Changes in the expression of E-cadherin repressors, Snail, Slug, SIP1, and Twist, in the development and progression of ovarian carcinoma: the important role of Snail in ovarian tumorigenesis and progression

Exosomes as a Nano-Carrier for Chemotherapeutics: A New Era of Oncology

Despite the considerable advancements in oncology, cancer remains one of the leading causes of death worldwide. Drug resistance mechanisms acquired by cancer cells and inefficient drug delivery limit the therapeutic efficacy of available chemotherapeutics drugs. However, studies have demonstrated that nano-drug carriers (NDCs) can overcome these limitations. In this sense, exosomes emerge as potential candidates for NDCs. This is because exosomes have better organotropism, homing capacity, cellular uptake, and cargo release ability than synthetic NDCs. In addition, exosomes can serve as NDCs for both hydrophilic and hydrophobic chemotherapeutic drugs. Thus, this review aimed to summarize the latest advances in cell-free therapy, describing how the exosomes can contribute to each step of the carcinogenesis process and discussing how these nanosized vesicles could be explored as nano-drug carriers for chemotherapeutics.

Expression of ZEB1 in different forms of endometriosis: A pilot study

OBJECTIVES

Epithelial-Mesenchymal Transition (EMT), a cellular process in which epithelial cells lose epithelial characteristics while acquire mesenchymal features, is believed to contribute to migration and invasion abilities of the endometriotic cells. Studies on gene expression of the transcription factor ZEB1, a crucial transcription factor of EMT, show that there is probably a modified expression in the endometriotic lesions. The aim of the study was to compare the expression levels of ZEB1 in types of endometriotic lesions with different biological behavior such as endometriomas and deep infiltrating endometriotic nodules.

STUDY DESIGN

We have studied 19 patients with endometriosis and 8 patients with benign gynecological lesions without endometriosis. The endometriosis patient group included 9 women with only endometriotic cysts without deep infiltrating endometriotic lesion (DIE) and 10 women with DIE who had developed concurrent endometriotic cysts. The technique applied to investigate ZEB1 expression levels is Real-Time PCR. The results of the reaction were normalized by simultaneously investigating the expression of the house-keeping gene G6PD.

RESULTS

Analysis of the samples showed underexpression of ZEB1 in the eutopic endometrium of women with only endometriotic cysts when compared to normal endometrium. A tendency of higher ZEB1 expression, without reaching significant difference, was found between the endometriotic cysts and their paired eutopic endometrium. In women with DIE, no significant difference was found between their eutopic and normal endometrium. No significant difference was found between the endometriomas and DIE lesions. ZEB1 shows different expression profile in the endometriotic cysts of women with and without DIE when the cyst is compared to their paired eutopic endometrium.

CONCLUSIONS

It therefore appears that ZEB1 expression differs between different types of endometriosis. The expression levels of ZEB1 in the eutopic endometrium could affect the development of infiltrating lesions or not. However, the most important observation is the different ZEB1 expression profile of endometriomas between women with and without DIE. Although, they both share the same histologic characteristics, they show different ZEB1 expression indicating different pathogenetic mechanisms of endometriomas in cases with and without DIE. Therefore, future research on endometriosis should consider DIE and ovarian endometriosis as different diseases.

CYP2E1-dependent upregulation of SIRT7 is response to alcohol mediated metastasis in hepatocellular carcinoma

Long-term alcohol use is a confirmed risk factor of liver cancer tumorigenesis and metastasis. Multiple mechanisms responsible for alcohol related tumorigenesis have been proposed, including toxic reactive metabolite production, oxidative stress and fat accumulation. However, mechanisms underlying alcohol-mediated liver cancer metastasis remain largely unknown. We have previously demonstrated that SIRT7 regulates chemosensitivity by altering a p53-dependent pathway in human HCC. In the current study, we further revealed that SIRT7 is a critical factor in promoting liver cancer metastasis. SIRT7 expression is associated with disease stage and high SIRT7 predicts worse overall and disease-free survival. Overexpression of SIRT7 promotes HCC cell migration and EMT while knockdown of SIRT7 showed opposite effects. Mechanistically, we found that SIRT7 suppresses E-Cadherin expression through FOXO3-dependent promoter binding and H3K18 deacetylation. Knockdown of FOXO3 abolished the suppressive effect of SIRT7 on E-cadherin transcription. More importantly, we identified that alcohol treatment upregulates SIRT7 and suppresses E-cadherin expression via a CYP2E/ROS axis in hepatocytes both in vitro and in vivo. Antioxidant treatment in primary hepatocyte or CYP2E1-/- mice fed with alcohol impaired those effects. Reducing SIRT7 activity completely abolished alcohol-mediated promotion of liver cancer metastasis in vivo. Taken together, our data reveal that SIRT7 is a pivotal regulator of alcohol-mediated HCC metastasis.

E-Cadherin Expression in Relation to Clinicopathological Parameters and Survival of Patients with Epithelial Ovarian Cancer

It is generally accepted that loss/reduction of E-cadherin expression on tumor cells promotes their migration, invasiveness, and metastasis. It is also an indicator of cancer cells' aggressiveness. The aim of this study was to assess how the expression of E-cadherin varies in primary ovarian cancer tissue in regard to overall survival of patients; FIGO stage; grade; histopathological type of tumor; and potential factors discriminating malignant and nonmalignant ovarian tumors. Our analysis was based on literature research (1 January 2000-8 November 2021) conducted according to the PRISMA guidelines. Most studies support the assumption that loss/reduced expression of E-cadherin results in shorter overall survival of EOC patients. Moreover, most research has shown that there is a correlation between the low level of E-cadherin and the advancement stage of disease, especially in high-grade serous ovarian carcinoma type. However, E-cadherin expression seems to not be helpful to distinguish malignant and nonmalignant tumors. In conclusion, reduced E-cadherin expression in primary ovarian cancer tissue may indicate a less favorable disease outcome and is associated with high advancement of the disease.

Dysregulated Immunological Functionome and Dysfunctional Metabolic Pathway Recognized for the Pathogenesis of Borderline Ovarian Tumors by Integrative Polygenic Analytics

The pathogenesis and molecular mechanisms of ovarian low malignant potential (LMP) tumors or borderline ovarian tumors (BOTs) have not been fully elucidated to date. Surgery remains the cornerstone of treatment for this disease, and diagnosis is mainly made by histopathology to date. However, there is no integrated analysis investigating the tumorigenesis of BOTs with open experimental data. Therefore, we first utilized a functionome-based speculative model from the aggregated obtainable datasets to explore the expression profiling data among all BOTs and two major subtypes of BOTs, serous BOTs (SBOTs) and mucinous BOTs (MBOTs), by analyzing the functional regularity patterns and clustering the separate gene sets. We next prospected and assembled the association between these targeted biomolecular functions and their related genes. Our research found that BOTs can be accurately recognized by gene expression profiles by means of integrative polygenic analytics among all BOTs, SBOTs, and MBOTs; the results exhibited the top 41 common dysregulated biomolecular functions, which were sorted into four major categories: immune and inflammatory response-related functions, cell membrane- and transporter-related functions, cell cycle- and signaling-related functions, and cell metabolism-related functions, which were the key elements involved in its pathogenesis. In contrast to previous research, we identified 19 representative genes from the above classified categories (IL6, CCR2 for immune and inflammatory response-related functions; IFNG, ATP1B1, GAS6, and PSEN1 for cell membrane- and transporter-related functions; CTNNB1, GATA3, and IL1B for cell cycle- and signaling-related functions; and AKT1, SIRT1, IL4, PDGFB, MAPK3, SRC, TWIST1, TGFB1, ADIPOQ, and PPARGC1A for cell metabolism-related functions) that were relevant in the cause and development of BOTs. We also noticed that a dysfunctional pathway of galactose catabolism had taken place among all BOTs, SBOTs, and MBOTs from the analyzed gene set databases of canonical pathways. With the help of immunostaining, we verified significantly higher performance of interleukin 6 (IL6) and galactose-1-phosphate uridylyltransferase (GALT) among BOTs than the controls. In conclusion, a bioinformatic platform of gene-set integrative molecular functionomes and biophysiological pathways was constructed in this study to interpret the complicated pathogenic pathways of BOTs, and these important findings demonstrated the dysregulated immunological functionome and dysfunctional metabolic pathway as potential roles during the tumorigenesis of BOTs and may be helpful for the diagnosis and therapy of BOTs in the future.

Comparison of Snail1, ZEB1, E-Cadherin Expression Levels in HPV-Induced Cervical Cancer

Background:

Molecular profiling techniques are the rapid detection of biomarkers in the human papillomavirus (HPV) infected cells. We aimed to measure the expression level of three cell factors including Snail1, ZEB-1, and E-cadherin in cervical cancer (CC), precancerous and healthy samples, simultaneously, to find potential biomarkers.

Methods:

The expression level of the mentioned cell factors were investigated in 72 CC patients, precancerous patients, and healthy controls by using Real-Time PCR.

Results:

The results demonstrated a significant reduction in the expression level of E-cadherin in cancer and precancerous cases than that in healthy cases; whereas the expression level of ZEB-1 and Snail1 were upregulated in cancer and precancerous samples. The receiver operating characteristic (ROC) analyses shows the highest AUC value emerged for Snail1: 1(95% CI: 1-1) in comparing CC and healthy groups with a sensitivity of 100.0 % and specificity of 100.0%.

Conclusion:

The molecular biomarker Snail1 may be helpful to early diagnosis and prognosis of CC in the HPV-infected human populations. Considering the increased expression level of Snail1 in cancer and precancerous tissue compared to healthy tissue as well as the area under the ROC curve, Snail1 can be used for early detection of CC.

Accurate assessment of estrogen receptor profiles in non-functioning pituitary adenomas using RT-digital PCR and immunohistochemistry

BACKGROUND

Non-functioning pituitary adenomas (NFPAs) are common pituitary tumors, and surgery is generally the only treatment option. Few attempts have been made to explore target molecules for the development of NFPA pharmacological treatments.

METHOD

We quantitatively assessed the expression profiles of estrogen receptor (ER) transcripts and proteins in NFPA samples, using reverse transcription-digital polymerase chain reaction (RT-dPCR) and immunohistochemistry, and further investigated the correlations between the expression levels of ER and those of downstream responsive genes. All patients had undergone surgery at the same high-volume hospital. A total of 20 patients with NFPAs were included. All patients were new-onset, and none were diagnosed with intratumoral hemorrhages or cysts.

RESULTS

NFPA samples exhibited a bimodal ESR1 expression pattern and were categorized into significantly different high- and low-ESR1 expression level groups (P < 0.05). In contrast, expression levels of ESR1 variants and ESR2 could barely be detected. Similar results were obtained through the immunohistochemical staining of NFPAs, using well-validated antibodies against ERs. The expression levels of ESR1 positively correlated with those of GREB1, an estrogen-responsive gene [correlation coefficient (r) = 0.623, P = 0.003].

CONCLUSIONS

ESR1 expression levels in NFPAs exhibited a bimodal pattern and were positively correlated with GREB1 expression levels. The accurate assessment of ER expression levels may further advance future NFPA-related research.

Plantamajoside inhibits hypoxia-induced migration and invasion of human cervical cancer cells through the NF-κB and PI3K/akt pathways

Plantamajoside (PMS) is a major compound of Plantago asiatica and possesses anti-tumor property in several types of cancers. However, the effect of PMS on cervical cancer has not been investigated. This study aimed to investigate the effect of PMS on the migration and invasion of cervical cancer cell lines under hypoxic condition. Our results demonstrated that PMS significantly inhibited hypoxia-caused increases in cell migration and invasion of cervical cancer cells. The hypoxia-induced epithelial-mesenchymal transition (EMT) process was prevented by PMS with increased E-cadherin expression, and decreased expression levels of N-cadherin and vimentin in cervical cancer cells. Besides, the expression levels of transcription factors slug and snail were suppressed by PMS in hypoxia-induced cervical cancer cells. The increased mRNA and protein levels of hypoxia-inducible factor 1alpha (HIF-1α) in hypoxia-induced cervical cancer cells were prevented by PMS. Furthermore, PMS blocked the hypoxia-induced activation of NF-κB and PI3K/Akt pathway in cervical cancer cells. Taken together, these findings suggest that PMS exerted an anti-tumor activity in cervical cancer through preventing the hypoxia-induced EMT. Thus, PMS might serve as a therapeutic agent for the treatment of cervical cancer.

Prognostic value of epithelial-mesenchymal transition-inducing transcription factors in head and neck squamous cell carcinoma: A meta-analysis

Epithelial-mesenchymal transition (EMT) plays a critical role in cancer progression and is primarily regulated by several EMT-inducing transcription factors (EMT-TFs), including TWIST1, TWIST2, SNAI1, SNAI2, ZEB1, and ZEB2. However, the prognostic value of EMT-TFs remains controversial in head and neck squamous cell carcinoma (HNSCC). Studies on the prognostic role of EMT-TFs in HNSCC were searched for in the Web of Science, Science Direct, Proquest, EMBASE, PubMed, and Cochrane Library. Meta-analysis was performed by using Revman 5.2 software. The pooled analysis showed that overexpression of EMT-TFs indicated a poor overall survival (OS) (HR = 1.93, 95% CI = 1.67-2.23) of HNSCC. Subgroup analysis for individual EMT-TFs revealed that overexpression of TWIST1 (HR = 1.61, 95% CI = 1.29-2.02), SNAI1 (HR = 2.17, 95% CI = 1.63-2.88), SNAI2 (HR = 1.90, 95% CI = 1.38-2.62), and ZEB1 (HR = 2.70, 95% CI = 1.61-4.53) were significantly associated with poor OS of HNSCC. These findings support the hypothesis that overexpression of EMT-TFs indicates a poor prognosis for HNSCC patients.

Schisandrin B inhibits TGF-β1-induced epithelial-mesenchymal transition in human A549 cells through epigenetic silencing of ZEB1

Purpose/Aim: More and more evidences suggest that airway remodeling of fibrotic lung diseases may be associated with epithelial-mesenchymal transition (EMT) of human A549 cells induced by transforming growth factor (TGF)-β1. Schisandrin B (Sch B) is the highest content of dibenzocyclooctadiene lignans in Schisandra chinensis. In this study, we assessed the inhibitory influences of Sch B on TGF-β1-stimulated EMT in human A549 cells. Materials and Methods: The influences of Sch B on cell viability, invasion and metastasis in TGF-β1-induced human A549 cells were detected by MTT, wound healing and transwell invasion assays. The expression levels of α-SMA, E-cadherin, ZEB1 and Twist1 were examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot. The enrichment of H3K4me3 and H3K9me3 at the ZEB1 promoter was determined by ChIP analysis. Results: Experimental results showed that Sch B increased the expression of the epithelial phenotype marker E-cadherin and inhibited the expression of the mesenchymal phenotype marker α-SMA during EMT induced by TGF-β1. The enhancement in invasion and migration of TGF-β1-induced A549 cells was inhibited by Sch B. Sch B also repressed the expression of ZEB1 transcription factor in EMT, by increasing the enrichment of H3K9me3 at the ZEB1 promoter to repress its transcription while the expression of the Twist1 transcription factor was unaffected. Conclusions: Our data suggest that Sch B can prevent TGF-β1-stimulated EMT in A549 cells through epigenetic silencing of ZEB1, which may be clinically related to the efficient treatment of EMT-associated fibrotic diseases.

MDM2 promotes epithelial-mesenchymal transition through activation of Smad2/3 signaling pathway in lung adenocarcinoma

Background

Mouse double minute 2 (MDM2) contributes to cancer metastasis and epithelial-mesenchymal transition (EMT). This study aimed to investigate small mothers against decapentaplegic (Smad) signaling in MDM2-mediated EMT in lung adenocarcinoma (LAC).

Materials and methods

Expression patterns of MDM2 in LAC tissues, adjacent tissues, and cell lines (BEAS-2B, PC9, H1975, and A549) were detected. We then overexpressed MDM2 in PC9 cells and knocked it down in H1975 cells. To explore whether MDM2 activates EMT through the Smad2/3 signaling pathway, Smad2 and Smad3 were also silenced by siRNA in H1975 cells. Male BALB/c nude mice were used in in vivo model to validate the effects of MDM2 on LAC cells.

Results

MDM2 was significantly upregulated in LAC tissues compared with adjacent tissues. The expression of MDM2 was relatively higher in PC9 cells and relatively lower in H1975 cells compared with A549 cells. Overexpression of MDM2 significantly increased cell proliferation, migration, and invasion in LAC cells, while inhibiting apoptosis in PC9 cells. On the contrary, silencing of MDM2 significantly inhibited the expression of EMT-related genes N-cadherin and vimentin, while promoting the expression of E-cadherin and β-catenin. In vivo, MDM2 knockdown inhibited tumor growth. In addition, the expression of Smad2/3 was correlated with MDM2 in H1975 cells transfected with Smad2 and Smad3 siRNAs, which inhibited EMT progress.

Conclusion

MDM2 can activate the Smad2/3 signaling pathway, which promotes the proliferation and EMT progress of LAC cells.

A Cell-Autonomous Oncosuppressive Role of Human RNASET2 Affecting ECM-Mediated Oncogenic Signaling

RNASET2 is an extracellular ribonuclease endowed with a marked antitumorigenic role in several carcinomas, independent from its catalytic activity. Besides its antitumorigenic role by the recruitment to the tumor mass of immune cells from the monocyte/macrophage lineage, RNASET2 is induced by cellular stress and involved in actin cytoskeleton remodeling affecting cell interactions with the extracellular matrix (ECM). Here, we aimed to investigate the effects of RNASET2 expression modulation on cell phenotype and behavior in epithelial ovarian cancer (EOC) cellular models. In silico analysis on two publicly available datasets of gene expression from EOC patients (n = 392) indicated that increased RNASET2 transcript levels are associated with longer overall survival. In EOC biopsies (n = 101), analyzed by immunohistochemistry, RNASET2 was found heterogeneously expressed among tumors with different clinical⁻pathological characteristics and, in some cases, its expression localized to tumor-associated ECM. By characterizing in vitro two models of EOC cells in which RNASET2 was silenced or overexpressed, we report that RNASET2 expression negatively affects growth capability by conferring a peculiar cell phenotype upon the interaction of EOC cells with the ECM, resulting in decreased src activation. Altogether, these data suggest that drugs targeting activated src might represent a therapeutic approach for RNASET2-expressing EOCs.

The investigation of transcriptional repression mediated by ZEB2 in canine invasive micropapillary carcinoma in mammary gland

The E-cadherin loss has frequently been associated with transcriptional repression mediated by transcription factors, such as the Zinc Finger E-Box Binding Homeobox-2 (ZEB2). Invasive micropapillary carcinomas (IMPCs) of the breast are aggressive neoplasms frequently related to lymph node metastasis and poor overall survival. In the canine mammary gland, IMPCs has just been reported and, based on its behavioral similarity with the human IMPCs, appears to be a good spontaneous model to this human entity. This study aimed to evaluate the relationship between E-cadherin and ZEB2 in a spontaneous canine model of invasive micropapillary carcinoma of the mammary gland. The correlation among gene expression (ZEB2 and CDH1) and clinicopathological findings was also explored. Nineteen cases of IMPC of the canine mammary gland were obtained, protein and mRNA expression were investigated through immunohistochemistry and RNA In Situ Hybridization, respectively. To better understand the relationship between E-cadherin and ZEB2, immunofluorescence was performed in canine IMPCs. Immunohistochemically, most of IMPCs showed 1+ (14/19, 73.7%) for E-cadherin; and positivity for ZEB2 was diagnosed in 47.4% of the IMPCs. Regarding the RNA In Situ Hybridization (ISH), most of IMPCs showed 4+ and 0+ for E-cadherin (CDH1) and ZEB2 respectively. Through immunofluorescence, the first and second more frequent combinatorial group were E-cadherin⁺ZEB2^- and E-cadherin⁺ZEB2⁺; neoplastic cells showing concomitantly weak expression for E-cadherin and positivity for ZEB2 were frequently observed. A negative correlation was observed between E-cadherin and progesterone receptor expression in IMPCs. Based on these results, canine mammary IMPCs show E-cadherin lost and, at times reveals nuclear positivity for the transcription factor ZEB2 that seems to exert transcriptional repression of the CDH1.

Hyaluronic acid conjugated nanoparticle delivery of siRNA against TWIST reduces tumor burden and enhances sensitivity to cisplatin in ovarian cancer

TWIST protein is critical to development and is activated in many cancers. TWIST regulates epithelial-mesenchymal transition, and is linked to angiogenesis, metastasis, cancer stem cell phenotype, and drug resistance. The majority of epithelial ovarian cancer (EOC) patients with metastatic disease respond well to first-line chemotherapy but most relapse with disease that is both metastatic and drug resistant, leading to a five-year survival rate under 20%. We are investigating the role of TWIST in mediating these relapses. We demonstrate TWIST-siRNA (siTWIST) and a novel nanoparticle delivery platform to reverse chemoresistance in an EOC model. Hyaluronic-acid conjugated mesoporous silica nanoparticles (MSN-HAs) carried siTWIST into target cells and led to sustained TWIST knockdown in vitro. Mice treated with siTWIST-MSN-HA and cisplatin exhibited specific tumor targeting and reduction of tumor burden. This platform has potential application for overcoming clinical challenges of tumor cell targeting, metastasis and chemoresistance in ovarian and other TWIST overexpressing cancers.

Reduced expression of FILIP1L, a novel WNT pathway inhibitor, is associated with poor survival, progression and chemoresistance in ovarian cancer

Filamin A interacting protein 1-like (FILIP1L) is an inhibitor of the canonical WNT pathway. WNT/β-catenin signaling and its downstream pathway, epithelial-to-mesenchymal transition (EMT), play a key role in ovarian cancer metastasis and chemoresistance. To study the clinical implications of FILIP1L in regulating the WNT/β-catenin pathway, the expression of FILIP1L, β-catenin, SNAIL and SLUG was analyzed by immunohistochemistry on tissue microarrays of 369 ovarian samples ranging from normal to metastatic. In addition, the results were validated in mouse model and in vitro cell culture. In the present study, we demonstrated that FILIP1L expression was inversely correlated with poor prognosis, stage and chemoresistance in ovarian cancer. Notably, low FILIP1L expression was independent negative prognostic factor with respect to overall and disease-free survival. FILIP1L inhibited peritoneal metastases in orthotopic mouse model. FILIP1L knockdown induced chemoresistance in ovarian cancer cells and this phenotype was rescued by simultaneous knockdown of FILIP1L and SLUG, an EMT activator. We also demonstrated that FILIP1L regulates β-catenin degradation. FILIP1L co-localizes with phospho-β-catenin and increases phospho-β-catenin at the centrosomes, destined for proteosomal degradation. Finally, we showed that FILIP1L regulates EMT. Overall, these findings suggest that FILIP1L promotes β-catenin degradation and suppresses EMT, thereby inhibiting metastases and chemoresistance. Our study provides the first clinical relevance of FILIP1L in human cancer, and suggests that FILIP1L may be a novel prognostic marker for chemotherapy in ovarian cancer patients. Further, the modulation of FILIP1L expression may have the potential to be a target for cancer therapy.

Expression of E-cadherin, Slug and NCAM and its relationship to tumor invasiveness in patients with acromegaly

Pituitary adenomas account for 10–15% of primary intracranial tumors. Growth hormone (GH)-secreting adenomas account for 13% of all pituitary adenomas and cause acromegaly. These tumors can be aggressive, invade surrounding structures and are highly recurrent. The objective of this study was to evaluate E-cadherin, Slug and neural cell adhesion molecule (NCAM) expression in GH-secreting pituitary adenomas and its relationship to tumor invasiveness. A cross–sectional study of patients who underwent hypophysectomy due to GH-secreting pituitary adenoma from April 2007 to December 2014 was carried out. The medical records were reviewed to collect clinical data. Immediately after surgery, tumor samples were frozen in liquid nitrogen and stored in a biofreezer at –80°C for assessment of E-cadherin 1 (CDH1), SLUG (SNAI2), and NCAM (NCAM1) by real-time PCR. The samples were fixed in formalin and embedded in paraffin for immunohistochemical analysis of E-cadherin and NCAM. Thirty-five patients with acromegaly were included in the study. Of these, 65.7% had invasive tumors. Immunohistochemically, E-cadherin was expressed in 96.7% of patients, and NCAM in 80% of patients. There was no statistically significant relationship between tumor grade or invasiveness and immunohistochemical expression of these markers. Regarding gene expression, 50% of cases expressed CDH1, none expressed SNAI2, and 53.3% expressed NCAM1. There was no statistically significant relationship between tumor grade or invasiveness and gene expression of CDH1, SNAI2, and NCAM1. The absence of Slug overexpression and of E-cadherin and NCAM suppression suggests that expression of these markers is not associated with tumor invasiveness in GH-secreting pituitary adenomas.

ZEB1 expression is a potential indicator of invasive endometriosis

INTRODUCTION

Although endometriosis is a benign disease, it shares some features with cancers, such as invasiveness and the potential to metastasize. This study sought to investigate the epithelial-mesenchymal transition status in human endometriotic lesions.

MATERIAL AND METHODS

Thirteen endometriosis patients and 10 control women without endometriosis undergoing surgery for benign indications were recruited. We examined the expression of E-cadherin, vimentin, and epithelial-mesenchymal transition-induced transcriptional factors, such as Snail and ZEB1, by immunohistochemistry. We evaluated the expression of each marker in epithelial cells of both endometriotic lesions (ovarian endometrioma, deep infiltrating endometriosis, adenomyosis) and normal endometria. The correlation between ZEB1 expression and serum level of CA125 was also investigated.

RESULTS

Immunohistochemical analysis revealed that although E-cadherin, vimentin, and Snail were expressed in epithelia of normal endometria and endometriotic lesions, ZEB1 expression was only expressed in epithelia of endometriotic lesions. Additionally, ZEB1 was most frequently observed in epithelial cells of invasive endometriosis. The endometriosis patients with high serum CA125 level were more likely to have ZEB1-positive lesions.

CONCLUSIONS

This is the first observation of ZEB1 expression in epithelial cells of benign disease. The preferential expression of ZEB1 in epithelial cells of endometriotic lesions suggests that these cells may have, at least in part, a higher level of mesenchymal features possibly via ZEB1-driven epithelial-mesenchymal transition than normal endometria and that ZEB1 can be a potential indicator of invasiveness or severity of endometriosis.

Epithelial-to-Mesenchymal Transition in the Female Reproductive Tract: From Normal Functioning to Disease Pathology

Epithelial-to-mesenchymal transition (EMT) is a physiological process that is vital throughout the human lifespan. In addition to contributing to the development of various tissues within the growing embryo, EMT is also responsible for wound healing and tissue regeneration later in adulthood. In this review, we highlight the importance of EMT in the development and normal functioning of the female reproductive organs (the ovaries and the uterus) and describe how dysregulation of EMT can lead to pathological conditions, such as endometriosis, adenomyosis, and carcinogenesis. We also summarize the current literature relating to EMT in the context of ovarian and endometrial carcinomas, with a particular focus on how molecular mechanisms and the tumor microenvironment can govern cancer cell plasticity, therapy resistance, and metastasis.

Quercetin suppresses the metastatic ability of lung cancer through inhibiting Snail-dependent Akt activation and Snail-independent ADAM9 expression pathways

Metastasis is the major cause of death from lung cancer. Quercetin, a widely distributed bioflavonoid, is well known to induce growth inhibition in a variety of human cancer cells, but how it affects lung cancer cell invasion and metastasis is unclear. Herein, we found that quercetin inhibited the migration/invasion of non-small cell lung cancer (NSCLC) cell lines and bone metastasis in an orthotopic A549 xenograft model by suppressing the Snail-mediated epithelial-to-mesenchymal transition (EMT). Moreover, survival times of animals were also prolonged after quercetin treatment. Mechanistic investigations found that quercetin suppressed Snail-dependent Akt activation by upregulating maspin and Snail-independent a disintegrin and metalloproteinase (ADAM) 9 expression pathways to modulate the invasive ability of NSCLC cells. In clinical samples, we observed that patients with Snail^high/p-Akt^high tumors had the shortest survival times. In addition, a lower survival rate was also found in ADAM9^high patients than in ADAM9^low patients. Overall, our results provide new insights into the role of quercetin-induced molecular regulation in suppressing NSCLC metastasis and suggest that quercetin has potential therapeutic applications for metastatic NSCLC.

CXCL11 mediates TWIST1-induced angiogenesis in epithelial ovarian cancer

To investigate the role of TWIST1 in tumor angiogenesis in epithelial ovarian cancer and to identify key molecules involved in angiogenesis. TWIST1 small interfering RNA was transfected into A2780 cells, while a complementary DNA vector was transfected into non-malignant human ovarian surface epithelial cells to generate a TWIST1-overexpressing cell line. To evaluate how this affects angiogenesis, human umbilical vein endothelial cell tube formation assays were performed using the control and transfected cell lines. An antibody-based cytokine array was used to identify the molecules involved in TWIST1-mediated angiogenesis. After knockdown of TWIST1 via transfection of TWIST1 small interfering RNA into A2780 cells, the number of tubes formed by human umbilical vein endothelial cells significantly decreased in a tube formation assay. In a cytokine array, TWIST1 downregulation did not significantly decrease the secretion of the common pro-angiogenic factor, vascular endothelial growth factor, but instead inhibited the expression of the CXC chemokine ligand 11, which was confirmed by both an enzyme-linked immunosorbent assay and western blotting. In contrast, TWIST1 overexpression resulted in increased secretion of CXC chemokine ligand 11. Conversely, CXC chemokine ligand 11 downregulation did not inhibit the expression of TWIST1. Furthermore, the ability of TWIST1-expressing A2780 cells to induce angiogenesis was found to be inhibited after CXC chemokine ligand 11 knockdown in a tube formation assay. TWIST1 plays an important role in angiogenesis in epithelial ovarian cancer and is mediated by a novel pro-angiogenic factor, CXC chemokine ligand 11. Downregulation of CXC chemokine ligand 11 can inhibit tumor angiogenesis, suggesting that anti-CXC chemokine ligand 11 therapy may offer an alternative treatment strategy for TWIST1-positive ovarian cancer.

Differential expression of the epithelial mesenchymal transition factors Snail, Slug, Twist, TGF-β, and E-cadherin in ameloblastoma

Epithelial mesenchymal transition (EMT), the transition of epithelial cells into motile mesenchymal cells, plays an important role in embryogenesis, cancer invasion, and metastasis. Ameloblastomas are common epithelial odontogenic tumors, occurring exclusively in the mandible with locally invasive growth. Thirty-seven ameloblastoma cases were evaluated for the involvement of EMT by immunohistochemical staining and western blotting using antibodies against Slug, Snail, Twist, TGF-β, and E-cadherin. Double immunostaining was also performed. Slug and TGF-β were expressed in the nuclei of peripheral and stellate reticulum cells of ameloblastoma nests. Twenty cases of Snail, 36 of Slug, 8 of Twist, and 19 of TGF-β showed strong expression in tumor cells in follicular and plexiform patterns. Expression of Slug and TGF-β increased in regions where the expression of E-cadherin was reduced. EMT was found to be associated with the local invasive growth of ameloblastoma. These data suggest that reduced expression of E-cadherin and over-expression of Slug, Snail, and TGF-β induce EMT. Given that ameloblastomas are characterized by local invasiveness, EMT might be related to their development. Thus, strong expression of Slug and TGF-β and reduced expression of E-cadherin might be related to the local invasiveness of ameloblastoma.

Targeting Twist expression with small molecules

Twist, as one of the important embryonic transcription factors, regulates epithelial-mesenchymal transition (EMT) and migration in embryo formation and cancer development. Both Twist-1 and Twist-2 are rarely detectable in healthy adult tissues, but are frequently overexpressed in multiple kinds of human cancer tissues, such as breast, prostate, uterus, liver, melanoma, etc. Twist is considered as a crucial EMT inductor and correlated with carcinoma aggression, invasion and metastasis. In the past decades, in-depth investigation has been reported in terms of the role of Twist in cancers; in addition, several kinds of small molecules have played important roles in studying the effect of Twist on cancer development, suggesting that Twist can be regarded as one of the important potential targets for cancer treatment. Hence we provide a brief overview of Twist and several small molecules targeting its expression, highlighting the biological features that make it a charming target for cancer therapy.

Nanoparticle delivery of siRNA against TWIST to reduce drug resistance and tumor growth in ovarian cancer models

Epithelial ovarian cancer (EOC) is the most deadly gynecologic malignancy on account of its late stage at diagnosis and frequency of drug resistant recurrences. Novel therapies to overcome these barriers are urgently needed. TWIST is a developmental transcription factor reactivated in cancers and linked to angiogenesis, metastasis, cancer stem cell phenotype, and drug resistance, making it a promising therapeutic target. In this work, we demonstrate the efficacy of TWIST siRNA (siTWIST) and two nanoparticle delivery platforms to reverse chemoresistance in EOC models. Polyamidoamine dendrimers and mesoporous silica nanoparticles (MSNs) carried siTWIST into target cells and led to sustained TWIST knockdown in vitro. Mice treated with cisplatin plus MSN-siTWIST exhibited lower tumor burden than mice treated with cisplatin alone, with most of the effect coming from reduction in disseminated tumors. This platform has potential application for overcoming the clinical challenges of metastasis and chemoresistance in EOC and other TWIST overexpressing cancers.

By inhibiting snail signaling and miR-23a-3p, osthole suppresses the EMT-mediated metastatic ability in prostate cancer

Here we showed that Osthole, 7-methoxy-8-(3-methyl-2-butenyl) coumarin, a bioactive coumarin derivative extracted from medicinal plants, inhibited migration, invasion, epithelial to mesenchymal transition (EMT) in androgen-independent prostate cancer (AIPC) cells in vitro and metastasis of AIPC in vivo. In patients, high Snail levels were correlated with a higher histological Gleason sum and poor survival rates. Osthole inhibited the TGF-β/Akt/MAPK pathways, reduced Snail-DNA-binding activity and induced E-cadherin. We found that osthole decreased miR-23a-3p. Ectopic miR-23a-3p suppressed E-cadherin 3′ untranslated region reporter activity and E-cadherin expression, and relieved the motility suppression caused by osthole treatment.

Role and prognostic significance of the epithelial-mesenchymal transition factor ZEB2 in ovarian cancer

ZEB2 is a key factor in epithelial-mesenchymal transition (EMT), a program controlling cell migration in embryonic development and adult tissue homeostasis. We demonstrated a role of ZEB2 in migration and anchorage-independent cell growth in ovarian cancer, as shown by ZEB2 silencing. We found that the RNA-binding protein HuR bound the 3′UTR of ZEB2 mRNA, acting as a positive regulator of ZEB2 protein expression. In Hey ovarian cell line, HuR silencing decreased ZEB2 and ZEB1 nuclear expression and impaired migration. In hypoglycemic conditions ZEB2 expression decreased, along with ZEB1, vimentin and cytoplasmic HuR, and a reduced cellular migration ability was observed. Analysis of ZEB2 and HuR expression in ovarian cancers revealed that nuclear ZEB2 is localized in tumor leading edge and co-localizes with cytoplasmic HuR. In a series of 143 ovarian cancer patients high expression of ZEB2 mRNA significantly correlated with a poor prognosis in term of both overall survival and progression- free survival. Moreover, at immunohistochemical evaluation, we found that prognostic significance of ZEB2 protein relies on its nuclear expression and co-localization with cytoplasmic HuR. In conclusion our findings indicated that nuclear ZEB2 may enhance progression of EMT transition and acquisition of an aggressive phenotype in ovarian cancer.

Epithelial-to-Mesenchymal Transition in Paclitaxel-Resistant Ovarian Cancer Cells Is Downregulated by Luteolin

Ovarian cancer (OVCA) is the deadliest of all gynecological cancers which is attributed to late presentation, persistence, and development of chemoresistance. The objectives were to evaluate the association between OVCA paclitaxel-resistance and epithelial-to-mesenchymal transition (EMT) and to determine the capability of luteolin to chemosensitize OVCA cells. X10 and X22 cells were 11.8-25.3-fold and 7.8-8.6-fold resistant to paclitaxel than 1AP cells. X10 and X22 cells exhibited a mesenchymal phenotype, while 1AP has an epithelial characteristics. Furthermore, the expression of the epithelial marker E-cadherin was downregulated, while mesenchymal markers Vimentin and N-cadherin were upregulated in X10 and X22 cells when compared to 1AP cells. Transcription factors Snail, Slug, and Twist1 were upregulated in X10 cells, while Twist1 was highly expressed in X22 cells. Luteolin treatment caused cytotoxicity being most potent to X10 OVCA cells. Treatment of non-cytotoxic dose of luteolin at 15.625 μM chemosensitized X10 and X22 OVCA cells to paclitaxel as evidenced by reduced ED₅₀ values from 11.8 to 0.2 μM and 8.6 to 3.6 μM for X10 and X22 cells, respectively. Moreover, luteolin treatment led to a more epithelial phenotype of X10 and X22 cells and modification of EMT markers indicating reversal of EMT. The mechanism involved is through reduction of phosphorylation of FAK and ERK leading to reduced nuclear translocation of p65. Our results highlight the significance of EMT in OVCA resistance to paclitaxel and warrant the investigation of luteolin as a potential therapeutic agent in chemoresistant OVCA. J. Cell. Physiol. 232: 391-401, 2017. © 2016 Wiley Periodicals, Inc.

TGFβ signaling regulates epithelial-mesenchymal plasticity in ovarian cancer ascites-derived spheroids

Epithelial-mesenchymal transition (EMT) serves as a key mechanism driving tumor cell migration, invasion, and metastasis in many carcinomas. Transforming growth factor-beta (TGFβ) signaling is implicated in several steps during cancer pathogenesis and acts as a classical inducer of EMT. Since epithelial ovarian cancer (EOC) cells have the potential to switch between epithelial and mesenchymal states during metastasis, we predicted that modulation of TGFβ signaling would significantly impact EMT and the malignant potential of EOC spheroid cells. Ovarian cancer patient ascites-derived cells naturally underwent an EMT response when aggregating into spheroids, and this was reversed upon spheroid re-attachment to a substratum. CDH1/E-cadherin expression was markedly reduced in spheroids compared with adherent cells, in concert with an up-regulation of several transcriptional repressors, i.e., SNAI1/Snail, TWIST1/2, and ZEB2. Treatment of EOC spheroids with the TGFβ type I receptor inhibitor, SB-431542, potently blocked the endogenous activation of EMT in spheroids. Furthermore, treatment of spheroids with SB-431542 upon re-attachment enhanced the epithelial phenotype of dispersing cells and significantly decreased cell motility and Transwell migration. Spheroid formation was significantly compromised by exposure to SB-431542 that correlated with a reduction in cell viability particularly in combination with carboplatin treatment. Thus, our findings are the first to demonstrate that intact TGFβ signaling is required to control EMT in EOC ascites-derived cell spheroids, and it promotes the malignant characteristics of these structures. As such, we show the therapeutic potential for targeted inhibition of this pathway in ovarian cancer patients with late-stage disease.

MicroRNA Regulation of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a central regulatory program that is similar in many aspects to several steps of embryonic morphogenesis. In addition to its physiological role in tissue repair and wound healing, EMT contributes to chemo resistance, metastatic dissemination and fibrosis, amongst others. Classically, the morphological change from epithelial to mesenchymal phenotype is characterized by the appearance or loss of a group of proteins which have come to be recognized as markers of the EMT process. As with all proteins, these molecules are controlled at the transcriptional and translational level by transcription factors and microRNAs, respectively. A group of developmental transcription factors form the backbone of the EMT cascade and a large body of evidence shows that microRNAs are heavily involved in the successful coordination of mesenchymal transformation and vice versa, either by suppressing the expression of different groups of transcription factors, or otherwise acting as their functional mediators in orchestrating EMT. This article dissects the contribution of microRNAs to EMT and analyzes the molecular basis for their roles in this cellular process. Here, we emphasize their interaction with core transcription factors like the zinc finger enhancer (E)-box binding homeobox (ZEB), Snail and Twist families as well as some pluripotency transcription factors.

MiR-548c impairs migration and invasion of endometrial and ovarian cancer cells via downregulation of Twist

BACKGROUND

MicroRNAs (miRNAs) are a class of small non-coding RNAs, which post-transcriptionally repress the expression of genes involved in cancer initiation and progression. Although some miRNAs that target many signaling pathways (also called universe miRNAs) are supposed to play a global role in diverse human tumors, their regulatory functions in gynecological cancers remain largely unknown. We investigated the biological role and underlying mechanism of miR-548c (one universe miRNA) in endometrial and ovarian cancer.

METHODS

The effects of miR-548c overexpression on cell proliferation, migration and invasion were studied in endometrial and ovarian cancer cells. TWIST1 (Twist) was identified as a direct miR-548c target by western blot analysis and luciferase activity assay. The expression of miR-548c and Twist were examined by qRT-PCR in endometrial and ovarian cancer tissues.

RESULTS

Here, we report that miR-548c is down-regulated in endometrial and ovarian cancer tissues when compared to normal tissues, and our meta-analysis reveal that decreased miR-548c expression correlates with poor prognosis in endometrial cancer patients. We show that in endometrial and ovarian cancer cells, ectopic expression of miR-548c significantly inhibits whereas knockdown of miR-548c dramatically induces cancer cell proliferation, migration and invasion. By using luciferase reporter assay, we demonstrate that Twist, a known oncogene in endometrial and ovarian cancers, is a direct target of miR-548c. Furthermore, the expression of Twist partially abrogates the tumor suppressive effects of miR-548c on cell migration and invasion.

CONCLUSION

These findings suggest that miR-548c directly downregulates Twist, and provide a novel mechanism for Twist upregulation in both endometrial and ovarian cancers. The use of miR-548c may hold therapeutic potential for the treatment of Twist-overexpressing tumors.

Epithelial-mesenchymal interconversions and the regulatory function of the ZEB family during the development and progression of ovarian cancer

This study assessed the role of epithelial-mesenchymal interconversions and the regulatory functions of the ZEB family during the development and progression of ovarian cancer. E-cadherin, vimentin, ZEB1 and ZEB2 were analyzed using immunohistochemistry in a series of ovarian tissues that included normal tissue, benign tumors, borderline tumors, malignant tumors and metastatic lesions. The correlation between E-cadherin and ZEB was analyzed. We also analyzed the association between the expression of the four factors and clinicopathological features in ovarian cancer. The results revealed that E-cadherin was weakly positive in normal ovarian epithelium. Cytoplasmic E-cadherin was significantly increased in benign tumors (P<0.01) and further increased in borderline tumors and ovarian cancers. However, cytoplasmic E-cadherin was markedly reduced in metastatic lesions (P<0.01). Membranous E-cadherin was increased in benign tumors, but decreased progressively in borderline, malignant and metastatic tumor tissues (P<0.05). The expression profile of vimentin was opposite to that of membranous E-cadherin. Membranous E-cadherin was negatively correlated with ZEB2 expression (r=-0.514). Additionally, cytoplasmic E-cadherin, ZEB1 and ZEB2 were associated with the FIGO stage of ovarian cancer. ZEB1 was also correlated with ascitic fluid volume. Our results suggest that epithelial-mesenchymal interconversions are dynamically regulated during the development and progression of ovarian tumors. ZEB2, but not ZEB1, may regulate the expression of membranous E-cadherin during these processes.

Significance of twist and iNOS expression in human breast carcinoma

Twist is a basic helix-loop-helix transcription factor family normally expressed during embryonic development and apparently activated in variety of tumours. Overexpression of twist is correlated with uncontrolled cell proliferation, differentiation, invasion and metastasis. Twist expression is associated with oestrogen receptor (ER); however, the molecular mechanism behind involvement of twist in progression of breast cancer is still unclear. Nitric oxide synthases (NOSs) which cause damage to the cellular DNA are also shown to be involved in cancer progression. The present study involves total number of n = 85 breast biopsies, which include 19 non-cancer and 66 cancerous lesions. We analysed twist, iNOS and ER expression pattern in human breast carcinomas by RT-PCR and also analysed twist cellular localisation by immunohistochemical analysis. iNOS expression pattern was correlated with different stages of breast carcinoma. Twist expression was significantly increased in cancer lesions when compared to the non-cancer. The breast cancer lesions positive to ER showed positivity to twist (72%) as well. The higher stages of cancer lesions showed a significant expression of twist localised in cytoplasm of the cancer cells. Collectively these data indicate that up-regulation of twist is correlated with the ER presenting breast cancer, and iNOS expression was positively correlated with tumour-node metastasis (TNM) staging of breast cancer. These findings suggest that expression of twist and iNOS may have a functional role in cancer progression.

Transcription Factors in Craniofacial Development: From Receptor Signaling to Transcriptional and Epigenetic Regulation

Craniofacial morphogenesis is driven by spatial-temporal terrains of gene expression, which give rise to stereotypical pattern formation. Transcription factors are key cellular components that control these gene expressions. They are information hubs that integrate inputs from extracellular factors and environmental cues, direct epigenetic modifications, and define transcriptional status. These activities allow transcription factors to confer specificity and potency to transcription regulation during development.

TWIST and ovarian cancer stem cells: implications for chemoresistance and metastasis

The transcription factor TWIST1 is a highly evolutionally conserved basic Helix-Loop-Helix (bHLH) transcription factor that functions as a master regulator of gastrulation and mesodermal development. Although TWIST1 was initially associated with embryo development, an increasing number of studies have shown TWIST1 role in the regulation of tissue homeostasis, primarily as a regulator of inflammation. More recently, TWIST1 has been found to be involved in the process of tumor metastasis through the regulation of Epithelial Mesenchymal Transition (EMT). The objective of this review is to examine the normal functions of TWIST1 and its role in tumor development, with a particular focus on ovarian cancer. We discuss the potential role of TWIST1 in the context of ovarian cancer stem cells and its influence in the process of tumor formation.

Expression and clinical significance of hypoxia-inducible factor 1α, Snail and E-cadherin in human ovarian cancer cell lines

The aim of the present study was to investigate the expression and clinical significance of hypoxia-inducible factor 1α (HIF-1α), Snail and E-cadherin in ovarian cancer. The expression levels were assessed in a number of ovarian cancer cell lines and ovarian cancer tissues, and correlations between the expression of the three proteins and clinical pathological factors were analyzed. Transwell assays showed that the invasive ability of the ovarian cancer cell lines SKOV3 and ES‑2 were significantly higher than those of TYK and 3AO (P<0.01). Furthermore, the expression levels of HIF‑1α and Snail in SKOV3 and ES‑2 were significantly higher than those in TYK and 3AO, whereas the expression levels of E‑cadherin in SKOV3 and ES‑2 were significantly lower than those in TYK and 3AO (P<0.05). In ovarian cancer tissues, the expression levels of HIF‑1α, Snail and E‑cadherin were correlated with clinical pathological factors (P<0.01); furthermore, there was a positive correlation between the expression levels of HIF‑1α and Snail (r=0.231; P=0.021), and a negative correlation between the expression levels of Snail and that of E‑cadherin (r=‑0.225; P=0.028). HIF‑1α was suggested to be able to suppress the expression of E‑cadherin by upregulating Snail, thus serving an important role in invasion and metastasis of ovarian cancer.

Overexpression of twist and matrix metalloproteinase-9 with metastasis and prognosis in gastric cancer

OBJECTIVE

Twist, a basic helix-loop-helix transcription factor, plays a key role in the metastatic progression of human cancer. Matrix metalloproteinase (MMP)-9 is an endopeptidase that digests basement membrane type IV collagen, therefore being possibly related to tumor progression. It has been reported that Twist and matrix metalloproteinase-9 (MMP-9) are expressed in gastric cancers. However, the exact roles of Twist and MMP-9 in tumor metastasis and prognosis remain unclear. The aim of this study was to casts light on this question.

METHODS

Twist and MMP-9 expression in tissue sections of 37 gastric carcinomas was evaluated with immunohistochemistry. The staining results were compared with clinicopathologic features and to patients'outcome.

RESULTS

Twist positive expression was significantly increased in gastric cancer cases with lymph node metastasis (P=0.023). But no correlations were found between MMP-9 overexpression and clinicopathologic features, such as recurrence, TNM stage, and lymph node metastasis. Overall survival (OS) was significantly correlated with recurrence, serosa invasion, TNM stages, distant metastasis, and MMP-9 (P=0.027, 0.021, 0.000, 0.024 and 0.036, respectively). Disease-free survival (DFS) was prominently related to recurrence location, serosa invasion and TNM stages (P=0.000, 0.038 and 0.003, respectively). In the Cox regression multivariate analysis, TNM stage, distant metastasis and MMP-9 were significantly associated with prognosis of gastric cancer (P=0.002, 0.019, and 0.032, respectively).

CONCLUSIONS

This study showed Twist positive expression to be significantly correlated with lymph node metastasis in gastric cancer. MMP-9 overexpression is associated with OS, suggesting that MMP-9 is a prognostic indicator for survival in patients with gastric cancer.

B-Myb regulates snail expression to promote epithelial-to-mesenchymal transition and invasion of breast cancer cell

Breast cancer is the leading cause of cancer death in women worldwide, which is closely related to metastasis. Recent studies argue that breast cancer cells that have undergone epithelial-to-mesenchymal transition (EMT) acquire aggressive malignant properties, but the molecular mechanisms underlying this transition are poorly understood. In this study, we found that siRNA-mediated attenuation of B-Myb expression restored E-cadherin expression and cell-cell junction formation in breast cancer cells, suppressing cell invasion, anchorage-independent growth, and tumor formation. In contrast, the forced B-Myb expression decreased the expression of the epithelial marker E-cadherin, but increased the mesenchymal markers in breast cancer cells. We found that B-Myb upregulated expression of the key EMT regulator snail and that it mediated EMT activation and cell invasion by B-Myb.

Modeling of hypo/hyperglycemia and their impact on breast cancer progression related molecules

Breast cancer (BC) arises commonly in women with metabolic dysfunction. The underlying mechanism by which glycemic load can exert its action on tumor metastasis is under investigated. In this study we showed that glycemic microenvironment alters the expression of three classes of proteins, VEGF and its receptors, cell to cell, and cell to extracellular matrix (ECM) adhesion proteins in MDA-MB-231 parental cells and its two metastatic variants to the bone and brain (MDA-MB-231BO and MDA-MB-231BR, respectively). Using western blotting, we showed that VEGFR2 levels were higher in these variant cells and persisted in the cells under extreme hypoglycemia. Hypoglycemia did not alter VEGFR2 expression per se but rather suppressed its posttranslational glycosylation. This was reversed rapidly upon the restoration of glucose, and cyclohexamide (CHX) treatment demonstrated that this deglycosylated VEGFR2 was not a product of de-novo protein synthesis. VEGFR2 co-receptor Neuropilin-1 was up-regulated four-fold in all MDA-MB-231 cells (parental and two variants) compared to VEGFR2 expression, and was also susceptible to glycemic changes but resistant to CHX treatment for up to 72 hrs. Hypoglycemia also resulted in a significant decrease in specific catenin, cadherin, and integrin proteins, as well as cellular proliferation and colony forming ability. However, MDA-MB-231BR cells showed a unique sensitivity to hypo/hyperglycemia in terms of morphological changes, colony formation ability, integrin β3 expression and secreted VEGF levels. In conclusion, this study can be translated clinically to provide insight into breast cancer cell responses to glycemic levels relevant for our understanding of the interaction between diabetes and cancer.

Prognostic role of Twist or Snail in various carcinomas: a systematic review and meta-analysis

BACKGROUND

Twist and Snail are considered as key transcriptional repressors of E-cadherin tightly related to epithelial-to-mesenchymal transition (EMT) and cancer progression. Numerous studies have investigated the prognostic value of Twist and Snail. However, the published results were controversial or even opposite. Our article aimed to evaluate the prognostic role of Twist and Snail in patients with cancer.

DESIGN

A comprehensive literature search of PubMed, Embase and Web of Science was conducted. Pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were assessed to quantify the prognostic role.

RESULTS

The pooled HR with 38 studies for Twist was 2·18 (95% CI: 1·77-2·68, I(2) = 69·8%, P = 0·000) and for Snail with 40 studies was 1·58 (95% CI: 1·33-1·87, I(2) = 70·0%, P = 0·000), suggesting high Twist/Snail expression predicted poor prognosis related to all clinical outcomes. For Twist, the pooled HR for overall survival (OS) was 2·07 (95% CI: 1·63-2·63, I(2) = 72·6%, P = 0·000) and for progression-free/recurrence-free/metastasis-free/disease-free/cancer-free survival (PFS/RFS/MFS/DFS/CFS) was 2·36 (95% CI: 1·76-3·17, I(2) = 65·0%, P = 0·000). For Snail, the pooled HR for OS was 1·63 (95% CI: 1·33-1·99, I(2) = 70·8%, P = 0·000) and for PFS/RFS/MFS/DFS/CFS was 1·54 (95% CI: 1·17-2·02, I(2) = 59·1%, P = 0·001). All of those results were suggesting that high Twist/Snail expression was associated with poor prognosis. Furthermore, when grouped into different types of cancers, the pooled HRs were also calculated for the subgroups. No publication bias was found except studies evaluating all clinical outcomes of Twist (P = 0·006 for Begg's test and 0·006 for Egger's test).

CONCLUSIONS

Elevated Twist or Snail expression in tumour tissue indicated poor prognosis for cancer.

ZEB2 and ZEB1 expression in a spontaneous canine model of invasive micropapillary carcinoma of the mammary gland

ZEB1 and ZEB2 have been recently related to cancer prognosis. We investigated their expression and its association with clinicopathological parameters and overall survival in invasive micropapillary carcinoma (IMPC), which is a metastasising neoplasm of the canine mammary gland. Immunohistochemical evaluation showed nuclear and cytoplasmic staining for ZEB2 and nuclear staining for ZEB1. 'In situ' areas presented higher positivity for cytoplasmic ZEB2 than invasive areas of IMPC did (p = 0.03). ZEB1 positivity was associated with a low histological grade (p = 0.01). A shorter overall survival rate was observed in IMPCs that were positive for cytoplasmic ZEB2 (p = 0.04). Antibodies specificity in canine species was confirmed by western blot. Our results indicated that cytoplasmic ZEB2 appears to be an important factor in the early stages of malignancy and predicts a poor overall survival rate for IMPC in this canine mammary cancer model. ZEB1 downregulation appears to be associated with the dedifferentiation process of IMPC.

The Role of TWIST in Ovarian Epithelial Cancers

Background

Epithelial-mesenchymal transition (EMT) is associated with tumor hypoxia. EMT is regulated, in part, by the action of TWIST, which inhibits of E-cadherin expression and may interfere with the p53 tumor-suppressor pathway.

Methods

We examined the expression of TWIST, E-cadherin, hypoxia-inducible factor 1α (HIF1α), and p53 by immunohistochemistry in 123 cases of ovarian epithelial cancers (OEC) to evaluate the role of TWIST in OEC. We assessed the association between protein expression and clinicopathologic parameters.

Results

The expression of TWIST, E-cadherin, HIF1α, and p53 proteins was found in 28.5%, 51.2%, 35.0%, and 29.3% of cases, respectively. TWIST expression was associated with higher histologic grade and unfavorable survival. TWIST expression was correlated with HIF1α expression and reduced E-cadherin expression. The altered HIF1α/TWIST/E-cadherin pathway was associated with lower overall survival (OS), while the co-expression of TWIST and p53 was correlated with lower progression-free survival. In the multivariate analyses, TWIST expression was an independent prognostic factor for OS.

Conclusions

Our data imply that TWIST expression could be a useful predictor of unfavorable prognosis for OEC. TWIST may affect the p53 tumor-suppressor pathway. Moreover, hypoxia-mediated EMT, which involves the HIF1α/TWIST/E-cadherin pathway may play an important role in the progression of OEC.

Clinical importance and therapeutic implication of E-cadherin gene methylation in human ovarian cancer

E-cadherin (E-cad) is widely expressed in epithelial cells and acts as a pivotal tumor suppressor. The promoter methylation of E-cad has been reported to closely relate to its downregulation in many kinds of cancers. E-cad expression and methylation status were detected by immunohistochemistry (IHC) and methylation-specific polymerase chain reaction (MS-PCR) in 50 ovarian cancer tissues. 5-Aza-2'-deoxycytidine (5-Aza-dC) was used to demethylate E-cad in SKOV3 and ES2 ovarian cancer cell lines, of which the effect was verified by Western blot and MS-PCR. Then MTT and transwell experiments were conducted to detect the capacity of cell proliferation and migration for these cells. Downregulation of E-cad expression was observed in 60 % of ovarian cancer tissues (30/50) by IHC, whereas MS-PCR result indicated that E-cad was methylated in 64 % of (32/50) ovarian cancer specimens. And E-cad expression was significantly correlated with E-cad methylation (P = 0.004). 5-Aza-dC was used to process SKOV3 and ES2 ovarian cancer cell lines. By MTT experiment, we found that the proliferation of 5-Aza-dC-treated SKOV3 and ES2 was significantly suppressed by 28.0 % (P < 0.05) and 32.3 % (P < 0.05). By transwell experiment, the motility of SKOV3 and ES2 was found to be significantly suppressed by 38.2 and 27.4 % (P < 0.05), respectively, after treated with 5-Aza-dC. E-cad methylation is one of the main reasons for the expression reduction in ovarian cancer. 5-Aza-dC treatment could significantly restore the expression of E-cad and suppress growth and invasion of SKOV3 and ES2 cells. These results suggest E-cad methylation may be a promising target for ovarian cancer therapy.

Expression and significance of twist and E-cadherin in ovarian cancer tissues

OBJECTIVE

To investigate the expression of Twist and E-cadherin in ovarian cancer tissues as well as the role of epithelial-mesenchymal transformation (EMT) in ovarian cancer metastasis.

METHOD

The expressions of Twist and E-cadherin in 54 cases of ovarian cancer and paracancerous tissues were detected by Western blottin g and reverse transcriptase polymerase chain reaction. We used RNA interference to silence Twist expression in human ovarian cancer cell line, and detected E-cadherin expression using Western blotting.

RESULTS

There was an increase in the relative abundance of Twist proteins and a decrease in E-cadherin in ovarian cancer compared with normal ovary tissues (P < 0.05). The expression levels of Twist and E-cadherin mRNA were 1.49 ± 0.53 and 0.82 ± 0.24 in ovarian cancer, and 1.14 ± 0.38 and 1.08 ± 0.19 in paracancerous tissues, respectively. The difference between the indicators in ovarian cancer and in paracancerous tissues was statistically significant (P < 0.05). When the Twist expression was silenced in an ovarian cancer cell line, the expression of the E-cadherin protein increased (P<0.05).

CONCLUSION

The expression of Twist is upregulated, whereas that of E-cadherin is downregulated in ovarian cancer. EMT, mediated by Twist, may be correlated with ovarian cancer metastasis.

Immunohistological insight into the correlation between neuropilin-1 and epithelial-mesenchymal transition markers in epithelial ovarian cancer

The mechanism by which neuropilin-1 (NRP-1) induces malignancy in Epithelial Ovarian Cancer (EOC) is still unknown. This study is the first to demonstrate the relationship between NRP-1 expression and EMT markers vimentin, N-cadherin, E-cadherin and Slug. We used tissue microarrays containing the three main subtypes of EOC tumors: serous, mucinous cystadenocarcinoma and endometrioid adenocarcinoma and representative cases retrieved from our pathology archives. Immunohistochemistry was performed to detect the expression levels and location of NRP-1 and the aforementioned EMT proteins. NRP-1 was mainly expressed on cancer cells but not in normal ovarian surface epithelium (OSE). The Immunoreactive Scoring (IRS) values revealed that the expression of NRP-1, Slug and E-cadherin in the malignant subtypes of ovarian tissues was significantly higher (5.18 ± 0.64, 4.84 ± 0.7, 4.98 ± 0.68, respectively) than their expression in the normal and benign tissues (1.04 ± 0.29, 0.84 ± 0.68, 1.71 ± 0.66, respectively), with no significant differences among the studied subtypes. Vimentin was expressed in the cancer cell component of 43% of tumors and it was exclusively localized in the stroma of all mucinous tumors. The Spearman's rho value indicated that NRP-1 is positively related to the EMT markers E-cadherin and Slug. This notion might indicate that NRP-1 is a partner in the EMT process in EOC tumors.

Expression profiles of epithelial-mesenchymal transition-associated proteins in epithelial ovarian carcinoma

Epithelial-mesenchymal transition (EMT) has been suggested to contribute to tumor progression and acquisition of therapeutic resistance. To assess the clinical significance of EMT-associated proteins, we evaluated the expression of Snail and Slug, the key regulators of EMT, in the primary ovarian cancer samples (n = 103) by immunohistochemistry. Snail was differentially expressed according to the histologic subtype (P = 0.001) and was predominantly expressed in serous and endometrioid types. In the serous and endometrioid adenocarcinomas, the expression of Snail remained high across the stage and grade, suggesting its role in the early phase of carcinogenesis. However, the expression of Snail and Slug was not related to chemoresistance and poor prognosis and did not serve as independent predictive or prognostic marker.

Regulation of the Epithelial-Mesenchymal Transition by Claudin-3 and Claudin-4

The mechanisms that control intracellular adhesion are central to the process of invasion and metastasis. Claudin-3 (CLDN3) and claudin-4 (CLDN4) are major structural molecules of the tight junctions that link epithelial cells. Our prior work has demonstrated that knockdown of the expression of either CLDN3 or CLDN4 produces marked changes in the phenotype of ovarian carcinoma cells including increases in growth rate in vivo, migration, invasion, metastasis, and drug resistance, similar to those produced by the epithelial-to-mesenchymal transition (EMT). We postulated that these changes may result from the ability of CLDN3 or CLDN4 to suppress EMT. In this study we found that knockdown of either CLDN3 or CLDN4 increased cell size and resulted in flattened morphology. While knockdown of CLDN3 or CLDN4 did not alter the expression of vimentin, it significantly down-regulated the level of E-cadherin and up-regulated N-cadherin expression. Conversely, over-expression of CLDN3 or CLDN4 in a cell line that does not express endogenous CLDN3 or CLDN4 decreased N-cadherin expression. Re-expression of E-cadherin in the CLDN3 or CLDN4 knockdown cells reduced migration, invasion and tumor growth in vivo. Loss of either CLDN3 or CLDN4 resulted in activation of the PI3K pathway as evidenced by increased Akt phosphorylation, elevated cellular PIP3 content and PI3K activity as well as up-regulation of the mRNA and protein levels of the transcription factor Twist. Taken together, these findings suggest that CLDN3 and CLDN4 function to sustain an epithelial phenotype and that their loss promotes EMT.