Demethylation of Secreted Frizzled-Related Protein2( SFRP2) Promoter Upregulates Wnt/β-Catenin Activity in Endometriosis

Wnt/β-catenin signalling contributes to the metastasis and invasion in the etiology and pathogenesis of endometriosis (EMS), but why the WNT pathway is dysregulated in EMS remains unclear. This study aimed to explore the effects of demethylation of SFRP2 promoter on the Wnt/β-catenin activity in EMS. Aberrantly methylated-differentially expressed genes were identified from GEO database microarray data. 5 ectopic endometrium and 5 normal endometrium were get, subsequently, ectopic endometrium epithelial cells (EEECs) and normal endometrium epithelial cells (NEECs) were isolated in vitro. MSP, BSP, luciferase reporter assay, Lentivirus infection of high expression of SFRP2 gene vector, low expression of DNMT1 gene vector, and 5-Aza stimulation, RT-PCR and western blot were performed in the tissues or cells. It was found that compared with the normal endometrium and NEECs, the RNA and protein expression levels of SFRP2 were significantly increased while the SFRP2 promoter was demethylated in ectopic endometrium and EEECs. The 5-Aza treatment significantly upregulated SFRP2 mRNA and protein levels in EEECs. Furthermore, after the knockdown of DNMT1 expression, the demethylation of the SFRP2 promoter and upregulation of SFRP2 mRNA and protein in EEECs were observed. Meanwhile, the expression of lentivirus carrying SFRP2 cDNA up-regulates the activity of Wnt signaling and the protein expression of β-catenin in EEECs. In summary, the increased SFRP2 expression-induced Wnt/β-catenin signaling due to the demethylation of the SFRP2 promoter plays an important role in the pathogenesis of EMS, suggesting that SFRP2 might be a therapeutic target for EMS treatment.

Ectopic Endometrium: The Pathologist’s Perspective

Endometriosis and adenomyosis are two frequent diseases closely linked, characterized by ectopic endometrium. Despite their benign nature, endometriosis and adenomyosis impair women’s quality of life by causing pain and infertility and an increase in the incidence of gynecological malignancies has been reported. Since the first description of ectopic endometrium in 1860, different attempts have been made to describe, classify and understand the origin of these diseases. Several theories have been proposed to describe the pathogenic mechanism leading to the development of adenomyosis or endometriosis. However, all the hypotheses show some limitations in explaining all the different aspects and manifestations of these diseases. Despite the remarkable progress made over recent years, the pathogeneses of endometriosis and adenomyosis remain unclear. Moreover, because of the lack of standardized protocols and diagnostic criteria in pathology practice it is difficult to study and to classify these disorders. The goal of this review is to summarize the pathological aspects of adenomyosis and endometriosis, spanning a historical perspective to newly reported data.

Phoenixin as a New Target in the Development of Strategies for Endometriosis Diagnosis and Treatment

Small integral membrane protein 20/phoenixin (SMIM20/PNX) and its receptor GPR173 (G Protein-Coupled Receptor 173) play a role in the regulation of the hypothalamic–pituitary–gonadal axis (HPG). The aim of the study was to determine PNX, FSH, LH, and 17β-estradiol association in women with endometriosis, and the expression of SMIM20/PNX signaling via GPR173. Serum PNX, FSH, LH, and 17β-estradiol concentrations were measured by enzyme and electrochemiluminescence immunoassay. SMIM20/PNX and GPR173 expression in the eutopic and ectopic endometrium was assessed by qPCR and immunohistochemistry. Reduced PNX level, increased LH/FSH ratio and elevated 17β-estradiol concentration were found in patients with endometriosis. No differences in SMIM20 expression were observed between the studied endometria. GPR173 expression was lower in ectopic than in eutopic endometria. SMIM20 expression was mainly restricted to stroma. GPR173 was detected in some eutopic and ectopic stromal cells and in eutopic glandular epithelial cells. Discriminant analysis indicates the diagnostic relevance of PNX and LH/FSH ratio in patients with endometriosis. In women with endometriosis, reduced PNX levels and GPR173 expression may be responsible for HPG axis dysregulation. These new insights may contribute to a better understanding of the pathophysiology of endometriosis and provide the basis for a new strategy for diagnosis and treatment of endometriosis.

Ovarian Cancer Tumour Biology: Genesis

Ovarian cancer (OC) is the fifth leading cause of cancer deaths among women, thus early diagnosis is of paramount importance to survival. A clear OC etiopathogenesis is not yet fully understood. Large histopathological variability predicts more initial tissue for carcinogenesis. Many connections of biologically different tissue as locus minoris resistentiae for carcinogenesis have been confirmed. Expansion of knowledge about OC etiopathogenesis may help to construct an algorithm for early diagnosis. Ovarian surface epithelium, ectopic Müllerian epithelium, and fallopian tubes, along with endometriosis, are significant in the process of OC development. An oxidative microenvironment caused by recurrent ovulation or arising due to a degradative process in ectopic endometrium, mainly endometriomas, play a prominent role in the development of OC.

Inhibition of METTL3/m6A/miR126 promotes the migration and invasion of endometrial stromal cells in endometriosis

N6-methyladenosine (m6A), one of the most abundant RNA modifications, is involved in the progression of many diseases, but its role and related molecular mechanisms in endometriosis remain unknown. To address these issues, we detected m6A levels in normal, eutopic and ectopic endometrium and found the m6A levels decreased in eutopic and ectopic endometrium compared with normal endometrium. In addition, we proved that methyltransferase-like 3 (METTL3) downregulation accounted for m6A reduction in endometriosis. Furthermore, we observed that METTL3 knockdown facilitated the migration and invasion of human endometrial stromal cells (HESCs), while METTL3 overexpression exerted opposite effects, suggesting that METTL3 downregulation might contribute to endometriosis development by enhancing cellular migration and invasion. Mechanistically, METTL3-dependent m6A was involved in the DGCR8-mediated maturation of primary microRNA126 (miR126, pri-miR126). Moreover, miR126 inhibitor significantly enhanced the migration and invasion of METTL3-overexpressing HESCs, whereas miR126 mimics attenuated the migration and invasion of METTL3-silenced HESCs. Our study revealed the METTL3/m6A/miR126 pathway, whose inhibition might contribute to endometriosis development by enhancing cellular migration and invasion. It also showed that METTL3 might be a novel diagnostic biomarker and therapeutic target for endometriosis.

Expression of BDNF and TrKB in Patients With Endometriosis and Their Correlation With Dysmenorrhea

Background: Brain-derived neurotrophic factor (BDNF) has been recognized as a regulator in the formation and maintenance of chronic pain in various chronic disorders. BDNF together with its high-affinity tyrosine kinase type B (TrkB) receptor were found to be extensively expressed in mammalian female reproductive system. However, BDNF and TrkB expression in different stages of endometriosis, and the correlation between their expression in ectopic lesions and endometriosis pain remains unclear.Methods: This study enrolled sixty-two women underwent laparoscopic surgery. Forty-six women diagnosed as ovarian endometrioma, were recruited in the study group. Sixteen women diagnosed as ovarian benign tumors were recruited in the control group. Samples from eutopic endometrium and ovarian endometriotic lesions were obtained at laparoscopic surgery. The message RNA (mRNA) level of BDNF and TrKB was detected by real-time PCR, while the protein level was detected by immunohistochemical staining for eutopic and ectopic endometrium in both groups. Dysmenorrhea was assessed by the visual analogue scale (VAS) before the surgery.Results: The expression of BDNF and TrKB were higher in ovarian endometriotic lesions than those in eutopic endometrium and normal endometrium (P<0.05), and there was no cyclical change. While their expression in eutopic endometrium were higher than those in the normal endometrium (P<0.05). The expression of BDNF and TrKB in ovarian endometriotic lesions stage IV were higher than those in stage III and II (P<0.05). Their expression in stage III were higher than those in stage II but there were no significance (P>0.05). Furthermore, the correlation between the mRNA expression of BDNF, TrKB in eutopic endometrium, and dysmenorrhea VAS score revealed that r=0.52 and 0.56, respectively (P<0.05). The correlation between BDNF and TrKB in both eutopic and ectopic endometrium were revealed that r=0.82 and 0.66, respectively (P<0.05).Conclusions: BDNF and TrKB may play essential roles in promoting disease progression during the development of endometriosis, and are closely related to dysmenorrhea caused by endometriosis.

Effect of bazedoxifene on expressions of VEGF, VEGFR2, COX-2 and inflammatory factors in a rat endometriosis model

Purpose: To study the effect of bazedoxifene on the expressions of vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor receptor 2 (sVEGFR2), cyclooxygenase synthase 2 (COX-2) and inflammatory factors in a rat endometriosis (EMS) model. Methods: Thirty rats (EMS) were divided into untreated control group, bazedoxifene group and celecoxib group (10 rats per group). Bazedoxifene and celecoxib were administered at doses of 3 and 25 mg/kg, respectively. Negative control rats served as control, and were given 0.9 % sodium chloride at a dose of 10 mL/kg. All treatments were given intragastrically for 21 days. Levels of VEGF, sVEGFR2 and COX-2 in uterine ectopic endometrium were assayed. Results: The levels of VEGF and sVEGFR2 in the serum and peritoneal fluid of the untreated control group were significantly higher than the corresponding control values, while VEGF and sVEGFR2 levels in the serum and peritoneal fluid of the bazedoxifene group were significantly lower than those in the untreated control group (p < 0.05). Bazedoxifene group had lower VEGFR2 and COX-2 levels than untreated control group (p < 0.05). Expression of COX-2 protein in the ectopic endometrium of celecoxib group was significantly lower than that in the untreated control group (p < 0.05). Conclusion: Bazedoxifene alleviates angiogenesis and inflammatory factors in serum and peritoneal fluid of EMS rats, inhibits the expression of sVEGFR2 and COX-2 in ectopic endometrium, and also inhibits the growth of ectopic endometrium. This finding may help to discover additional new drugs.

Endometriosis diagnosis and medical treatment: Present and future

The objective was to review the different diagnostic methods and medical treatments for endometriosis. It was reviewed the Latin-American and international bibliography using the Pub-Med, Google Scholar, Springer, the Cochrane Library, Embase, Scielo, Imbiomed-L, Redalyc, and Latindex websites. The searches included the keywords: endometriosis, endometriotic, endometrial and ectopic endometrium, angiogenesis, angiogenesis and endometriosis, endometriosis, and medical treatment, endometriosis, and new treatment.

Up-regulation of DNA2 results in cell proliferation and migration in endometriosis

Accumulating evidence has suggests that women with advanced endometriosis exhibit alterations in the expression of genes in the endometrium compared to healthy controls. Furthermore, replication stress is a characteristic feature of cancer cells, which results from sustained proliferative signaling induced by either the activation of oncogenes or the loss of tumor suppressors. In the present study, we propose that DNA replication ATP-dependent helicase/nuclease 2 (DNA2) might be upregulated in endometriosis. Immunohistochemical staining results confirmed the hypothesis that DNA2 is overexpressed in the eutopic/ectopic endometrium compared to that in a control endometrium from a healthy donor. Subsequently, ectopic endometrium-derived endometrial mesenchymal stem cells (EMSCs) showed the highest level of DNA2 and checkpoint kinase 1 (CHK1), as well as the strongest proliferation and migration capabilities, followed by eutopic endometrium-derived EMSCs, and then control EMSCs. To further analyze the function of DNA2, we knocked-down DNA2 expression in KLE cells. As expected, proliferation and migration declined when cells were transfected with DNA2 small interfering RNA. Taken together, our study demonstrated the overexpression of DNA2 in human endometriosis, which might be responsible for the upregulated cell proliferation and migration. This study provides insights into the mechanisms underlying human endometriosis.