An update of Wnt signalling in endometrial cancer and its potential as a therapeutic target

Clinical significance of TROAP in endometrial cancer and the antiproliferative and proapoptotic effects of TROAP knockdown in endometrial cancer cells: integrated utilization of bioinformatic analysis and in vitro test verification

Trophinin-associated protein (TROAP), a cytoplasmic protein essential for spindle assembly and centrosome integrity during mitosis, has been reported to serve as an oncogene in various tumors. However, its role in endometrial cancer (EC) progression is still undefined. TROAP expression in EC was analyzed via GEPIA and HPA databases. The diagnostic and prognostic values of TROAP were examined by ROC curve analysis and Kaplan-Meier plotter, respectively. Cell proliferation was evaluated using CCK-8 and EdU incorporation assays. Apoptosis was assessed using TUNEL and flow cytometry assays. GSEA was performed to explore TROAP-related pathways in EC. Expression of TROAP, proliferating cell nuclear antigen (PCNA), Ki-67, cleaved-caspase-3 (cl-caspase-3), caspase-3, active β-catenin, and total β-catenin was detected using western blot analysis. TROAP was upregulated in EC. TROAP served as a potential diagnostic and prognostic marker in EC patients. TROAP silencing suppressed proliferation and enhanced apoptosis in EC cells. GSEA revealed that EC and Wnt signaling pathways were related to the expression of TROAP. We further demonstrated that TROAP knockout repressed the Wnt/β-catenin pathway in EC cells. Moreover, SKL2001, a Wnt/β-catenin activator, partially abrogated the effects of TROAP silencing on EC cell proliferation and apoptosis, while the signaling inhibitor XAV-939 had the opposite effect. In conclusion, TROAP knockout retarded proliferation and elicited apoptosis in EC cells by blocking the Wnt/β-catenin pathway.

WNT4 Gene and Protein Expression in Endometrial Cancer and Its Significance

BACKGROUND

The inappropriate action of WNT4 and estrogens affects uterine homeostasis and function, and may lead to endometrial cancer (EC).

OBJECTIVE

The aim was to evaluate the alterations of WNT4 gene expression and WNT4 protein immunoreactivity (Ir) in EC, considering tumor characteristics, the clinicopathological association and estrogen dependence.

METHODS

WNT4 mRNA levels were compared between benign (control) endometrium (n = 8) and endometroid EC (EEC) and non-endometroid EC (non-EEC) samples (n = 28) using the real-time PCR technique. The WNT4-Ir and ERα-Ir were evaluated by immunohistochemistry (IHC). WNT4 mRNA gene and WNT4-Ir were correlated with clinicopathological and blood morphological parameters. Overall survival (OS) was assessed. The bioanalysis was utilized to study WNT4 expression in large patient cohort (n = 549).

RESULTS

WNT4 gene expression was decreased in EC samples (specifically in EEC but not in non-EEC) compared to the control. The WNT4 gene expression was also decreased in EC samples categorized by the tumor characteristics. There was no statistical difference in WNT4-Ir or ERα-Ir between the control and EC. There was no correlation between OS and WNT4 gene expression and WNT4-Ir. Bioanalysis showed that WNT4 and ESR1 gene expression alterations tended to be mutually exclusive. An alteration in WNT4 expression was found in different histological tumor types in a large group of EC patients.

CONCLUSIONS

There is a great need to evaluate the molecular background of EC. Our study suggests that the WNT4 gene has the potential to be a marker of functional estrogen signaling in EEC.

Evaluation of sterol‑o‑acyl transferase 1 and cholesterol ester levels in plasma, peritoneal fluid and tumor tissue of patients with endometrial cancer: A pilot study

Endometrial cancer (EC) is the most prevalent gynecological malignancy. Abnormal accumulation of sterol-O-acyl transferase 1 (SOAT1) and SOAT1-mediated cholesterol ester (CE) contributes to cancer progression in various malignancies, including ovarian cancer. Therefore, it was hypothesized that similar molecular changes may occur in EC. The present study aimed to evaluate the diagnostic and/or prognostic potential of SOAT1 and CE in EC by: i) Determining SOAT1 and CE levels in plasma, peritoneal fluid and endometrial tissue from patients with EC and control subjects; ii) performing receiver operating characteristic curve analysis to determine diagnostic performance; iii) comparing SOAT1 and CE expression to that of the tumor proliferation marker Ki67; and iv) assessing the association between SOAT1 expression and survival. Enzyme-linked immunosorbent assay was used to determine the levels of SOAT1 protein in tissue, plasma and peritoneal fluid. The mRNA and protein expression levels of SOAT1 and Ki67 in tissues were detected by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively. CE levels were determined colorimetrically in plasma and peritoneal fluid. SOAT1-associated survival data from the cBioPortal cancer genomics database were used to assess prognostic relevance. The results revealed that SOAT1 and CE levels were significantly elevated in tumor tissue and peritoneal fluid samples collected from the EC group. By contrast, the plasma levels of SOAT1 and CE in the EC and control groups were similar. Significant positive associations between CE and SOAT1, SOAT1/CE and Ki67, and SOAT1/CE and poor overall survival in patients with EC suggested that SOAT1/CE may be associated with malignancy, aggressiveness and poor prognosis. In conclusion, SOAT1 and CE may serve as potential biomarkers for prognosis and target-specific treatment of EC.

Association of Membranous WNT-1 and Nuclear mTOR with Endometrial Cancer Grade

Endometrial cancer remains a common cancer affecting the female reproductive system. There is still a need for more efficient ways of determining the degree of malignancy and optimizing treatment. WNT and mTOR are components of signaling pathways within tumor cells, and dysfunction of either protein is associated with the pathogenesis of neoplasms. Therefore, the aim of our study was to assess the impact of subcellular WNT-1 and mTOR levels on the clinical course of endometrial cancer. WNT-1 and mTOR levels in the plasma membrane, nucleus, and cytoplasm were evaluated using immunohistochemical staining in a group of 64 patients with endometrial cancer of grades 1-3 and FIGO stages I-IV. We discovered that the levels of WNT-1 and mTOR expression in the cellular compartments were associated with tumor grade and staging. Membranous WNT-1 was negatively associated, whereas cytoplasmic WNT-1 and nuclear mTOR were positively associated with higher grading of endometrial cancer. Furthermore, nuclear mTOR was positively associated with FIGO stages IB-IV. To conclude, we found that the assessment of WNT-1 in the cell membrane may be useful for exclusion of grade 3 neoplasms, whereas cytoplasmic WNT-1 and nuclear mTOR may be used as indicators for confirmation of grade 3 neoplasms.

Combination CDC-like kinase inhibition (CLK)/Dual-specificity tyrosine-regulated kinase (DYRK) and taxane therapy in CTNNB1-mutated endometrial cancer

SM08502 (cirtuvivint) is a novel pan CDC-like kinase (CLK) and Dual specificity tyrosine kinase (DYRK) inhibitor that targets mRNA splicing and is optimized for Wnt pathway inhibition. Previous evaluation of single agent CLK/DYRK inhibition (SM04690) demonstrated inhibition of tumor progression and β-catenin/TCF transcriptional activity in CTNNB1-mutant endometrial cancer (EC). In-vitro analysis of SM08502 similarly decreases Wnt transcriptional activity and cellular proliferation while increasing cellular apoptosis. SM08502 is an active single-agent therapy with IC50's in the nanomolar range for all EC cell lines evaluated. Combination of SM08502 with paclitaxel has synergistic effect in vitro, as demonstrated by Combination Index <1, and inhibits tumor progression in four endometrial cancer models (HEC265, Ishikawa, Ishikawa-S33Y, and SNGM). In our in vivo mouse models, Ishikawa demonstrated significantly lower tumor volumes of combination vs SM08502 alone (Repeated Measures one-way ANOVA, p = 0.04), but not vs paclitaxel alone. HEC265, SNGM, and Ishikawa-S33Y tumors all had significantly lower tumor volumes with combination SM08502 and paclitaxel compared to single-agent paclitaxel (Repeated Measures one-way ANOVA, p = 0.01, 0.004, and 0.0008, respectively) or single-agent SM08502 (Repeated Measures one-way ANOVA, p = 0.002, 0.005, and 0.01, respectively) alone. Mechanistically, treatment with SM08502 increases alternative splicing (AS) events compared to treatment with paclitaxel. AS regulation is an important post-transcriptional mechanism associated with the oncogenic process in many cancers, including EC. Results from these studies have led to a Phase I evaluation of this combination in recurrent EC.

The association of Wnt-signalling and EMT markers with clinical characteristics in women with endometrial cancer

Endometrial cancer is the most common gynecologic malignancy in the developed world. Risk stratification and treatment approaches are changing due to better understanding of tumor biology. Upregulated Wnt signaling plays an important role in cancer initiation and progression with promising potential for development of specific Wnt inhibitor therapy. One of the ways in which Wnt signaling contributes to progression of cancer, is by activating epithelial-to-mesenchymal transition (EMT) in tumor cells, causing the expression of mesenchymal markers, and enabling tumor cells to dissociate and migrate. This study analyzed the expression of Wnt signaling and EMT markers in endometrial cancer. Wnt signaling and EMT markers were significantly correlated with hormone receptors status in EC, but not with other clinico-pathological characteristics. Expression of Wnt antagonist, Dkk1 was significantly different between the ESGO-ESTRO-ESP patient risk assessment categories using integrated molecular risk assessment.

Clinicopathologic Evaluation of CTNNB1 Mutations in High-Intermediate Risk Endometrial Endometrioid Carcinoma

CTNNB1 mutations convey increased risk of recurrence in low-risk endometrial endometrioid carcinoma (EEC). Results from previous high-intermediate risk (HIR) cohorts are mixed. The aims of this study were to correlate CTNNB1 mutational status with clinical outcomes and to evaluate the relationship between CTNNB1 mutations and the 4 prognostic subgroups defined by The Cancer Genome Atlas in HIR EEC. CTNNB1 mutational status was determined by Sanger sequencing of exon 3 of the CTNNB1 gene. Mismatch repair, POLE , p53, and L1 cell-adhesion molecule (L1CAM) status were also evaluated. Descriptive statistics and survival analyses were performed. Eighty-eight cases of HIR EEC were identified, of which 22 (25%) were CTNNB1 mutant ( CTNNB1 -mut) and 66 (75%) were wild-type ( CTNNB1 -WT). Median follow-up was 60 mo. Recurrence occurred in 13/88 (15%) patients. Recurrence rates were not significantly different between patients with CTNNB1- mut and CTNNB1- WT tumors (14% vs. 15%, P =0.86). Recurrence-free survival and overall survival were not significantly different (recurrence-free survival hazard ratio: 0.97, 95% confidence interval: 0.27-3.52, P =0.96; overall survival hazard ratio: 0.23, 95% confidence interval: 0.03-1.71, P =0.15). Mismatch repair deficiency was more prevalent in CTNNB1 -WT compared with CTNNB1 -mut tumors (46% vs. 14%, P =0.01); prevalence of POLE mutations and aberrant p53 were not significantly different. In contrast to patients with low-risk EEC, no differences in recurrence or survival were found in patients with HIR EEC with CTNNB1- mut compared with CTNNB1 -WT tumors.

miR-219-5p attenuates cisplatin resistance of ovarian cancer by inactivating Wnt/β-catenin signaling and autophagy via targeting HMGA2

Our previous study confirmed that miR-219-5p inhibits the progression of ovarian cancer (OC) by targeting high mobility group AT-hook 2 (HMGA2), while the role of miR-219-5p on the chemoresistance of OC is unclear. HMGA2 and miR-219-5p expression in OC tumors and various types of OC cells were determined by reverse transcription-quantitative PCR (RT-qPCR) and western blotting. The miRNA profiles in A2780 and cisplatin-resistant A2780 cells were investigated via bulk miRNA sequencing, and the interactions of miR-219-5p and HMGA2 were determined by luciferase reporter activity assay. Cell function was verified through Cell Counting Kit-8, invasion assay, wound-healing, and TUNEL assays. HMGA2 level is highly expressed in cisplatin-resistant OC cell lines compared to normal OC cells, while the expression trend of miR-219-5p is the opposite. In addition, we found that miR-219-5p is one of the miRNAs that have the most significant reduction in levels in the cisplatin-resistant A2780/DDP cell line compared to A2780 cells. Then, we reveal that miR-219-5p directly targets HMGA2 in cisplatin-resistant OC cells, and upregulation of miR-219-5p significantly reduces the resistance of OC cells to cisplatin both in vitro and in vivo. Finally, our results suggest that Wnt/β-catenin signaling and autophagy pathway is involved in the role of miR-219-5p/HMGA2 on resistance of OC cells to cisplatin via gain-of-function experiments. Collectively, the present study shows that miR-219-5p decreases the resistance of OC cells to cisplatin via Wnt/β-catenin signaling and autophagy by regulating HMGA2, which provides a feasible solution for the resistance of OC to chemotherapy.

6-Bromoindirubin-3′-Oxime Regulates Colony Formation, Apoptosis, and Odonto/Osteogenic Differentiation in Human Dental Pulp Stem Cells

6-bromoindirubin-3′-oxime (BIO) is a candidate small molecule that effectively modulates Wnt signalling owing to its stable property. The present study investigated the influence of BIO on the odonto/osteogenic differentiation of human dental pulp stem cells (hDPSCs). hDPSCs were treated with 200, 400, or 800 nM BIO, and the effects on hDPSC responses and osteogenic differentiation were assessed. BIO-mediated Wnt activation was confirmed by β-catenin nuclear translocation detected by immunofluorescence staining. BIO attenuated colony formation and cell migration determined by in vitro wound-healing assay. BIO increased early apoptotic cell population evaluated using flow cytometry. For osteogenic induction, BIO promoted alkaline phosphatase (ALP) activity and mineralisation in a dose-dependent manner. ALP, RUNX2, OCN, OSX, ANKH, DMP1, and DSPP mRNA expression were significantly upregulated. The OPG/RANKL expression ratio was also increased. Further, BIO attenuated adipogenic differentiation as demonstrated by decreased lipid accumulation and adipogenic-related gene expression. Bioinformatic analysis of RNA sequencing data from the BIO-treated hDPSCs revealed that BIO modulated pathways related to autophagy and actin cytoskeleton regulation. These findings demonstrated that BIO treatment promoted hDPSC osteogenic differentiation. Therefore, this small molecule is a strong candidate as a bioactive molecule to enhance dentin repair.

The roles and therapeutic applications of cytokines in endometrial cancer

Endometrial cancer (EC) is a common gynecological cancer globally and the most frequent gynecologic malignancy in industrialized countries. Patients are typically diagnosed when the disease is still restricted to the uterus. 5-year overall survival ranges from 70 % to 90 % in patients without metastatic disease; however, the metastatic form of the disease affects 16 % of EC patients, with a 5-year survival rate of 16.8 %. The immune system can detect abnormal cells as non-self in the early stages of carcinogenesis, producing the appropriate pro-inflammatory environment to eliminate cancer cells. In a second phase, cancer cells use various immune-editing systems to alter the profile of the immune response from pro to anti-inflammatory, resulting in immune escape. The directors of this immune switching mechanism are cytokines. Studies have reported the increased expression of several pro-and anti-inflammatory cytokines in EC tissues and cell lines, including Interleukin (IL)- 6, IL-8, IL-31, IL-33, IL-10, TGF-β, VEGF, and IL-1Ra. Immune cells producing these cytokines have also been reported to be present in EC tissues. Therefore, in this study, we aimed to show the possible mechanisms of the mentioned cytokines on EC progression, as well as the most current and prospective advancements in cytokine-based therapeutic applications.

FBXO17 Inhibits the Wnt/β-Catenin Pathway and Proliferation of Ishikawa Cells

Uterine corpus endometrial carcinoma (UCEC) is one of the most common types of cancer in women, and the incidence is rapidly increasing. Studies have shown that various signaling pathways serve crucial roles in the tumorigenesis of UCEC, amongst which the Wnt/β-catenin pathway is of great interest due to its crucial role in cell proliferation and the huge potential as a therapeutic target. In the present study, it was shown that FBXO17, which is a member of the F-box family, is abnormally downregulated in UCEC tissues compared with non-tumor endometrial tissues, and this was significantly associated with the clinical histological grade, as well as the abnormal proliferation of the UCEC cell line, Ishikawa, both in vitro and in vivo. Besides, the results suggested that FBXO17 may inhibit the Wnt/β-catenin signaling pathway and influence the expression of adhesion molecules, such as E-cadherin and N-cadherin in Ishikawa cells. In conclusion, these findings indicate that FBXO17 is a novel inhibitor of endometrial tumor development and it likely exerts effects via regulation of the Wnt signaling pathway.

Tumor relevant protein functional interactions identified using bipartite graph analyses

An increased surge of -omics data for the diseases such as cancer allows for deriving insights into the affiliated protein interactions. We used bipartite network principles to build protein functional associations of the differentially regulated genes in 18 cancer types. This approach allowed us to combine expression data to functional associations in many cancers simultaneously. Further, graph centrality measures suggested the importance of upregulated genes such as BIRC5, UBE2C, BUB1B, KIF20A and PTH1R in cancer. Pathway analysis of the high centrality network nodes suggested the importance of the upregulation of cell cycle and replication associated proteins in cancer. Some of the downregulated high centrality proteins include actins, myosins and ATPase subunits. Among the transcription factors, mini-chromosome maintenance proteins (MCMs) and E2F family proteins appeared prominently in regulating many differentially regulated genes. The projected unipartite networks of the up and downregulated genes were comprised of 37,411 and 41,756 interactions, respectively. The conclusions obtained by collating these interactions revealed pan-cancer as well as subtype specific protein complexes and clusters. Therefore, we demonstrate that incorporating expression data from multiple cancers into bipartite graphs validates existing cancer associated mechanisms as well as directs to novel interactions and pathways.

Identification of the prognostic value of a 2-gene signature of the WNT gene family in UCEC using bioinformatics and real-world data

Background

The WNT gene family plays an important role in the occurrence and development of malignant tumors, but its involvement has not been systematically analyzed in uterine corpus endometrial carcinoma (UCEC). This study aimed to evaluate the prognostic value of the WNT gene family in UCEC.

Methods

Pan-cancer transcriptome data of the UCSC Xena database and Genotype-Tissue Expression (GTEx) normal tissue data were downloaded to analyze the expression and prognosis of 19 WNT family genes in UCEC. A cohort from The Cancer Genome Atlas-Uterine Corpus Endometrial Carcinoma (TCGA-UCEC) was used to analyze the expression of the WNT gene family in different immune subtypes and clinical subgroups. The STRING database was used to analyze the interaction of the WNT gene family and its biological function. Univariate Cox regression analysis and Lasso cox analysis were used to identify the genes associated with significant prognosis and to construct multi signature prognosis model. An immunohistochemical assay was used to verify the predictive ability of the model. Risk score and the related clinical features were used to construct a nomogram.

Results

The expression levels of WNT2, WNT3, WNT3A, WNT5A, WNT7A, and WNT10A were significantly different among different immune subtypes and correlated with TP53 mutation. According to the WNT family genes related to the prognosis of UCEC, UCEC was classified into two subtypes (C1, C2). The prognosis of subtype C1 was significantly better than that of subtype C2. A 2-gene signature (WNT2 and WNT10A) was constructed and the two significantly prognostic groups can be divided based on median Risk score. These results were verified using real-world data, and the nomogram constructed using clinical features and Risk score had good prognostic ability.

Conclusions

The 2-gene signature including WNT2 and WNT10A can be used to predict the prognosis of patients with UCEC, which is important for clinical decision-making and individualized therapy for patients with UCEC.

Systematic Next Generation Sequencing is feasible in clinical practice and identifies opportunities for targeted therapy in women with uterine cancer: Results from a prospective cohort study

BACKGROUND

Both incidence and mortality of uterine cancer are on the rise and mortality is higher for African American women. The aim of our study was to evaluate how Next Generation Sequencing (NGS) may facilitate identification of and intervention for treatment disparities when integrated into clinical workflows.

RESULTS

Our cohort included 159 uterine cancer patients with recurrent/progressive and newly diagnosed advanced stage and/or high-risk histology. The most common tumor histological subtypes included EEC (n = 67), SEC (n = 34), UCS (n = 20), and mixed (n = 14). Black patients were most likely to present with aggressive histology: (SEC, 34.0%) and carcinosarcoma (UCS, 14.0%). The four most common mutations across all subtypes were TP53, PIK3CA, PTEN, and ARID1A. There was racial disparity between Black versus non-Black patients who were initiated on targeted therapy (28.2% vs. 38.2%, respectively) and clinical trial (15% vs. 22.6%, respectively). Compared to non-Black patients, Black patients had a significantly higher percentage TP53 mutations (p < 0.05) and a significantly lower percentage ARID1A mutations (p < 0.05).

CONCLUSIONS

NGS for uterine malignancies provides actionable information for targetable mutations and/or clinical trial enrollment in most patients; further investigation is necessary to identify potentially modifiable factors contributing to current disparities that may improve targeted therapy uptake and clinical trial participation.

Inhibiting Wnt/beta-catenin in CTNNB1-mutated endometrial cancer

The role of β-catenin/TCF transcriptional activity in endometrial cancer (EC) recurrence is not well understood. We assessed the impact of Wnt/β-catenin inhibition in EC models. In an analysis of the Cancer Genome Atlas, we confirmed that CTNNB1 mutations are enriched in recurrent low-risk EC and showed that aberrant Wnt/β-catenin pathway activation is associated with recurrence. We studied CTNNB1-wildtype (HEC1B, Ishikawa) and CTNNB1-mutant (HEC108, HEC265, HEC1B-S33Y, Ishikawa-S33Y) EC cell lines. Dose response curves were determined for 5 Wnt/β-catenin pathway inhibitors (Wnt-C59, XAV-939, PyrPam, PRI-724, SM04690). XAV939, Wnt-C59 and PyrPam inhibited function upstream of β-catenin transcriptional activity and were ineffective at inhibiting cell viability. In contrast, PRI724 and SM04690 indirectly inhibited β-catenin transcriptional activity and significantly reduced cell viability in CTNNB1-mutant cell lines. Treatment with SM04690 reduced cell viability (Licor Cell stain) in all EC cell lines, but viability was significantly lower in CTNNB1-mutant cell lines (p < 0.01). Mechanistically, SM04690 significantly inhibited proliferation measured via 5'-bromo-2'-deoxyuridine incorporation and reduced T cell factor (TCF) transcriptional activity. HEC1B, HEC1B-S33Y and HEC265 tumor-bearing mice were treated with vehicle or SM04690. Tumors treated with SM04690 had smaller mean volumes than those treated with vehicle (p < 0.001, p = 0.014, p = 0.06). In HEC1B-S33Y and HEC265 tumors, SM04690 treatment significantly reduced Ki67 H-scores compared to vehicle (p = 0.035, p = 0.024). Targeting the Wnt/β-catenin pathway in CTNNB1-mutant EC effectively inhibited proliferation and β-catenin/TCF transcriptional activity and blunted tumor progression in in vivo models. These studies suggest β-catenin transcriptional inhibitors are effective in EC and particularly in CTNNB1-mutant EC, highlighting a potential therapeutic vulnerability for treatment of CTNNB1-mutant EC.

Targeting Wnt Signaling in Endometrial Cancer

Simple Summary

Wnt has diverse regulatory roles at multiple cellular levels and numerous targeting points, and aberrant Wnt signaling has crucial roles in carcinogenesis, metastasis, cancer recurrence, and chemotherapy resistance; based on these facts, Wnt represents an appealing therapeutic target for cancer treatment. Although preclinical data supports a role for the Wnt signaling pathway in uterine carcinogenesis, this area remains understudied. In this review, we identify the functions of several oncogenes of the Wnt/β-catenin signaling pathway in tumorigenesis and address the translation approach with potent Wnt inhibitors that have already been established or are being investigated to target key components of the pathway. Further research is likely to expand the potential for both biomarker and cancer drug development. There is a scarcity of treatment choices for advanced and recurrent endometrial cancer; investigating the sophisticated connections of Wnt signaling networks in endometrial cancer could address the unmet need for new therapeutic targets.

Abstract

This review presents new findings on Wnt signaling in endometrial carcinoma and implications for possible future treatments. The Wnt proteins are essential mediators in cell signaling during vertebrate embryo development. Recent biochemical and genetic studies have provided significant insight into Wnt signaling, in particular in cell cycle regulation, inflammation, and cancer. The role of Wnt signaling is well established in gastrointestinal and breast cancers, but its function in gynecologic cancers, especially in endometrial cancers, has not been well elucidated. Development of a subset of endometrial carcinomas has been attributed to activation of the APC/β-catenin signaling pathway (due to β-catenin mutations) and downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway also appears to be linked to estrogen and progesterone, and new findings implicate it in mTOR and Hedgehog signaling. Therapeutic interference of Wnt signaling remains a significant challenge. Herein, we discuss the Wnt-activating mechanisms in endometrial cancer and review the current advances and challenges in drug discovery.

Nuclear Beta-Catenin Expression in Endometrioid Intraepithelial Neoplasia (Atypical Hyperplasia) Does Not Predict Carcinoma on Subsequent Hysterectomy

Beta-catenin (BC) mutations are associated with a high risk of recurrence in otherwise low-grade, early-stage uterine endometrioid adenocarcinomas. Recent literature suggests nuclear BC expression by immunohistochemistry is highly sensitive and specific for BC mutations. The significance of BC expression in endometrioid intraepithelial neoplasia (EIN/atypical hyperplasia) and its relationship to altered differentiation patterns in EIN has yet to be fully explored. Cases meeting current diagnostic criteria for EIN based on H&E examination were obtained from 2 institutions (years 1999-2014). Patterns of altered differentiation (eg, tubal, squamous morular metaplasia, mucinous, secretory) were noted. Representative blocks were stained for BC, and expression patterns recorded. Follow-up and demographic data was obtained from the electronic medical record. Ninety-six cases were included (84 biopsies, 12 hysterectomies). BC nuclear expression was identified in 41 cases (42.7%), with 33 of 41 demonstrating foci of nonmorular BC staining. BC staining in any component of EIN was not significantly associated with the presence of carcinoma on subsequent hysterectomy (P=0.79). When restricting to nonmorular BC, the results were the same (P=0.56). Cases with tubal differentiation were significantly less likely to demonstrate nonmorular BC than cases with no specific pattern of differentiation (P<0.01). EIN frequently demonstrates BC nuclear positivity, especially in cases without tubal differentiation. BC nuclear expression in EIN does not appear to be associated with an increased likelihood of carcinoma on subsequent hysterectomy. Our results do not support routine use of BC immunohistochemistry as a prognostic biomarker in cases of EIN.

Efficacy of the LNG-IUS for treatment of endometrial hyperplasia and early stage endometrial cancer: Can biomarkers predict response?

Endometrial Cancer (EC) is the most common gynaecologic malignancy in the developed world, and is increasing in premenopausal women. The surgical standard of care for early-stage EC is not possible in women with concurrent comorbidities or women who desire a fertility sparing approach. The Levonorgestrel Intrauterine System (LNG-IUS) is gaining traction as an alternative treatment for endometrial hyperplasia and early stage EC in inoperable women. Whilst early evidence appears promising, predictive biomarkers need to be established to determine non-responders, which make up one in three women. This timely review discusses the current literature around the identification of clinical, molecular and novel biomarkers that show potential to predict response to progesterone treatment, including the LNG-IUS.

Wilms' Tumor 1-Associated Protein Contributes to Chemo-Resistance to Cisplatin Through the Wnt/β-Catenin Pathway in Endometrial Cancer

BACKGROUND

Cisplatin remains the mainstay of endometrial cancer (EC) chemotherapy. Wilms' tumor 1-associated protein (WTAP), playing a critical role in transcriptional and post-transcriptional regulation, has been reported as an oncogene, and its expression is elevated in multiple types of human tumors. Recent evidence has shown that the increased expression of WTAP is also closely related to chemo-resistance. However, its specific role in the susceptibility of human EC cells to cisplatin remains largely unexplored.

METHODS

WTAP over-expression and WTAP depletion cell lines as well as their corresponding controls were constructed by transfection with lentivirus. Western blotting analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to detect the expression of WTAP. Cell proliferation assay, colony formation assay, cell cycle assay, and apoptosis analysis were adopted to evaluate the effect of WTAP on the chemo-sensitivity of EC cells to cisplatin as well as its underlying mechanism. Immunofluorescence staining was used to assess the translocation of β-catenin. Moreover, a subcutaneous xenograft tumor model was established to assess the effect of WTAP on tumor growth after cisplatin treatment.

RESULTS

Depletion of WTAP in RL95-2 cells significantly enhanced the chemo-susceptibility of cells to cisplatin and increased the cell apoptosis, while WTAP over-expression in ARK-2 cells exhibited the opposite effects. Additionally, WTAP depletion significantly suppressed xenograft-tumor growth and enhanced sensitivity and apoptosis of tumor cells in vivo. Mechanistic analysis exhibited that WTAP over-expression facilitated the cytoplasm-to-nucleus translocation of β-catenin and enhanced the GSK3β phosphorylation at Ser9, while WTAP depletion revealed the opposite results, indicating that WTAP rendered chemo-resistance of EC cells to cisplatin by promoting the Wnt/β-catenin pathway.

CONCLUSIONS

WTAP might promote the chemo-resistance of EC cells to cisplatin through activating the Wnt/β-catenin pathway. Collectively, our findings offered novel insights into EC treatment.

MicroRNA-202 inhibits cell migration and invasion through targeting FGF2 and inactivating Wnt/β-catenin signaling in endometrial carcinoma

Recently, many mircroRNAs (miRNAs) involved in the development and progression of cancer have been reported to regulate cell growth and metastasis, including microRNA-202 (miR-202). The purpose of the present study was to elucidate the effect of miR-202 on endometrial carcinoma (EC) cell migration and invasion. First, qRT-PCR showed that miR-202 was down-regulated in EC tissues, which was associated with poor prognosis in EC patients. Functionally, transwell assay indicated that miR-202 inhibited cell migration and invasion in EC cells. In addition, miR-202 also blocked epithelial-mesenchymal transition (EMT) through suppressing N-cadherin and Vimentin expressions and promoting E-cadherin expression. Moreover, the dual-luciferase reporter assay showed that fibroblast growth factor 2 (FGF2) is a direct target gene for miR-202 in EC cells. Furthermore, up-regulation of FGF2 attenuated the inhibitory effect of miR-202 on cell migration and invasion in EC. Besides that, miR-202 inactivated the Wnt/β-catenin signaling by suppressing β-catenin expression in EC. In conclusion, miR-202 inhibited cell migration and invasion by targeting FGF2 and inactivating the Wnt/β-catenin signaling in EC.

Wnt Signaling in Gynecologic Malignancies

Gynecologic malignancies, including ovarian cancer, endometrial cancer, and cervical cancer, affect hundreds of thousands of women worldwide every year. Wnt signaling, specifically Wnt/β-catenin signaling, has been found to play an essential role in many oncogenic processes in gynecologic malignancies, including tumorigenesis, metastasis, recurrence, and chemotherapy resistance. As such, the Wnt/β-catenin signaling pathway has the potential to be a target for effective treatment, improving patient outcomes. In this review, we discuss the evidence supporting the importance of the Wnt signaling pathways in the development, progression, and treatment of gynecologic malignancies.

Novel miRNA markers for the diagnosis and prognosis of endometrial cancer

As endometrial cancer (EC) is a major threat to female health worldwide, the ability to provide an accurate diagnosis and prognosis of EC is promising to improve its treatment guidance. Since the discovery of miRNAs, it has been realized that miRNAs are associated with every cell function, including malignant transformation and metastasis. This study aimed to explore diagnostic and prognostic miRNA markers of EC. In this study, differential analysis and machine learning were performed, followed by correlation analysis of miRNA-mRNA based on the miRNA and mRNA expression data. Nine miRNAs were identified as diagnostic markers, and a diagnostic classifier was established to distinguish between EC and normal endometrium tissue with overall correct rates >95%. Five specific prognostic miRNA markers were selected to construct a prognostic model, which was confirmed more effective in identifying EC patients at high risk of mortality compared with the FIGO staging system. This study demonstrates that the expression patterns of miRNAs may hold promise for becoming diagnostic and prognostic biomarkers and novel therapeutic targets for EC.

Development of prediction models for lymph node metastasis in endometrioid endometrial carcinoma

BACKGROUND

In endometrioid endometrial cancer (EEC), current clinical algorithms do not accurately predict patients with lymph node metastasis (LNM), leading to both under- and over-treatment. We aimed to develop models that integrate protein data with clinical information to identify patients requiring more aggressive surgery, including lymphadenectomy.

METHODS

Protein expression profiles were generated for 399 patients using reverse-phase protein array. Three generalised linear models were built on proteins and clinical information (model 1), also with magnetic resonance imaging included (model 2), and on proteins only (model 3), using a training set, and tested in independent sets. Gene expression data from the tumours were used for confirmatory testing.

RESULTS

LNM was predicted with area under the curve 0.72-0.89 and cyclin D1; fibronectin and grade were identified as important markers. High levels of fibronectin and cyclin D1 were associated with poor survival (p = 0.018), and with markers of tumour aggressiveness. Upregulation of both FN1 and CCND1 messenger RNA was related to cancer invasion and mesenchymal phenotype.

CONCLUSIONS

We demonstrate that data-driven prediction models, adding protein markers to clinical information, have potential to significantly improve preoperative identification of patients with LNM in EEC.

Cyclooxygenase-2 and β-Catenin as Potential Diagnostic and Prognostic Markers in Endometrial Cancer

Objectives: Explore the diagnostic and prognostic value of cyclooxygenase-2 and wnt3a/β-catenin pathway in endometrial cancer.

Methods: A prospective cohort study of 93 women underwent hysterectomy at the China-Japan Friendship Hospital (61 patients with primary endometrial carcinoma, and 32 control patients with uterine prolapse or leiomyoma of uterus). Cox2 and β-catenin expression were determined by immunohistochemistry. The serum levels of cox2 and wnt3a were detected via ELISA assays.

Results: Patients with endometrial cancer showed overexpression of cox2 and β-catenin, as well as significantly higher serum levels of cox2 and wnt3a. The serum cox2 level, which is highly significant in predicting the risk of disease progression (RR, 9.617, 95% confidence interval, 1.162–79.622, P = 0.036), showed good diagnostic and prognostic potential, with cut-off of 55 U/L, but alongside β-catenin expression in tissues, were related to poor prognosis (RR, 12.426; 95% confidence interval, 1.618–95.450; P = 0.015).

Conclusion: Serum levels of cox2 and wnt3a exhibited diagnostic value for endometrial cancer. Cox2 serum levels and β-catenin expression also showed potential value of prognostic prediction. Cox2 serum levels might be a potential marker for early diagnosis and prognosis prediction in endometrial cancer.

CARLo-5 as an oncogenic gene in endometrial carcinoma

The long noncoding RNA CARLo-5 is dysregulated in multiple types of human cancers. High CARLo-5 is a promising predictive factor for various cancers, including endometrial carcinoma (EC). Our previous study showed that the expression level of CARLo-5 was associated with advanced FIGO stage (The International Federation of Gynecology and Obstetrics), lymph node metastasis, and the poor survival of patients with EC. In the present study, we demonstrated that the downregulation of CARLo-5 could affect the proliferation, cell cycle, migration, and invasion of EC cell lines HEC-1B and KLE cells. The oncogenic activity of CARLo-5 was also confirmed with in vivo data. Mechanistically, CARLo-5 could affect the expression of CDK/CDKN1A and MMP2/9, which have been reported to be regulated by CARLo-5 and associated with cell cycle and motility. In conclusion, this study is the first to discover the biological function and mechanism of CARLo-5 in regulating the biological characteristics of EC cells. Targeting CARLo-5 and its pathway might provide new biomarkers or potential therapies target for patients with EC. Environ. Mol. Mutagen. 61:256-265, 2020. © 2019 Wiley Periodicals, Inc.

Changes in the expression of Notch and Wnt signalling molecules in human endometrial cancer

Background

Endometrial cancer is the  sixth most frequent type of cancer among women worldwide. Type  I adenocarcinomas account for 80-85% of endometrial cancer cases and sometimes require more aggressive treatment than the remaining part of this group. Therefore, molecular markers to stratify adenocarcinomas are needed.

Materials and methods

In this study, we analysed Notch and Wnt signalling in human endometrial cancer cases to evaluate these pathway elements as potential biomarkers for type  I endometrial cancer. Endometrial samples were obtained from 47 women undergoing surgery for stage I-IV endometrial cancer in the National Cancer Institute (Vilnius, Lithuania) in 2015-2016. The expression at the mRNA level of signalling molecules genes (NOTCH1, NOTCH2, NOTCH3, NOTCH4, JAG1, JAG2, DLL1, HES1, AXIN2 and CTNNB1) was analysed by the quantitative real-time polymerase chain reaction. Relative expression of NOTCH1, NOTCH4, HES1 and β-catenin proteins in endometrioid adenocarcinoma was evaluated by the Western blot method.

Results

The  expression level of Notch receptors, ligands, and the target gene, as well as CTNNB1 and AXIN2, was reduced in stage I endometrioid adenocarcinoma if compared to the adjacent non-tumour tissue. The expression of all receptors, ligands, and target molecules was reduced in adenocarcinomas of later stages. The statistically significant correlations between transcript amounts of Notch receptors and ligands were found. There was a statistically significant difference in the  gene expression of Notch signalling pathway components between different tumour differentiation grade samples. A positive correlation between mRNA and protein the expression level of NOTCH1, NOTCH4, HES1 was determined in stage I samples.

Conclusions

Analysis of 47 human endometrial cancer samples revealeda reduction in the transcript levels of Notch and Wnt signalling molecule compared to the adjacent non-tumour tissue. These results suggest tumour suppressor function of Notch and Wnt signalling in human endometrial cancer. More detailed research on these signalling pathways should reveal their importance as potential biomarkers.

Pharmacogenomic analysis of patient-derived tumor cells in gynecologic cancers

Background

Gynecologic malignancy is one of the leading causes of mortality in female adults worldwide. Comprehensive genomic analysis has revealed a list of molecular aberrations that are essential to tumorigenesis, progression, and metastasis of gynecologic tumors. However, targeting such alterations has frequently led to treatment failures due to underlying genomic complexity and simultaneous activation of various tumor cell survival pathway molecules. A compilation of molecular characterization of tumors with pharmacological drug response is the next step toward clinical application of patient-tailored treatment regimens.

Results

Toward this goal, we establish a library of 139 gynecologic tumors including epithelial ovarian cancers (EOCs), cervical, endometrial tumors, and uterine sarcomas that are genomically and/or pharmacologically annotated and explore dynamic pharmacogenomic associations against 37 molecularly targeted drugs. We discover lineage-specific drug sensitivities based on subcategorization of gynecologic tumors and identify TP53 mutation as a molecular determinant that elicits therapeutic response to poly (ADP-Ribose) polymerase (PARP) inhibitor. We further identify transcriptome expression of inhibitor of DNA biding 2 (ID2) as a potential predictive biomarker for treatment response to olaparib.

Conclusions

Together, our results demonstrate the potential utility of rapid drug screening combined with genomic profiling for precision treatment of gynecologic cancers.

Knockdown of estrogen receptor β increases proliferation and affects the transcriptome of endometrial adenocarcinoma cells

Background

Estrogen receptor β (ERβ) has been repeatedly suggested to play important roles in hormone-dependent cancer like in tumors of the breast, ovary or prostate. In this study, we intended to further elucidate its role in endometrial cancer.

Methods

For this purpose, we knocked down ERβ expression in two endometrial cancer cell lines, the ERα-negative/ERβ-positive line HEC-1A and the ERα/β-positive cell line RL95/2, by means of siRNA transfection. Cell proliferation after transfection was assessed using the fluorescent CTB Assay (Promega). In order to elucidate possible molecular mechanisms which might underlie the effect on proliferation, we performed transcriptome analyses by means of human Affymetrix Human Gene Chip 2.0. Additionally, we treated the employed cell lines with different ERβ modulators to examine their effect on proliferation.

Results

siRNA-mediated knockdown of ERβ significantly increased proliferation of both endometrial cancer cell lines. In HEC-1A cells, proliferation was significantly increased 4, 5 and 6 days after transfection, with a maximum of about 1.7-fold (p < 0.05) on day 6. Endometrial RL95/2 cells with an ERβ knockdown exhibited a clearly enhanced proliferation on day 3 and days 4 to 8, when even 2.4-fold higher numbers of viable cells were detected (p < 0.01). Transcriptome analysis revealed that this was accompanied by increased expression of several genes being known to be upregulated in cancer, including proliferation-associated genes and oncogenes, and by repression of genes associated with differentiation, apoptosis or growth inhibition. Corroborating the observed knockdown effects, treatment with the ERβ antagonists PHTTP and (R, R) THC was also able to induce proliferation of both cell lines.

Conclusions

Our data clearly support the putative role of ERβ as tumor suppressor in endometrium as previously suggested in studies on other tissues and encourage further studies to find out to what extent this molecule might be a potential therapy target in this cancer entity.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5928-2) contains supplementary material, which is available to authorized users.

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.

MicroRNA-142-3p/MALAT1 inhibits lung cancer progression through repressing β-catenin expression

MALAT1 is well documented to be highly expressed in non-small cell lung cancer (NSCLC) and its overexpression closely associates the malignant phenotype of NSCLC cells and poor prognosis of NSCLC patients. MALAT1 is also identified to enhance β-catenin expression and under the negative regulation of miR-142-3p. However, the role of miR-142-3p/MALAT1/β-catenin in the occurrence and development of NSCLC remains unclear. The objective of this study was to explore it. The results showed that miR-142-3p expression was reduced in NSCLC tissues, while β-catenin and MALAT1 expression levels were elevated. MTT, transwell chamber, flow cytometry assays demonstrated that up-regulation of miR-142-3p with mimic transfection significantly inhibited the proliferation, migration and promoted the apoptosis of NSCLC H1299 cells, and induced a G0/G1 phase arrest and S phase reduction. Besides, miR-142-3p negatively decreased MALAT1 expression as detected by RT-PCR and luciferase reporter assays. Moreover, up-regulation of miR-142-3p decreased β-catenin expression through down-regulating MALAT1 in H1299 cells. And in vivo experiment showed that miR-142-3p up-regulation, as well as the knockdown of either β-catenin or MALAT1 significantly reduced the tumorigenesis of NSCLC cells. Taken together, our study makes clear that miR-142-3p functions as a tumor suppressor in NSCLC progression through inhibiting MALAT1/β-catenin signaling.

Epithelial to Mesenchymal Transition and Cell Biology of Molecular Regulation in Endometrial Carcinogenesis

Endometrial carcinogenesis is involved in several signaling pathways and it comprises multiple steps. The four major signaling pathways-PI3K/AKT, Ras/Raf/MEK/ERK, WNT/β-catenin, and vascular endothelial growth factor (VEGF)-are involved in tumor cell metabolism, growth, proliferation, survival, and angiogenesis. The genetic mutation and germline mitochondrial DNA mutations also impair cell proliferation, anti-apoptosis signaling, and epithelial⁻mesenchymal transition by several transcription factors, leading to endometrial carcinogenesis and distant metastasis. The PI3K/AKT pathway activates the ransforming growth factor beta (TGF-β)-mediated endothelial-to-mesenchymal transition (EMT) and it interacts with downstream signals to upregulate EMT-associated factors. Estrogen and progesterone signaling in EMT also play key roles in the prognosis of endometrial carcinogenesis. In this review article, we summarize the current clinical and basic research efforts regarding the detailed molecular regulation in endometrial carcinogenesis, especially in EMT, to provide novel targets for further anti-carcinogenesis treatment.