Expression In Normal Endometrium Research Articles

Telomeres and telomerase in endometrial cancer and hyperplasia.

The study aimed to measure telomeres length (TL) and telomerase expression in normal endometrium and endometrial hyperplasia and cancer. Total RNA and DNA were isolated from endometrium samples of 117 patients. The RT-PCR method was used to determine telomerase expression and relative telomere length. The control group had the longest telomeres in comparison to the hyperplasia and endometrial cancer groups. Only in the endometrial cancer group was telomerase expressed and positively correlated with telomere length. Telomere extension in endometrial cancer is mediated by telomerase, but telomere length may not be an indicator of endometrioid cancer development.

Characterization of epidermal growth factor-like domain 7 (EGFL7) expression in normal endometrium and in the endometrium of women with poor reproductive outcomes.

Could epidermal growth factor-like domain 7 (EGFL7) be a factor involved in the preparation of the endometrium for implantation and could its dysregulation be implicated in poor reproductive outcomes? EGFL7 is highly expressed in the endothelium and glandular epithelium throughout the menstrual cycle; it is upregulated by stromal cells in secretory phase and appears strongly reduced in endometrial biopsies and isolated stromal cells of women with unexplained recurrent pregnancy loss (uRPL) and recurrent implantation failure (RIF). The secreted factor EGFL7, originally identified as a gene primarily expressed in endothelial cells, is also expressed by the mouse blastocyst and by mouse and human trophoblast cells. It regulates trophoblast migration and invasion by activating NOTCH1 signaling. NOTCH1 has been demonstrated to play a fundamental role in endometrial receptivity and its dysregulation may be involved in selected pregnancy complications characterized by altered endometrial receptivity, such as uRPL. This is an exploratory study for which 84 endometrial biopsies were collected from normally fertile women, as well as from women with uRPL and RIF. Samples were collected from women in both the proliferative and secretory phases of the menstrual cycle and stratified into three sub-groups according to the patient clinical history: 20 fertile women (8 in proliferative and 12 in secretory phase), 41 women with uRPL (6 in proliferative and 35 in secretory phase), and 27 women with RIF (8 in proliferative and 19 in secretory phase). Immunohistochemistry, real-time PCR, and western blot analyses were performed to study the expression of EGFL7 and NOTCH1, as well as the NOTCH target genes. Analysis of spatial and temporal distribution of EGFL7 in endometrial biopsies from fertile women revealed higher levels of EGFL7 in samples from the secretory phase compared to proliferative phase. The expected expression of EGFL7 in endothelial cells was shown as well as the novel, not previously reported, expression in endometrial glands and stromal cells. EGFL7 was significantly reduced in the endometrium of women with uRPL and RIF in the secretory phases and this was associated with a downregulation of the NOTCH1 signaling pathway. Human recombinant EGFL7 was able to activate the NOTCH1 signaling pathway in endometrial stromal cells (EndSCs) obtained from fertile women but not in cells from uRPL or RIF patients. EndSCs from fertile women and decidualized in vitro for three days showed an upregulation of EGFL7 expression, whereas cells obtained from women with uRPL and RIF and decidualized in vitro did not. This study was conducted with a relatively small number of patient samples. Although results are highly reproducible and consistent, additional observations from multicentric cohorts would strengthen the relevance of the data. Moreover, this is an in vitro study, which might only partially represent the in vivo conditions. Our results demonstrate for the first time that EGFL7 is new player involved in decidualization and provide new insights into the pathophysiology of selected implantation defects and early pregnancy complications. Our studies have revealed that alterations in EGFL7 expression and the consequent dysregulation of NOTCH signaling are potential underlying causes of RIF and uRPL. Our results might have therapeutic relevance, as the EGFL7/NOTCH pathway may represent a potential target for medical intervention. This study has been supported by the Grant for Fertility Innovation 2017 (Merck KGaA). There are no competing interests to disclose. Not applicable.

Regulation of HAND2 Expression by LncRNA HAND2-AS1 in Ovarian Endometriosis Involving DNA Methylation.

HAND2 is a critical mediator of progesterone receptor signaling in endometrium. Silencing of HAND2 expression is associated with female infertility and endometrial cancers. We recently observed that lncRNA HAND2-AS1 and HAND2 are expressed coordinately in human endometrial stromal cells. To investigate involvement of HAND2-AS1 and HAND2 in pathogenesis of endometriosis, we employed immunohistochemistry, in situ hybridization, and quantitative real-time PCR to assess their expression in normal endometrium and the ectopic lesions obtained from patients with ovarian endometriosis. HAND2 promoter methylation was also monitored in these samples. Our results revealed that HAND2 and HAND2-AS1 expression levels were reduced but promoter methylation was enhanced significantly in ectopic endometrium when compared with the normal controls. Fluorescence in situ hybridization showed that HAND-AS1 is predominantly localized in the nuclei of endometrial stromal cells in contrast to the cytoplasmic distribution in epithelial cell compartment. To further investigate regulation of HAND2 expression by HAND2-AS1, HAND2-AS1 was silenced or overexpressed in human endometrial stromal cells. Our studies showed that expression levels of HAND2 and its direct target IL15 were attenuated markedly in HAND2-AS1 silenced cells but enhanced significantly in the overexpressed human endometrial stromal cells. Silencing of HAND2-AS1 also impaired endometrial stromal cell decidualization as indicated by downregulation of decidual biomarkers IGFBP1 and PRL. In addition, HAND2 promoter methylation was also enhanced upon HAND2-AS1 silencing. RNA immunoprecipitation studies further revealed that HAND2-AS1 is capable of binding to DNA methyltransferase DNMT1, indicating that HAND2-AS1 governs HAND2 expression epigenetically involving DNA methylation.

Activation of α7 nicotinic acetylcholine receptor retards the development of endometriosis

BackgroundWomen with endometriosis have been shown to have a reduced vagal tone as compared with controls and vagotomy promoted while vagus nerve stimulation (VNS) decelerated the progression of endometriosis in mice. Extensive research also has shown that the activation of the cholinergic anti-inflammatory pathway by VNS activates α7 nicotinic acetylcholine receptor (α7nAChR), potently reducing inflammation. Yet whether α7nAChR plays any role in endometriosis is unknown. We evaluated its expression in normal endometrium, ovarian and deep endometriotic lesions, and evaluated its role in the development of endometriosis.MethodsImmunohistochemistry analyses of α7nAChR in endometriotic lesions as well as control endometrium, and quantification of tissue fibrosis by Masson trichrome staining were performed. Mouse experiments were conducted to evaluate the impact of α7nAChR activation or suppression on lesional progression and possible therapeutic effect. Finally, in vitro experiments were conducted to evaluate the effect of activation of α7nAChR on epithelial-mesenchymal transition (EMT), fibroblast-to-myofibroblast transdifferentiation (FMT), smooth muscle metaplasia (SMM) and fibrogenesis in an endometriotic epithelial cell line and primary endometriotic stromal cells derived from ovarian endometrioma tissue samples.ResultsImmunostaining of α7nAChR was significantly reduced in human endometriotic epithelial cells as compared with their counterpart in normal endometrium. Lesional α7nAChR staining levels correlated negatively with lesional fibrosis and the severity of dysmenorrhea. The α7nAChR agonist significantly impeded the development of endometriotic lesions in mouse models possibly through hindrance of EMT and FMT. It also demonstrated therapeutic effects in mice with induced deep endometriosis. Treatment of endometriotic epithelial and stromal cells with an α7nAChR agonist significantly abrogated platelet-induced EMT, FMT and SMM, and suppressed cellular contractility and collagen production.Conclusionsα7nAChR is suppressed in endometriotic lesions, and its activation by pharmacological means can impede EMT, FMT, SMM, and fibrogenesis of endometriotic lesions. As such, α7nAChR can be rightfully viewed as a potential target for therapeutic invention.Trial registrationNot applicable.

YTHDF2 is a novel diagnostic marker of endometrial adenocarcinoma and endometrial atypical hyperplasia/ intraepithelial neoplasia

Numerous studies show that some biomarkers are aberrantly expressed in endometrial endometrioid adenocarcinoma (EMAC) and endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (EAH/EIN) compared to endometrial benign lesions. Because of low sensitivity and/or specificity, the utility of these markers to distinguish EMAC and EAH/EIN from benign endometrial lesions is limited. YTH domain family 2 (YTHDF2) is a functional N6-methyladenosine (m6A)-specific reader protein that mainly regulates mRNA stability. Aberrant YTHDF2 expression has been reported in many cancers and plays important functions in tumorigenesis and cancer progression. However, its expression in endometrial benign and malignant lesions has not been investigated. We evaluated YTHDF2 mRNA and protein expression in EMAC and normal endometrium using the UALCAN database and validated the bioinformatic results in EMAC cells using qRT-PCR, Western blot, and immunohistochemical (IHC) staining. We found that YTHDF2 was weakly expressed in normal endometrium, benign endometrial lesions, endometrial hyperplasia without atypia, and adenomyosis. In contrast, YTHDF2 was upregulated in EAH/EIN and EMAC. These results indicate that YTHDF2 immunostaining may be a useful tool to distinguish EAH/EIN from EHWA. Finally, YTHDF2 expression can accurately assess the depth of myometrial invasion (DMI) in EMAC when EMAC coexists with adenomyosis.

Abstract 658: CRABP2 - a novel biomarker for high risk endometrial cancer

Abstract Introduction: The incidence of endometrial cancer (EC) is rising - a consequence of the current obesity epidemic. An improved understanding of obesity-induced EC is needed to manage this growing cohort of patients. Here-in we present Cellular Retinoic Acid Binding Protein 2 (CRABP2), which was identified as an obesity-related gene in the BDII/Han rat spontaneous EC model, as a novel biomarker in high-risk EC. Methods:BDII/Han rats were fed either a high (N=12) or low calorie (N=7) diet for 15 months. RNA-seq, - differential gene expression and gene set enrichment analysis (GSEA) were performed on endometrial tumors from both groups. The association between CRABP2 mRNA expression and standard clinico-pathological features was examined in human EC using the TCGA. Following dichotomization of patients based on their CRABP2 mRNA expression using regression tree analysis, univariate and multivariate Cox regression survival analyses were performed. Differential gene expression analysis and GSEA were performed on human tumors stratified according to CRABP2 expression levels. In-silico findings were validated using immunohistochemistry (IHC) assessing CRABP2 expression in normal endometrium, primary and metastatic endometrial carcinoma. Results:Weight gain in high fat diet (HFD) rats was double that of normal chow diet rats (50 g vs. 25 g). The incidence of cancer was similar in both groups (4/7-57% vs. 4/12-33%; p=0.37). 368 differentially expressed genes (DEGs) were identified between both groups. CRABP2 was upregulated in tumors from the HFD group. Regression tree analysis identified 60 (11%) tumors in the TCGA with increased CRABP2 mRNA expression. Increased CRABP2 expression was associated with serous EC (p<0.001), grade 3 (p<0.001) and advanced stage (p=0.015). Univariate Cox regression analysis revealed that high CRABP2 expression is associated with reduced overall survival (HR=2.67, 95% CI 1.64-4.33, p<0.001). This remained true following multivariate cox regression analysis in which age, histological type, stage and grade were confounded for (HR=2.06, 95% CI 1.24-3.41, p=0.004). 224 DEGs were identified between CRABP2 high (N=60) and low (N=468) tumors in the TCGA. GSEA analysis revealed an enrichment of pathways involved in developmental biology and embryonic stem cell-like gene expression signatures in the CRABP2-high cohort. IHC confirmed increased expression of cytoplasmic CRABP2 in EC compared to normal endometrium. CRABP2 expression was significantly increased in serous compared to endometrioid cancer (p<0.05) and a comparison between primary and metastatic serous carcinoma demonstrated increased expression in metastatic cases. Conclusion: A HFD increased CRABP2 expression in rat EC. In humans, increased expression of CRABP2 is associated with high-risk EC. Transcriptomic analysis and validation using IHC suggests that CRABP2 and retinoic acid signalling may be an important therapeutic target in advanced EC. Citation Format: Donagh Egan, Bruce Moran, Michael Wilkinson, William Gallagher, Xavier Matias-Guiu, Walter Kolch, Carel LeRoux, Donal Brennan. CRABP2 - a novel biomarker for high risk endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 658.

Endometrial estrogen and progesterone receptors in infertility and abnormal uterine bleeding

Introduction: Evaluation of endometrial histology can be made more meaningful with the study of Estrogen and Progesterone receptor (ER and PR) status. Present study aimed at studying ER and PR status of normal endometrium and endometrium in infertility and abnormal uterine bleeding and elucidating its relevance and utility. Materials and Methods: This case control study was carried out on prospectively registered patients. It included 12 cases of infertility, 24 cases of abnormal uterine bleeding, 14 cases of uterine leiomyoma and 22 cases of age matched controls undergoing endometrial sampling for causes other than above mentioned conditions. The cases were subjected to thorough clinical evaluation. The study of endometrium was done with routine histology. Endometrial ER and PR expression was studied immunohistochemically. The data collected was analyzed to find out the variability of expression of endometrial ER and PR in normal and abnormal endometrium with student’s t-test and correlation t-test (SPSS software version 11). Results: The ER and PR expression in normal endometrium showed cyclical variation. It was highest in the proliferative phase followed by the periovulatory phase followed by a significant decline in the late secretory phase. In cases of infertility and abnormal uterine bleeding with endometrial dysfunction; late secretory endometrium showed increased ER expression as compared to controls. Conclusion: Variations noted in endometrial ER and PR expression in infertility and abnormal uterine bleeding provided insight in its pathogenesis and helped in contemplating treatment options. Keywords: ER, PR, Endometrium, Infertility, Abnormal uterine bleeding, Uterine leiomyoma

Long non-coding RNA CCAT1 is overexpressed in endometrial cancer and regulates growth and transcriptome of endometrial adenocarcinoma cells.

Long non-coding RNAs (lncRNAs) play important roles in regulation of gene expression and are involved in pathogenesis of different diseases including cancer. Recent studies suggested the lncRNA Colon cancer associated transcript-1 (CCAT1) to act as putative oncogene. In this study, to elucidate the role of this lncRNA in endometrial cancer, we examined its expression in normal endometrium and type 1 endometrial cancer and knocked down its expression in endometrial cancer cell lines followed by transcriptome and pathway analyses. CCAT1 expression was examined in 100 tissue samples of normal endometrium and type 1 endometrial cancer tissues by means of RT-qPCR. Knockdown of CCAT1 expression in HEC-1B and RL95/2 endometrial cancer cells was performed by siRNA transfection. Affymetrix GeneChip arrays were used to elucidate the effect of both lncRNAs on the transcriptome of these cell lines. Median CCAT1 expression was found to be 9.3-fold higher in endometrial cancer when compared to normal endometrium (p < 0.05). In contrast to premenopausal endometrium and G1, G2 and G3 graded endometrial cancer, CCAT1 expression was nearly absent in postmenopausal tissue. Knockdown of CCAT1 by transient siRNA transfection significantly reduced proliferation of HEC-1B cancer cells in vitro by 35.5 % 6 days after transfection and notably reduced their colony formation ability. Affymetrix microarray and Ingenuity pathway analyses revealed a set of up- or down-regulated genes in transfected ERα-negative HEC-1B cells forming a network controlled by the key regulators TNF and TP53, including genes known to be involved in growth control, providing putative molecular mechanisms underlying the observed growth inhibition of HEC-1B cells. In contrast, CCAT1 knockdown in ERα-positive RL95/2 cells did not significantly affect proliferation, but resulted in down-regulation of a network of ERα target genes. Given that the lncRNA CCAT1 was found to be overexpressed in endometrial cancer, affected the growth of HEC-1B cells and the expression of growth regulatory genes, our data suggest CCAT1 to exert oncogenic functions in endometrial cancer and encourage further studies to examine to what extent this lncRNA might be a potential therapy target in this cancer entity.

Pyruvate Kinase M2 Expression: A Potential Metabolic Biomarker to Differentiate Endometrial Precancer and Cancer That Is Associated with Poor Outcomes in Endometrial Carcinoma.

Background: Pyruvate kinase M2 (PKM2) is a regulator of the processes of glycolysis and oxidative phosphorylation, but the roles that it plays in endometrial cancer remain largely unknown. This study evaluated the PKM2 expression in normal endometrium, endometrial hyperplasia, and endometrial carcinoma, and its prognostic value was investigated in endometrial carcinoma patients. Methods: A hospital-based retrospective review was conducted to examine the immunohistochemical PKM2 distribution in 206 endometrium samples from biopsies or hysterectomies. The immunoreactivity of PKM2 was divided into groups of low and high scores according to the extent and intensity of staining. Results: Intense cytoplasmic staining was observed for the PKM2 protein in malignant endometrial lesions. A high PKM2 score was observed in many endometrial carcinoma samples (50.0%), but there was a low percentage in endometrial atypical hyperplasia (12.5%). High PKM2 expression was not found in the normal endometrium (0.0%) nor endometrial hyperplasia without atypia (0.0%). The PKM2 protein score was significantly higher in endometrial carcinoma samples than premalignant endometrial lesions (p < 0.001). Notably, higher PKM2 scores in cases of endometrial carcinoma correlated with poor overall survival (p = 0.006), and the hazard ratio for death was 3.40 (95% confidence interval, 1.35–8.56). Conclusions: Our results indicate that the prevalence of PKM2high tumor cells in endometrial carcinoma is significantly associated with worse prognostic factors and favors a poor prognosis. The expression of PKM2 is also a potential histopathological biomarker for use in the differential diagnosis of malignant and premalignant endometrial lesions.

The Significance of Galectin-1 and Galectin-9 Expression in Endometrial Carcinoma

Objectives: To explore the expression of Galectin-1 and -9 and clinicopathological features in endometrial carcinoma (EC). Methods: Normal endometrium (NE), atypical endometrial hyperplasia (AH), and endometrial cancer were collected, and immunohistochemistry was used to detect the expression of Galectin-1 and -9 in all specimens in the same condition. Results: The positive rate of Galectin-1 expression in NE, AH, and endometrial cancer was 30, 70, and 90.2%. The positive rate of Galectin-9 expression in them was 20, 75, and 78.4%, respectively. The expression of Galectin-1 and -9 in the EC and AH was significantly higher than that in the NE (p< 0.05). However, there was no significant difference between the EC and the AH (p > 0.05). The expression of Galectin-1 in endometrial adenocarcinoma was significantly different among tissues of different histological grades, pathological stages, degrees of myometrial infiltration, or lymph node metastasis (p > 0.05). The expression of Galectin-9 in endometrial adenocarcinoma was significantly different among different historical grades, pathological stages, degrees of myometrial infiltration, and lymph node metastasis (p < 0.05). The expression of Galectin-9 in tissues at an early stage, with the degree of myometrial infiltration <1/2, and without lymph node metastasis, was significantly stronger than in those in the late stage, with a degree of myometrial infiltration ≥1/2 and lymph node metastasis. Conclusion: Both Galectin-1 and -9 were associated with the occurrence of EC and its pathological behavior. High expression of Galectin-1 suggests a poor prognosis, whereas high expression of Galectin-9 was associated with early pathological changes. Galectin-1 and -9 can provide references for early screening and indicate the prognosis of endometrial lesions, which are of great significance for patients’ quality of life.

Expression of PAX2 and PTEN in Oestrogen-Driven Endometrial Hyperplasia and Neoplasia

Endometrial hyperplasia is of paramount clinical implication as it is usually seen to precede endometrioid adenocarcinoma. However, clinicians and pathologists have always been uncertain about the distinction between innocuous hyperplasia from their sinister counterparts. This has serious implications, for the latter lesion has a greater propensity for progressing into adenocarcinoma and needs deft clinical intervention in the form of adequate progestational exposure or surgery. Thirty cases diagnosed as endometrial hyperplasia on endometrial biopsies were retrieved from the archives and reclassified as per the EIN criteria. Thirty cases each of proliferative endometrium and endometrioid carcinoma were also included. Immunohistochemistry with antibodies against PAX2 and PTEN was performed, and the extent of loss of expression was scored. A total of ten cases of EIN were identified, all of whom were initially diagnosed as complex hyperplasia with atypia. All cases of proliferative endometrium showed retained expression of PAX2 and PTEN. In contrast, all cases of endometrioid carcinoma showed complete loss of PAX2 and PTEN. The EIN cases showed partial loss of both PAX2 and PTEN expression. Loss of PAX2 expression in EIN showed a specificity and positive predictive value of 90% and 83.33%, respectively. The advent of the EIN criteria has made identification of clinically significant endometrial precancerous lesion more acceptable and reproducible. However, in cases of ambiguity, the use of antibodies against certain protein molecules which reflect the genes involved in the stepwise carcinogenesis would be of great utility in the hands of the pathologist. In comparison with PTEN, the use of PAX2, which gives a crisp nuclear positivity and has a lower percentage of loss of expression in normal endometrium, can be used as part of the algorithm in accurately identifying the precancerous endometrium.

Expression of the Receptor for Hyaluronic Acid-Mediated Motility (RHAMM) in Endometrial Cancer is Associated With Adverse Histologic Parameters and Tumor Progression.

Endometrial cancer is one of the most common gynecologic malignancies worldwide. Only 2 agents have been approved by Food and Drug Administration for endometrial cancer since 1971. There is a need to identify molecular targets to treat advanced endometrial cancer. The receptor for hyaluronic acid-mediated motility (RHAMM) is upregulated in various types of cancer. Here, we aimed to determine the clinical significance of RHAMM expression in endometrial cancer. Two hundred twenty-five cases of endometrial cancer, including serous and endometrioid types, and 8 cases of normal endometrium were used for studying RHAMM protein levels. The Cancer Genome Atlas database was also queried for RHAMM mRNA expression in endometrial cancer. Increased expression of RHAMM protein was seen in endometrial cancer compared with no or weak expression in normal endometrium. RHAMM expression positively correlated with tumor grade. RHAMM expression was significantly increased in endometrial serous carcinomas, which are high-grade, aggressive types of endometrial cancer, compared with the relatively less aggressive endometrioid carcinomas. RHAMM expression also correlated with the presence of lymphovascular invasion. RHAMM mRNA expression correlated with decreased survival in The Cancer Genome Atlas cohort. Therefore, increased RHAMM expression in endometrial cancer is associated with high-grade tumors and is indicative of more aggressive behavior. These findings suggest RHAMM as a prognostic factor in endometrial cancer and as a potential therapeutic target in advanced endometrial cancer for future studies.

Could E-Cadherin and CD10 Expression be Used to Differentiate Between Atypical Endometrial Hyperplasia and Endometrial Carcinoma?

Endometrial carcinoma contributes to morbidity and mortality among female individuals worldwide. The role of E-cadherin expression, as an adhesion molecule, in endometrial carcinoma is controversial. Moreover, the role of CD10-expressing stromal cells in endometrial carcinoma is still unclear. The aim of this work was to evaluate E-cadherin and CD10 expression in normal endometrium, atypical endometrial hyperplasia, and endometrial carcinoma, and assess their role to differentiate atypical endometrial hyperplasia from endometrial carcinoma. The association of E-cadherin and CD10 expression with clinicopathologic parameters of endometrial carcinoma was also determined. This retrospective study was carried out on 80 cases including 36 cases of endometrial adenocarcinoma (all were of endometrioid type), 34 cases of atypical endometrial hyperplasia, and another 10 cases of normal endometrial tissue. Immunohistochemistry for E-cadherin and CD10 was conducted. The studied patients were in their sixth and seventh decades of life with a mean age of 60.97 yr. Most of the carcinoma cases (18 cases) were grade 1, 10 cases were grade 2, and only 2 cases were grade 3. With regard to International Federation of Gynecology and Obstetrics (FIGO) staging, 28 cases were stage I, and only 2 cases were stage II. E-cadherin in normal endometrial tissue and atypical hyperplastic endometrial tissue showed predominantly membranous homogenous reactivity, and CD10 was detected as membranocyptoplasmic staining. However, we noticed the subcellular change of E-cadherin reactivity to be heterogenous and predominantly membranocytoplasmic in endometrial carcinoma, whereas CD10 remained membranocytoplasmic. Concerning E-cadherin expression, there was a statistically significant relationship between E-cadherin expression, tumor grade and FIGO staging, whereas there was an insignificant relationship between E-cadherin expression and patients' age, specimen type, tumor gross pattern, and histopathologic types. With regard to CD10 expression, there was a statistically significant relation between CD10 expression and tumor grade and FIGO staging with insignificant relation with patients' age, tumor gross pattern, specimen type, and tumor histologic types (villoglandular vs. usual endometrial adenocarcinoma). There was also a highly statistically significant positive relationship between E-cadherin expression and CD10 expression. This study puts the spot light on their role in differentiating between atypical endometrial hyperplasia and endometrial carcinoma, which is often difficult.

Expression and clinical significance of MIIP and PAK1 in endometrial carcinoma

Objective: To investigate the expressions of migration and invasion inhibitory protein (MIIP) and p21-activated kinase 1 (PAK1) in endometrial carcinoma (EC) and their correlation with clinicopathological features. Methods: The protein levels of MIIP and PAK1 in 135 paraffin-embedded EC tissues, 55 atypical hyperplasia of endometrium (AHE) and 88 normal endometrium (NE) tissues were quantified by immunohistochemistry, the clincial significance and the relationship of these two proteins were also analyzed. Results: The positive rates of MIIP expression in NE, AHE and EC tissues were 52.3%(46/88), 41.8% (23/55) and 34.8% (47/135), respectively. The expression of MIIP in EC was significantly lower than that of MIIP in NE (P<0.05). The positive rates of PAK1 expression in NE, AHE and EC tissues were 45.5% (40/88), 50.9% (28/55) and 62.2% (84/135), respectively. The expression of PAK1 in EC tissues was significantly higher than that of PAK1 in NE tissues (P<0.05). The expression of MIIP in EC tissues was significantly associated with myometrial invasion, International Federation of Gynaecology and Obstetrics (FIGO) stage and lymph node metastasis (P<0.05). The expression of PAK1 in EC tissues was significantly related with differentiation, myometrial invasion, FIGO stage and lymph node metastasis (P<0.05). The expressions of MIIP and PAK1 in EC tissues were marginally related with the overall survival of patients (P=0.092, P=0.052). The expression of MIIP in EC was negatively correlated with PAK1 (r=-0.329, P<0.001). Conclusions: The down-regulation of MIIP and up-regualtion of PAK1 paticipate in the initiation and development of EC, which are correlated with the poor prognosis of EC. The protein expression of MIIP is inversely related with PAK1 in EC.

Targeting stearoyl-CoA desaturase 1 to repress endometrial cancer progression.

Stearoyl-CoA desaturase 1 (SCD1) is an established molecular target in many primary tumors including breast, lung, pancreatic, colon and hepatocellular carcinomas. However, its potential role in supporting endometrial cancer growth and progression has not yet been determined. In this study, we evaluated the value of SCD1 as a candidate therapeutic target in human endometrial cancer. Compared with secretory and post-menopausal endometrium, SCD1 was highly expressed in normal endometrium of proliferative phase, endometrial hyperplasia and endometrial carcinoma, while was absent or low expression in non-malignant control stromal cells and adjacent normal endometrium. Knockdown of SCD1 significantly repressed endometrial cancer cell growth and induced cell apoptosis. Both short hairpin RNA targeted knockdown and chemical inhibitor of SCD1 suppressed the foci formation of AN3CA, a metastatic endometrial cell line. Xenograft model further demonstrated that reduced SCD1 expression impaired endometrial cancer growth in vivo. Taken together, these findings indicate that SCD1 is a potentially therapeutic target in human endometrial cancer. Inhibiting lipid metabolism in cancer cells would be a promising strategy for anti-cancer therapy.

PTEN, PAX2 and PINCH protein expression in normal endometrium, endometrial hyperplasia, and endometrioid adenocarcinomas

PTEN, PAX2 and PINCH protein expression in normal endometrium, endometrial hyperplasia, and endometrioid adenocarcinomas

NAC1 Regulates Somatic Cell Reprogramming by Controlling Zeb1 and E-cadherin Expression.

SummaryReprogramming somatic cells to induced pluripotent stem cells (iPSCs) is a long and inefficient process. A thorough understanding of the molecular mechanisms underlying reprogramming is paramount for efficient generation and safe application of iPSCs in medicine. While intensive efforts have been devoted to identifying reprogramming facilitators and barriers, a full repertoire of such factors, as well as their mechanistic actions, is poorly defined. Here, we report that NAC1, a pluripotency-associated factor and NANOG partner, is required for establishment of pluripotency during reprogramming. Mechanistically, NAC1 is essential for proper expression of E-cadherin by a dual regulatory mechanism: it facilitates NANOG binding to the E-cadherin promoter and fine-tunes its expression; most importantly, it downregulates the E-cadherin repressor ZEB1 directly via transcriptional repression and indirectly via post-transcriptional activation of the miR-200 miRNAs. Our study thus uncovers a previously unappreciated role for the pluripotency regulator NAC1 in promoting efficient somatic cell reprogramming.

MicroRNAs in endometrial cancers from black and white patients

Previous studies have identified differences in gene mutations among endometrial cancers from whites and blacks suggesting that differences in tumor biology may explain racial disparities in patient outcome. Micro RNAs (miRNAs) have emerged as regulators of transcript expression and their aberrant expression has been discovered in many diseases, including endometrial cancer. We performed quantitative polymerase chain reaction-based analysis in a set of endometrial cancers to identify whether there are racial differences in miRNA expression. Tumor cells from 50 stage-I endometrioid endometrial cancer specimens from 41 white and 9 black patients were prepared by laser microdissection and miRNA extracts were analyzed using TaqMan (Life Technologies, Carlsbad, CA) low-density arrays. Statistically significant, differentially expressed miRNAs between blacks and whites were identified using multidimensional scaling, Wilcoxon testing, and analysis of variance. There were no global differences in miRNA expression between endometrial cancers from 41 white and 9 black patients. To minimize potential bias introduced by unbalanced sample size, we performed a subset analysis with stage- and histology-matched specimens from 9 whites and 9 blacks that identified 18 differentially abundant miRNAs (>2-fold at P < .005). Quantitative polymerase chain reaction validated miRNA-337-3p in an independent set of endometrial cancer specimens from 23 white and 24 black women. There were no racial differences in hsa-miR-337-3p expression in normal endometrium. These data indicate that hsa-mir-337-3p is more frequently down-regulated in endometrial cancers from whites compared to blacks. Future studies are focused on determining the phenotypic impact of miR-337-3p and whether its differential expression is associated with clinical outcome.

Expression and clinical significance of FXYD3 in endometrial cancer.

FXYD3 expression is upregulated in numerous cancer cell types. The present study compared the FXDY3 expression in normal endometrium, premalignant lesion and endometrial cancer tissue samples, and investigated the correlation between FXDY3 expression and clinicopathological features. FXYD3 expression was analyzed by streptavidin-peroxidase immunohistochemistry in 21 normal endometrial tissue samples, 18 atypical endometrial hyperplasia samples and 50 tissues obtained from patients diagnosed with endometrial cancer. The percentage of FXYD3-positive cell expression in the normal endometrium, atypical hyperplasia and endometrial cancer tissues samples was 0, 22, and 26%, respectively. The differences between the atypical hyperplasia and endometrial cancer groups were statistically significant when compared with the normal group (P=0.007 and P=0.037, respectively). There was no significant difference between the atypical hyperplasia and endometrial cancer groups. The percentage of FXYD3-positive cells correlated with the fertility frequency (P<0.05). In conclusion, FXYD3 is a potential biomarker for endometrial cancer, and its upregulation may be an early event in endometrial carcinoma progression. In addition, FXYD3 expression in endometrial carcinoma correlates with fertility frequency.

AUF-1 is regulated in the menstrual cycle and repressed in ectopic endometrium: implications for regulation of cytokine and growth factor expression in normal endometrium and endometriosis

Cytokines and growth factors contribute to cyclic the turnover of normal endometrium and to the pathogenesis of endometriosis. Messenger RNAs (mRNAs) encoding cytokines or growth factors undergo rapid turnover that is primarily mediated by AU-rich elements (ARE) located in their 3' untranslated region (3'-UTR). AUF-1 is an RNA-binding protein that destabilizes ARE containing mRNAs and down-regulates their expression. We hypothesized that AUF-1 may play a role in the regulation of cytokine expression during normal menstrual cycle and in endometriosis.