured endometriotic stromal cells was performed by flow cytometry.

RESULT(S)

Dienogest at concentration of 10(-7) M and 10(-6) M significantly inhibited BrdU incorporation into DNA at 24 and 48 hours. Dienogest significantly increased the cells in G0/G1 phase and reduced the cells in S phase and G2/M phase in 24 and 48 hours.

CONCLUSION(S)

The present study indicates that dienogest can inhibit the proliferation of the endometriotic stromal cells with G0/G1 arrest, suggesting a possible direct effect of dienogest in the treatment of endometriosis.

The role of progestins in treating the pain of endometriosis

Progestins, synthetic progestational agents, have been used in the management of symptomatic endometriosis both as primary therapy and as an adjunct to surgical resection. A variety of oral agents have been employed in this regard with investigators demonstrating differing degrees of benefit. Unfortunately, due to the lack of large-scale, appropriately controlled, randomized trials, or dose-ranging studies, no single agent can be demonstrated to be truly efficacious. The lack of a standardized instrument to evaluate painful symptoms makes comparative analysis more difficult. Injectable administration of long-acting depot medroxyprogesterone acetate preparations intramuscularly or subcutaneously has been investigated in three randomized trials. The lower dose subcutaneous injection holds promise with an apparent reduction in side effects. Issues of reversible bone mineral density loss, breakthrough bleeding, and return of menses have not been completely resolved. Selective progesterone receptor modulators represent an intriguing alternative. These orally administered agents have been shown in preliminary investigations to be not only efficacious in reducing symptoms but also associated with minimal side effects. Further investigation of these agents is clearly required.

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.

Progesterone and progestational compounds attenuate tumor necrosis factor alpha-induced interleukin-8 production via nuclear factor kappa B inactivation in endometriotic stromal cells

OBJECTIVE

To investigate whether and how P, dienogest (synthetic progestin), and danazol affected tumor necrosis factor alpha (TNFalpha)-induced interleukin-8 (IL-8) expression in endometriotic stromal cells.

DESIGN

Prospective study.

SETTING

Department of Obstetrics and Gynecology, Tottori University Hospital, Yonago, Japan.

PATIENT(S)

Ten patients who underwent laparoscopic surgery.

INTERVENTION(S)

Endometriotic stromal cells were obtained from chocolate cyst linings of the ovary.

MAIN OUTCOME MEASURE(S)

In the presence of TNFalpha (0.1 ng/mL) and E2 (10(-7) mol/L), the cells were cultured in medium with P (10(-6) mol/L), danazol (10(-6) mol/L), or dienogest (10(-7) mol/L). The expression of the IL-8 gene and protein was determined by Northern blotting and ELISA, respectively. Activation of nuclear factor (NF)-kappaB was evaluated by electrophoretic mobility shift assay.

RESULT(S)

Adding TNFalpha (0.1 ng/mL) together with E2 markedly enhanced gene and protein expression of IL-8. The up-regulation of the IL-8 gene and protein expression by TNFalpha and E2 was significantly reduced by the addition of P, dienogest, or danazol. Electrophoretic mobility shift assay revealed that incubation with TNFalpha and E2 induced NF-kappaB activation. Adding P, dienogest, or danazol attenuated NF-kappaB activation.

CONCLUSION(S)

The present study demonstrates for the first time that P and progestational compounds attenuate the expression of IL-8 by reducing TNFalpha-induced NF-kappaB activation in endometriotic stromal cells, suggesting a possible molecular mechanism of hormone therapy for controlling the growth of endometriosis.

Microarray analysis of genes controlled by progesterone in human endometrial stromal cells in vitro

The steroid hormone progesterone is a key factor in establishment and maintenance of pregnancy in the human endometrium. To obtain a global view and identify new target genes for progesterone in human endometrial stromal cells in short-term (3 days) culture, we used a screening strategy to analyze the expression of nearly 1000 human genes by DNA microarray analysis. The results showed that six genes were up-regulated (at least a two-fold increase), and 27 genes were down-regulated (at least a two-fold decrease) after progesterone treatment compared with control. Progesterone stimulated the expression of the interleukin (IL)-1 receptor type 1, fibulin-1, fibulin-2, microsomal glutathione S-transferase 1, fumarylacetoacetate hydrolase and orphan G protein-coupled receptor (RDC1). Progesterone inhibited the expression of insulin-like growth factor binding protein-5, heparin-binding epidermal growth factor-like growth factor, and IL-13 receptor alpha2. In addition, progesterone inhibited the expression of genes involved in immune modulators, DNA/chromatin-related proteins, signal transduction, transcription factors, transport proteins, enzyme, receptor and structural proteins. Our results demonstrate that microarray analysis can be used to identify progesterone-regulated genes in endometrial stromal cells, thus contributing to a more detailed understanding of the molecular mechanisms in response to progesterone in the endometrium during the preparatory period for implantation.

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 prolonged gonadotropin-releasing hormone agonist therapy on the outcome of in vitro fertilization-embryo transfer in patients with endometriosis

OBJECTIVE

To evaluate the effect of a 3-month course of GnRH agonist administered immediately before IVF-ET in infertile patients with endometriosis.

DESIGN

Prospective, randomized trial.

SETTING

Three tertiary care assisted reproductive technology programs.

PATIENT(S)

IVF-ET candidates with surgically confirmed endometriosis.

INTERVENTION(S)

Twenty-five patients received three courses of a long-acting GnRH agonist, 3.75 mg i.m. every 28 days, followed by standard controlled ovarian hyperstimulation. Twenty-six patients received standard controlled ovarian hyperstimulation with mid-luteal phase GnRH agonist down-regulation or microdose flare regimens.

MAIN OUTCOME MEASURE(S)

Response to controlled ovarian hyperstimulation, ongoing pregnancy rates per cycle, group implantation rates, and implantation rate per embryo transfer procedure.

RESULT(S)

The extent of surgically confirmed endometriosis was greater in patients who received the long-acting GnRH regimen for 3 months before IVF-ET. The groups did not differ significantly in terms of dose or duration of gonadotropin stimulation, number of oocytes retrieved, fertilization rate, or number of embryos transferred. Patients who received the long-acting GnRH regimen had significantly higher ongoing pregnancy rates (80% vs. 53.85%) and a trend toward higher implantation rates (42.68% vs. 30.38%).

CONCLUSION(S)

Prolonged use of GnRH agonist before IVF-ET in patients with endometriosis resulted in significantly higher ongoing pregnancy rates than did standard controlled ovarian hyperstimulation regimens. No deleterious effect on ovarian response was observed.

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.

Expression of GnRH receptor gene in human ectopic endometrial cells and inhibition of their proliferation by leuprolide acetate

The present study was conducted to investigate whether GnRH-receptor (GnRH-R) gene is expressed in endometriosis ovarian implants and whether a GnRH-analogue (GnRH-a) may exert an effect on endometriosis cell proliferation in vitro. The presence of GnRH-R transcripts in ovarian endometriosis cells was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and further confirmed by Southern blot analysis. GnRH-R mRNA was detected in all the 13 samples examined. In contrast, GnRH-R transcripts were not detectable in endometriosis-free peritoneal tissue. In the second part of the study, endometriosis cells were cultured for 9 days with different doses of leuprolide acetate (ranging from 0 to 10(-5) M). In 4 out of 13 cases, a significant anti-proliferative effect was observed at doses of leuprolide acetate ranging from 10(-9) to 10(-5) M. In one case, a significant inhibition of cell proliferation was observed only at 10(-5) M leuprolide acetate concentration. In contrast, the GnRH-a did not affect cell growth, regardless of the expression of GnRH-R transcripts and the given doses, in the remaining 8 experiments. To date, this is the first evidence indicating that GnRH-R mRNA is expressed in human ovarian endometriomas. Moreover, the inhibition of endometriosis cell proliferation induced by the GnRH-a in vitro suggests that, at least in some cases, this compound might exert a direct effect on endometriosis lesions.

Leukocyte subpopulation changes in rats with autotransplanted endometrium and the effect of danazol

PROBLEM

This study examines immune cell populations in rats with autotransplanted endometrium and determines the effect of danazol on leukocyte subsets.

METHODS

As an experimental model of endometriosis, an autologous endometrial segment was implanted in the rat peritoneum. We used flow cytometry to analyze lymphocyte subsets in the peripheral blood (PB) and peritoneal fluid (PF) of the following groups of rats: no treatment, sham operation, endometrial implantation, endometrial implantation treated with danazol, and normal rats treated with danazol.

RESULTS

The natural killer (NK) cell population was decreased in both the PB and PF of rats with autotransplanted endometrium. Moreover, NK cells increased in a dose-dependent manner following danazol administration. Surgery itself increased the number of peritoneal macrophages as compared with the untreated group. This elevation was suppressed partially by endometrium-implantation and was attenuated by subsequent administration of danazol in a dose-dependent fashion.

CONCLUSIONS

These data suggest that ectopic endometrial cells may release immunosuppressive factors. This is the first documentation that rats with autotransplanted endometrium show the same immunologic changes as humans with endometriosis, and establishes the utility of this model for the study of endometriosis.

Therapeutic effects of danazol on endometrial cells may be activated by the presence of extracellular matrix

OBJECTIVE

To demonstrate the direct effect of danazol on the endometrium in the presence of various types of extracellular matrix.

STUDY DESIGN

Human endometrial cells (epithelial and stromal cells) were cultured over various extracellular matrix in the absence or presence of danazol. The effects of danazol on the growth of endometrial cells and the specific glandular structure were studied.

RESULTS

Danazol (10(-7) mol/L) inhibited endometrial cell growth, and in the presence of Matrigel, the same danazol concentration demonstrated a stronger inhibitory effect on epithelial cell growth. Danazol inhibited the formation of the specific glandular structure. Its effect depended on the culture substrates used and was reversible. Danazol did not inhibit growth of cells cultured over type V collagen substrate, whereas growth of those grown over type IV collagen was greatly inhibited.

CONCLUSION

The results indicate that a distinctive extracellular matrix around ectopic endometriotic tissue modulates cell growth and differentiation. Endometrium associated with a normal extracellular matrix is apparently protected from therapeutic drugs, whereas endometriotic tissue growing over a deranged extracellular matrix would be sensitive to therapeutic drugs, such as danazol.