Human Endometrial Tissue Research Articles

Expression of neuritin in human lung squamous cell carcinoma

Background: This study aimed to investigate the expression of neuritin in four common cancers, and to explore the association between neuritin expression and the occurrence and development of cancer. Methods: We initially examined neuritin expression in human cervical, endometrial, oesophageal, and lung cancer tissues by immunohistochemistry (IHC). Based on these results, we further examined its expression in lung squamous cell carcinoma (LUSC) tissues by IHC and reverse transcription-polymerase chain reaction (RT-PCR). Results: Neuritin expression levels were higher in all cancer tissues compared with normal control tissues. Neuritin protein and gene expression levels were significantly higher in LUSC tissues compared with normal lung tissues (P<0.001), according to IHC and RT-PCR, respectively. Neuritin expression levels decreased significantly with increased clinical TNM stage (I-IV) and distant metastasis (P<0.05). Conclusion: Neuritin may have clinical value as a novel diagnostic and prognostic marker in patients with LUSC.

MiR-21a inhibits decidual cell apoptosis by targeting Pdcd4

Decidualization of endometrial stromal cells (ESCs) accompanied with embryo implantation is a key process in mammalian reproduction. Evidence suggests that maintenance of decidual cells function is essential. As a critical part in post-transcriptional gene regulation, microRNAs (miRNAs/miR) have been confirmed to be involved in decidualization. However, whether microRNAs regulate decidual cells function has not been reported. Aiming to clarify the role and potential mechanism of miRNAs in decidual cells, artificial induced decidualization model in mice was established. There are 94 differentially expressed miRNAs (≥two-fold change) between decidualized and non-decidualized tissues, including 60 upregulated and 34 downregulated miRNAs. Of the differentially expressed miRNAs, mmu-miR-21a is up-regulated. RT-qPCR also confirmed the up-regulation of mmu-miR-21a following decidualization in vivo and in vitro, and bioinformatic analysis and luciferase activity assay revealed Pdcd4 to be the target gene of mmu-miR-21a. Inhibition of mmu-miR-21a restrained secretory function of decidual cells induced by mESCs, accompanied with increase of Pdcd4 expression and resulted in the increase of cell apoptosis. In addition, we also determined the expression of hsa-miR-21 and Pdcd4 in human proliferative endometrial tissues and decidua tissues. hsa-miR-21 showed higher expression in human decidua tissues compared with proliferative endometrial tissues, while expression of Pdcd4 was contrary to that of hsa-miR-21. Similarly, cell apoptosis increased significantly in human endometrial stromal cell line in response to inhibition of hsa-miR-21. Collectively, we conclude that mmu-miR-21a/hsa-miR-21 may play a key role in regulating the function of decidual cells by inhibiting cell apoptosis through targeting Pdcd4.

Expression of neuritin in human lung squamous cell carcinoma.

BackgroundThis study aimed to investigate the expression of neuritin in four common cancers, and to explore the association between neuritin expression and the occurrence and development of cancer.MethodsWe initially examined neuritin expression in human cervical, endometrial, oesophageal, and lung cancer tissues by immunohistochemistry (IHC). Based on these results, we further examined its expression in lung squamous cell carcinoma (LUSC) tissues by IHC and reverse transcription-polymerase chain reaction (RT-PCR).ResultsNeuritin expression levels were higher in all cancer tissues compared with normal control tissues. Neuritin protein and gene expression levels were significantly higher in LUSC tissues compared with normal lung tissues (P<0.001), according to IHC and RT-PCR, respectively. Neuritin expression levels decreased significantly with increased clinical TNM stage (I-IV) and distant metastasis (P<0.05).ConclusionNeuritin may have clinical value as a novel diagnostic and prognostic marker in patients with LUSC.

Isolation and culture of human endometrial derived cells as an in vitro model for future implantation studies

Introduction: Monthly regeneration of endometrium after cyclical mensturation confirmed the ability of specific population of the cells that presence in the basalis layer and undergone consecutive hormonal changes that could prepared the endometrial layer for probable implantation. These cells, known as, stem cell. The aim of this study was the isolation and culture of human endometrial derived mesenchymal stem/stromal cells (EnMSCs). Methods: .In this study, human endometrial tissues were collected after fully-informed patient consent, which attended the Research and Clinical Center for Infertility. After washing and enzymatic treatment, EnMSCs were isolated and cultured in vitro. Results: Cells from endometrium were successfully isolated using enzymatically treatment and mechanically dissociation, then cultured and expanded for several passages for further characterization and evaluations. Endometrium derived cells were morphologically similar to mesenchymal stem/stromal cells (MSCs). Conclusion: The results of the present study confirm previous reports in vitro studies for the isolation and culture of human EnMSCs. Endometrial tissue is a part of uterus with available source of MSCs with self-renewal and differentiation capacity that undergoes a cyclical regeneration every month in normal women’s life span. In this regard, human EnMSCs could be used for future novel therapeutic methods in regenerative medicine for treatment of uterine-factor infertile patients, which can lead to recurrent pregnancy loss (RPL) and finally resolve of surrogacy problems.

Role of Tricellular Tight Junction Protein Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Cancer Cells.

Maintaining a robust epithelial barrier requires the accumulation of tight junction proteins, LSR/angulin-1 and tricellulin, at the tricellular contacts. Alterations in the localization of these proteins temporarily cause epithelial barrier dysfunction, which is closely associated with not only physiological differentiation but also cancer progression and metastasis. In normal human endometrial tissues, the endometrial cells undergo repeated proliferation and differentiation under physiological conditions. Recent observations have revealed that the localization and expression of LSR/angulin-1 and tricellulin are altered in a menstrual cycle-dependent manner. Moreover, it has been shown that endometrial cancer progression affects these alterations. This review highlights the differences in the localization and expression of tight junction proteins in normal endometrial cells and endometrial cancers and how they cause functional changes in cells.

N-glycosylation of uterine endometrium determines its receptivity.

Glycosylation alters the molecular and functional features of glycoproteins, which is closely related with many physiological processes and diseases. During "window of implantation", uterine endometrium transforms into a receptive status to accept the embryo, thereby establishing successful embryo implantation. In this article, we aimed at investigating the role of N-glycosylation, a major modification type of glycoproteins, in the process of endometrial receptivity establishment. Results found that human uterine endometrial tissues at mid-secretory phase exhibited Lectin PHA-E+L (recognizes the branched N-glycans) positive N-glycans as measured by the Lectin fluorescent staining analysis. By utilizing in vitro implantation model, we found that de-N-glycosylation of human endometrial Ishikawa and RL95-2 cells by tunicamycin (inhibitor of N-glycosylation) and peptide-N-glycosidase F (PNGase F) impaired their receptive ability to human trophoblastic JAR cells. Meanwhile, N-glycosylation of integrin αvβ3 and leukemia inhibitory factor receptor (LIFR) are found to play key roles in regulating the ECM-dependent FAK/Paxillin and LIF-induced STAT3 signaling pathways, respectively, thus affecting the receptive potentials of endometrial cells. Furthermore, in vivo experiments and primary mouse endometrial cells-embryos coculture model further verified that N-glycosylation of mouse endometrial cells contributed to the successful implantation. Our results provide new evidence to show that N-glycosylation of uterine endometrium is essential for maintaining the receptive functions, which gives a better understanding ofthe glycobiology of implantation.

Immunohistochemical Analysis of Somatostatin Receptors in Endometriosis Tissue Samples: A Retrospective Study.

Three types of endometriosis are described: superficial peritoneal endometriosis (SPE), ovarian endometrioma (OMA), and deep infiltrating endometriosis (DIE). The expression of somatostatin receptors (SSTR1, 2, and 5) in human endometrial tissue and its ectopic form has been previously studied and may be different in each type of endometriosis. The aim of this study was to assess the immunohistochemical expression of SSTR1, 2, and 5 in tissue samples of SPE, OMA, and DIE. We performed a retrospective analysis in the pathology department database. Patients aged <50 yr and diagnosed with endometriosis have been identified and sorted into 3 groups according to their endometriosis type: SPE, OMA, and DIE. For each selected patient, formalin-fixed paraffin-embedded blocks were retrieved in order to make new sections to be incubated with polyclonal rabbit antibodies anti-SSTR1, 2, and 5. Receptor status was considered as positive on the sections when >50% of the cells showed immunostaining. Seventy-six patients were included in the analysis. SSTR1 and 5 were expressed in 95.4% and 77.2% of SPE, respectively, in 95.8% and 83.3% of OMA, respectively, and in 100% and 80% of DIE, respectively. There was no significant difference between SPE, OMA, and DIE with regard to the SSTR1 (P=0.5) and SSTR5 (P=0.9) expression. We observed a significant difference between SPE (9.0%), OMA (16.6%), and DIE (63.3%) with regard to SSTR2 expression (P<0.05). The present study identifies 2 different immunohistochemical patterns of endometriosis lesions with regard to their SSTR expression: SSTR1+/SSTR2-/SSTR5+ for SPE and OMA, and SSTR1+/SSTR2+/SSTR5+ for DIE.

Abstract 1733: Role of the SIX1 oncofetal protein in endometrial basal cell metaplasia and carcinogenesis following neonatal exposure to diethylstilbestrol

Abstract Early-life exposure to estrogenic chemicals can increase cancer risk, likely by disrupting normal patterns of cellular differentiation. In a model of this process, female mice exposed to the potent synthetic estrogen diethylstilbestrol (DES) on postnatal days 1-5 develop endometrial adenobasal carcinoma as adults. Neoplastic glands are comprised of abnormal populations of basal cells (cytokeratin (CK)14+), luminal cells (CK18+), and low numbers of "mixed” basal/luminal cells (CK14+/18+), all of which express the oncofetal protein sine oculis homeobox 1 (SIX1). We hypothesized that DES-induced SIX1 expression is necessary for aberrant endometrial differentiation patterns and carcinogenesis. To test this hypothesis, a conditional knockout model was generated in which floxed Six1 was excised in the uterus using progesterone receptor (Pgr) cre. The most prominent change in DES-exposed SIX1 knockout (DES-Six1d/d) mice was the absence of basal cells in the uterine horns. There was a greater than 10-fold decrease in CK14 labeling in the uterine horns of DES-Six1d/d mice compared to DES-exposed SIX1 wildtype (DES-Six1+/+) mice as determined by quantitative image analysis. However, DES-Six1d/d mice exhibited a 42% increase in cancer incidence compared to DES-Six1+/+ mice at 6 months of age (16/18 DES-Six1d/d vs. 7/15 DES-Six1+/+). Interestingly, mixed cells were still present in DES-Six1d/d mice. These findings demonstrate that SIX1 is a cellular differentiation factor necessary for DES-induced basal cells but not mixed cell development or cancer. Furthermore, these data suggest that DES-induced SIX1 expression decreases endometrial carcinogenesis by facilitating basal cell differentiation. Studies investigating the mixed cell population as a putative cancer progenitor cell population are ongoing. Interestingly, mixed cells were present in 35% (63/181) of malignant human endometrial tissue biopsies and in 0% (0/29) of normal endometrial tissue biopsies, suggesting that the DES mouse model has significant similarities to human endometrial cancer. Citation Format: Alisa A. Suen, Wendy N. Jefferson, Charles E. Wood, Anna C. Kenan, Carmen J. Williams. Role of the SIX1 oncofetal protein in endometrial basal cell metaplasia and carcinogenesis following neonatal exposure to diethylstilbestrol [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1733.

Melatonin activity and receptor expression in endometrial tissue and endometriosis.

Are melatonin receptors (melatonin receptor 1A (MR1A) and melatonin receptor 1B (MR1B)) expressed in human endometrium and endometriotic tissue, and does melatonin affect endometrial cell proliferation? Melatonin receptors are expressed in human eutopic endometrium, endometriomas and peritoneal lesions, although to different extents, and melatonin treatment attenuated estradiol-induced endometrial epithelial cell proliferation in culture. Melatonin decreased endometriotic lesion volume in a rat model of endometriosis. Melatonin treatment reduced pain scores in and analgesic use by women with endometriosis. Basic science study using human endometrial tissue and an endometrial epithelial cell line. Measurement of melatonin receptor expression (mRNA and protein) in women with surgically confirmed endometriosis (endometrioma (n = 20) or peritoneal lesion (n = 11) alone) and women without surgical evidence of endometriosis (control, n = 15). Collection of endometrial and endometriotic tissue samples, gynecologic history and demographic information. Quantification of estradiol (1.0nM) and melatonin (0.1nM-1.0μM) ± estradiol-induced endometrial epithelial cell proliferation in cultures of endometrial epithelial cells (CRL-1671) following 24 and 48hours of culture. MR1A and MR1B were localized by immunohistochemistry in glandular epithelial cells of endometrial biopsies from women with and without endometriosis. Both receptors were expressed in eutopic and ectopic endometrial tissue. mRNA expression of MR1A and MR1B was significantly greater in peritoneal lesions than in either endometriomas or eutopic endometrium. However, protein expression of MR1A was decreased in peritoneal lesions compared to control eutopic endometrium, whereas MR1B expression did not differ between the groups. Melatonin (0.1nM-1.0μM) treatment inhibited estradiol (1.0nM)-induced endometrial epithelial cell proliferation at 48hours but not 24hours of culture. Beneficial effects of melatonin seen in culture have yet to be comprehensively evaluated in women with endometriosis. Our data suggest that melatonin may be useful as an adjunct to current endometriosis treatments. This study was supported by the Canadian Institutes of Health Research (grant MOP142230 to W.G.F.). A.A.M. is supported by a resident research grant through the Physicians Services Incorporated Foundation. The authors have no conflicts of interest.

Proteomic Analysis of Stromal and Epithelial Cell Communications in Human Endometrial Cancer Using a Unique 3D Co-Culture Model.

Epithelial and stromal communications are essential for normal uterine functions and their dysregulation contributes to the pathogenesis of many diseases including infertility, endometriosis, and cancer. Although many studies have highlighted the advantages of culturing cells in 3D compared to the conventional 2D culture system, one of the major limitations of these systems is the lack of incorporation of cells from non-epithelial lineages. In an effort to develop a culture system incorporating both stromal and epithelial cells, 3D endometrial cancer spheroids are developed by co-culturing endometrial stromal cells with cancerous epithelial cells. The spheroids developed by this method are phenotypically comparable to in vivo endometrial cancer tissue. Proteomic analysis of the co-culture spheroids comparable to human endometrial tissue revealed 591 common proteins and canonical pathways that are closely related to endometrium biology. To determine the feasibility of using this model for drug screening, the efficacy of tamoxifen and everolimus is tested. In summary, a unique 3D model system of human endometrial cancer is developed that will serve as the foundation for the further development of 3D culture systems incorporating different cell types of the human uterus for deciphering the contributions of non-epithelial cells present in cancer microenvironment.

Whole genome amplification of single epithelial cells dissociated from snap-frozen tissue samples in microfluidic platform.

Single cell sequencing is a technology capable of analyzing the genome of a single cell within a population. This technology is mostly integrated with microfluidics for precise cell manipulation and fluid handling. So far, most of the microfluidic-based single cell genomic studies have been focused on lab-cultured species or cell lines that are relatively easy to handle following standard microfluidic-based protocols without additional adjustments. The major challenges for performing single cell sequencing on clinical samples is the complex nature of the samples which requires additional sample processing steps to obtain intact single cells of interest without using amplification-inhibitive agents. Fluorescent-activated cell sorting is a common option to obtain single cells from clinical samples for single cell applications but requires >100 000 viable cells in suspension and the need for specialized laboratory and personnel. In this work, we present a protocol that can be used to obtain intact epithelial cells from snap-frozen postsurgical human endometrial tissues for single cell whole genome amplification. Our protocol includes sample thawing, cell dissociation, and labeling for genome amplification of targeted cells. Between 80% and 100% of single cell replicates lead to >25 ng of DNA after amplification with no measurable contamination, sufficient for downstream sequencing.

Noninvasive Monitoring of Lesion Size in a Heterologous Mouse Model of Endometriosis.

Here, we describe a protocol for the implementation of a heterologous mouse model in which progression of endometriosis can be assessed in real time through noninvasive monitoring of fluorescence emitted by implanted ectopic human endometrial tissue. For this purpose, biopsies of human endometrium are obtained from donor women ongoing oocyte donation. Human endometrial fragments are cultured in the presence of adenoviruses engineered to express cDNA for the reporter fluorescent protein mCherry. Upon visualization, labeled tissues with an optimal rate of fluorescence after infection are subsequently chosen for the implantation in recipient mice. One week prior to the implantation surgery, recipient mice are oophorectomized, and estradiol pellets are placed subcutaneously to sustain the survival and growth of lesions. On the day of surgery mice are anesthetized, and peritoneal cavity accessed through a small (1.5 cm) incision by the linea-alba. Fluorescently labeled implants are tweezed, briefly soaked in glue and attached to the peritoneal layer. Incisions are sutured, and animals left to recover for a couple of days. Fluorescence emitted by endometriotic implants is usually non-invasively monitored every 3 days for 4 weeks with an in vivo imaging system. Variations in the size of endometriotic implants can be estimated in real time by quantification of the mCherry signal and normalization against the initial time-point showing maximal fluorescence intensity. Traditional preclinical rodents of models of endometriosis do not allow non-invasive monitoring of lesion in real time but rather allow evaluation of the effects of drugs assayed at the end point. This protocol allows one to track lesions in real time and is more useful to explore the therapeutic potential of drugs in preclinical models of endometriosis. The main limitation of the model thus generated is that non-invasive monitoring is not possible over long periods of time due to the episomal expression of Ad-virus.

Macrophages infiltrating endometriosis-like lesions exhibit progressive phenotype changes in a heterologous mouse model

Endometriotic lesion development involves complex interactions between endometrial tissue, the peritoneum and immune cells. Macrophages are essential in this process; however their precise roles are not defined. To investigate whether infiltrating macrophages acquire functionally different phenotypes during lesion development, human endometrial tissues were grafted into immunodeficient mice expressing macrophage-specific green fluorescent protein (GFP). Although the numbers of GFP-positive macrophages were similar in lesions 4, 7, 10 and 14 days after grafting, their surface markers changed over time. Inflammatory markers MHC class II (MHC II) and iNOS were present on 36% and 41% of macrophages respectively early in lesion development at day 4, whereas abundance of tissue remodelling markers peaked later, with arginase 1 most highly expressed on 57% of macrophages at day 7 and scavenger receptor A (CD204) on 66% of macrophages at day 14. This is consistent with a transition from classical M1 macrophage activity to an alternate M2 profile, which correlates to histological hallmarks of initially acute inflammation followed by tissue remodelling during lesion development. This progressive shift in phenotype is likely to be relevant to the mechanisms by which macrophages are central players in endometriosis-like lesion development.

Osteoprotegerin (OPG) Interacts with Syndecan-1 to Mediate Human Endometrial Stromal Decidualization &lt;i&gt;via&lt;/i&gt; Decreasing Akt Phosphorylation

Methods: Human endometrial tissues from proliferative stage to secretory stage of normal menstrual cycle, and decidua tissues from normal pregnancy and recurrent pregnancy loss patients were collected to analyze the expression of OPG. Human endometrial stromal cells (HESCs) and primary human endometrial stromal cells (ESCs) were performed to explore the function and mechanism of OPG during decidualization. Findings: OPG expressed in human endometrium across menstrual cycle and during the human endometrial stromal cell decidualization. Knockdown experiments revealed that decrease of OPG impaired the expression of decidual markers prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1) without interference with the cell proliferation. Knockdown of OPG increased the phosphorylation of Akt and ERK1/2 during HESCs decidualization. Inhibition of PI3K signaling can rescue the impaired expression of decidual markers PRL and IGFBP-1 in response to OPG knockdown, but the ERK1/2 inhibition cannot. Further experiments revealed that OPG mediates human endometrial stromal decidualization by interacting with Syndecan-1 via decreasing Akt phosphorylation. Finally, endometrial expression of OPG was significantly lower in recurrent pregnancy loss (RPL) endometrial samples than that in normal pregnancy samples during the first trimester. Interpretation: OPG is required for decidualization, and the decrease of OPG is associated with recurrent pregnancy loss. These findings would provide a new candidate for diagnosis and treatment of infertility in women. Funding: This work was supported by the National Natural Science Foundation of China. Declaration of Interest: The authors declare that there is no conflict of interests. Ethical Approval: This study was approved by the Medical Ethics Committee of The First Affiliated Hospital of Xiamen University and written informed consent was obtained from all participants in accordance with the guidelines in The Declaration of Helsinki 2000.

Comparison of T and NK lymphocyte subsets between human endometrial tissue and peripheral blood.

Immune profiles in endometrium may be changed in patients with IVF failure and its possible correlations with immune parameters in peripheral blood are important for the diagnostic approach. Such correlations in healthy women are unknown and have been studied in the present research. The expression of CD56, CD158a, HLA DR, CD69 in T lymphocytes, CD4 T lymphocytes, CD8+ T lymphocytes and NK cells were studied by flow-cytometry in endometrium and peripheral blood in healthy 24 donors of oocytes aged 25-32 years. Levels of T lymphocyte and T helper cells were lower in endometrium and no differences in CD8 T lymphocytes were registered between endometrium and peripheral blood. The expression of HLA DR and especially CD69 was higher in CD3, CD4, CD8 T cells in endometrium in comparison with peripheral blood. The endometrium lymphocyte population was enriched by NK cells that were generally CD56++ with a higher expression of HLA DR and almost in total were CD69 positive. Strong positive correlations of CD8 expression in NK cells (r = 0.6478, p < 0.001) and HLA DR expression in CD8 T cells (r = 0.6107, p < 0.01) between peripheral blood and endometrium were registered in fertile women. The endometrial CD56 expression in CD8+ T cells negatively correlated with endometrial CD8 expression in NK cells (r = –0.5252, p < 0.01) which possibly reflected a suppressive and regulating mechanism in the endometrium. CD8+ NK cells and HLA DR+ CD8 T cells in endometrium were related to the same subsets in peripheral blood.

Co-localization of Coagulation Factor X and its Inhibitory System, PZ/ZPI, in Human Endometrial Cancer Tissue.

Hemostatic system components contribute to cancer progression independently from their roles in hemostasis. It has been shown that protein Z (PZ)/protein Z-dependent protease inhibitor (ZPI) inhibit coagulation factor X (FX). The aim of the study was to analyze the expression of PZ/ZPI in relation to the main coagulation factor - FX in human endometrial cancer tissue. Immunohistochemical analysis was performed on 21 endometrial cancer specimens employing antibodies against ZPI, PZ and FX. Endometrial cancer cells showed a strong expression of ZPI and PZ and medium expression of FX. Normal endometrial tissue showed no expression of ZPI, PZ or FX. Strong expression of PZ and ZPI in endometrial cancer cells suggests a role of these proteins in endometrial cancer.

MRP4 sustains Wnt/β-catenin signaling for pregnancy, endometriosis and endometrial cancer.

Rationale: Abnormal Wnt/β-catenin signaling in the endometrium can lead to both embryo implantation failure and severe pathogenic changes of the endometrium such as endometrial cancer and endometriosis. However, how Wnt/β-catenin signaling is regulated in the endometrium remains elusive. We explored possible regulation of Wnt/β-catenin signaling by multi-drug resistance protein 4 (MRP4), a potential target in cancer chemotherapy, and investigated the mechanism.Methods: Knockdown of MRP4 was performed in human endometrial cells in vitro or in a mouse embryo-implantation model in vivo. Immunoprecipitation, immunoblotting and immunofluorescence were used to assess protein interaction and stability. Wnt/β-catenin signaling was assessed by TOPflash reporter assay and quantitative PCR array. Normal and endometriotic human endometrial tissues were examined. Data from human microarray or RNAseq databases of more than 100 participants with endometriosis, endometrial cancer or IVF were analyzed. In vitro and in vivo tumorigenesis was performed.Results: MRP4-knockdown, but not its transporter-function-inhibition, accelerates β-catenin degradation in human endometrial cells. MRP4 and β-catenin are co-localized and co-immunoprecipitated in mouse and human endometrium. MRP4-knockdown in mouse uterus reduces β-catenin levels, downregulates a series of Wnt/β-catenin target genes and impairs embryo implantation, which are all reversed by blocking β-catenin degradation. Analysis of human endometrial biopsy samples and available databases reveals significant and positive correlations of MRP4 with β-catenin and Wnt/β-catenin target genes in the receptive endometrium in IVF, ectopic endometriotic lesions and endometrial cancers. Knockdown of MRP4 also inhibits in vitro and in vivo endometrial tumorigenesis.Conclusion: A previously undefined role of MRP4 in stabilizing β-catenin to sustain Wnt/β-catenin signaling in endometrial cells is revealed for both embryo implantation and endometrial disorders, suggesting MRP4 as a theranostic target for endometrial diseases associated with Wnt/β-catenin signaling abnormality.

Non-steroidal anti-inflammatory drugs increase MRP4 expression in an endometriotic epithelial cell line in a PPARa dependent manner.

Endometriosis is a debilitating disease characterized by chronic inflammation. The transporter multidrug resistance-associated protein 4 (MRP4/ABCC4) is expressed in human endometrial tissue; it is overexpressed in ectopic endometrial tissue, and is modulated by the anti-inflammatory lipid Lipoxin A4 (LXA4). Recently, it was demonstrated that aspirin induces platelet MRP4 over-expression, through genomic modulation in megakaryocytes. Since patients with endometriosis frequently use aspirin or other non-aspirin Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), the aim of this study was to verify whether aspirin and other NSAIDs enhance MRP4 expression in 12Z human endometriotic epithelial cells and whether this was peroxisome proliferator-activated receptor alpha (PPARa) dependent. MRP4 and PPARa expression was analyzed by Q-RT-PCR using TaqMan® Master Mix and TaqMan® Assay Reagents (Life Technologies, Monza, Italy) and Western blot. In 12Z cells, aspirin and other NSAIDs enhanced MRP4 mRNA and protein expression; these treatments also induced PPARa expression. Aspirin and diclofenac-induced increases in MRP4 expression were not observed in cells where PPARa was knocked down using siRNA. NSAIDs-induced MRP4 expression was correlated with augmented PGE2 secretion, indicating functional relevance. MRP4 expression was increased in cells treated with NSAIDs and the nuclear receptor PPARa is involved. Elevated PGE2 levels in cell supernatants correlate with its increased transport by MRP4 after NSAID treatment. More importantly, we provide evidence that in endometriotic epithelial cells aspirin and non-aspirin NSAIDs treatments alter gene expression.

MicroRNA‑409 may function as a tumor suppressor in endometrial carcinoma cells by targeting Smad2.

MicroRNAs (miRNAs) are frequently dysregulated in human cancer and can act as either potent oncogenes or tumor suppressor genes. The aberrant expression of miRNA‑409 (miR‑409) has been found in certain types of cancer, however, its expression and potential biological role in endometrial cancer remain to be fully elucidated. In the present study, a total of 16 pairs of tissue samples from 16patients with endometrial cancer were used in the present study, each of which consisted of human endometrial cancer tissue and matched adjacent normal tissue from the same patient. The expression of miR‑409 of the tissue were detected and its associations with Ishikawa and HEC‑1B human endometrial cancer cell lines were studied. The results of the present study demonstrated that miR‑409 was downregulated in human endometrial cancer, and it suppressed the growth of Ishikawa and HEC‑1B human endometrial cancer cell lines. Bioinformatics analysis indicated that small mothers against decapentaplegic 2 (Smad2) was a putative target of miR‑409. In a luciferase reporter system, it was confirmed that Smad2 was a direct target gene of miR‑409. It was also demonstrated that Smad2 was upregulated in human endometrial cancer tissues, and this was inversely correlated with the expression of miR‑409. These findings indicated that miR‑409 targeted the Smad2 transcript and suppressed endometrial cancer cell growth, suggesting that miR‑409 has a tumor suppressive role in the pathogenesis of human endometrial cancer.

The sialyltransferase ST3Gal3 facilitates the receptivity of the uterine endometrium in vitro and in vivo.

The receptive uterine endometrium specifically expresses certain glycosyltransferases, and the corresponding oligosaccharides play important roles in accepting the embryo. The sialyltransferase β-galactoside-α2,3-sialyltransferase III (ST3Gal3) is the key enzyme responsible for sialyl Lewis X (sLeX) oligosaccharide biosynthesis, but the expression and function of ST3Gal3 in the receptive endometrium is still elusive. Here, we found that human endometrial tissues at secretory phase expressed a 4-fold higher ST3Gal3 level relative to the tissues at proliferative phase. Meanwhile, downregulation of ST3Gal3 or sLeX epitope blockage significantly impaired the receptive ability of human endometrial RL95-2 cells to trophoblastic cells invitro and inhibited implantation in pregnant mice. This study suggests that ST3Gal3 facilitates endometrial receptivity through increasing sLeX oligosaccharide, which gives a better understanding of the glycobiology of implantation.