Decreased expression of pigment epithelium-derived factor and increased microvascular density in ovarian endometriotic lesions in women with endometriosis

RON Mediates Tumor-Promoting Effects in Endometrial Adenocarcinoma

Endometrial adenocarcinoma is one of the most prevalent female reproductive tract cancers in the world, and the development of effective treatment is still the main goal of its current research. Epithelial-mesenchymal transition (EMT) plays a significant part in the occurrence and development of epithelial carcinoma, including endometrial adenocarcinoma. Recepteur d'origine nantais (RON) induces EMT and promotes proliferation, migration, and invasion in various epithelial-derived cancers, but its role in endometrial adenocarcinoma is still poorly studied. The purpose of this study is to verify the overexpression of RON in endometrial adenocarcinoma and to explore its specific roles. RON expression in tumor lesions was verified by immunohistochemical staining, HEC-1B cells were used to construct stable cell lines with RON overexpression or knockdown to investigate the effects of RON on the function of endometrial adenocarcinoma cells, and xenotransplantation experiment was carried out in nude mice to explore the effect of RON on the growth of endometrial adenocarcinoma in vivo. This study revealed that RON could promote the proliferation, migration, and invasion of HEC-1B cells and induce EMT, and these effects were regulated through the Smad pathway. RON overexpression could promote growth of endometrial adenocarcinoma cells in nude mice, while its inhibitor BMS777607 could restrict this role. RON played an important role in endometrial adenocarcinoma and had a potential to become a new therapeutic target for endometrial adenocarcinoma.

Recepteur d'origine nantais contributes to the development of endometriosis via promoting epithelial-mesenchymal transition of a endometrial epithelial cells

Endometriosis is a benign, chronic inflammatory disease that commonly occurs in reproductive‐aged women. Epithelial‐mesenchymal transition (EMT) of endometrial epithelial cells plays an important role in the development of endometriosis. Recepteur d'origine nantais (RON), a receptor tyrosine kinase, has been reported to promote EMT and progression in tumours. However, whether and how RON mediates the EMT and endometriosis development is not known. Here, we found that RON activation could improve the migratory and invasive capabilities, change cellular morphologies, and decrease expression of E‐cadherin and increase expression of N‐cadherin in endometrial epithelial cells. Inhibition or knockdown of RON expression suppressed the migration and invasion of endometrial epithelial cells. Our studies also indicated that RON played its part in endometrial epithelial cells through protein kinase B (Akt) and mitogen‐activated protein kinase (MAPK) pathways. Treatment with a RON inhibitor could decrease the number of ectopic lesions in a mouse model of endometriosis and mediate expression of EMT markers in endometriotic lesions. These data suggest that RON contributed to endometriosis development by promoting EMT of endometrial epithelial cells. Therefore, RON may be a new therapeutic target for endometriosis.

The Usefulness of CD34, PCNA Immunoreactivity, and Histopathological Findings for Prediction of Pain Persistence After the Removal of Endometrioma

Endometriosis is an estrogen-dependent inflammatory disease that causes infertility and chronic pelvic pain. Ovarian endometrioma is the most common form of endometriosis, and conservative surgery is the main preferred therapeutic approach for endometrioma-associated symptoms. The aim of this study was to investigate the persistence of cyclic and noncyclic pelvic pain (NCPP) after endometrioma excision and their relationship to clinical and histopathological findings. In this prospective observational study, 41 symptomatic patients were evaluated for the presence of pain symptoms 3 to 6 months after endometrioma excision. Tissue specimens of endometrioma were collected during the operation and embedded in paraffin. The persistence of pain was 41.4%. Surgical excision of endometrioma significantly decreased NCPP and dysmenorrhea, but not dyspareunia ( P < .0001, P = .0001, and P = .25, respectively). Histopathological changes, including depth of endometriosis penetration into the cyst wall, the presence of macrophage infiltration, and vascularity of endometrioma cyst walls were significantly higher in patients with pain persistence than in patients without pain persistence ( P = .0034, P = .0042, and P = .0007, respectively). Moreover, proliferating cell nuclear antigen (PCNA) and CD34 immunoreactivity in both glandular and stromal cells and vascular endothelium were significantly higher in patients with pain persistence ( P = .0079 and P = .0025, respectively). Additionally, these histopathological changes and PCNA and CD34 immunoreactivity were significantly correlated with the persistence of NCPP and dysmenorrhea. The discovered differences in patients with endometrioma with or without pain persistence may indicate a possible relationship between endometrioma-associated pain and histopathological variability of endometrioma.

P2X3 receptor involvement in endometriosis pain via ERK signaling pathway

The purinergic receptor P2X ligand-gated ion channel 3 (P2X3) is crucially involved in peripheral nociceptive processes of somatic and visceral pain. Endometriosis pain is considered as a kind of inflammatory and neuropathic pain. However, whether P2X3 is involved in endometriosis pain has not been reported up to date. Here, we aimed to determine whether P2X3 expression in endometriotic lesions is involved in endometriosis pain, which is regulated by inflammatory mediators through extracellular regulated protein kinases (ERK) signalling pathway. We found that P2X3 expressions in endometriosis endometrium and endometriotic lesions were both significantly higher as compared with control endometrium (P<0.05), and both positively correlated with pain (P<0.05). The expression levels of phosphorylated –ERK (p-ERK), phosphorylated-cAMP-response element binding protein (p-CREB), and P2X3 in endometriotic stromal cells (ESCs) were all significantly increased in comparison to the initial levels after treated with interleukin (IL)-1β (P<0.05) or adenosine triphosphate (ATP) (P<0.05), respectively, and did not increase after the ESCs were pre-treated with ERK1/2 inhibitor. Additionally, P2X3 and calcitonin gene related peptide (CGRP) were co-expressed in endometriotic lesions. These obtained results suggest that P2X3 might be involved in endometriosis pain signal transduction via ERK signal pathway.

Effects of silencing endothelin-1 on invasion and vascular formation in lung cancer

Endothelin-1 (ET-1), which exists not only in the vascular endothelium but is also widely present in various tissues and cells, is an important cardiovascular regulatory factor that serves an important role in maintaining the basal vascular tone and homeostasis in the cardiovascular system. In the present study, the ET-1 gene was silenced by RNA interference, and the effects on lung cancer cell proliferation and tumor cell invasion were then detected by Cell Counting kit-8 and Transwell assays. In addition, the expression of apoptosis, growth and invasion-associated proteins, including RhoA/C, vascular endothelial growth factor, pigment epithelium-derived factor, AKT, E-cadherin and cyclooxygenase-2 was evaluated by western blotting upon silencing ET-1. In the present study, Endostar, a recombinant human endostatin injectable drug, was also used, and it was assessed whether the sensitivity of tumor cells to this drug could be increased by silencing ET-1. Both in vivo and in vivo tests were carried out in the present study. The experimental data indicated that ET-1 silencing can inhibit tumor cell proliferation and invasion, particularly in the presence of Endostar.

Elevated RON protein expression in endometriosis and disease-associated ovarian cancers

BACKGROUND

Recepteur d'origine nantais (RON) protein expression has been demonstrated to correlate with tumor progression, metastasis, and prognosis, and its mRNA expression increases in deeply infiltrating endometriotic lesions. However, it remains unclear whether RON protein expression also increases in endometriotic lesions, and may be a risk factor of malignant transformation in endometriotic lesions.

METHODS

The protein expression of RON in control (n = 19), eutopic (n = 16), and ectopic (n = 51) endometria, as well as in endometriosis-associated ovarian cancers (EAOC, n = 16) was determined by immunohistochemical (IHC) staining.

RESULTS

Endometriotic lesions expressed low levels of RON protein, but no RON protein expression appeared in matched eutopic or control endometrium. EAOC exhibited high levels of RON protein. The frequency and IHC score of RON protein expression were both significantly higher in EAOC [100.0% (14/14), 5.37 ± 0.74] than those in endometriotic lesions [51.0% (26/51), 2.15 ± 1.12; P = 0.002, 0.001]. Multivariate analysis of covariance only revealed a correlation of RON protein expression and EAOC (P = 0.006), but no correlations of RON protein expression and clinical parameters (P > 0.05).

CONCLUSIONS

These obtained results suggest that increased RON expression might be involved in the pathogenesis of endometriosis and disease-associated ovarian cancers.

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

Contrast-Enhanced Sonographic Features Before and After Interventional Treatment of Ovarian Endometrial Cysts

OBJECTIVES

The purpose of this study was to assess contrast-enhanced sonography features before and after interventional treatment of ovarian endometrial cysts.

METHODS

We retrospectively analyzed 53 patients with ovarian endometrial cysts who underwent contrast-enhanced sonography before and after interventional treatment to assess the sonographic features of the cysts at these different times. The sonographic features and quantitative parameters for the cysts were compared before and after treatment.

RESULTS

The wash-in mode showed rapid annular enhancement of the cyst wall and slow wash-out with even and uneven enhancement types. Compared to the internal iliac artery, the enhancement intensity was weaker, and the wash-in and wash-out times were longer in the cyst wall; furthermore, all 5 quantitative parameters differed between the cyst wall and internal iliac artery. The wash-in and wash-out characteristics of the cysts before and after interventional treatment were almost identical. The enhancement was primarily even before treatment and uneven after treatment; the enhancement intensity was low in all cases. Although the wash-in time before and after treatment did not differ, the wash-out time for the cysts before treatment was significantly lower than that observed after treatment. Two quantitative parameters differed before and after treatment.

CONCLUSIONS

The contrast-enhanced sonographic features and quantitative parameters for the walls of ovarian endometrial cysts differed before and after ultrasound-guided interventional treatment. These characteristics could be valuable for evaluating the efficacy of interventional treatment of ovarian endometrial cysts.

Hormonal regulation of pigment epithelium-derived factor (PEDF) expression in the endometrium

Pigment epithelium-derived factor (PEDF) is highly expressed in the female reproductive system and is subjected to regulation by steroid hormones in the ovary. As the uterine endometrium exhibits morphological and functional changes in response to estrogen (E2) and progesterone (P4), we aimed at characterizing the expression of PEDF in this component of the female reproductive tract and further at exploring the hormonal regulation of its expression. We found that PEDF is expressed in human and mouse endometrium. We further showed that this expression is subjected to regulation by steroid hormones, both in vivo and in vitro, as follows: E2 decreased PEDF expression and P4 increased its levels. In human endometrial samples, PEDF levels were dynamically altered along the menstrual cycle; they were low at the proliferative and early secretory phases and significantly higher at the late secretory phase. The expression levels of PEDF were inversely correlated to that of vascular endothelial growth factor (VEGF). We also showed that PEDF receptor was expressed in the endometrium and that its stimulation reduced VEGF expression. Illustrating the pattern of PEDF expression during the menstrual cycle may contribute to our understanding of the endometrial complexity.

The role of placental protein 14 in the pathogenesis of endometriosis

Placental protein 14 (PP-14) is the principal secretory phase product of endometrium and has been shown to inhibit cell immune function. But its role in the pathogenesis of endometriosis is controversy. The objective of this study is to determine the concentrations of PP-14 in peritoneal fluid (PF) and serum and PP-14 protein expression in endometriotic lesions in women with ovarian endometriosis (n = 75) when compared to women without endometriosis (n = 49) between day 7 and day 20 of their menstrual cycle. Concentrations of PP-14 in PF and serum as well as PP-14 protein expression in endometriotic lesions in women with and without endometriosis were evaluated by using enzyme-linked immunosorbent assay and immunohistochemical staining, respectively. Serum PP-14 concentrations were significantly increased in women with endometriosis (7.5 ± 1.4 ng/mL) compared to those in women without endometriosis (5.8 ± 0.9 ng/mL; P < .05) and statistically decreased after surgery and further reduced by using gonadotropin-releasing hormone agonist therapy (P < .05). However, the concentrations of PP-14 in PF did not reach a significant difference between women with and without endometriosis (P > .05). In women with endometriosis, scores of PP-14 protein expression in the lesions (n = 50, 2.2 [0~5.8]) were significantly correlated with serum PP-14 concentrations (n = 50, 7.6 ± 1.3 ng/mL; P < .01). Our results suggest that PP-14 may play an important role in the pathogenesis of endometriosis.

The distinguishing cellular and molecular features of the endometriotic ovarian cyst: from pathophysiology to the potential endometrioma-mediated damage to the ovary

BACKGROUND

Clinical data suggest that the presence of an ovarian endometrioma may cause per se damage to the surrounding otherwise healthy ovarian tissue. However, the basic research has so far done a limited job in trying to understand the potential detrimental effect of an endometrioma presence in the context of the ovarian physiology. We have reviewed the literature with the aim of characterizing the pathophysiology of the endometrioma focusing mostly on factors and mechanisms potentially affecting the surrounding, otherwise normal, ovarian tissue.

METHODS

Comprehensive searches of PUBMED were conducted to identify human studies published from 1991 to 2013 in the English language on the cellular and molecular characterization of the various endometrioma components.

RESULTS

An endometrioma contains free iron, reactive oxygen species (ROS), proteolytic enzymes and inflammatory molecules in concentrations from tens to hundreds of times higher than those present in peripheral blood or in other types of benign cysts. The cyst fluid causes substantial changes in the endometriotic cells that it baths from gene expression modifications to genetic mutations The physical barrier between the cyst contents and the normal ovarian tissue is a thin wall composed of the ovarian cortex itself or fibroreactive tissue. ROS potentially permeating the surrounding tissues and proteolytic substances degrading the adjacent areas are likely to cause the substitution of normal ovarian cortical tissue with fibrous tissue in which the cortex-specific stroma is reduced. The fibrosis is associated with smooth muscle metaplasia and followed by follicular loss and intraovarian vascular injury. Follicular density in tissue surrounding the endometriotic cyst was consistently shown to be significantly lower than in healthy ovaries but this pathological change does not appear to be caused by the stretching of surrounding tissues owing to the presence of a cyst.

CONCLUSIONS

There is sufficient molecular, histological and morphological evidence, in part deriving from knowledge of the pathophysiology, to support a deleterious effect of the endometrioma on the adjacent ovarian cortical tissue, independent of the mere mechanical stretching owing to its size.

Pigment epithelial-derived factor expression in endometriotic lesions in a rat model of endometriosis

Angiogenesis is a prerequisite for endometriotic lesion formation and development. Pigment epithelium-derived factor (PEDF) is a potential inhibitor of angiogenesis. The objective of this study was to detect PEDF immunolocalization in endometriotic lesions and the correlation with vascular endothelial growth factor (VEGF) and microvascular density (MVD) in a rat model of endometriosis. A subcutaneous endometriosis rat model was established by using auto-transplantation. Expression of PEDF, VEGF and MVD labeled by von Willebrand factor (v-WF) in endometriotic lesions and endometrial tissues was evaluated using immunohistochemical staining. We detected lower PEDF immunostaining and higher VEGF and MVD immunostaining in active lesions in a rat model of endometriosis than that in endometriosis endometrium or control endometrium (P<0.05), but no differences between endometriosis and control endometrium were found (P>0.05). In lesions, PEDF expression was negatively correlated with VEGF expression, MVD or sizes of cysts (P<0.01). On the contrary, both VEGF expression and MVD were positively correlated with lesion sizes (P<0.05). In addition, VEGF expression was positively correlated with MVD (P<0.01). Our results suggest that PEDF might be involved in the pathogenesis of endometriosis and may lead to novel treatment for this disease.