Proliferation In Endometriosis Research Articles

Retracted] The AMPK‑mTOR axis requires increased MALAT1 expression for promoting granulosa cell proliferation in endometriosis.

[This retracts the article DOI: 10.3892/etm.2020.9453.].

P-370 Impaired endometrial decidualization with a hyperinflammation environment is involved in poor reproductive outcomes in adenomyosis patients

Abstract Study question Do patients with adenomyosis have an impaired inflammatory state of the endometrium that could affect implantation and pregnancy? Summary answer Adenomyosis patients show increased proinflammatory cytokines expression and deregulated decidualization markers expression in eutopic endometrium which could lead to altered endometrial receptivity and impaired implantation. What is known already Adenomyosis is an estrogen-dependent chronic inflammatory condition, characterized by the presence of endometrial glands and stroma within the myometrium. Adenomyosis patients present altered decidualization and defective embryo-endometrium communication, resulting in implantation failure, miscarriage, and other fertility-related disorders. Although the underlying mechanisms of this infertility remain unknown, it is known that a favorable immune and inflammatory uterine environment is necessary for developmental pregnancy. It has been proposed that a uterine hyperinflammatory state could be involved in adenomyosis-related infertility. For this reason, we aim to evaluate the inflammatory and endometrial receptivity status during implantation in eutopic endometrium from adenomyosis patients. Study design, size, duration Sixteen endometrial samples were collected from infertile patients with and without adenomyosis undergoing hormonal replacement therapy before in vitro fertilization (IVF) at IVIRMA Valencia between January to December 2022. Participants/materials, setting, methods Eutopic endometrial samples were obtained at secretory phase (LH + 7) from patients diagnosed with adenomyosis (n = 8) by ultrasound or hysteroscopy and patients without gynecological diseases (control, n = 8). Total RNA extraction was performed to later determine the gene expression of the decidualization-related genes Prolactin (PRL), SPP1 and PAEP by qRT-PCR. In addition, proteins were extracted from eutopic endometrium using a lysis buffer and the relative expression levels of human cytokines were measured by Human Cytokine Array (Raybiotech). Main results and the role of chance Gene expression evaluation in endometrium from adenomyosis patients compared to control showed a significant downregulation of the key marker of decidualization PRL (fold change [fc] = 0.56, p = 0.0047) and a significant upregulation of SPP1 (fc = 1.75, p = 0.009) and PAEP (fc = 1.56, p = 0.0192), both involved in endometrial receptivity and in immune regulation. Regarding cytokines expression, array results showed upregulation of different interleukins (IL) involved in the mediation of the immune and inflammatory response previously described in adenomyosis. Specifically, IL1ß (12±19.63 vs. 1.37±2.77, p = 0.009) that regulates several inflammatory responses, including cell proliferation, differentiation, and apoptosis; and IL6 (584.7±121.8 vs. 488.4±57.44, p = 0.06) that acts on the inflammation and maturation of B cells, contributing to the development of autoimmune diseases. Similarly, cytokines related to the promotion of inflammation and cellular proliferation in endometriosis, IL17a (173.6±44.75 vs. 102.10±71.85, p = 0.04) and TNFβ (430.9±139.6 vs. 315.3±37.09, p = 0.04), were also upregulated in adenomyosis compared to control. There were also other cytokines upregulated with diverse functions like an anti-inflammation response, growth factors or immune modulation: IL5 (308.1±88.77 vs. 202.6±45.72, p = 0.01), IL2 (341.4±60.38 vs. 270.8±35.13, p = 0.014), TGFα (215.3±27.04 vs. 117.8±36.67, p = 0.002), IL31 (77.74±40.57 vs. 14±15.96, p = 0.0012), IL7 (739.1±147.1 vs. 511.8±103.7, p = 0.003) and IL15 (301.9±95.73 vs. 209.8±50.62, p = 0.03). Limitations, reasons for caution Our findings are limited by the relatively small sample size and inherent biological variability of human samples. Wider implications of the findings Adenomyosis patients showed impaired decidualization and a hyperinflammatory endometrial environment that could be affecting the endometrial receptivity and consequently, the embryo implantation. These findings open insight to further investigations to study the mechanism by which exaggerated inflammation affects fertility in the context of adenomyosis to define new management approaches. Trial registration number Not applicable

Melatonin inhibits endometriosis development by disrupting mitochondrial function and regulating tiRNAs.

Endometriosis is a benign gynecological disease characterized by abnormal growth of endometrial-like cells outside the uterus. Melatonin, a hormone secreted by the pineal gland, has been shown to have therapeutic effects in various diseases, including endometriosis. However, the underlying molecular mechanisms are yet to be elucidated. The results of this study demonstrated that melatonin and dienogest administration effectively reduced surgically induced endometriotic lesions in a mouse model. Melatonin suppressed proliferation, induced apoptosis, and dysregulated calcium homeostasis in endometriotic cells and primary endometriotic stromal cells. Melatonin also caused mitochondrial dysfunction by permeating through the mitochondrial membrane to disrupt redox homeostasis in the endometriotic epithelial and stromal cells. Furthermore, melatonin affected oxidative phosphorylation systems to decrease ATP production in End1/E6E7 and VK2/E6E7 cells. This was achieved through messenger RNA-mediated downregulation of respiratory complex subunits. Melatonin inhibited the PI3K/AKT and ERK1/2 pathways and the mitochondria-associated membrane axis and further suppressed the migration of endometriotic epithelial and stromal cells. Furthermore, we demonstrated that tiRNAGluCTC and tiRNAAspGTC were associated with the proliferation of endometriosis and that melatonin suppressed the expression of these tiRNAsin primary endometriotic stromal cells and lesions in a mouse model. Thus, melatonin can be used as a novel therapeutic agent to manage endometriosis.

Phosphorylation of PFKFB4 by PIM2 promotes anaerobic glycolysis and cell proliferation in endometriosis

Endometriosis (EM) is one of the vanquished wonted causes of chronic pelvic sting in women and is closely associated with infertility. The long-term, complex, systemic, and post-treatment recurrence of EM wreaks havoc on women’s quality of life. Extensive metabolic reprogramming (aerobic glycolysis, glucose overweening intake, and high lactate production) and cancer-like changes have been found in EM, which bears striking similarities to tumorigenesis. The key glycolysis regulator PFKFB4 is overexpressed in EM. However, the mechanism of PFKFB4 in EM remains unknown. We found that PFKFB4 was upregulated and was closely related to the progression of EM. We identified focus PIM2 as a new pioneering adjoin protein of PFKFB4. Vigorous biochemical methods were used to confirm that PIM2 phosphorylated site Thr140 of PFKFB4. PIM2 also could enhance PFKFB4 protein expression through the ubiquitin–proteasome pathway. Moreover, PIM2 expression was really corresponding prevalent with PFKFB4 in endometriosis in vivo. Importantly, phosphorylation of PFKFB4 on Thr140 by PIM2 promoted EM glycolysis and cell growth. Our study demonstrates that PIM2 mediates PFKFB4 Thr140 phosphorylation thus regulating glycolysis and EM progression. We illustrated a new mechanism that PIM2 simulated a central upstream partnership in the regulation of PFKFB4, and reveal a novel means of PIM2-PFKFB4 setting EM growth. Our research provided new theoretical support for further clarifying the reprogramming of EM glucose metabolism, and provided new clues for exploring non-contraceptive treatments for EM.

The AMPK-mTOR axis requires increased MALAT1 expression for promoting granulosa cell proliferation in endometriosis.

Endometriosis is a common reproductive disorder in women, with a global prevalence of 10-15%. Long noncoding RNAs (lncRNAs) are critical to gene transcription, cell cycle modulation and immune response. The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) reportedly mediates autophagy of endometrial stromal cells in endometriosis. The present study aimed to evaluate the role and mechanism of MALAT1 in granulosa cells (GCs) in endometriosis. Consequently, MALAT1 expression was upregulated in GCs obtained from patients with endometriosis and in the steroidogenic human granulosa-like tumor cell line KGN. However, MALAT1 knockdown consequently decreased the proliferation and viability of these cells, as determined by MTT and 5-ethynyl-2'-deoxyuridine staining assays. Both Annexin V-fluorescein isothiocyanate/propidium iodide flow cytometry and western blotting performed to detect proapoptotic factors indicated that MALAT1 depletion might promote KGN cell apoptosis. Furthermore, MALAT1 knockdown increased GC autophagy, as evidenced by microtubule-associated protein 1A/1B-light chain 3 (LC3) cleavage upregulation and p62 degradation. In addition, although 5'-AMP-activated protein kinase (AMPK) mRNA expression and protein levels decreased in GCs obtained from patients with endometriosis and KGN cells, MALAT1 knockdown restored AMPK levels. However, addition of BML-275 (MALAT1 inhibitor) to MALAT1-knockdown KGN cells recovered their viability and proliferative capacity and simultaneously reduced their apoptotic and autophagic capacity. Therefore, MALAT1 may regulate GC proliferation via AMPK-mTOR-mediated cell apoptosis and autophagy.

Oncogenic mutation in RAS-RAF axis leads to increased expression of GREB1, resulting in tumor proliferation in colorectal cancer.

BRAFV600E mutation accounts for up to 90% of all BRAF mutations in human colorectal cancer (CRC), and constitutively activates the MEK‐MAPK pathway. It is recognized that neutralizing mAbs for epidermal growth factor receptor alone are not effective for CRC with BRAFV600E mutation. Therefore, there is increasing interest in identification of the possible therapeutic targets in downstream of BRAF mutation in CRCs. To address this, we studied genome engineered mouse models for colonic neoplasia that has BrafV600E mutation on the basis of Apc inactivation, induced in 2 distinct Cre mouse models, CDX2P‐G22Cre and CDX2P‐CreERT2 mice. We carried out oligonucleotide microarray analysis for colonic neoplasia generated in these mouse models, and compared gene expression profiles among Kras/Braf WT, Kras‐mutated, and Braf‐mutated mouse colon tumors to seek new molecular targets corresponding to the KRAS‐BRAF‐MAPK axis. We found that the expression of the growth regulation by estrogen in breast cancer protein 1 (Greb1) was the most upregulated gene in Braf‐mutated mouse tumors compared to Kras/Braf WT counterparts. The silencing of GREB1 significantly reduced the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GREB1 promoted cell proliferation. Although GREB1 was first identified as a hormone‐responsive gene mediating estrogen‐stimulated cell proliferation in endometriosis, breast, and ovarian cancers, these results suggest that RAS‐RAF‐MAPK signaling upregulates GREB1 expression in CRC, resulting in cellular proliferation. Thus, GREB1 is a possible therapeutic target for CRCs with BrafV600E mutation.

Endometriosis Cell Proliferation Induced by Bone Marrow Mesenchymal Stem Cells.

Endometriosis is an estrogen-dependent gynecological disorder that affects 10% of reproductive-aged women and causes pelvic pain and infertility. Bone marrow-derived stem cells (BMDCs) are known to engraft endometriosis in association with lesion growth; however, they do not undergo significant clonal expansion. The indirect effects of BMDCs on endometriosis growth and cell proliferation are not well characterized. Here, we demonstrate that BMDCs' co-culture increased endometrial stromal cell proliferation. In vitro studies using endometrial cells showed that BMDCs increased cell proliferation and activation of CDK1 in both an endometriosis cell line and primary endometrial stromal cells from women with endometriosis, however not in normal endometrial cells. In vivo studies using a mouse model of endometriosis showed increased CDK1+ expression associated with engrafted GFP + BMDCs. These results suggest that endometrial cell proliferation is induced by stem cell-derived trophic factors leading to the growth of endometriotic lesions. Targeting the specific signaling molecules secreted by BMDC may lead to novel therapeutic strategies for controlling cell proliferation in endometriosis.

RhoA/ROCK pathway mediates the effect of oestrogen on regulating epithelial-mesenchymal transition and proliferation in endometriosis.

Endometriosis is a benign gynaecological disease appearing with pelvic pain, rising dysmenorrhoea and infertility seriously impacting on 10% of reproductive‐age females. This research attempts to demonstrate the function and molecular mechanism of RhoA/ROCK pathway on epithelial‐mesenchymal transition (EMT) and proliferation in endometriosis. The expression of Rho family was abnormally changed in endometriotic lesions; in particular, RhoA and ROCK1/2 were significantly elevated. Overexpression of RhoA in human eutopic endometrial epithelial cells (eutopic EECs) enhanced the cell mobility, epithelial‐mesenchymal transition (EMT) and proliferation, and RhoA knockdown exhibited the opposite function. Oestrogen up‐regulated the RhoA activity and expression of RhoA and ROCK1/2. RhoA overexpression reinforced the effect of oestrogen on promoting EMT and proliferation, and RhoA knockdown impaired the effect of oestrogen. oestrogen receptor α (ERα) was involved with the regulation of oestrogen on EMT and proliferation and up‐regulated RhoA activity and expression of RhoA and ROCK1/2. The function of ERα was modulated by the change in RhoA expression. Furthermore, phosphorylated ERK that was enhanced by oestrogen and ERα promoted the protein expression of RhoA/ROCK pathway. Endometriosis mouse model revealed that oestrogen enhanced the size and weight of endometriotic lesions. The expression of RhoA and phosphorylated ERK in mouse endometriotic lesions was significantly elevated by oestrogen. We conclude that abnormal activated RhoA/ROCK pathway in endometriosis is responsible for the function of oestrogen/ERα/ERK signalling, which promoted EMT and proliferation and resulted in the development of endometriosis.

Thalidomide Reduces Cell Proliferation in Endometriosis Experimentally Induced in Rats.

To analyze the effect of thalidomide on the progression of endometriotic lesions experimentally induced in rats and to characterize the pattern of cell proliferation by immunohistochemical Proliferating Cell Nuclear Antigen (PCNA) labeling of eutopic and ectopic endometrium. Fifteen female Wistar rats underwent laparotomy for endometriosis induction by resection of one uterine horn, isolation of the endometrium and fixation of a tissue segment to the pelvic peritoneum. Four weeks after, the animals were divided into 3 groups: control (I), 10mg/kg/day (II) and 1mg/kg/day (III) intraperitoneal thalidomide for 10 days. The lesion was excised together with the opposite uterine horn for endometrial gland and stroma analysis. Eutopic and ectopic endometrial tissue was submitted to immunohistochemistry for analysis of cell proliferation by PCNA labeling and the cell proliferation index (CPI) was calculated as the number of labeled cells per 1,000 cells. Group I showed a mean CPI of 0.248 ± 0.0513 in the gland and of 0.178 ± 0.046 in the stroma. In contrast, Groups II and III showed a significantly lower CPI, that is, 0.088 ± 0.009 and 0.080 ± 0.021 for the gland (p < 0.001) and 0.0945 ± 0.0066 and 0.075 ± 0.018 for the stroma (p < 0.001), respectively. Also, the mean lesion area of Group I was 69.2 mm2, a significantly higher value compared with Group II (49.4 mm2, p = 0.023) and Group III (48.6 mm2, p = 0.006). No significant difference was observed between Groups II and III. Thalidomide proved to be effective in reducing the lesion area and CPI of the experimental endometriosis implants both at the dose of 1 mg/kg/day and at the dose of 10 mg/kg/day.

LIM Kinase 1 Mediates Estradiol Effects on the Phosphorylation of Cofilin1 in Eutopic Endometrial Stromal Cells During the Invasion and Proliferation of Endometriosis.

Endometriosis is an estrogen-dependent gynecological disease; however, the mechanism by which estradiol promotes the development of endometriosis, including invasion and proliferation, remains unclear. Estradiol is involved in cell invasion and proliferation by regulating the cytoskeleton. The abnormally high expression of cytoskeletal regulators (LIM kinase 1 [LIMK1] and cofilin1) is closely related to increased invasiveness and proliferation of eutopic endometrial stromal cells from endometriosis patients compared to normal eutopic endometrial cells. The aim of this study was to analyze the role of estradiol during invasion and proliferation through the LIMK1/cofilin1 pathway in the endometrium of women with endometriosis. To address this, primary eutopic endometrial stromal cells were isolated from the uteri of patients with endometriosis and cultured without estradiol. The phosphorylation of cofilin1 was analyzed by western blotting. Cell invasiveness and proliferation were evaluated following LIMK1 knockdown by RNA interference technology. We found that, before LIMK1silencing, the phosphorylation levels of cofilin1 and LIMK1 of eutopic endometrial stromal cells from endometriosis patients treated with estradiol were higher than cells not treated with estradiol (P < .05 and P < .01, respectively). The total levels of cofilin1 and LIMK1 protein did not change (P > .05 and P > .05, respectively). After LIMK1 silencing, the phosphorylation of cofilin1 by estradiol was significantly reduced, and invasiveness and proliferation were clearly and concurrently decreased (P < .05 and P < .05, respectively). Thus, the phosphorylation of cofilin1 by estradiol is mediated by LIMK1, and estradiol is involved in regulating cell invasion and proliferation in endometriotic patients through the LIMK1/cofilin1 pathway.

LncRNA H19 over-expression inhibited Th17 cell differentiation to relieve endometriosis through miR-342-3p/IER3 pathway

ObjectiveTo investigate the mechanism of LncRNA H19 in Th17 cell differentiation and endometrial stromal cells (ESCs) proliferation in endometriosis (EMS).MethodsLncRNA H19, miR-342-3p and IER3 expressions were detected by qRT-PCR and western blot. The percentage of Th17 cells/CD4+ T cells was detected by flow cytometry. IL-17 level was measured by ELISA. The interaction of miR-342-3p and IER3 was confirmed by Luciferase reporter assay.ResultsLncRNA H19 and IER3 expressions were down-regulated in mononuclear cells from peritoneal fluid (PFMCs) of patients with EMS or under Th17 differentiation conditions, whereas miR-342-3p expression was up-regulated and the percentage of Th17 cells was increased in PFMCs of patients with EMS or under Th17 differentiation conditions. Over-expression of LncRNA H19 decreased IL-17 level and the percentage of Th17 cells/CD4+ T cells. Besides, we confirmed that miR-342-3p could target to IER3 and negatively regulate IER3 expression. LncRNA H19 over-expression suppressed Th17 differentiation and ESC proliferation through regulating miR-342-3p/IER3. In vivo experiments showed LncRNA H19 over-expression suppressed the growth of Th17 cell differentiation-induced endometriosis-like lesions.ConclusionLncRNA H19 was down-regulated in PFMC of patients with EMS or under Th17 polarizing conditions, and LncRNA H19 over-expression suppressed Th17 cell differentiation and ESCs proliferation through miR-342-3p/IER3 pathway.

SNP rs710886 A>G in long noncoding RNA PCAT1 is associated with the risk of endometriosis by modulating expression of multiple stemness-related genes via microRNA-145 signaling pathway.

MiR-145 has been shown to suppress cell invasiveness and proliferation in endometriosis, whereas prostate cancer-associated transcript 1 (PCAT1) was reported to act as a sponge of miR-145 with one single-nucleotide polymorphism (SNP), rs710886, located in the chromosomal segment of PCAT1. Therefore, this study aimed to explore the association between rs710886 SNP and the risk of endometriosis, as well as the effect of this SNP on the activation of the signaling pathway downstream of PCAT1. Real-time polymerase chain reaction (PCR) was performed to observe the expression of miR-145 in transfected cells, while Matrigel invasion chamber assays and MTT assay were conducted to examine the invasiveness/proliferation among different cell groups. Moreover, bioinformatics tools, luciferase assays, real-time PCR, and Western blot analysis were used to measure the expression of these target genes in the presence of miR-145. Finally, a statistical analysis was conducted to compare the genotypes of rs710886 SNP between fertile healthy women and infertile women with endometriosis. PCAT1 small interfering RNA (siRNA) evidently increased the expression of miR-145 but reduced the invasiveness/proliferation of cells. P-PCAT1 exhibited an opposite effect as that of PCAT1 siRNA, indicating PCAT1 could promote the proliferation and invasiveness of endometriosis stem cells via inhibiting the expression of miR-145. Meanwhile, FASCIN1, SOX2, MSI2, SERPINE1, and JAM-A were identified as target genes of miR-145 via computational analysis and luciferase assays. Finally, a significant genetic effect was observed in both the dominant (AG+GG vs AA) and recessive models (GG vs AG+AA), indicating the presence of an association between the genotype of SNP rs710886 and the risk of endometriosis. SNP rs710886 A>G could lower the expression of PCAT1, thus leading to the overexpression of miR-145. Highly expressed miR-145 would inhibit the invasiveness and proliferation of endometriosis stem cells via targeting specific genes, thus decreasing the risk of endometriosis.

Daidzein-rich isoflavone aglycones inhibit cell growth and inflammation in endometriosis

Endometriosis is an estrogen-dependent disease, and isoflavones interact with estrogen receptors. The purposes of this study are to investigate the in vitro and in vivo effects of daidzein-rich isoflavone aglycones (DRIAs), dietary supplements, on cellular proliferation in endometriosis. Stromal cells isolated from ovarian endometrioma (OESCs) and normal endometrium (NESCs) were cultured with DRIAs, i.e., each of the DRIA components (daidzein, genistein, or glycitein), or isoflavone glycosides (IG; DRIA precursors). A mouse model of endometriosis was established by transplanting donor-mouse uterine fragments into recipient mice. Our results showed that DRIAs (0.2–20 μM) inhibited the proliferation of OESCs (P < 0.05 for 0.2 μM; P < 0.01 for 2 and 20 μM) but not of NESCs. However, daidzein, genistein, glycitein, and IG did not inhibit their proliferation. DRIA-induced suppression was reversed by inhibition of the estrogen receptor (ER)β by an antagonist, PHTPP, or by ERβ siRNA (P < 0.05), but not by MPP, an ERα antagonist. In OESCs, DRIAs led to reduced expression of IL-6, IL-8, COX-2, and aromatase, as well as reduced aromatase activity, serum glucocorticoid-regulated kinase levels, and PGE2 levels (P < 0.05). Western blot and immunofluorescence assays revealed that DRIAs inhibited TNF-α-induced IκB phosphorylation and p65 uptake into the nuclei of OESCs. In the mouse model, a DRIA-containing feed significantly decreased the number, weight, and Ki-67 proliferative activity of endometriosis-like lesions compared to in mice fed with an IG-containing feed and the control feed (P < 0.01). In conclusion, DRIAs inhibit cellular proliferation in endometriosis, thus representing a potential therapeutic option for the management of endometriosis.

Enhanced epithelial to mesenchymal transition (EMT) and upregulated MYC in ectopic lesions contribute independently to endometriosis.

BackgroundEpithelial to mesenchymal transition (EMT) is a process in which epithelial cells lose polarity and cell-to-cell contacts and acquire the migratory and invasive abilities of mesenchymal cells. These abilities are thought to be prerequisites for the establishment of endometriotic lesions. A hallmark of EMT is the functional loss of E-cadherin (CDH1) expression in epithelial cells. TWIST1, a transcription factor that represses E-cadherin transcription, is among the EMT inducers. SNAIL, a zinc-finger transcription factor, and its close relative SLUG have similar properties to TWIST1 and are thus also EMT inducers. MYC, which is upregulated by estrogens in the uterus by an estrogen response cis-acting element (ERE) in its promoter, is associated with proliferation in endometriosis. The role of EMT and proliferation in the pathogenesis of endometriosis was evaluated by analyzing TWIST1, CDH1 and MYC expression.MethodsCDH1, TWIST1, SNAIL and SLUG mRNA expression was analyzed by qRT-PCR from 47 controls and 74 patients with endometriosis. Approximately 42 ectopic and 62 eutopic endometrial tissues, of which 30 were matched samples, were collected during the same surgical procedure. We evaluated TWIST1 and MYC protein expression by immunohistochemistry (IHC) in the epithelial and stromal tissue of 69 eutopic and 90 ectopic endometrium samples, of which 49 matched samples were analyzed from the same patient. Concordant expression of TWIST1/SNAIL/SLUG and CDH1 but also of TWIST1 and MYC was analyzed.ResultsWe found that TWIST1, SNAIL and SLUG are overexpressed (p < 0.001, p = 0.016 and p < 0.001) in endometriosis, while CDH1 expression was concordantly reduced in these samples (p < 0.001). Similar to TWIST1, the epithelial expression of MYC was also significantly enhanced in ectopic endometrium compared to eutopic tissues (p = 0.008). We found exclusive expression of either TWIST1 or MYC in the same samples (p = 0.003).ConclusionsEpithelial TWIST1 is overexpressed in endometriosis and may contribute to the formation of endometriotic lesions by inducing epithelial to mesenchymal transition, as CDH1 was reduced in ectopic lesions. We found exclusive expression of either TWIST1 or MYC in the same samples, indicating that EMT and proliferation contribute independently of each other to the formation of endometriotic lesions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12958-015-0063-7) contains supplementary material, which is available to authorized users.

Effects of AKT and MEK1/2 inhibition on stromal cell viability and proliferation in endometriosis

Endometriosis is characterized by progesterone resistance and hyperactivity of the AKT and MAPK pathways. We previously demonstrated that inhibition of AKT or MEK1/2 increases progesterone receptor levels in endometriotic stromal cells, and that aberrantly active AKT and MAPK may contribute to the pathogenesis of the disease. The objective of this study was to measure the effects of AKT and MEK1/2 inhibition on endometriotic stromal cell viability and proliferation.

Reconstruction of Endometrium from Human Endometrial Side Population Cell Lines

Endometrial regeneration is mediated, at least in part, by the existence of a specialized somatic stem cell (SSC) population recently identified by several groups using the side population (SP) technique. We previously demonstrated that endometrial SP displays genotypic, phenotypic and the functional capability to develop human endometrium after subcutaneous injection in NOD-SCID mice. We have now established seven human endometrial SP (hESP) cell lines (ICE 1–7): four from the epithelial and three from the stromal fraction, respectively. SP cell lines were generated under hypoxic conditions based on their cloning efficiency ability, cultured for 12–15 passages (20 weeks) and cryopreserved. Cell lines displayed normal 46XX karyotype, intermediate telomerase activity pattern and expressed mRNAs encoding proteins that are considered characteristic of undifferentiated cells (Oct-4, GDF3, DNMT3B, Nanog, GABR3) and those of mesodermal origin (WT1, Cardiac Actin, Enolase, Globin, REN). Phenotype analysis corroborated their epithelial (CD9+) or stromal (vimentin+) cell origin and mesenchymal (CD90+, CD73+ and CD45−) attributes. Markers considered characteristic of ectoderm or endoderm were not detected. Cells did not express either estrogen receptor alpha (ERα) or progesterone receptor (PR). The hESP cell lines were able to differentiate in vitro into adipocytes and osteocytes, which confirmed their mesenchymal origin. Finally, we demonstrated their ability to generate human endometrium when transplanted beneath the renal capsule of NOD-SCID mice. These findings confirm that SP cells exhibit key features of human endometrial SSC and open up new possibilities for the understanding of gynecological disorders such as endometriosis or Asherman syndrome. Our cell lines can be a valuable model to investigate new targets for endometrium proliferation in endometriosis.

17βE 2 promotes cell proliferation in endometriosis by decreasing PTEN via NFκB-dependent pathway

The objective of this study was to explore the mechanism of phosphatase and tensin homolog (PTEN) loss in endometriosis. We found that aberrant PTEN expression and mitogen-activated protein kinases (MAPK)/ERK, phosphoinositide 3-kinase (PI3K)/AKt, and nuclear factor-kappaB (NFκB) signaling overactivities coexisted in endometriosis. In vitro, 17β-estradiol rapidly activated the 3 pathways in endometriotic cells and specific inhibitions on the 3 pathways respectively blocked 17β-estradiol-induced cell proliferation. 17β-estradiol suppressed PTEN transcription and expression in endometriotic cells which was abolished by specific NFκB inhibition. Conclusion(s) Total/nuclear PTEN-loss and MAPK/ERK, PI3K/AKt, and NFκB signal overactivities coexist in endometriosis. In vitro, 17β-estradiol can promotes cell proliferation in endometriosis by activating PI3K/AKt pathway via an NFκB/PTEN-dependent pathway. For the first time we propose the possibility of the presence of a positive feedback-loop: 17β-estradiol → high NFκB → low PTEN → high PI3K → high NFκB, in endometriosis, which may finally promote the proliferation of ectopic endometrial epithelial cells and in turn contributes to the progression of the disease.

Endometriotic stromal cells lose the ability to regulate cell-survival signaling in endometrial epithelial cells in vitro

In normal endometrium, stromal factors regulate the growth of epithelial cells. However, epithelial cells in endometriotic lesions display increased proliferation and decreased apoptosis. This work tested the hypothesis that in endometriosis stromal cells lose the ability to regulate survival signaling and cell growth in epithelial cells. Primary normal, endometriotic eutopic and ectopic epithelial cells were cultured in the presence of medium conditioned by normal, eutopic and ectopic endometriotic endometrial stromal cells. Endometriotic epithelial cells showed higher Survivin expression than normal epithelial cells. Conditioned medium (CM) from normal or eutopic endometriotic stromal cells significantly inhibited the Survivin expression and AKt phosphorylation in normal or eutopic endometriotic epithelial cells. However, CM from ectopic endometriotic stromal cells did not have an inhibitory effect on normal or ectopic endometriotic epithelial cells. Inhibition of AKt phosphorylation and Survivin expression in normal or eutopic endometriotic epithelial cells in the presence of stromal factors from normal or eutopic endometriotic stromal cells was enhanced by progesterone, whereas progesterone had little effect in the presence of stromal factors from ectopic endometriotic stromal cells. The inability of ectopic endometriotic stromal cells to regulated PI3K/AKt/Survivin signaling and mediate the progesterone response in endometriotic epithelial cells may facilitate epithelial cell proliferation in endometriosis and promote the survival of endometriotic lesions.

Cyclooxygenase-2 overexpression in ovarian endometriomas is associated with higher risk of recurrence

Cyclooxegenase-2 expression was evaluated by immunohistochemistry in endometrioma tissue samples taken from 109 patients, of whom 53 had recurrence by 30 months after surgery and 56 did not. Cyclooxegenase-2 overexpression, along with previous medical treatment of endometriosis and the presence of adhesion, is predictive of recurrence of ovarian endometrioma within 30 months after surgery, with a resultant sensitivity of 72.5% and a specificity of 72.4%, suggesting that there are intrinsic and identifiable biomarkers that confer recurrence risk.

The role of cytotoxic cells and interferon system in regulation of processes of proliferation in endometriosis

Introduction: Various components of immune system take part in pathogenesis of endometriosis. Their role might be paramount or minor during different periods of the disease.