Analysis of biomarker expression in severe endometriosis and determination of possibilities for targeted intraoperative imaging

Targeting NGF but not VEGFR1 or BDNF signaling reduces endometriosis-associated pain in mice

INTRODUCTION

Endometriosis is a chronic inflammatory disease that affects ∼10 % of women. A significant fraction of patients experience limited or no efficacy with current therapies. Tissue adjacent to endometriosis lesions often exhibits increased neurite and vascular density, suggesting that disease pathology involves neurotrophic activity and angiogenesis.

OBJECTIVES

We aim to evaluate the potential for key tyrosine-kinase-receptor-coupled neurotrophic molecules to contribute to endometriosis-associated pain in mice.

METHODS

Peritoneal fluid was collected from endometriosis patients undergoing surgery and the levels of NGF and VEGFR1 regulators (VEGFA, VEGFB, PLGF, and sVEGFR1) were quantified by ELISA. VEGFR1 regulator concentrations were used to calculate VEGFR1 occupancy. We used genetic depletion, neutralizing antibodies, and pharmacological approaches to specifically block neurotrophic ligands (NGF or BDNF) or receptors (VEGFR1, TRKs) in a murine model of endometriosis-associated pain. Endometriosis-associated pain was measured using von Frey filaments, quantification of spontaneous abdominal pain-related behavior, and thermal discomfort. Disease parameters were evaluated by lesion size and prevalence. To evaluate potential toxicity, we measured the effect of entrectinib dose and schedule on body weight, liver and kidney function, and bone structure (via micro-CT).

RESULTS

We found that entrectinib (pan-Trk inhibitor) or anti-NGF treatments reduced evoked pain, spontaneous pain, and thermal discomfort. In contrast, even though calculated receptor occupancy revealed that VEGFR1 agonist levels are sufficient to support signaling, blocking VEGFR1 via antibody or tamoxifen-induced knockout did not reduce pain or lesion size in mice. Targeting BDNF-TrkB with an anti-BDNF antibody also proved ineffective. Notably, changing dosing schedule to once weekly eliminated entrectinib-induced bone-loss without decreasing efficacy against pain.

CONCLUSIONS

This suggests NGF-TrkA signaling, but not BDNF-TrkB or VEGF-VEGFR1, mediates endometriosis-associated pain. Moreover, entrectinib blocks endometriosis-associated pain and reduces lesion sizes. Our results also indicated that entrectinib-like molecules are promising candidates for endometriosis treatment.

PARP-1, EpCAM, and FRα as potential targets for intraoperative detection and delineation of endometriosis: a quantitative tissue expression analysis

BACKGROUND

Endometriosis is a gynecological disease characterized by the presence of endometrial tissue in abnormal locations, leading to severe symptoms, inflammation, pain, organ dysfunction, and infertility. Surgical removal of endometriosis lesions is crucial for improving pain and fertility outcomes, with the goal of complete lesion removal. This study aimed to analyze the location and expression patterns of poly (ADP-ribose) polymerase 1 (PARP-1), epithelial cell adhesion molecule (EpCAM), and folate receptor alpha (FRα) in endometriosis lesions and evaluate their potential for targeted imaging.

METHODS

Gene expression analysis was performed using the Turku endometriosis database (EndometDB). By immunohistochemistry, we investigated the presence and distribution of PARP-1, EpCAM, and FRα in endometriosis foci and adjacent tissue. We also applied an ad hoc platform for the analysis of images to perform a quantitative immunolocalization analysis. Double immunofluorescence analysis was carried out for PARP-1 and EpCAM, as well as for PARP-1 and FRα, to explore the expression of these combined markers within endometriosis foci and their potential simultaneous utilization in surgical treatment.

RESULTS

Gene expression analysis revealed that PARP-1, EpCAM, and FOLR1 (FRα gene) are more highly expressed in endometriotic lesions than in the peritoneum, which served as the control tissue. The results of the immunohistochemical study revealed a significant increase in the expression levels of all three biomarkers inside the endometriosis foci compared to the adjacent tissues. Additionally, the double immunofluorescence analysis consistently demonstrated the presence of PARP-1 in the nucleus and the expression of EpCAM and FRα in the cell membrane and cytoplasm.

CONCLUSION

Overall, these three markers demonstrate significant potential for effective imaging of endometriosis. In particular, the results emphasize the importance of PARP-1 expression as a possible indicator for distinguishing endometriotic lesions from adjacent tissue. PARP-1, as a potential biomarker for endometriosis, offers promising avenues for further investigation in terms of both pathophysiology and diagnostic-therapeutic approaches.

Biomarker identification for endometriosis as a target for real-time intraoperative fluorescent imaging: A new approach using transcriptomic analysis to broaden the search for potential biomarkers

Intra-operative fluorescent imaging of endometriosis could help to optimize surgical treatment. Potential biomarkers to use as target for endometriosis-binding fluorescent probes were identified using a new five-phase transcriptomics-based approach to broaden the search for biomarkers. Using publicly available datasets, a differentially expressed gene (DEG) analysis was performed for endometriosis versus surgically relevant surrounding tissue (peritoneum, bladder, sigmoid, rectum, transverse colon, small intestine, vagina, and fallopian tubes) for which data was available. The remaining relevant surrounding tissues were analyzed for low expression levels. DEGs with a predicted membranous or extracellular location and with low expression levels in surrounding tissue were identified as candidate targets. Modified Target Selection Criteria were used to rank candidate targets based on the highest potential for use in fluorescent imaging. 29 potential biomarkers were ranked, resulting in Folate receptor 1 as the most potential biomarker. This is a first step towards finding a fluorescent tracer for intra-operative visualization of endometriosis. Additionally, this approach, using transcriptomics analysis to identifying candidate targets for a specific type of tissue for use in fluorescence-guided surgery could be translated to other surgical fields. TWEETABLE ABSTRACT: A new approach using transcriptomics analysis is shown to identify candidate targets for intra-operative fluorescent imaging for endometriosis, resulting in 29 potential candidates.

CXC chemokines influence immune surveillance in immunological disorders: Polycystic ovary syndrome and endometriosis

Reproductive health is a worldwide challenge, but it is of particular significance to women during their reproductive age. Several female reproductive problems, including polycystic ovary syndrome (PCOS) and endometriosis, affect about 10 % of women and have a negative impact on their health, fertility, and quality of life. Small, chemotactic, and secreted cytokines are CXC chemokines. Both PCOS and endometriosis demonstrate dysregulation of CXC chemokines, which are critical to the development and progression of both diseases. Recent research has shown that both in humans and animals, CXC chemokines tend to cause inflammation. It has also been found that CXC chemokines are necessary for promoting angiogenesis and inflammatory responses. CXC chemokine overexpression is frequently associated with poor survival and prognosis. CXC chemokine levels in PCOS and endometriosis patients impact their circumstances significantly. Hence, CXC chemokines have significant potential as diagnostic and prognostic biomarkers and therapeutic targets. The molecular mechanisms through which CXC chemokines promote inflammation and the development of PCOS and endometriosis are currently unknown. This article will discuss the functions of CXC chemokines in the promotion, development, and therapy of PCOS and endometriosis, as well as future research directions. The current state and future prospects of CXC chemokine -based therapeutic strategies in the management of PCOS and endometriosis are also highlighted.

Fallopian tubal histogenesis of ovarian endometriosis-A study of folate receptor-alpha expression

Background

Ovary is a common organ site involved by endometriosis. We previously found that fallopian tube may contribute to the histogenesis of ovarian endometriosis. The finding was novel and requires further studies. We addressed this issue by examining a differentially expressed gene folate receptor alpha (FOLR1) and its protein (FRA) in this study.

Results

A total of 144 tissue samples were studied. These included 32-paired tubal-endometrial-ovarian endometriosis samples (n = 96), 18 samples of ovarian endometriosis without corresponding fallopian tube or endometrium, and 30 ovarian tissue samples with ovarian surface epithelia but without endometriosis. Multiple comparisons among groups of ovarian endometriosis, normal fallopian tube and benign endometrium were performed. FOLR1 was highly expressed in the epithelia of fallopian tube and ovarian endometriosis, with paired endometrial samples showing a significantly lower level of expression. Similar differential studies for FRA protein were performed through Western blot and immunohistochemistry (IHC). The expression of folate receptor alpha at both mRNA and protein levels in the tissues (fallopian tube or ovarian endometriosis vs. the endometrium) were significantly different (p < 0.001). All ovarian surface mesothelial epithelia showed negative expression of FRA by IHC.

Conclusion

The results further support that the fallopian tube may contribute to the development of ovarian endometriosis. Understanding the tubal contribution to ovarian endometriosis should ultimately contribute to ongoing investigative efforts aimed at identifying alternative ways to prevent and treat endometriosis. High level of FRA expression in the fallopian tube and endometriosis might be considered as potential tissue sites for targeted therapy.

Nanomedicines for Endometriosis: Lessons Learned from Cancer Research

Endometriosis is an incurable gynecological disease characterized by the abnormal growth of endometrium-like tissue, characteristic of the uterine lining, outside of the uterine cavity. Millions of people with endometriosis suffer from pelvic pain and infertility. This review aims to discuss whether nanomedicines that are promising therapeutic approaches for various diseases have the potential to create a paradigm shift in endometriosis management. For the first time, the available reports and achievements in the field of endometriosis nanomedicine are critically evaluated, and a summary of how nanoparticle-based systems can improve endometriosis treatment and diagnosis is provided. Parallels between cancer and endometriosis are also drawn to understand whether some fundamental principles of the well-established cancer nanomedicine field can be adopted for the development of novel nanoparticle-based strategies for endometriosis. This review provides the state of the art of endometriosis nanomedicine and perspective for researchers aiming to realize and exploit the full potential of nanoparticles for treatment and imaging of the disorder.

Increased expression of epithelial cell adhesion molecule and its possible role in epithelial-mesenchymal transition in endometriosis

AIM

To study the involvement and interrelationship of epithelial cell adhesion molecule (EpCAM) and epithelial-mesenchymal transition (EMT) in endometriosis.

METHODS

Samples from 114 patients undergoing endometrial biopsy or operation for endometriosis and 23 premenopausal women undergoing endometrial biopsy for non-endometriotic benign disease. Immunohistochemistry was used to detect expression level of EpCAM, E-cadherin and N-cadherin in endometrium from patients with (n = 24) and without endometriosis (n = 23), and in lesions from bowel (n = 46), peritoneal (n = 20) and ovarian (n = 24) endometriosis.

RESULTS

There was no significant difference in the expression level of EpCAM, E-cadherin and N-cadherin, respectively, between endometrium from women with and without endometriosis (P > 0.05). There was also no significant difference in the expression level of EpCAM, E-cadherin and N-cadherin, respectively, among lesions from the bowel, peritoneal and ovarian endometriosis (P > 0.05). We found that the immunoreactivity of endometriotic epithelial cells to EpCAM and N-cadherin was significantly higher than that of eutopic endometrium, but decreased to E-cadherin (P < 0.05). According to the expression level of EpCAM, the expression level of E-Cadherin was significantly lower in endometriotic lesions with EpCAM expression above the mean level compared with that of endometriotic lesions with EpCAM expression below mean level, while the expression level of N-cadherin was contrary (P < 0.001). EpCAM staining level was negatively correlated with E-cadherin but positively correlated with N-cadherin (P < 0.001).

CONCLUSIONS

These data suggest that overexpression of EpCAM, accompanied by an EMT, might be involved in endometriosis. EMT may be induced by the overexpression of EpCAM, thus promoting the development of endometriosis, which needs future studies to confirm for the pathogenesis of endometriosis.

Oestrogen receptors and hypoxia inducible factor 1 alpha expression in abdominal wall endometriosis

RESEARCH QUESTION

What are the protein levels and localization of oestrogen receptors (including ERa, ERb and G protein-coupled oestrogen receptor [GPER]) and hypoxia-inducible factor-1alpha (HIF-1a) in normal control endometrium (COEM) and ectopic endometrium from abdominal wall endometriosis (AWE).

DESIGN

AWE (n = 20) were obtained during surgery; COEM (n = 40) were collected by curettage. All tissues were obtained during the proliferative or secretory phase. Formalin-fixed paraffin-embedded tissues were used for immunohistochemical study for oestrogen receptors and HIF-1a proteins.

RESULT(S)

The expression of oestrogen receptors and HIF-1a in AWE differed from that in the corresponding menstrual cycle phase of COEM. Compared with COEM, ERa and HIF-1a were decreased whereas ERb and GPER were increased in AWE. The greatest difference was in GPER, with increased protein expression in both the cytoplasm and nucleus of endometrial epithelial and stromal cells, as well as a distinct change in localization from cytoplasmic expression to nuclear and cytoplasmic expression, compared with COEM.

CONCLUSIONS

Our data suggest that the expression changes of oestrogen receptors and HIF-1a, especially GPER, are associated with AWE, which may provide new clues to understanding the cause of endometriosis.

Discovering endometriosis biomarkers with multiplex cytokine arrays

Background

Chronic pelvic pain is often overlooked during primary examinations because of the numerous causes of such “vague” symptoms. However, this pain can often mask endometriosis, a smoldering disease that is not easily identified as a cause of the problem. As such, endometriosis has been shown to be a potentially long-term and often undiagnosed disease due to its vague symptoms and lack of any non-invasive testing technique. Only after more severe symptoms arise (severe pelvic pain, excessive vaginal bleeding, or infertility) is the disease finally uncovered by the attending physician. Due to the nature and complexity of endometriosis, high throughput approaches for investigating changes in protein levels may be useful for elucidating novel biomarkers of the disease and to provide clues to help understand its development and progression.

Methods

A large multiplex cytokine array which detects the expression levels of 260 proteins including cytokines, chemokines, growth factors, adhesion molecules, angiogenesis factors and other was used to probe biomarkers in plasma samples from endometriosis patients with the intent of detecting and/or understanding the cause of this disease. The protein levels were then analyzed using K-nearest neighbor and split-point score analysis.

Results

This technique identified a 14-marker cytokine profile with the area under the curve of 0.874 under a confidence interval of 0.81–0.94. Our training set further validated the panel for significance, specificity, and sensitivity to the disease samples.

Conclusions

These findings show the utility and reliability of multiplex arrays in deciphering new biomarker panels for disease detection and may offer clues for understanding this mysterious disease.

Electronic supplementary material

The online version of this article (10.1186/s12014-019-9248-y) contains supplementary material, which is available to authorized users.

Folate receptor-α targeted near-infrared fluorescence imaging in high-risk endometrial cancer patients: a tissue microarray and clinical feasibility study

Objective

Detection and resection of all malignant lesions is pivotal in staging and cytoreductive surgery (CRS) of endometrial cancer (EC). Intraoperative EC detection could be enhanced using OTL-38, a fluorescent-labelled folate receptor-α (FRα) targeted imaging agent. The objectives of this study were to investigate which subgroups of high-risk EC patients express FRα and assess feasibility of intraoperative EC detection using OTL-38.

Results

FRα expression on TMA was significantly correlated with tumor type (p < 0.01). Eighty-two percent of serous and clear cell carcinomas showed FRα expression. Four patients were enrolled in the clinical study. Using fluorescence imaging all omental (n = 3) and lymph node (LN) metastases (n = 16) could be clearly identified, including one otherwise undetected omental metastasis. However, false-positive fluorescence was identified in 17/50 non-metastatic LNs, caused by OTL-38 targeting of FRβ, expressed by tumor-associated activated macrophages.

Conclusions

This study describes high FRα expression in serous and clear cell EC and demonstrates the first experience of intraoperative FRα-targeted tumor detection in patients with these subtypes of EC. Although all metastases could be clearly identified using OTL-38, the role of tumor-associated macrophages should be further evaluated.

Methods

Immunohistochemical (IHC) staining of FRα expression was performed on tissue micro arrays (TMA) of 116 patients with high-risk EC features. Patients with either serous or clear cell EC, planned for staging or CRS, were eligible for inclusion in the clinical study and received an intravenous dose of 0.0125 mg/kg OTL-38, 2-3 hours prior to surgery. Resected lesions, identified by standard-of-care and/or fluorescence imaging, were histopathologically assessed for FRα and tumor status.

Soluble VCAM-1/soluble ICAM-1 ratio is a promising biomarker for diagnosing endometriosis

Study question

Do cell adhesion molecules play a role in endometriosis, and can they be used as a biomarker for diagnosing endometriosis?

Summary answer

Altered expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in the endometrium and peritoneum may play a key role in endometriosis and the soluble VCAM-1/soluble ICAM-1 ratio is a promising biomarker.

What is known already

Cell adhesion molecules are cell surface proteins that mediate cellular adherence, inflammatory and immune responses, and cancer-related biological processes. Altered expression of VCAM-1 and ICAM-1 in women with endometriosis has been investigated previously; however, gene expression levels in tissues and protein levels in the serum have not been investigated in the same patients.

Study design size, duration

We performed a prospective, longitudinal study (the Endometriosis Marker Austria) in patients who underwent a laparoscopy for benign gynecological pathology in a university-based tertiary referral center for endometriosis. From a total of 138 women who were included in the study from July 2013 through September 2014, 97 had not received hormonal treatment for at least 3 months prior to recruitment and were included in the analysis; 49 (50.5%) of these women had endometriosis, and the 48 (49.5%) who did not have endometriosis served as a control group.

Participants/materials setting methods

During laparoscopy, tissue samples were obtained from ectopic and eutopic endometrium, and from normal pelvic peritoneum. In addition, serum samples were collected immediately before and 6-10 weeks after surgery. The mRNA levels of VCAM-1, ICAM-1 and epithelial cell adhesion molecule (EpCAM) were measured using quantitative real-time PCR, and serum protein levels of soluble VCAM-1 (sVCAM-1), ICAM-1 (sICAM-1) and EpCAM (sEpCAM) were measured using ELISA and correlated with endometriosis status.

Main results and the role of chance

The mRNA levels of both VCAM-1 and ICAM-1 were higher in ectopic endometriotic lesions than in eutopic endometrium (P < 0.001). Moreover, the mRNA levels of both VCAM-1 and ICAM-1 were higher in normal peritoneum samples obtained from women with endometriosis compared to those from controls (P = 0.038 and P = 0.009). The mRNA levels of VCAM-1 were also higher in the eutopic endometrium samples obtained from women with endometriosis compared to controls (P = 0.018). With respect to serum protein levels, compared to controls, the women with endometriosis had lower serum levels of sICAM-1 (P = 0.042) and higher levels of sVCAM-1 (P < 0.001). Our analysis revealed that the serum levels of sVCAM-1 were not affected by lesion entity, menstrual cycle phase or disease severity. An receiver operating characteristics curve, calculated to determine whether preoperative serum sVCAM-1 concentration can be used to predict endometriosis, found an AUC of 0.868 with 80% specificity and 84% sensitivity at a cutoff value of 370 pg/ml. This predictive performance can be further improved by calculation of the sVCAM-1/sICAM-1 ratio, leading to an AUC of 0.929 with 86.7% specificity and 90.3% sensitivity at a cutoff ratio value of 1.55.

Large scale data

Not applicable.

Limitations reasons for caution

The relatively small sample size in the expression analyses is a possible limitation of this study.

Wider implications of the findings

Our findings could contribute to an improved understanding of the pathogenesis of endometriosis and the role of cell adhesion molecules. In addition, the results may lead to the development of new, non-invasive tools for diagnosing endometriosis. The ability to diagnose patients by measuring serum sVCAM-1 levels or the sVCAM-1/sICAM-1 ratio would have considerable clinical value.

Study funding/competing interest(s)

The Ingrid Flick Foundation (Grant no. FA751C0801), which played no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors declare no competing interests.

Endometriosis and Stem Cell Trafficking

Adult stem cells have a major role in endometrial physiology, remodeling, and repair, but they also have a critical role in the development and progression of endometriosis. Bone marrow-derived stem cells (BMDSCs) engraft eutopic endometrium and endometriotic lesions, showing stromal and epithelial fate. Nevertheless, circulating BMDSCs are in limited supply, and the presence of endometriosis depletes stem cells from the blood circulation, preventing their homing in the uterus. Furthermore, stem cells migrate from endometriotic lesion into the uterus, leading to a dysfunctional endometrium. Stem cell trafficking is a central feature of endometriosis. Understanding molecular mechanisms regulating cell mobility and engraftment in endometriosis may reveal new targets for treatment.

Towards an understanding of the molecular mechanism of endometriosis: unbalancing epithelial-stromal genetic conflict

OBJECTIVES

Despite the high incidence of endometriosis, the etiology is poorly understood. Much work has been carried out to elucidate the genetic basis of endometriosis owing to the advent of genomic analysis and new network-based analysis methods.

METHODS

This article reviews the English literature for (epi)genome-wide profiling and association studies on the pathogenesis and pathophysiology of endometriosis.

RESULTS

The characteristic 82 up- and 45 down-regulated unique genes in endometriosis included genes encoding cell cycle, growth factors, signal transduction, transcription factors, hormones, cytokines, chemokines and (pro)inflammation, proteases, cell adhesion and motility, stress response and detoxification, immune response, metabolism and others. There appear to be at least two types of genes: some genes (n = 50) may evolve mainly for the benefit of the endometrial growth, and the other genes (n = 55) evolve as a protective mechanism for the endometrial decidualization. The present review has shed new light on the overlapping genetic signatures between endometriosis development and decidualization process.

CONCLUSION

In conclusion, insufficient decidualization due to unbalancing epithelial-stromal genetic conflict may result in future endometriosis.