Loss of polarity alters proliferation and differentiation in low-grade endometrial cancers by disrupting Notch signaling

Notch Signaling: An Emerging Paradigm in the Pathogenesis of Reproductive Disorders and Diverse Pathological Conditions

The highly conserved Notch pathway, a pillar of juxtacrine signaling, orchestrates intricate intercellular communication, governing diverse developmental and homeostatic processes through a tightly regulated cascade of proteolytic cleavages. This pathway, culminating in the migration of the Notch intracellular domain (NICD) to the nucleus and the subsequent activation of downstream target genes, exerts a profound influence on a plethora of molecular processes, including cell cycle progression, lineage specification, cell-cell adhesion, and fate determination. Accumulating evidence underscores the pivotal role of Notch dysregulation, encompassing both gain and loss-of-function mutations, in the pathogenesis of numerous human diseases. This review delves deep into the multifaceted roles of Notch signaling in cellular dynamics, encompassing proliferation, differentiation, polarity maintenance, epithelial-mesenchymal transition (EMT), tissue regeneration/remodeling, and its intricate interplay with other signaling pathways. We then focus on the emerging landscape of Notch aberrations in gynecological pathologies predisposing individuals to infertility. By highlighting the exquisite conservation of Notch signaling in Drosophila and its power as a model organism, we pave the way for further dissection of disease mechanisms and potential therapeutic interventions through targeted modulation of this master regulatory pathway.

The consistent anti-cancer effect of a simple exercise (Ou MC decrescendo phenomenon exercise) may hold promise for low-cost cancer prevention

The causal relationship between physical activity and anti-cancer effect are not proved by the current studies. However, Ou MC decrescendo phenomenon treatment (OuDPt), a simple exercise treatment, has shown consistent anti-cancer effects, which evinces the consequent anti-cancer effect by physical activity. The anti-cancer effects through OuDPt in the context of physical activity and human body anatomical axes showed to induce apoptosis, restore apical-basal polarity of cancer cells and mitigate epithelial-mesenchymal transition (EMT) with concomitant clinical regression of uterine endometrial cancer, suppression of ovarian and pancreatic cancer growth, regression of early suspicious pancreatic cancer, enhancement of chemotherapy effect of pancreatic cancer and cessation of cancer-related bleeding, which underlines the most important anti-cancer mechanisms. Although such anti-cancer effects by OuDPt show insufficient efficacy for advanced cancer in long-term treatment, OuDPt may be availed as an Ou MC decrescendo phenomenon exercise for cancer prevention. Further study is warranted.

Notch1 cortical signaling regulates epithelial architecture and cell-cell adhesion

Notch receptors control tissue morphogenic processes that involve coordinated changes in cell architecture and gene expression, but how a single receptor can produce these diverse biological outputs is unclear. Here, we employ a 3D model of a human ductal epithelium to reveal tissue morphogenic defects result from loss of Notch1, but not Notch1 transcriptional signaling. Instead, defects in duct morphogenesis are driven by dysregulated epithelial cell architecture and mitogenic signaling which result from the loss of a transcription-independent, Notch1 cortical signaling mechanism that ultimately functions to stabilize adherens junctions and cortical actin. We identify that Notch1 localization and cortical signaling are tied to apical-basal cell restructuring and discover that a Notch1-FAM83H interaction underlies control of epithelial adherens junctions and cortical actin. Together, these results offer new insights into Notch1 signaling and regulation and advance a paradigm in which transcriptional and cell adhesive programs might be coordinated by a single receptor.

Tripartite motif containing 33 demonstrated anticancer effect by degrading c‑Myc: Limitation of glutamine metabolism and proliferation in endometrial carcinoma cells

Tripartite motif containing 33 (TRIM33) has been reported to be involved in various tumor progression. However, its role in endometrial carcinoma (EC) remains to be elucidated. By mining the publicly available databases UALCAN and TIMER, low expression of TRIM33 was found in tumor tissues of EC patients. Clinically, downregulation of TRIM33 in EC tissues was positively correlated with the extensive muscle invasion and poor differentiation grade. In vitro, experiments performed on human HEC‑1‑A and AN3CA cells showed that overexpression of TRIM33 inhibited the proliferation, migration and invasion of EC cells, whereas TRIM33 knockdown resulted in the opposite results. Furthermore, upregulation of TRIM33 significantly inhibited the glutamine uptake and decreased the intracellular glutamate in EC cells, which is evidenced by the reduction of solute carrier family 1 member 5 and glutaminase. In vivo, TRIM33 also dramatically inhibited tumor growth and glutamine metabolism. Additionally, co‑immunoprecipitation assay confirmed the interaction between TRIM33 and c‑Myc. Overexpression of TRIM33 could reduce the protein stability of c‑Myc by promoting its degradation. In addition, upregulation of c‑Myc could reverse the effects of TRIM33 on EC cells. Together, the present study demonstrated that TRIM33 acted as a tumor suppressor in EC, which is manifested in its inhibition of glutamine metabolism and cell growth via promoting c‑Myc protein degradation.

Characterizing the extracellular matrix transcriptome of cervical, endometrial, and uterine cancers

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The matrisome plays a critical role in the progression of cancer, but the matrisomes of gynecological cancers have not been well characterized.

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We built an in silico analysis pipeline to analyze publicly available bulk RNA-seq datasets of cervical, endometrial, and uterine cancers.

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Using a machine learning approach, we identified genes and gene networks that held inferential significance for cancer stage and patient survival.

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Cervical, endometrial, and uterine cancers are highly distinct from one another and should be analyzed separately.

Increasingly, the matrisome, a set of proteins that form the core of the extracellular matrix (ECM) or are closely associated with it, has been demonstrated to play a key role in tumor progression. However, in the context of gynecological cancers, the matrisome has not been well characterized. A holistic, yet targeted, exploration of the tumor microenvironment is critical for better understanding the progression of gynecological cancers, identifying key biomarkers for cancer progression, establishing the role of gene expression in patient survival, and for assisting in the development of new targeted therapies. In this work, we explored the matrisome gene expression profiles of cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), uterine corpus endometrial carcinoma (UCEC), and uterine carcinosarcoma (UCS) using publicly available RNA-seq data from The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx) portal. We hypothesized that the matrisomal expression patterns of CESC, UCEC, and UCS would be highly distinct with respect to genes which are differentially expressed and hold inferential significance with respect to tumor progression, patient survival, or both. Through a combination of statistical and machine learning analysis techniques, we identified sets of genes and gene networks which characterized each of the gynecological cancer cohorts. Our findings demonstrate that the matrisome is critical for characterizing gynecological cancers and transcriptomic mechanisms of cancer progression and outcome. Furthermore, while the goal of pan-cancer transcriptional analyses is often to highlight the shared attributes of these cancer types, we demonstrate that they are highly distinct diseases which require separate analysis, modeling, and treatment approaches. In future studies, matrisome genes and gene ontology terms that were identified as holding inferential significance for cancer stage and patient survival can be evaluated as potential drug targets and incorporated into in vitro models of disease.

Dual Function of Par3 in Tumorigenesis

Cell maintenance and the establishment of cell polarity involve complicated interactions among multiple protein complexes as well as the regulation of different signaling pathways. As an important cell polarity protein, Par3 is evolutionarily conserved and involved in tight junction formation as well as tumorigenesis. In this review, we aimed to explore the function of Par3 in tumorigenesis. Research has shown that Par3 exhibits dual functions in human cancers, both tumor-promoting and tumor-suppressive. Here, we focus on the activities of Par3 in different stages and types of tumors, aiming to offer a new perspective on the molecular mechanisms that regulate the functions of Par3 in tumor development. Tumor origin, tumor microenvironment, tumor type, cell density, cell–cell contact, and the synergistic effect of Par3 and other tumor-associated signaling pathways may be important reasons for the dual function of Par3. The important role of Par3 in mammalian tumorigenesis and potential signaling pathways is context dependent.

Role of Leptin and Adiponectin in Endometrial Cancer

Endometrial cancer is the most common malignancy of the female genital tract. Obesity is a strong risk factor for endometrial cancer. Adipose tissue is an active endocrine organ that synthesizes biologically active cytokine peptides, called adipokines. Adiponectin and leptin are the main cytokines of adipose tissue, which may influence the development of metabolic diseases and carcinogenesis. In this scenario, we describe the role of leptin and adiponectin in the development of endometrial cancer. A better understanding of the signalling pathway of these cytokines in endometrial cancerogenesis will provide an opportunity for effective target therapy and may be usable in fertility-sparing treatment. In the future, clinical trials focusing on adipokines, molecular biology, and genetics of the tumour will be needed.

Ezrin Regulates the Cell Surface Localization of PD-L1 in HEC-151 Cells

Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule widely expressed on the surface of cancer cells and is an attractive immunotherapeutic target for numerous cancer cell types. However, patients with endometrial cancer derive little clinical benefit from immune checkpoint blockade therapy because of their poor response rate. Despite the increasingly important function of PD-L1 in tumor immunology, the mechanism of PD-L1 localization on endometrial cancer cell surfaces is largely unknown. We demonstrated the contribution of the ezrin, radixin, and moesin (ERM) family, which consists of scaffold proteins that control the cell surface localization of several transmembrane proteins to the localization of PD-L1 on the cell surface of HEC-151, a human uterine endometrial cancer cell line. Confocal immunofluorescence microscopy and immunoprecipitation analysis revealed the colocalization of all the ERM with PD-L1 on the cell surface, as well as their protein–protein interactions. The RNA-interference-mediated knockdown of ezrin, but not radixin and moesin, significantly reduced the cell surface expression of PD-L1, as measured by flow cytometry, with little impact on the PD-L1 mRNA expression. In conclusion, among the three ERM proteins present in HEC-151 cells, ezrin may execute the scaffold function for PD-L1 and may be mainly responsible for the cell surface localization of PD-L1, presumably via the post-translational modification process.

Emerging Cnidarian Models for the Study of Epithelial Polarity

Epithelial tissues are vital to the function of most organs, providing critical functions such as secretion, protection, and absorption. Cells within an epithelial layer must coordinate to create functionally distinct apical, lateral, and basal surfaces in order to maintain proper organ function and organism viability. This is accomplished through the careful targeting of polarity factors to their respective locations within the cell, as well as the strategic placement of post-mitotic cells within the epithelium during tissue morphogenesis. The process of establishing and maintaining epithelial tissue integrity is conserved across many species, as important polarity factors and spindle orientation mechanisms can be found in many phyla. However, most of the information gathered about these processes and players has been investigated in bilaterian organisms such as C. elegans, Drosophila, and vertebrate species. This review discusses the advances made in the field of epithelial polarity establishment from more basal organisms, and the advantages to utilizing these simpler models. An increasing number of cnidarian model organisms have been sequenced in recent years, such as Hydra vulgaris and Nematostella vectensis. It is now feasible to investigate how polarity is established and maintained in basal organisms to gain an understanding of the most basal requirements for epithelial tissue morphogenesis.

Components of NOTCH Signaling for Uterine Cancer Patients’ Prognosis

New molecular biomarkers that could have an independent prognostic value in endometrial cancer are currently under investigation. Recently, it was suggested that genetic changes in the Notch signaling pathway could be associated with the development of endometrial carcinoma. This study aimed to determine the expression of the Notch signaling pathway components in tumour and adjacent normal uterine tissue and to evaluate their importance for the survival of uterine cancer patients. The present study was performed on uterine body samples collected from 109 patients and paired adjacent noncancerous endometrial tissue samples. Kaplan–Meier curves and Cox regression were used for survival analyses. Expression alterations of NOTCH2, NOTCH3, NOTCH4, JAG2, and HES1 were evaluated as independent and significant prognostic factors for uterine cancer patients.

RasV12; scrib-/- Tumors: A Cooperative Oncogenesis Model Fueled by Tumor/Host Interactions

The phenomenon of how oncogenes and tumor-suppressor mutations can synergize to promote tumor fitness and cancer progression can be studied in relatively simple animal model systems such as Drosophila melanogaster. Almost two decades after the landmark discovery of cooperative oncogenesis between oncogenic Ras^V12 and the loss of the tumor suppressor scribble in flies, this and other tumor models have provided new concepts and findings in cancer biology that has remarkable parallels and relevance to human cancer. Here we review findings using the Ras^V12; scrib^-/- tumor model and how it has contributed to our understanding of how these initial simple genetic insults cooperate within the tumor cell to set in motion the malignant transformation program leading to tumor growth through cell growth, cell survival and proliferation, dismantling of cell-cell interactions, degradation of basement membrane and spreading to other organs. Recent findings have demonstrated that cooperativity goes beyond cell intrinsic mechanisms as the tumor interacts with the immediate cells of the microenvironment, the immune system and systemic organs to eventually facilitate malignant progression.

The Wnt/PCP formin Daam1 drives cell-cell adhesion during nephron development

E-cadherin junctions facilitate assembly and disassembly of cell contacts that drive development and homeostasis of epithelial tissues. In this study, using Xenopus embryonic kidney and Madin-Darby canine kidney (MDCK) cells, we investigate the role of the Wnt/planar cell polarity (PCP) formin Daam1 (Dishevelled-associated activator of morphogenesis 1) in regulating E-cadherin-based intercellular adhesion. Using live imaging, we show that Daam1 localizes to newly formed cell contacts in the developing nephron. Furthermore, analyses of junctional filamentous actin (F-actin) upon Daam1 depletion indicate decreased microfilament localization and slowed turnover. We also show that Daam1 is necessary for efficient and timely localization of junctional E-cadherin, mediated by Daam1’s formin homology domain 2 (FH2). Finally, we establish that Daam1 signaling promotes organized movement of renal cells. This study demonstrates that Daam1 formin junctional activity is critical for epithelial tissue organization.

How cells remodel their adhesions through cell-surface proteins such as E-cadherin is a central question in epithelial tissue biology. Krneta-Stankic et al. show that the Wnt/PCP formin Daam1 regulates cytoskeletal membrane dynamics and E-cadherin localization within developing nephrons. These findings provide a new framework for studying cell-cell adhesion and nephron morphogenesis.

The polarity protein PARD3 and cancer

Tissue disorganisation is one of the main hallmarks of cancer. Polarity proteins are responsible for the arrangement of cells within epithelial tissues through the asymmetric organisation of cellular components. Partition defective 3 (PARD3) is a master regulator of the Par polarity complex primarily due to its ability to form large complexes via its self-homologous binding domain. In addition to its role in polarity, PARD3 is a scaffolding protein that binds to intracellular signalling molecules, many of which are frequently deregulated in cancer. The role of PARD3 has been implicated in multiple solid cancers as either a tumour suppressor or promoter. This dual functionality is both physiologically and cell context dependent. In this review, we will discuss PARD3's role in tumourigenesis in both laboratory and clinical settings. We will also review several of the mechanisms underpinning PARD3's function including its association with intracellular signalling pathways and its role in the regulation of asymmetric cell division.

Notch and Endometrial Cancer

The human endometrium is a unique, highly dynamic tissue that undergoes cyclic changes of cell proliferation, differentiation, and death. Endometrial cancer is the most common malignancy among women in developed countries. Importantly, the incidence of endometrial cancer is rising in high-income countries. Currently histological classification is used for subtyping of endometrial cancer, while ongoing research is evaluating markers for more accurate molecular classification. Evolutionary conserved Notch signaling pathway regulates diverse cellular processes such as proliferation, differentiation, and cell invasion. Accumulating evidence links aberrant Notch signaling with diseases such as hyperplasia and endometrial cancer. This chapter summarizes the current state of Notch signaling investigations in the endometrium, endometriosis, and endometrial cancer.

Proteomic analysis of malignant and benign endometrium according to obesity and insulin-resistance status using Reverse Phase Protein Array

Obesity and hyperinsulinemia are known risk factors for endometrial cancer, yet the biological pathways underlying this relationship are incompletely understood. This study investigated protein expression in endometrial cancer and benign tissue and its correlation with obesity and insulin resistance. One hundred and seven women undergoing hysterectomy for endometrial cancer or benign conditions provided a fasting blood sample and endometrial tissue. We performed proteomic expression according to body mass index, insulin resistance, and serum marker levels. We used linear regression and independent t test for statistical analysis. Proteomic data from 560 endometrial cancer cases from The Cancer Genome Atlas (TCGA) databank were used to assess reproducibility of results. One hundred and twenty seven proteins were significantly differentially expressed between 66 cancer and 26 benign patients. Protein expression involved in cell cycle progression, impacting cytoskeletal dynamics (PAK1) and cell survival (Rab 25), were most significantly altered. Obese women with cancer had increased PRAS40_pT246; a downstream marker of increased PI3K-AKT signaling. Obese women without cancer had increased mitogenic and antiapoptotic signaling by way of upregulation of Mcl-1, DUSP4, and Insulin Receptor-b. This exploratory study identified a number of candidate proteins specific to endometrioid endometrial cancer and benign endometrial tissues. Obesity and insulin resistance in women with benign endometrium leads to specific upregulation of proteins involved in insulin and driver oncogenic signaling pathways such as the PI3K-AKT-mTOR and growth factor signaling pathways which are mitogenic and also disruptive to metabolism.

Changes in the expression and distribution of junction and polarity proteins in the porcine endometrium during early pregnancy period

The maternal endometrium undergoes transformations during early pregnancy period to regulate the paracellular permeability across the epithelium and to enable adhesion between the trophoblast and endometrial epithelial cells. These transformations, under the influence of ovarian hormones, are associated with a partial loss in polarity of epithelial cell that is regulated by tight junctions (TJ), adherens junctions (AJ) and associated polarity protein complexes. This study examined the change in expression and distribution of proteins associated with TJs, AJs and apical partition defective (PAR) complex in porcine endometrium on Days 10, 13 and 16 of estrous cycle and pregnancy. Moreover, effect of hormones, progesterone (P4) and 17-β estradiol (E2) on polar phenotype of endometrial epithelial cells was also investigated in vitro. There was pregnancy induced increase in gene and protein expression of TJ associated claudin-1 (CLDN1) on Day 13 of pregnancy as compared to corresponding day of estrous cycle and a decrease in TJ protein, zona occludens-1 (ZO-1) and PAR complex associated PAR6 expression levels on Day 16 of pregnancy (P < 0.05). Immunofluorescence studies revealed that on Days 10 and 13, TJ proteins occludin (OCLN) and ZO-1were primarily present in the apical region of lateral epithelial membrane. On Day 16 of pregnancy, whereas, OCLN redistributed into cytoplasm, ZO-1 decreased apically but was found to localize in the basal epithelium. The AJ proteins cadherin and β-catenin were located at the apical epithelium on Day 10 of estrous cycle and pregnancy and Day 13 of estrous cycle. On Days 13 and 16 of pregnancy both proteins were expressed in the lateral membrane and co-localization between these proteins was observed on Day 16. On Day 10, PAR complex proteins PAR3, cell division control protein 42 (CDC42) and atypical protein kinase C (aPKC) ζ were observed in apical epithelium and in lateral membrane and CDC42 was also present in the cytoplasm of epithelium. Pregnancy induced redistribution of aPKCζ to cytoplasm and CDC42 to apical surface of luminal epithelium was observed on Days 13 and 16. The in vitro P4 and E2 treatment of epithelial cells mimicked in vivo results. These results indicate that P4 and E2 regulate alterations in epithelium that may facilitate embryo implantation and given the role of cadherin, catenin and CDC42 in embryo invasion, change in distribution of these proteins may limit the invasiveness of porcine conceptuses into the stroma.

Divergent roles of the Wnt/PCP Formin Daam1 in renal ciliogenesis

Kidneys are composed of numerous ciliated epithelial tubules called nephrons. Each nephron functions to reabsorb nutrients and concentrate waste products into urine. Defects in primary cilia are associated with abnormal formation of nephrons and cyst formation in a wide range of kidney disorders. Previous work in Xenopus laevis and zebrafish embryos established that loss of components that make up the Wnt/PCP pathway, Daam1 and ArhGEF19 (wGEF) perturb kidney tubulogenesis. Dishevelled, which activates both the canonical and non-canonical Wnt/PCP pathway, affect cilia formation in multiciliated cells. In this study, we investigated the role of the noncanoncial Wnt/PCP components Daam1 and ArhGEF19 (wGEF) in renal ciliogenesis utilizing polarized mammalian kidney epithelia cells (MDCKII and IMCD3) and Xenopus laevis embryonic kidney. We demonstrate that knockdown of Daam1 and ArhGEF19 in MDCKII and IMCD3 cells leads to loss of cilia, and Daam1's effect on ciliogenesis is mediated by the formin-activity of Daam1. Moreover, Daam1 co-localizes with the ciliary transport protein Ift88 and is present in cilia. Interestingly, knocking down Daam1 in Xenopus kidney does not lead to loss of cilia. These data suggests a new role for Daam1 in the formation of primary cilia.

Expression of TRA2B in endometrial carcinoma and its regulatory roles in endometrial carcinoma cells

Expression levels of Transformer 2 protein homolog beta (TRA2B) in patients with endometrial carcinoma were assessed to investigate the impact of TRA2B on endometrial carcinoma cells. Furthermore, we analyzed the expression of several genes in the tissue samples from patients with endometrial cancer (EC) to identify whether cancer related genes we chose are differently expressed between the endometrial carcinoma tissues and adjacent normal tissues. The results of RT-qPCR analysis, western blot technology and immunofluorescence method consistently manifested that the expression of several genes in endometrial carcinoma tissue was significantly dysregulated between the two groups. Among the dysregulated genes, the strongly upregulated TRA2B in the tissues and serum from patients with EC was selected for further analysis. Endometrial carcinoma cells were transfected with chemically synthesized TRA2B plasmid, siRNA-TRA2B and their corresponding negative control respectively to assess the effects of TRA2B on the EC cells. Overexpression of TRA2B increased both the cell viability and proliferation potency of EC cells. Whereas, the viability and the proliferation ability of EC cells were strongly decreased by siRNA-TRA2B treatment. Furthermore, the invasion of EC cells was promoted by transfection of TRA2B and overexpression of TRA2B decreased the apoptosis of EC cells. Moreover, siRNA-TRA2B transfection inhibited the invasion but accelerated apoptosis of EC cells. Our results demonstrated that TRA2B is closely related to the development of endometrial carcinoma, and inhibition of TRA2B can decrease viability, proliferation and invasion of endometrial carcinoma, suggesting TRA2B is associated with the pathogenesis of human EC. Knockdown of TRA2B may be used for treatment of endometrial carcinoma, furthermore, these findings suggest an experimental foundation to clinical prognostic role of TRA2B in patients with endometrial carcinoma.

Bisphenol S increases EZRIN expression and the detrimental effects induced by dehydroepiandrosterone in rat endometrium

The use of Bisphenol S (BPS) was proposed as an alternative to Bisphenol A (BPA), a chemical employed in the production of polycarbonate plastics and epoxy resins. BPA is a xenoestrogen that affects normal physiology in several species. It was reported that BPS may also act as a xenoestrogen with harmful effects in the reproductive system. Here we studied the effects of BPS during the induction of a polycystic ovarian syndrome (PCOS)-like condition in rats. Animals were injected daily with vehicle, DHEA 60 mg/kg, BPS 1 μg/kg and DHEA-BPS, for 20 days. Cell apoptosis, cell proliferation, and EZRIN expression were analyzed by immunohistochemistry. We found an increase in PCNA expression, which correlates with cytoplasmic accumulation of the polarization marker, EZRIN, in the BPS treated groups. Additionally, the administration of BPS in the DHEA treated group augmented the stratification and number of "intraepithelial lumina" in the endometrial surface epithelium.

The ERM family member Merlin is required for endometrial gland morphogenesis

Disruption of endometrial gland formation or function can cause female infertility. Formation of endometrial glands via tubulogenesis of luminal epithelial cells requires the establishment and maintenance of cell polarity and cell adhesion. The FERM domain-containing protein Merlin coordinates epithelial cell polarity and cell adhesion and is critical for epithelial tissue function in the skin and kidney. We now demonstrate a requirement for Merlin in endometrial gland development. Conditional deletion of Merlin in the endometrium results in female infertility caused by the absence of gland formation. Interestingly, we observed glandular epithelial markers within discrete groups of cells in the Merlin-deficient luminal epithelium. Wnt signaling, a pathway necessary for endometrial gland development is maintained in Merlin-deficient endometrium, suggesting the glandular fate program is active. Instead, we observe increased levels of apical actin and markers indicative of high membrane tension on the basal surface of the Merlin-deficient luminal epithelium. These findings suggest that the structural integrity of the luminal epithelium during gland formation is required for appropriate endometrial tubulogenesis and tissue function. Moreover, our work implicates Merlin-dependent regulation of mechanical tension in the proper formation of endometrial gland architecture and function.

FGFR2-activating mutations disrupt cell polarity to potentiate migration and invasion in endometrial cancer cell models

Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases that control a diverse range of biological processes during development and in adult tissues. We recently reported that somatic FGFR2 mutations are associated with shorter survival in endometrial cancer. However, little is known about how these FGFR2 mutations contribute to endometrial cancer metastasis. Here, we report that expression of the activating mutations FGFR2^N550K and FGFR2^Y376C in an endometrial cancer cell model induce Golgi fragmentation, and loss of polarity and directional migration. In mutant FGFR2-expressing cells, this was associated with an inability to polarise intracellular pools of FGFR2 towards the front of migrating cells. Such polarization defects were exacerbated in three-dimensional culture, where FGFR2 mutant cells were unable to form well-organised acini, instead undergoing exogenous ligand-independent invasion. Our findings uncover collective cell polarity and invasion as common targets of disease-associated FGFR2 mutations that lead to poor outcome in endometrial cancer patients.

Expression of Notch receptors and their ligands in pancreatic ductal adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer-associated mortality in developed countries. Pancreatic ductal adenocarcinoma (PDAC) accounts for ~90% of all pancreatic cancer cases. The Notch signaling pathway serves a crucial role in embryonic development, as well as during the tumorigenesis of different types of cancer. However, Notch signaling serves either oncogenic or tumor suppressor roles depending on the tissue type. There are four Notch receptors (Notch1-4) and five ligands [Jagged1, Jagged2, δ-like ligand protein (DLL)1, DLL3 and DLL4]; therefore, it has been suggested that the different Notch receptors serve distinct roles in the same type of tissue. To determine whether this is the case, the present study measured the expression of all Notch receptors and their ligands in PDAC tissue samples and cells. Immunohistochemistry was performed to measure the expression of Notch receptors and their ligands in paraffin-embedded PDAC tissue samples. Immunofluorescence was used to detect the expression of Notch receptors in the pancreatic cancer cell lines human pancreatic adenocarcinoma (HPAC) and PANC-1. In addition, levels of Notch receptors and ligands in HPAC and PANC-1 cells were analyzed by western blot analysis. The results revealed that levels of Notch1 and Notch3 were increased in PDAC tissues, whereas levels of Notch2 and Notch3 were not. The expression of Notch receptors in the pancreatic cancer cell lines HPAC and PANC-1 was consistent with their expression in PDAC tissues. Additionally, levels of the ligands DLL1, DLL3 and DLL4 were increased in HPAC and PANC-1 cells, as well as PDAC tissue samples. However, the expression of Jagged1 and 2 remained low. These results indicate that Notch1, Notch3, DLL1, DLL3 and DLL4 are upregulated in PDAC, a positive correlation was observed between the expression of Notch1 and Notch3, and between Notch1 and the ligands DLL1, DLL3 and DLL4. whereas Notch2, Notch4, Jagged1 and Jagged2 are not. The interaction of Notch1 and Notch3 with Notch ligands DLL1, DLL3 and DLL4 may be important in maintaining the tumor phenotype of pancreatic cancer.