New treatment strategies and emerging drugs in endometriosis

PPARγ Agonists: Emergent Therapy in Endometriosis

Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.

Malignant Transformation and Associated Biomarkers of Ovarian Endometriosis: A Narrative Review

This review focuses on pathogenesis of endometriosis, its possible biomarkers and role in endometriosis-associated ovarian cancer. We analyzed various databases to obtain new insights, theories, and biomarkers associated with endometriosis. There are several theories of endometriosis development and biomarker changes including atypical forms. A number of studies have attempted to establish specific, reliable biomarkers to help diagnose endometriosis and endometriosis-associated diseases on the basis of different pathogenetic pathways. Nevertheless, despite intensive research extending even to the molecular level, the origin, natural history, malignant transformation, and laboratory management of endometriosis and related diseases are not yet clearly defined. Therefore, early laboratory diagnoses of endometriosis, its atypical form, and endometriosis-associated ovarian tumors are important problems that require further study in the context of advanced therapeutic strategies to provide maximal health benefits to patients.

Investigational luteinizing hormone releasing hormone (LHRH) agonists and other hormonal agents in early stage clinical trials for prostate cancer

INTRODUCTION

The treatment and management of prostate cancer continues to evolve; newer classes of agents and combination therapies are being developed and some are being investigated in early phase clinical trials.

AREAS COVERED

We discuss investigational hormonal agents for the treatment of prostate cancer and focus primarily on luteinizing hormone releasing hormone (LHRH) agonists in early stage trials. We look at agents that target the hormonal axis, including anti-androgens, gonadotropins, estrogenic agents and progestogenic agents and other non-hormonal agents often used in combination with LHRH agonists. We review these candidates in the specific clinical niche in which they might find utility.

EXPERT OPINION

Of all candidate compounds being evaluated in clinical trials, very few will receive FDA approval. Few, if any of the investigational agents discussed here will be used routinely in clinical practice for treating prostate cancer. Recognizing the reasons for the failure of agents to advance to later stage trials is important. Furthermore, a thorough understanding of the mechanisms underlying prostate cancer pathogenesis, including various points in the HGPA and parallel pathways, will help identify potentially actionable targets.

Endometriosis and endometriosis-associated cancers: new insights into the molecular mechanisms of ovarian cancer development

Endometriosis is a fascinating disease that we strive to better understand. Molecular techniques are shedding new light on many important aspects of this disease: from pathogenesis to the recognition of distinct disease variants like deep infiltrating endometriosis. The observation that endometriosis is a cancer precursor has now been strengthened with the knowledge that mutations that are present in endometriosis-associated cancers can be found in adjacent endometriosis lesions. Recent genomic studies, placed in context, suggest that deep infiltrating endometriosis may represent a benign neoplasm that invades locally but rarely metastasises. Further research will help elucidate distinct aberrations which result in this phenotype. With respect to identifying those patients who may be at risk of developing endometriosis-associated cancers, a combination of molecular, pathological, and inheritance markers may define a high-risk group that might benefit from risk-reducing strategies.

Lipoxin A4 Suppresses Estrogen-Induced Epithelial-Mesenchymal Transition via ALXR-Dependent Manner in Endometriosis

OBJECTIVE

Epithelial-mesenchymal transition (EMT) is essential for embryogenesis, fibrosis, and tumor metastasis. Aberrant EMT phenomenon has been reported in endometriotic tissues of patients with endometriosis (EM). In this study, we further investigated the molecular mechanism of which lipoxin A₄ (LXA₄) suppresses estrogen (E₂)-induced EMT in EM.

STUDY DESIGN

The EMT markers were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot in eutopic endometrial epithelial cells (EECs) or investigated by immunohistochemistry and qRT-PCR in endometriotic lesion of EM mice. The invasion and migration under different treatments were assessed by transwell assays with or without Matrigel. The messenger RNA (mRNA) and activities of matrix metalloproteinase 2 (MMP-2) and MMP-9 were determined by qRT-PCR and gelatin zymography, respectively. Luciferase reporter assay was used to measure the activity of zinc finger E-box binding homeobox 1(ZEB1) promoter. The level of E₂ in endometriotic tissues was assessed by enzyme-linked immunosorbent assay.

RESULTS

In eutopic EECs, stimulatory effects of E₂ on EMT progress, migration, and invasion were all diminished by LXA₄. Lipoxin A₄ reduced E₂-induced ZEB1 promoter activity. Lipoxin A₄ also attenuated the phosphorylation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase induced by E₂. Co-incubation with Boc-2 rather than DMF antagonized the influence of LXA₄. Animal experiments showed that LXA₄ inhibited the EMT progress, MMP expression, and proteinase activities of endometriotic lesion in an LXA₄ receptor (ALXR) manner, which suppressed the progression of EM. ZEB1 mRNA expression was upregulated and well correlated with E₂ level in human endometrium.

CONCLUSION

Lipoxin A₄ suppresses E₂-induced EMT via ALXR-dependent manner in eutopic EECs, which reveals a novel biological effect of LXA₄ in EM.

Evaluation of peritoneal endometriosis treatment using intralesional acetylsalicylic acid injection in rabbits

PURPOSE

To investigate the efficacy of intralesional 20% aspirin injection for treatment of experimental peritoneal endometriosis.

METHODS

Peritoneal endometriosis was experimentally induced in forty adult nulligravid female rabbits. On day 30 post-endometriosis induction, rabbits were randomly divided to assess early (10 days) and late (20 days) effects of intralesional injection of physiological saline solution (control groups) in comparison to intralesional injection of 20% bicarbonate aspirin solution (experimental groups) as follows: control group 1 (10 days, n=10); control group 2 (20 days, n=10); experimental group 3 (10 days, n=10); experimental group 4 (20 days, n=10). Resected tissues, including endometriosis foci, were qualitatively (general morphology and signs of inflammatory cells infiltrate, necrosis and apoptosis) and quantitatively (remaining endometriosis area) assessed by histopathological analysis.

RESULTS

Extensive necrosis, hemorrhage, apoptosis, and fibrosis were observed in the experimental groups 3 and 4. Groups 1 and 2 presented typical endometrial tissue cysts, respectively. Groups 3 and 4 showed sparse endometrial tissue foci and no endometrial tissue, respectively. Quantitative analysis revealed that aspirin-treated groups 3 and 4 had significantly (p<0.05) smaller remaining endometriosis area, compared to control groups 1 and 2.

CONCLUSION

Intralesional 20% aspirin injection caused total destruction of peritoneal endometriosis foci in rabbits.

Evaluating CA125 and VAS Pain Modifications following Gnrh Analog to Exclude Superficial Endometriosis as Cause of Chronic Pelvic Pain

Background

The study aim was to assess the reliability in the diagnosis of superficial endometriosis of the combined evaluation of 2 parameters: modifications of serum CA125 and VAS pain score following 1 dose of GnRH analog (GnRH-a).

Methods

Women with chronic pelvic pain (CPP) were managed by GnRH-a administration and diagnostic laparoscopy. Serum CA125 and VAS pain score were assessed for each patient at the early follicular phase and 2 months after the administration of 11.25 mg GnRH-a. Following laparoscopy, subjects were grouped into groups A (72 women with endometriosis) and B (46 women without endometriosis). A multivariate model for CA125 and VAS reduction and for the combination of the 2 markers was calculated using logistic regression and diagnostic performance was evaluated as the AUC of ROC curve. Main outcome measure was the accuracy of the modifications of serum CA125 levels and VAS score following GnRH-a, in patients with histological diagnosis of superficial endometriosis.

Results

At baseline, both groups showed similar CA125 levels and VAS scores. Two months after GnRH-a, a significant reduction (delta [Δ]) in CA125 levels and VAS pain score was observed in group A only. AUCs for ΔCA125, ΔVAS score and for combination of these 2 deltas were 0.90, 0.83 and 0.97, respectively.

Conclusions

The assessment of serum CA125 and VAS pain score following GnRH-a demonstrates good reliability to exclude superficial endometriosis in patients with CPP. The response to GnRH-a administration in these women could therefore be employed as an ex juvantibus criterion for endometriosis diagnosis.

Characterization of anastrozole effects, delivered by an intravaginal ring in cynomolgus monkeys

STUDY QUESTION

Is it feasible to deliver anastrozole (ATZ), an aromatase inhibitor (AI), by a vaginal polymer-based drug delivery system in the cynomolgus monkey (Macaca fascicularis) to describe the pharmacokinetic profile?

SUMMARY ANSWER

The present study showed the effective release of ATZ into the systemic circulation from intravaginal rings in cynomolgus monkeys.

WHAT IS KNOWN ALREADY

ATZ is a marketed drug with well documented pharmacological and safety profiles for oral administration. Aromatase is the key enzyme catalyzing estrogen biosynthesis and is overexpressed in endometriotic lesions. AIs show therapeutic efficacy in endometriosis in exploratory clinical trials.

STUDY DESIGN, SIZE, DURATION

The pharmacokinetics of the in vivo release and the pharmacodynamic activity of ATZ released by intravaginal rings (IVR) were investigated in healthy cycling female cynomolgus monkeys in three different dose groups (n = 5) for one menstrual cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

IVRs for the cynomolgus monkey, releasing three different doses of ATZ were designed and tested for in vitro/in vivo release for up to 42 days. For pharmacokinetic and pharmacodynamic evaluation, plasma samples were taken once daily from Day 1 to 3 and then every third day until menses occurred (17-42 days).

MAIN RESULTS AND THE ROLE OF CHANCE

ATZ was shown to be compatible with the IVR drug delivery system. An average in vivo release of 277 µg/day/animal of ATZ for one menstrual cycle was effective in causing a decrease of systemic estradiol (E₂) levels by ∼30% without inducing counter regulation such as the elevation of FSH or the formation of ovarian cysts.

LIMITATIONS, REASONS FOR CAUTION

The study was limited to three dose groups in which only the highest dose decreased the E₂ level. Hence, additional research with IVRs releasing higher amounts of ATZ is required to define the threshold for an ATZ-dependent ovarian stimulation in cynomolgus monkeys.

WIDER IMPLICATIONS OF THE FINDINGS

The release rate administered from IVRs is sufficient and in a range that supports feasibility of IVR administration of ATZ as a new approach for long-term therapy of estrogen-dependent diseases such as endometriosis in human.

Synergistic effects of E2MATE and norethindrone acetate on steroid sulfatase inhibition: a randomized phase I proof-of-principle clinical study in women of reproductive age

The combination of a progestin such as norethindrone acetate (NETA) reducing the ovarian estrogen production with a steroid sulfatase (STS) inhibitor (STS-I) decreasing the local estrogen production could result in a new treatment option for endometriosis. The study reported was a randomized, double-blind, and placebo-controlled study to investigate the pharmacodynamics, pharmacokinetics, and safety of the STS-I PGL2001 (E2MATE) and NETA. A total of 24 healthy women of reproductive age were treated with weekly doses of PGL2001 or daily doses of NETA or a combination of both compounds for 4 weeks. Four weeks of treatment with PGL2001 or PGL2001 + NETA reduced the STS activity in the endometrium by 91% (±3%) and 96% (±4%), respectively, and comparable values were observed 1 month after the treatment was stopped. The combined treatment of PGL2001 + NETA led to significantly higher STS inhibition at both times (P < .01 and P < .05, respectively). This study showed that administration of PGL2001 alone at 4 mg/week or combined with NETA to healthy women of reproductive age led to STS inhibition and changes in functional STS biomarkers in the endometrium, resulting in synergistic effects of PGL2001 and NETA on STS activity.

PPARγ activation inhibits growth and survival of human endometriotic cells by suppressing estrogen biosynthesis and PGE2 signaling

Endometriosis is a chronic inflammatory disease of reproductive age women leading to chronic pelvic pain and infertility. Current antiestrogen therapies are temporizing measures, and endometriosis often recurs. Potential nonestrogenic or nonsteroidal targets are needed for treating endometriosis. Peroxisome proliferator-activated receptor (PPAR)γ, a nuclear receptor, is activated by thiazolidinediones (TZDs). In experimental endometriosis, TZDs inhibit growth of endometriosis. Clinical data suggest potential use of TZDs for treating pain and fertility concurrently in endometriosis patients. Study objectives were to 1) determine the effects of PPARγ action on growth and survival of human endometriotic epithelial and stromal cells and 2) identify the underlying molecular links between PPARγ activation and cell cycle regulation, apoptosis, estrogen biosynthesis, and prostaglandin E2 biosynthesis and signaling in human endometriotic epithelial and stromal cells. Results indicate that activation of PPARγ by TZD ciglitazone 1) inhibits growth of endometriotic epithelial cells 12Z up to 35% and growth of endometriotic stromal cells 22B up to 70% through altered cell cycle regulation and intrinsic apoptosis, 2) decreases expression of PGE2 receptors (EP)2 and EP4 mRNAs in 12Z and 22B cells, and 3) inhibits expression and function of P450 aromatase mRNA and protein and estrone production in 12Z and 22B cells through EP2 and EP4 in a stromal-epithelial cell-specific manner. Collectively, these results indicate that PGE2 receptors EP2 and EP4 mediate actions of PPARγ by incorporating multiple cell signaling pathways. Activation of PPARγ combined with inhibition of EP2 and EP4 may emerge as novel nonsteroidal therapeutic targets for endometriosis-associated pain and infertility, if clinically proven safe and efficacious.

Defining future directions for endometriosis research: workshop report from the 2011 World Congress of Endometriosis In Montpellier, France

Endometriosis, defined as estrogen-dependent lesions containing endometrial glands and stroma outside the uterus, is a chronic and often painful gynecological condition that affects 6% to 10% of reproductive age women. Endometriosis has estimated annual costs of US $12 419 per woman (approximately €9579), comprising one-third of the direct health care costs with two-thirds attributed to loss of productivity. Decreased quality of life is the most important predictor of direct health care and total costs. It has been estimated that there is a mean delay of 6.7 years between onset of symptoms and a surgical diagnosis of endometriosis, and each affected woman loses on average 10.8 hours of work weekly, mainly owing to reduced effectiveness while working. To encourage and facilitate research into this debilitating disease, a consensus workshop to define future directions for endometriosis research was held as part of the 11th World Congress on Endometriosis in September 2011 in Montpellier, France. The objective of this workshop was to review and update the endometriosis research priorities consensus statement developed following the 10th World Congress on Endometriosis in 2008.(1) A total of 56 recommendations for research have been developed, grouped under 6 subheadings: (1) diagnosis, (2) classification and prognosis, (3) clinical trials, treatment, and outcomes, (4) epidemiology, (5) pathophysiology, and (6) research policy. By producing this consensus international research priorities statement, it is the hope of the workshop participants that researchers will be encouraged to develop new interdisciplinary research proposals that will attract increased funding support for work on endometriosis.

Interleukin-19 and interleukin-22 serum levels are decreased in patients with ovarian endometrioma

OBJECTIVE

To determine the serum levels of interleukin (IL)-10 family ILs in women with ovarian endometriosis and investigate the correlation of these levels with disease activity.

DESIGN

A case-control laboratory study.

SETTING

Tertiary-care university hospital.

PATIENT(S)

Two hundred nineteen women, with (n = 112) and without (n = 107) endometriosis.

INTERVENTION(S)

Complete surgical excision with pathological analysis.

MAIN OUTCOME MEASURE(S)

Blood samples were obtained during surgical procedures. IL-10, -19, -20, and -22 were assayed by ELISA in sera, and the concentrations correlated with the extent and the severity of the disease.

RESULT(S)

IL-19 was detectable in 18.3% and IL-22 in 47.9% of sera samples from all 219 women studied. Serum IL-19 was lower in women with endometriosis (median, 292.7 pg/mL; range, 32.2-1,339.3) than in endometriosis-free women (median, 1,035.8 pg/mL; range, 32.2-2,000.0). In addition, serum IL-22 levels were decreased in women affected by endometriosis (median, 352.0 pg/mL; range, 31.2-1,392.2) as compared with endometriosis-free women (median, 709.2 pg/mL; range, 73.3-2,012.0). We found significant correlations between serum IL-22 concentrations and intensity of deep dyspareunia (r = -0.303) and noncyclic chronic pelvic pain (r = -0.212). IL-19 was correlated with the intensity of deep dyspareunia (r = -0.749).

CONCLUSION(S)

Serum IL-19 and IL-22 are decreased in women with ovarian endometrioma. IL-10 family ILs may be involved in the pathogenesis of endometriosis.

Rectosigmoid endometriosis: Practical approaches to improve the possibility of obtaining a definite preoperative biopsy diagnosis

AIM: To discuss the methods for improving the accuracy of preoperative diagnosis of rectosigmoid endometriosis.

METHODS: From December 2002 up to now, six patients with intestinal endometriosis were treated at our hospital. The clinical manifestations, enteroscopic findings, and histopathological manifestations of preoperative biopsy specimens and postoperative specimens removed by laparotomy or laparoscope resection were analyzed. A review of the literature was also performed.

RESULTS: Four (66.7%) cases of the rectosigmoid endometriosis were misdiagnosed clinically, including 1 case misdiagnosed as glandular dysplasia and 3 cases as chronic inflammation (including 1 case as ulcers). Immunohistochemical staining for ER, PR, CK7, K20 and CD10 were performed. Normal colorectal epithelia were negative for CK7, ER, and PR, whereas rectosigmoid endometriosis was positive for CK7, ER, and PR and showed endometrial stromal expression of CD10.

CONCLUSION: Combination of clinical manifestations, colonoscopic findings, and immunohistochemistry can improve the accuracy of preoperative diagnosis of endometriosis.

Ectopic uterine tissue as a chronic pain generator

While chronic pain is a main symptom in endometriosis, the underlying mechanisms and effective therapy remain elusive. We developed an animal model enabling the exploration of ectopic endometrium as a source of endometriosis pain. Rats were surgically implanted with autologous uterus in the gastrocnemius muscle. Within two weeks, visual inspection revealed the presence of a reddish-brown fluid-filled cystic structure at the implant site. Histology demonstrated cystic glandular structures with stromal invasion of the muscle. Immunohistochemical studies of these lesions revealed the presence of markers for nociceptor nerve fibers and neuronal sprouting. Fourteen days after surgery rats exhibited persistent mechanical hyperalgesia at the site of the ectopic endometrial lesion. Intralesional, but not contralateral, injection of progesterone was dose-dependently antihyperalgesic. Systemic administration of leuprolide also produced antihyperalgesia. In vivo electrophysiological recordings from sensory neurons innervating the lesion revealed a significant increase in their response to sustained mechanical stimulation. These results are consistent with clinical and pathological findings observed in patients with endometriosis, compatible with the ectopic endometrium as a source of pain. This model of endometriosis allows mechanistic exploration at the lesion site facilitating our understanding of endometriosis pain.

Abdominal wall endometrioma mimicking an incarcerated hernia: a case report

The case of a tender, isolated abdominal wall tumor within a Pfannenstiel incision due to a seeding deposit of endometrial tissue secondary to a previous obstetric operation (caesarean section) in a 39-year-old female without previously reported pelvic endometriosis is presented. The lesion clinically mimicked the appearance of an incarcerated incisional hernia at the outer corner of the healed Pfannenstiel incision. The preoperative differential diagnosis also included that of a locally forming post-operative tender granuloma and the remote possibility of an incisional endometrioma (although no link to menstruation could be made). Local malignancy was not taken as a serious possibility. Definitive diagnosis of the excised lesion was made at histology. The pre-operative diagnostic dilemma is presented, along with a short review of the literature.