EGF-induced EMT and invasiveness in serous borderline ovarian tumor cells: a possible step in the transition to low-grade serous carcinoma cells?

Microphysiological systems as models for immunologically 'cold' tumors

The tumor microenvironment (TME) is a diverse milieu of cells including cancerous and non-cancerous cells such as fibroblasts, pericytes, endothelial cells and immune cells. The intricate cellular interactions within the TME hold a central role in shaping the dynamics of cancer progression, influencing pivotal aspects such as tumor initiation, growth, invasion, response to therapeutic interventions, and the emergence of drug resistance. In immunologically 'cold' tumors, the TME is marked by a scarcity of infiltrating immune cells, limited antigen presentation in the absence of potent immune-stimulating signals, and an abundance of immunosuppressive factors. While strategies targeting the TME as a therapeutic avenue in 'cold' tumors have emerged, there is a pressing need for novel approaches that faithfully replicate the complex cellular and non-cellular interactions in order to develop targeted therapies that can effectively stimulate immune responses and improve therapeutic outcomes in patients. Microfluidic devices offer distinct advantages over traditional in vitro 3D co-culture models and in vivo animal models, as they better recapitulate key characteristics of the TME and allow for precise, controlled insights into the dynamic interplay between various immune, stromal and cancerous cell types at any timepoint. This review aims to underscore the pivotal role of microfluidic systems in advancing our understanding of the TME and presents current microfluidic model systems that aim to dissect tumor-stromal, tumor-immune and immune-stromal cellular interactions in various 'cold' tumors. Understanding the intricacies of the TME in 'cold' tumors is crucial for devising effective targeted therapies to reinvigorate immune responses and overcome the challenges of current immunotherapy approaches.

Mechanism of epithelial-mesenchymal transition in cancer and its regulation by natural compounds

Epithelial-mesenchymal transition (EMT) is a complex process with a primordial role in cellular transformation whereby an epithelial cell transforms and acquires a mesenchymal phenotype. This transformation plays a pivotal role in tumor progression and self-renewal, and exacerbates resistance to apoptosis and chemotherapy. EMT can be initiated and promoted by deregulated oncogenic signaling pathways, hypoxia, and cells in the tumor microenvironment, resulting in a loss-of-epithelial cell polarity, cell-cell adhesion, and enhanced invasive/migratory properties. Numerous transcriptional regulators, such as Snail, Slug, Twist, and ZEB1/ZEB2 induce EMT through the downregulation of epithelial markers and gain-of-expression of the mesenchymal markers. Additionally, signaling cascades such as Wnt/β-catenin, Notch, Sonic hedgehog, nuclear factor kappa B, receptor tyrosine kinases, PI3K/AKT/mTOR, Hippo, and transforming growth factor-β pathways regulate EMT whereas they are often deregulated in cancers leading to aberrant EMT. Furthermore, noncoding RNAs, tumor-derived exosomes, and epigenetic alterations are also involved in the modulation of EMT. Therefore, the regulation of EMT is a vital strategy to control the aggressive metastatic characteristics of tumor cells. Despite the vast amount of preclinical data on EMT in cancer progression, there is a lack of clinical translation at the therapeutic level. In this review, we have discussed thoroughly the role of the aforementioned transcription factors, noncoding RNAs (microRNAs, long noncoding RNA, circular RNA), signaling pathways, epigenetic modifications, and tumor-derived exosomes in the regulation of EMT in cancers. We have also emphasized the contribution of EMT to drug resistance and possible therapeutic interventions using plant-derived natural products, their semi-synthetic derivatives, and nano-formulations that are described as promising EMT blockers.

Spatially Annotated Single Cell Sequencing for Unraveling Intratumor Heterogeneity

Intratumor heterogeneity is a major obstacle to effective cancer treatment. Current methods to study intratumor heterogeneity using single-cell RNA sequencing (scRNA-seq) lack information on the spatial organization of cells. While state-of-the art spatial transcriptomics methods capture the spatial distribution, they either lack single cell resolution or have relatively low transcript counts. Here, we introduce spatially annotated single cell sequencing, based on the previously developed functional single cell sequencing (FUNseq) technique, to spatially profile tumor cells with deep scRNA-seq and single cell resolution. Using our approach, we profiled cells located at different distances from the center of a 2D epithelial cell mass. By profiling the cell patch in concentric bands of varying width, we showed that cells at the outermost edge of the patch responded strongest to their local microenvironment, behaved most invasively, and activated the process of epithelial-to-mesenchymal transition (EMT) to migrate to low-confluence areas. We inferred cell-cell communication networks and demonstrated that cells in the outermost ∼10 cell wide band, which we termed the invasive edge, induced similar phenotypic plasticity in neighboring regions. Applying FUNseq to spatially annotate and profile tumor cells enables deep characterization of tumor subpopulations, thereby unraveling the mechanistic basis for intratumor heterogeneity.

A cytokine in turmoil: Transforming growth factor beta in cancer

Cancer remains one of the debilitating health threats to mankind in view of its incurable nature. Many factors are complicit in the initiation, progression and establishment of cancers. Early detection of cancer is the only window of hope that allows for appreciable management and possible limited survival. However, understanding of cancer biology and knowledge of the key factors that interplay at multi-level in the initiation and progression of cancer may hold possible avenues for cancer treatment and management. In particular, dysregulation of growth factor signaling such as that of transforming growth factor beta (TGF-β) and its downstream mediators play key roles in various cancer subtypes. Expanded understanding of the context/cell type-dependent roles of TGF-β and its downstream signaling mediators in cancer may provide leads for cancer pharmacotherapy. Reliable information contained in original articles, reviews, mini-reviews and expert opinions on TGF-β, cancer and the specific roles of TGF-β signaling in various cancer subtypes were retrieved from major scientific data bases including PubMed, Scopus, Medline, Web of Science core collections just to mention but a sample by using the following search terms: TGF-β in cancer, TGF-β and colorectal cancer, TGF-β and brain cancer, TGF-β in cancer initiation, TGF-β and cell proliferation, TGF-β and cell invasion, and TGF-β-based cancer therapy. Retrieved information and reports were carefully examined, contextualized and synchronized into a coherent scientific content to highlight the multiple roles of TGF-β signaling in normal and cancerous cells. From a conceptual standpoint, development of pharmacologically active agents that exert non-specific inhibitory effects on TGF-β signaling on various cell types will undoubtedly lead to a plethora of serious side effects in view of the multi-functionality and pleiotropic nature of TGF-β. Such non-specific targeting of TGF-β could derail any beneficial therapeutic intention associated with TGF-β-based therapy. However, development of pharmacologically active agents designed specifically to target TGF-β signaling in cancer cells may improve cancer pharmacotherapy. Similarly, specific targeting of downstream mediators of TGF-β such as TGF-β type 1 and II receptors (TβRI and TβRII), receptor-mediated Smads, mitogen activated protein kinase (MAPK) and importing proteins in cancer cells may be crucial for cancer pharmacotherapy.

Advances in Understanding TKS4 and TKS5: Molecular Scaffolds Regulating Cellular Processes from Podosome and Invadopodium Formation to Differentiation and Tissue Homeostasis

Scaffold proteins are typically thought of as multi-domain "bridging molecules." They serve as crucial regulators of key signaling events by simultaneously binding multiple participants involved in specific signaling pathways. In the case of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR) binding, the activated EGFR contacts cytosolic SRC tyrosine-kinase, which then becomes activated. This process leads to the phosphorylation of SRC-substrates, including the tyrosine kinase substrates (TKS) scaffold proteins. The TKS proteins serve as a platform for the recruitment of key players in EGFR signal transduction, promoting cell spreading and migration. The TKS4 and the TKS5 scaffold proteins are tyrosine kinase substrates with four or five SH3 domains, respectively. Their structural features allow them to recruit and bind a variety of signaling proteins and to anchor them to the cytoplasmic surface of the cell membrane. Until recently, TKS4 and TKS5 had been recognized for their involvement in cellular motility, reactive oxygen species-dependent processes, and embryonic development, among others. However, a number of novel functions have been discovered for these molecules in recent years. In this review, we attempt to cover the diverse nature of the TKS molecules by discussing their structure, regulation by SRC kinase, relevant signaling pathways, and interaction partners, as well as their involvement in cellular processes, including migration, invasion, differentiation, and adipose tissue and bone homeostasis. We also describe related pathologies and the established mouse models.

Mucinous borderline ovarian tumors with and without Intraepithelial Carcinoma: Differences in clinicopathologic features and fertility results

AIM

To investigate the clinicopathologic characteristic and fertility results of patients with mucinous borderline ovarian tumors (MBOTs), and the effects of intraepithelial carcinoma (IECA) on them.

METHODS

Fifty-two patients treated for MBOTs with or without IECA were retrospectively analyzed.

RESULTS

Patients with IECA were more frequently observed at stage Ic (3/12 vs 1/40, P = 0.034) and accompanied by microinvasive carcinoma (3/12 vs 1/40, P = 0.034). The detected rate of IECA by intraoperative frozen section (5/12, 41.7%) was much lower than that of MBOTs (82.5%, P = 0.010). About 61.5% patients in our study underwent fertility-sparing surgery. Follow-up information was retained completely in 41 patients. And all four tumor recurrences were observed (9.8%) in conservative surgery group in 66 months, though there was no statistical association (P = 0.280). There were three patients who recurred more than once, even one occurred tumor-related death. Only one recurrent patient was in IECA group (P > 0.05). However, patients with IECA were more likely to receive adjuvant chemotherapy (3 of 12 vs 0 of 40, P = 0.010) and surgical staging (75% vs 52.5%, P = 0.200). As for fertility results, nine patients wished to be pregnant and seven of them (77.8%) were successful.

CONCLUSION

For young patients with MBOTs, fertility results are satisfactory after conservative surgery. But patients should be fully informed about the relative high recurrent rate. And IECA has no statistical negative effects on MBOTs till now, but a long-term follow-up is required.

The Many Microenvironments of Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is the most common and deadly subtype of ovarian cancer as it is commonly diagnosed after substantial metastasis has already occurred. The past two decades have been an active era in HGSOC research, with new information on the origin and genomic signature of the tumor cell. Additionally, studies have begun to characterize changes in the HGSOC microenvironment and examine the impact of these changes on tumor progression and response to therapies. While this knowledge may provide valuable insight into better prognosis and treatments for HGSOCs, its collection, synthesis, and application are complicated by the number of unique microenvironments in the disease-the initiating site (fallopian tube), first metastasis (ovary), distal metastases (peritoneum), and recurrent/platinum-resistant setting. Here, we review the state of our understanding of these diverse sites and highlight remaining questions.

Absence of the Tks4 Scaffold Protein Induces Epithelial-Mesenchymal Transition-Like Changes in Human Colon Cancer Cells

Epithelial to mesenchymal transition (EMT) is a multipurpose process involved in wound healing, development, and certain pathological processes, such as metastasis formation. The Tks4 scaffold protein has been implicated in cancer progression; however, its role in oncogenesis is not well defined. In this study, the function of Tks4 was investigated in HCT116 colon cancer cells by knocking the protein out using the CRISPR/Cas9 system. Surprisingly, the absence of Tks4 induced significant changes in cell morphology, motility, adhesion and expression, and localization of E-cadherin, which are all considered as hallmarks of EMT. In agreement with these findings, the marked appearance of fibronectin, a marker of the mesenchymal phenotype, was also observed in Tks4-KO cells. Analysis of the expression of well-known EMT transcription factors revealed that Snail2 was strongly overexpressed in cells lacking Tks4. Tks4-KO cells showed increased motility and decreased cell–cell attachment. Collagen matrix invasion assays demonstrated the abundance of invasive solitary cells. Finally, the reintroduction of Tks4 protein in the Tks4-KO cells restored the expression levels of relevant key transcription factors, suggesting that the Tks4 scaffold protein has a specific and novel role in EMT regulation and cancer progression.

Antifibrotic Mechanism of Cinobufagin in Bleomycin-Induced Pulmonary Fibrosis in Mice

Idiopathic pulmonary fibrosis (IPF) is a progressive and usually fatal lung disease that is characterized by fibroblast proliferation and extracellular matrix remodeling, which result in irreversible distortion of the lung's architecture and the formation of focal fibrous hyperplasia. The molecular mechanism by which pulmonary fibrosis develops is not fully understood, and no satisfactory treatment currently exists. However, many studies consider that aberrant activation of TGF-β1 frequently promotes epithelial-mesenchymal transition (EMT) and fibroblast activation in pulmonary fibrosis. Cinobufagin (CBG), a traditional Chinese medicine, has been widely used for long-term pain relief, cardiac stimulation, and anti-inflammatory and local anesthetic treatments. However, its role in pulmonary fibrosis has not yet been established. We investigated the hypothesis that cinobufagin plays an inhibitory role on TGF-β1 signaling using a luciferase-reporter assay. We further explored the effect of cinobufagin on pulmonary fibrosis both in vitro and in vivo. The in vitro experiments showed that cinobufagin suppresses TGF-β1/Smad3 signaling in a dose-dependent manner, attenuates the activation and differentiation of lung fibroblasts and inhibits EMT induced by TGF-β1 in alveolar epithelial cells. The in vivo experiments indicated that cinobufagin significantly alleviates bleomycin-induced collagen deposition and improves pulmonary function. Further study showed that cinobufagin could attenuate bleomycin-induced inflammation and inhibit fibroblast activation and the EMT process in vivo. In summary, cinobufagin attenuates bleomycin-induced pulmonary fibrosis in mice via suppressing inflammation, fibroblast activation and epithelial-mesenchymal transition.

miR-16 regulates proliferation and invasion of lung cancer cells via the ERK/MAPK signaling pathway by targeted inhibition of MAPK kinase 1 (MEK1)

Objective

The ERK/MAPK signaling pathway regulates cell proliferation and invasion. MAPK kinase 1 (MEK1) is a protein kinase upstream of ERK that can activate the pathway. Expression of microRNA (miR)-16 in lung cancer tissues is decreased. The aim of this study was to determine roles of miR-16 in proliferation and invasion of lung cancer cells.

Methods

We used a luciferase reporter assay to determine a regulatory relationship between miR-16 and MEK1 and assessed expression of MEK1 in normal lung cells and lung cancer cell lines. Plate cloning, flow cytometry, and Transwell experiments demonstrated the proliferation and invasion ability of cells transfected with wild-type and mutant MEK1.

Results

We confirmed a regulatory relationship between miR-16 and MEK1 mRNA. Expression of miR-16 was decreased and that of MEK1 and p-ERK1/2 were increased in lung cancer cell lines compared with normal cells. Transfection with miR-101 mimic or small interfering (si)-MEK1 significantly downregulated expression of MEK1 and p-ERK1/2 in Anip973 cells.

Conclusions

Decreased miR-16 expression may play a role in upregulating expression of MEK1 and promoting proliferation and invasion of lung cancer cells. Overexpression of miR-16 downregulated the ERK/MAPK pathway by inhibiting MEK1 expression, attenuating clone formation and invasion, and inhibiting cell proliferation.

Cancer Cell Derived Small Extracellular Vesicles Contribute to Recipient Cell Metastasis Through Promoting HGF/c-Met Pathway

Cancer progression is frequently caused by metastasis and leads to significantly increased mortality. Cell derived extracellular vesicles, including exosomes, in the microenvironment play key roles in cellular signal transduction, whereas their biological function in cancer metastasis and progression needs in-depth investigation. Here, we initially demonstrate that the small extracellular vesicles (sEVs) derived from highly metastatic lung cancer cells exhibited great capacity to promote the progression of recipient cells. Quantitative proteomics was employed to comprehensively decipher the proteome of cell derived sEVs and more than 1400 sEVs proteins were identified. Comparison analysis indicates that sEVs-HGF is a potential metastasis related protein and our verification data from clinical lung cancer plasma samples and in vivo experiments further confirmed the association. We found that sEVs-HGF could induce epithelial-mesenchymal transition and the coordination between HGF and c-Met was confirmed through corresponding target knockdown and kinase inhibition. Our data collectively demonstrate that cancer cell derived sEVs contribute to recipient cell metastasis through promoting HGF/c-Met pathway, which are potential targets for the prevention and treatment of cancer metastasis.

Ddx4+ Oogonial Stem Cells in Postmenopausal Women's Ovaries: A Controversial, Undefined Role

Recent studies support the existence of oogonial stem cells (OSCs) in the ovarian cortex of different mammals, including women.These cells are characterized by small size, membrane expression of DEAD(Asp-Glu-Ala-Asp)-box polypeptide-4 (Ddx4), and stemness properties (such as self-renewal and clonal expansion) as well as the ability to differentiate in vitro into oocyte-like cells. However, the discovery of OSCs contrasts with the popular theory that there is a numerically defined oocyte pool for female fertility which undergoes exhaustion with menopause. Indeed, in the ovarian cortex of postmenopausal women OSCs have been detected that possess both viability and capability to differentiate into oocytes, which is similar to those observed in younger patients. The pathophysiological role of this cell population in aged women is still debated since OSCs, under appropriate stimuli, differentiate into somatic cells, and the occurrence of Ddx4⁺ cells in ovarian tumor samples also suggests their potential involvement in carcinogenesis. Although further investigation into these observations is needed to clarify OSC function in ovary physiology, clinical investigators and researchers studying female infertility are presently focusing on OSCs as a novel opportunity to restore ovarian reserve in both young women undergoing early ovarian failure and cancer survivors experiencing iatrogenic menopause.

MEIS1 knockdown may promote differentiation of esophageal squamous carcinoma cell line KYSE-30

Background

MEIS1 (Myeloid ecotropic viral integration site 1), as a homeobox (HOX) transcription factor, has a dual function in different types of cancer. Although numerous roles are proposed for MEIS1 in differentiation, stem cell function, gastrointestinal development and tumorigenesis, the involved molecular mechanisms are poor understood. Our aim in this study was to elucidate the functional correlation between MEIS1, as regulator of differentiation process, and the involved genes in cell differentiation in human esophageal squamous carcinoma (ESC) cell line KYSE‐30.

Methods

The KYSE‐30 cells were transduced using recombinant retroviral particles containing specific shRNA sequence against MEIS1 to knockdown MEIS1 gene expression. Following RNA extraction and cDNA synthesis, mRNA expression of MEIS1 and the selected genes including TWIST1, EGF, CDX2, and KRT4 was examined using relative comparative real‐time PCR.

Results

Retroviral transduction caused a significant underexpression of MEIS1 in GFP‐hMEIS1 compared to control GFP cells approximately 5.5‐fold. While knockdown of MEIS1 expression caused a significant decrease in EGF and TWIST1 mRNA expression, nearly ‐8‐ and ‐12‐fold respectively, it caused a significant increase in mRNA expression of differentiation markers including KRT4 and CDX2, approximately 34‐ and 1.14‐fold, correspondingly.

Conclusion

MEIS1 gene silencing in KYSE‐30 cells increased expression of epithelial markers and decreased expression of epithelial‐mesenchymal transition (EMT) marker TWIST1. It may highlight the role of MEIS1 in differentiation process of KYSE‐30 cells. These results may confirm that MEIS1 silencing promotes differentiation and decreases EMT capability of ESC cell line KYSE‐30.

DDR1 regulates thyroid cancer cell differentiation via IGF-2/IR-A autocrine signaling loop

Patients with thyroid cancers refractory to radioiodine (RAI) treatment show a limited response to various therapeutic options and a low survival rate. The recent use of multikinase inhibitors has also met limited success. An alternative approach relies on drugs that induce cell differentiation, as the ensuing increased expression of the cotransporter for sodium and iodine (NIS) may partially restore sensitivity to radioiodine. The inhibition of the ERK1/2 pathway has shown some efficacy in this context. Aggressive thyroid tumors overexpress the isoform-A of the insulin receptor (IR-A) and its ligand IGF-2; this IGF-2/IR-A loop is associated with de-differentiation and stem-like phenotype, resembling RAI-refractory tumors. Importantly, IR-A has been shown to be positively modulated by the non-integrin collagen receptor DDR1 in human breast cancer. Using undifferentiated human thyroid cancer cells, we now evaluated the effects of DDR1 on IGF-2/IR-A loop and on markers of cell differentiation and stemness. DDR1 silencing or downregulation caused significant reduction of IR-A and IGF-2 expression, and concomitant increased levels of differentiation markers (NIS, Tg, TSH, TPO). Conversely, markers of epithelial-to-mesenchymal transition (Vimentin, Snail-2, Zeb1, Zeb2 and N-Cadherin) and stemness (OCT-4, SOX-2, ABCG2 and Nanog) decreased. These effects were collagen independent. In contrast, overexpression of either DDR1 or its kinase-inactive variant K618A DDR1-induced changes suggestive of less differentiated and stem-like phenotype. Collagen stimulation was uneffective. In conclusion, in poorly differentiated thyroid cancer, DDR1 silencing or downregulation blocks the IGF-2/IR-A autocrine loop and induces cellular differentiation. These results may open novel therapeutic approaches for thyroid cancer.

Reciprocal regulation of the cholinic phenotype and epithelial-mesenchymal transition in glioblastoma cells

Glioblastoma (GBM) is the most malignant brain tumor with very limited therapeutic options. Standard multimodal treatments, including surgical resection and combined radio-chemotherapy do not target the most aggressive subtype of glioma cells, brain tumor stem cells (BTSCs). BTSCs are thought to be responsible for tumor initiation, progression, and relapse. Furthermore, they have been associated with the expression of mesenchymal features as a result of epithelial-mesenchymal transition (EMT) thereby inducing tumor dissemination and chemo resistance. Using high resolution proton nuclear magnetic resonance spectroscopy (¹H NMR) on GBM cell cultures we provide evidence that the expression of well-known EMT activators of the ZEB, TWIST and SNAI families and EMT target genes N-cadherin and VIMENTIN is associated with aberrant choline metabolism. The cholinic phenotype is characterized by high intracellular levels of phosphocholine and total choline derivatives and was associated with malignancy in various cancers. Both genetic and pharmacological inhibition of the cardinal choline metabolism regulator choline kinase alpha (CHKα) significantly reduces the cell viability, invasiveness, clonogenicity, and expression of EMT associated genes in GBM cells. Moreover, in some cell lines synergetic cytotoxic effects were observed when combining the standard of care chemotherapeutic temozolomide with the CHKα inhibitor V-11-0711. Taken together, specific inhibition of the enzymatic activity of CHKα is a powerful strategy to suppress EMT which opens the possibility to target chemo-resistant BTSCs through impairing their mesenchymal transdifferentiation. Moreover, the newly identified EMT-oncometabolic network may be helpful to monitor the invasive properties of glioblastomas and the success of anti-EMT therapy.

Activin B promotes endometrial cancer cell migration by down-regulating E-cadherin via SMAD-independent MEK-ERK1/2-SNAIL signaling

High-risk type II endometrial cancers account for ~30% of cases but ~75% of deaths due, in part, to their tendency to metastasize. Histopathological studies of type II endometrial cancers (non-endometrioid, mostly serous) suggest overproduction of activin B and down-regulation of E-cadherin, both of which are associated with reduced survival. Our previous studies have shown that activin B increases the migration of type II endometrial cancer cell lines. However, little is known about the relationship between activin B signaling and E-cadherin in endometrial cancer. We now demonstrate that activin B treatment significantly decreases E-cadherin expression in both a time- and concentration-dependent manner in KLE and HEC-50 cell lines. Interestingly, these effects were not inhibited by knockdown of SMAD2, SMAD3 or SMAD4. Rather, the suppressive effects of activin B on E-cadherin were mediated by MEK-ERK1/2-induced production of the transcription factor SNAIL. Importantly, activin B-induced cell migration was inhibited by forced-expression of E-cadherin or pre-treatment with the activin/TGF-β type I receptor inhibitor SB431542 or the MEK inhibitor U0126. We have identified a novel SMAD-independent pathway linking enhanced activin B signaling to reduced E-cadherin expression and increased migration in type II endometrial cancer.

Betacellulin induces Slug-mediated down-regulation of E-cadherin and cell migration in ovarian cancer cells

Epithelial ovarian cancer is the leading cause of death among gynaecological cancers. Previous studies have demonstrated that epidermal growth factor receptor (EGFR) ligands can induce ovarian cancer cell invasion by down-regulating E-cadherin. Betacellulin is a unique member of the EGF family. It is overexpressed in a variety of cancers and is associated with reduced survival. However, the biological functions and clinical significance of betacellulin in ovarian cancer remain unknown. In the current study, we tested the hypothesis that betacellulin induces ovarian cancer cell migration by suppressing E-cadherin expression. Treatment of SKOV3 and OVCAR5 ovarian cancer cell lines with betacellulin down-regulated E-cadherin, but not N-cadherin. In addition, betacellulin treatment increased the expression of Snail and Slug, and these effects were completely blocked by pre-treatment with EGFR inhibitor AG1478. Interestingly, only knockdown of Slug reversed the down-regulation of E-cadherin by betacellulin. Betacellulin treatment induced the activation of both the MEK-ERK and PI3K-Akt signaling pathways, and it also significantly increased ovarian cancer cell migration. Importantly, the effects of betacellulin on E-cadherin, Slug and cell migration were attenuated by pre-treatment with either U0126 or LY294002. Our results suggest that betacellulin induces ovarian cancer migration and Slug-dependent E-cadherin down-regulation via EGFR-mediated MEK-ERK and PI3K-Akt signaling.

MiR-5100 targets TOB2 to drive epithelial-mesenchymal transition associated with activating smad2/3 in lung epithelial cells

Idiopathic pulmonary fibrosis (IPF) is a devastating disease and the pathogenesis of IPF remains unclear. Our previous study indicated that miR-5100 promotes the proliferation and metastasis of lung epithelial cells. In this study, we investigated the effect and mechanism of miR-5100 on bleomycin (BLM)-induced mouse lung fibrosis and transforming growth factor β (TGF-β1) or epidermal growth factor (EGF) induced EMT-model in A549 and Beas-2B cells. The elevated level of miR-5100 was observed in both the mouse lung fibrosis tissues and EMT cell model. Furthermore, the exogenous expression of miR-5100 promoted the EMT-related changes, enhanced TGF-β1 or EGF-induced EMT and activated the smad2/3 in lung epithelial cells, while silencing miR-5100 had the converse effects. In addition, transwell assay showed that miR-5100 can enhance cell migration. Using target prediction software and luciferase reporter assays, we identified TOB2 as a specific target of miR-5100 and miR-5100 can decrease the accumulation of endogenous TOB2 in A549 and Beas-2B cells. Moreover, the exogenous expression of TOB2 relieves the promotion of miR-5100 on EMT process and migration ability. Taken together, our results indicate that miR-5100 promotes the EMT process by targeting TOB2 associated with activating smad2/3 in lung epithlium cells. Our findings may provide novel insights into the pathogenesis of IPF.

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.

Plasticity of tumor cell invasion: governance by growth factors and cytokines

Tumor cell migration, the basis for metastatic dissemination, is an adaptive process which depends upon coordinated cell interaction with the environment, influencing cell-matrix and cell-cell adhesion, cytoskeletal dynamics and extracellular matrix remodeling. Growth factors and cytokines, released within the reactive tumor microenvironment and their intracellular effector signals strongly impact mechanocoupling functions in tumor cells and thereby control the mode and extent of tumor invasion, including collective and single-cell migration and their interconversions. Besides their role in controlling tumor cell growth and survival, cytokines and growth factors thus provide complex orchestration of the metastatic cascade and tumor cell adaptation to environmental challenge. We here review the mechanisms by which growth factors and cytokines control the reciprocal interactions between tumor cells and their microenvironment, and the consequences for the efficacy and plasticity of invasion programs and metastasis.

Fabrication of an EGF modified nanodiamonds-based anti-cancer drug targeted delivery system and drug carrier uptake visualization by 3D Raman microscopy

We developed a nanodiamond-based anti-cancer drug targeted delivery system, epidermal growth factor–nanodiamonds–cisplatin (ENC) bioconjugate, which could selectively kill tumor cells and be located through 3D confocal Raman imaging.

Fascin-1 expression as stratification marker in borderline epithelial tumours of the ovary

AIMS

To evaluate the actin-bundling protein fascin-1 (FSCN1) as marker for borderline ovarian tumours (BOTs).

METHODS

We analysed a retrospective cohort of 140 BOTs with validated diagnosis by an independent pathologist. Immunohistochemical detection of FSCN1 was quantified as combined immunoreactive score (CIS) blinded to clinical patient data. Analyses were first performed for FSCN1 positive versus negative, and then verified using three categories derived from the observed distribution (negative, weak, strong; CIS 0, 1-2, 3-9).

RESULTS

We detected FSCN1 positivity in 51.4%, and strong expression (CIS 3-9) in 14.3% of the samples. FSCN1 positivity was associated with serous subtype (p<0.001) and micropapillary pattern (p<0.001). Correlation with micropapillary pattern remained significant within the serous BOT (SBOT) subgroup (p=0.022). Strong FSCN1 expression (CIS 3-9) was associated both with the presence of implants (p=0.022), and a higher International Federation of Gynecology and Obstetrics (FIGO) stage (p=0.020).

CONCLUSIONS

Our analysis links FSCN1 with SBOT with micropapillary pattern. Strong expression is associated with higher FIGO stage and the presence of implants, both related to elevated risk of recurrence. Hence, FSCN1 is an interesting marker worth further analyses of its prognostic value in BOTs.

CD40 ligand induces RIP1-dependent, necroptosis-like cell death in low-grade serous but not serous borderline ovarian tumor cells

Ovarian high-grade serous carcinomas (HGSCs) and invasive low-grade serous carcinomas (LGSCs) are considered to be distinct entities. In particular, LGSCs are thought to arise from non-invasive serous borderline ovarian tumors (SBOTs) and show poor responsiveness to conventional chemotherapy. The pro-apoptotic effects of CD40 ligand (CD40L) have been demonstrated in HGSC, though the underlying mechanisms are not fully understood. Conversely, the therapeutic potential of the CD40L-CD40 system has yet to be evaluated in LGSC. We now show that CD40 protein is focally expressed on tumor cells in two of five primary LGSCs compared with no expression in eight primary SBOTs. Treatment with CD40L or agonistic CD40 antibody decreased the viability of LGSC-derived MPSC1 and VOA1312 cells, but not SBOT3.1 cells. Small interfering RNA (siRNA) targeting CD40 was used to show that it is required for these reductions in cell viability. CD40L treatment increased cleaved caspase-3 levels in MPSC1 cells though, surprisingly, neither pan-caspase inhibitor nor caspase-3 siRNA reversed or even attenuated CD40L-induced cell death. In addition, CD40-induced cell death was not affected by knockdown of the mitochondrial proteins apoptosis-inducing factor (AIF) and endonuclease G (EndoG). Interestingly, CD40L-induced cell death was blocked by necrostatin-1, an inhibitor of receptor-interacting protein 1 (RIP1), and attenuated by inhibitors of RIP3 (GSK'872) or MLKL (mixed lineage kinase domain-like; necrosulfonamide). Our results indicate that the upregulation of CD40 may be relatively common in LGSC and that CD40 activation induces RIP1-dependent, necroptosis-like cell death in LGSC cells.

Celecoxib induces epithelial-mesenchymal transition in epithelial ovarian cancer cells via regulating ZEB1 expression

PURPOSE

The purpose of our study was to investigate the therapeutic potential of Celecoxib for epithelial ovarian cancer, especially on cellular morphological changes, proliferation invasion and epithelial-mesenchymal transition (EMT).

METHOD

The MTT and transwell assays were performed to evaluate the effect of Celecoxib on proliferation and invasion ability of ovarian cancer cell lines, respectively. Western blot was carried out to detect the expression of epithelial phenotypes, E-cadherin and Keratin, and mesenchymal phenotypes, N-cadherin and Vimentin, as well as p-AKT, p-ERK and ZEB1. ZEB1 small-interfering RNA (siRNA) was used to downregulate the expression of ZEB1 to further inquiring into the downstream of Celecoxib-induced EMT.

RESULTS

Cellular morphological assessment revealed that both A2780 and SKOV3 cells gradually appeared in the morphology of mesenchymal cells after Celecoxib treatment. The MTT assay demonstrated that celecoxib had no effect on cell proliferation. Transwell assay showed that Celecoxib significantly increased the cell invasion ability. Western blot data proved that the expression of E-cadherin and keratin was elevated, whereas the expression of N-cadherin and Vimentin was decreased in a dose-dependent manner compared with the untreated cells, the expression of p-AKT, p-ERK and ZEB1 was also obviously elevated. However, ZEB1 siRNA reversed Celecoxib-induced E-cadherin expression and N-cadherin expression, as well as cellular invasiveness.

CONCLUSION

Our results indicated that Celecoxib might induce EMT and increase cellular invasiveness in ovarian cancer cells in vitro, which also implied that it needed a comprehensive evaluation in preclinical researches before introducing Celecoxib into the clinical regimen.

Triclosan potentiates epithelial-to-mesenchymal transition in anoikis-resistant human lung cancer cells

Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT) in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt) and Ras-related C3 botulinum toxin substrate 1 (Rac1), which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients.

COX2 and PGE2 mediate EGF-induced E-cadherin-independent human ovarian cancer cell invasion

Elevated expression of cyclooxygenase 2 (COX2 (PTGS2)) has been reported to occur in human ovarian cancer and to be associated with poor prognosis. We have previously demonstrated that COX2-derived prostaglandin E2 (PGE2) promotes human ovarian cancer cell invasion. We had also demonstrated that epidermal growth factor (EGF) induces human ovarian cancer cell invasion by downregulating the expression of E-cadherin through various signaling pathways. However, it remains unclear whether COX2 and PGE2 are involved in the EGF-induced downregulation of E-cadherin expression and cell invasion in human ovarian cancer cells. In this study, we showed that EGF treatment induces COX2 expression and PGE2 production in SKOV3 and OVCAR5 human ovarian cancer cell lines. Interestingly, COX2 is not required for the EGF-induced downregulation of E-cadherin expression. In addition, EGF treatment activates the phosphatidylinositol-3-kinase (PI3K)/Akt and cAMP response element-binding protein (CREB) signaling pathways, while only the PI3K/Akt pathway is involved in EGF-induced COX2 expression. Moreover, we also showed that EGF-induced cell invasion is attenuated by treatment with a selective COX2 inhibitor, NS-398, as well as PGE2 siRNA. This study demonstrates an important role for COX2 and its derivative, PGE2, in the mediation of the effects of EGF on human ovarian cancer cell invasion.

EGF/EGFR axis contributes to the progression of cholangiocarcinoma through the induction of an epithelial-mesenchymal transition

BACKGROUND & AIMS

Epithelial-mesenchymal transition (EMT) is a cellular process involved in cancer progression. The first step of EMT consists in the disruption of E-cadherin-mediated adherens junctions. Cholangiocarcinoma (CCA), a cancer with a poor prognosis due to local invasion and metastasis, displays EMT features. EGFR, a receptor tyrosine kinase, plays a major role in CCA progression. The aim of the study was to determine if EMT is induced by EGFR in CCA cells.

METHODS

In vivo, the expression of E-cadherin was analysed in CCA tumours of 100 patients and correlated with pathological features and EGFR expression, and in a xenograft model in mice treated with gefitinib, an inhibitor of EGFR. In vitro, the regulation of EMT by EGFR was investigated in CCA cell lines.

RESULTS

In human CCA, a cytoplasmic localization of E-cadherin occurred in 50% of the tumours was associated with the peripheral type of CCA, tumour size, the presence of satellite nodules and EGFR overexpression. In xenografted tumours, E-cadherin displayed a cytoplasmic pattern whereas the treatment of mice with gefitinib restored the membranous expression of E-cadherin. In vitro, EGF induced scattering of CCA cells that resulted from the disruption of adherens junctions. Internalization and decreased expression of E-cadherin, as well as nuclear translocation of β-catenin, were observed in EGF-treated CCA cells. In these cells, EMT-transcription factors (i.e., Slug and Zeb-1) and mesenchymal markers (i.e., N-cadherin and α-SMA) were induced, favoring cell invasiveness through cytoskeleton remodeling. All these effects were inhibited by gefitinib.

CONCLUSIONS

The EGF/EGFR axis triggers EMT in CCA cells highlighting the key role of this pathway in CCA progression.

Targeting EMT in cancer: opportunities for pharmacological intervention

The spread of cancer cells to distant organs represents a major clinical challenge in the treatment of cancer. Epithelial-mesenchymal transition (EMT) has emerged as a key regulator of metastasis in some cancers by conferring an invasive phenotype. As well as facilitating metastasis, EMT is thought to generate cancer stem cells and contribute to therapy resistance. Therefore, the EMT pathway is of great therapeutic interest in the treatment of cancer and could be targeted either to prevent tumor dissemination in patients at high risk of developing metastatic lesions or to eradicate existing metastatic cancer cells in patients with more advanced disease. In this review, we discuss approaches for the design of EMT-based therapies in cancer, summarize evidence for some of the proposed EMT targets, and review the potential advantages and pitfalls of each approach.

Epidermal growth factor-like domain-containing protein 7 (EGFL7) enhances EGF receptor-AKT signaling, epithelial-mesenchymal transition, and metastasis of gastric cancer cells

Epidermal growth factor-like domain-containing protein 7 (EGFL7) is upregulated in human epithelial tumors and so is a potential biomarker for malignancy. Indeed, previous studies have shown that high EGFL7 expression promotes infiltration and metastasis of gastric carcinoma. The epithelial-mesenchymal transition (EMT) initiates the metastatic cascade and endows cancer cells with invasive and migratory capacity; however, it is not known if EGFL7 promotes metastasis by triggering EMT. We found that EGFL7 was overexpressed in multiple human gastric cancer (GC) cell lines and that overexpression promoted cell invasion and migration as revealed by scratch wound and transwell migration assays. Conversely, shRNA-mediated EGFL7 knockdown reduced invasion and migration. Furthermore, EGFL7-overexpressing cells grew into larger tumors and were more likely to metastasize to the liver compared to underexpressing CG cells following subcutaneous injection in mice. EGFL7 overexpression protected GC cell lines against anoikis, providing a plausible mechanism for this enhanced metastatic capacity. In excised human gastric tumors, expression of EGFL7 was positively correlated with expression levels of the mesenchymal marker vimentin and the EMT-associated transcription repressor Snail, and negatively correlated with expression of the epithelial cell marker E-cadherin. In GC cell lines, EGFL7 knockdown reversed morphological signs of EMT and decreased both vimentin and Snail expression. In addition, EGFL7 overexpression promoted EGF receptor (EGFR) and protein kinase B (AKT) phospho-activation, effects markedly suppressed by the EGFR tyrosine kinase inhibitor AG1478. Moreover, AG1478 also reduced the elevated invasive and migratory capacity of GC cell lines overexpressing EGFL7. Collectively, these results strongly suggest that EGFL7 promotes metastasis by activating EMT through an EGFR-AKT-Snail signaling pathway. Disruption of EGFL7-EGFR-AKT-Snail signaling may a promising therapeutic strategy for gastric cancer.

Chromatinized protein kinase C-θ directly regulates inducible genes in epithelial to mesenchymal transition and breast cancer stem cells

Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) promotes EMT by acting as a critical chromatin-anchored switch for inducible genes via transforming growth factor β (TGF-β) and the key inflammatory regulatory protein NF-κB. Chromatinized PKC-θ exists as an active transcription complex and is required to establish a permissive chromatin state at signature EMT genes. Genome-wide analysis identifies a unique cohort of inducible PKC-θ-sensitive genes that are directly tethered to PKC-θ in the mesenchymal state. Collectively, we show that cross talk between signaling kinases and chromatin is critical for eliciting inducible transcriptional programs that drive mesenchymal differentiation and CSC formation, providing novel mechanisms to target using epigenetic therapy in breast cancer.

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.

MicroRNA-7 inhibits tumor metastasis and reverses epithelial-mesenchymal transition through AKT/ERK1/2 inactivation by targeting EGFR in epithelial ovarian cancer

Epidermal growth factor receptor (EGFR) overexpression and activation result in increased proliferation and migration of solid tumors including ovarian cancer. In recent years, mounting evidence indicates that EGFR is a direct and functional target of miR-7. In this study, we found that miR-7 expression was significantly downregulated in highly metastatic epithelial ovarian cancer (EOC) cell lines and metastatic tissues, whereas the expression of, EGFR correlated positively with metastasis in both EOC patients and cell lines. Overexpression of miR-7 markedly suppressed the capacities of cell invasion and migration and resulted in morphological changes from a mesenchymal phenotype to an epithelial-like phenotype in EOC. In addition, overexpression of miR-7 upregulated CK-18 and β-catenin expression and downregulated Vimentin expression, accompanied with EGFR inhibition and AKT/ERK1/2 inactivation. Similar to miR-7 transfection, silencing of EGFR with this siRNA in EOC cells also upregulated CK-18 and β-catenin expression and downregulated Vimentin expression, and decreased phosphorylation of both Akt and ERK1/2, confirming that EGFR is a target of miR-7 in reversing EMT. The pharmacological inhibition of PI3K-AKT and ERK1/2 both significantly enhanced CK-18 and β-catenin expression and suppressed vimentin expression, indicating that AKT and ERK1/2 pathways are required for miR-7 mediating EMT. Finally, the expression of miR-7 and EGFR in primary EOC with matched metastasis tissues was explored. It was showed that miR-7 is inversely correlated with EGFR. Taken together, our results suggested that miR-7 inhibited tumor metastasis and reversed EMT through AKT and ERK1/2 pathway inactivation by reducing EGFR expression in EOC cell lines. Thus, miR-7 might be a potential prognostic marker and therapeutic target for ovarian cancer metastasis intervention.

Overexpressed FOXC2 in ovarian cancer enhances the epithelial-to-mesenchymal transition and invasion of ovarian cancer cells

Ovarian cancer is a highly invasive and metastatic disease with poor prognosis, particularly if this disease is diagnosed at an advanced stage, which is often the case. Researchers have argued that ovarian cancer cells that have undergone epithelial‑to‑mesenchymal transition (EMT) acquire aggressive malignant properties; however, the relevant molecular mechanisms in this setting are poorly understood. In cancer cases, the transcription factor forkhead box protein C2 (FOXC2) has been detected, but the function of this factor in ovarian cancer tumorigenesis remains unclear. In the present study, FOXC2 was overexpressed in invasive ovarian cancer cell lines and tissues. The invasive potential of ovarian cancer cells was significantly increased by ectopic FOXC2 expression but it was significantly decreased by RNA interference targeting FOXC2. E‑cadherin and vimentin expression levels were modulated by FOXC2. These results indicated that FOXC2 was required for the maintenance of the mesenchymal phenotype after TGF‑β1 induced EMT in human ovarian cancer cells. Thus, FOXC2 or its associated gene expression program may provide an effective target for anti-EMT-based therapies. These therapies can then be performed to treat invasive ovarian tumor.

Akt/Ezrin Tyr353/NF-κB pathway regulates EGF-induced EMT and metastasis in tongue squamous cell carcinoma

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a crucial programme in cancer metastasis. Epidermal growth factor (EGF) is a key inducer of EMT, and Ezrin has an important role in this process. However, how Ezrin is activated and whether it mediates EGF-induced EMT in tongue squamous cell carcinomas (TSCCs) through activating NF-κB remains obscure.

METHODS

We used two TSCC cell lines as a cell model to study invasion and EMT in vitro, and used nude mice xenografts model to evaluate metastasis of TSCC cells. Finally, we evaluated the level of pEzrin Tyr353, nuclear p65 and EMT markers in TSCC clinical samples.

RESULTS

Ezrin Tyr353 was phosphorylated through Akt (but not ERK1/2, ROCK1) pathway, and lead to the activation of NF-κB in EGF-treated TSCC cells. Akt and NF-κB inhibitors blocked EGF-induced EMT, and suppressed invasion and migration of TSCC cells. In vivo, silencing Ezrin significantly suppressed EGF-enhanced metastasis of TSCC xenografts. Finally, high levels of expression of pEzrin Tyr353, nuclear p65, vimentin and low level of expression of E-cadherin were correlated with cancer metastasis and poor patient prognosis.

CONCLUSION

Our data suggest that Akt/Ezrin Tyr353/NF-κB pathway regulates EGF-induced EMT and metastasis inTSCC, and Ezrin may serve as a therapeutic target to reverse EMT in tongue cancers and prevent TSCC progression.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) induction on Snail expression during mouse decidualization

Embryo implantation requires a precise synchronism between the receptive uterus and activated blastocyst and is regulated by complicated molecular networks. Although many implantation-related genes have been identified, the crosstalk among them is still unknown. Snail, a transcription repressor, plays a central role during epithelial-mesenchymal transition. Our previous study showed that Snail is highly expressed at implantation site in mouse uterus. This study was to examine how Snail is related with other implantation-related genes in mice. Uterine stromal cells were isolated from mouse uteri on day 4 of pregnancy and treated with HB-EGF. Snail was induced significantly by HB-EGF. By using specific inhibitors and siRNA, we demonstrated that HB-EGF induction on Snail expression is dependent on the EGFR-ERK-Stat3 pathway. Cox-2 was regulated by Snail. The current findings demonstrate that Snail can relate with HB-EGF, Stat3 and Cox-2 and may play a role during mouse embryo implantation and decidualization.

TACC3 is essential for EGF-mediated EMT in cervical cancer

The third member of transforming acidic coiled-coil protein (TACC) family, TACC3, has been shown to be an important player in the regulation of centrosome/microtubule dynamics during mitosis and found to be deregulated in a variety of human malignancies. Our previous studies have suggested that TACC3 may be involved in cervical cancer progression and chemoresistance, and its overexpression can induce epithelial-mesenchymal transition (EMT) by activating the phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated protein kinases (ERKs) signal transduction pathways. However, the upstream mechanisms of TACC3-mediated EMT and its functional/clinical importance in human cervical cancer remain elusive. Epidermal growth factor (EGF) has been shown to be a potent inducer of EMT in cervical cancer and associated with tumor invasion and metastasis. In this study, we found that TACC3 is overexpressed in cervical cancer and can be induced upon EGF stimulation. The induction of TACC3 by EGF is dependent on the tyrosine kinase activity of the EGF receptor (EGFR). Intriguingly, depletion of TACC3 abolishes EGF-mediated EMT, suggesting that TACC3 is required for EGF/EGFR-driven EMT process. Moreover, Snail, a key player in EGF-mediated EMT, is found to be correlated with the expression of TACC3 in cervical cancer. Collectively, our study highlights a novel function for TACC3 in EGF-mediated EMT process and suggests that targeting of TACC3 may be an attractive strategy to treat cervical cancers driven by EGF/EGFR signaling pathways.

Downregulated E-cadherin expression indicates worse prognosis in Asian patients with colorectal cancer: evidence from meta-analysis

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays a crucial role in the progression and aggressiveness of colorectal carcinoma. E-cadherin is the best-characterized molecular marker of EMT, but its prognostic significance for patients with CRC remains inconclusive.

METHODOLOGY

Eligible studies were searched from the PubMed, Embase and Web of Science databases. Correlation between E-cadherin expression and clinicopathological features and prognosis was analyzed. Subgroup analysis was also performed according to study location, number of patients, quality score of studies and cut-off value.

PRINCIPAL FINDINGS

A total of 27 studies comprising 4244 cases met the inclusion criteria. Meta-analysis suggested that downregulated E-cadherin expression had an unfavorable impact on overall survival (OS) of CRC (n = 2730 in 14 studies; HR = 2.27, 95%CI: 1.63-3.17; Z = 4.83; P = 0.000). Subgroup analysis indicated that low E-cadherin expression was significantly associated with worse OS in Asian patients (n = 1054 in 9 studies; HR = 2.86, 95%CI: 2.13-3.7, Z = 7.11; P = 0.000) but not in European patients (n = 1552 in 4 studies; HR = 1.14, 95%CI: 0.95-1.35, Z = 1.39; P = 0.165). In addition, reduced E-cadherin expression indicated an unfavorable OS only when the cut off value of low E-cadherin expression was >50% (n = 512 in 4 studies; HR = 2.08, 95%CI 1.45-2.94, Z = 4.05; P = 0.000). Downregulated E-cadherin expression was greatly related with differentiation grade, Dukes' stages, lymphnode status and metastasis. The pooled OR was 0.36(95%CI: 0.19-0.7, Z = 3.03, P = 0.002), 0.34(95%CI: 0.21-0.55, Z = 6.61, P = 0.000), 0.49(95%CI: 0.32-0.74, Z = 3.02, P = 0.002) and 0.45(95%CI: 0.22-0.91, Z = 3.43, P = 0.001), respectively.

CONCLUSIONS

This study showed that low or absent E-cadherin expression detected by immunohistochemistry served as a valuable prognostic factor of CRC. However, downregulated E-cadherin expression seemed to be associated with worse prognosis in Asian CRC patients but not in European CRC patients. Additionally, this meta-analysis suggested that the negative threshold of E-cadherin should be >50% when we detected its expression in the immunohistochemistry stain.

GSK3β controls epithelial-mesenchymal transition and tumor metastasis by CHIP-mediated degradation of Slug

Glycogen synthase kinase 3 beta (GSK3β) is highly inactivated in epithelial cancers and is known to inhibit tumor migration and invasion. The zinc-finger-containing transcriptional repressor, Slug, represses E-cadherin transcription and enhances epithelial-mesenchymal transition (EMT). In this study, we find that the GSK3β-pSer9 level is associated with the expression of Slug in non-small cell lung cancer. GSK3β-mediated phosphorylation of Slug facilitates Slug protein turnover. Proteomic analysis reveals that the carboxyl terminus of Hsc70-interacting protein (CHIP) interacts with wild-type Slug (wtSlug). Knockdown of CHIP stabilizes the wtSlug protein and reduces Slug ubiquitylation and degradation. In contrast, nonphosphorylatable Slug-4SA is not degraded by CHIP. The accumulation of nondegradable Slug may further lead to the repression of E-cadherin expression and promote cancer cell migration, invasion and metastasis. Our findings provide evidence of a de novo GSK3β-CHIP-Slug pathway that may be involved in the progression of metastasis in lung cancer.

Epithelial-mesenchymal transition in carcinomas of the female genital tract

Invasion is a defining feature of malignancy, but the mechanisms of invasion in many common cancers, including gynaecological malignancies, remain unclear. However, it has been proposed that malignant cells may usurp a normal embryological process, epithelial-mesenchymal transition (EMT), as a means of acquiring migratory capacity. The synergistic role of the tumour microenvironment in EMT induction has also been explored and helps to explain the spatially restricted distribution of EMT at the deep tumour margin (invasive front). Furthermore, tumour cells undergoing EMT may acquire cancer stem cell characteristics, and this may be relevant to the entire metastatic process and to tumour recurrence and treatment failure. Nevertheless, doubts persist regarding the role of EMT in malignant progression in vivo, partly because few studies have correlated molecular and histological alterations in clinical pathology specimens. In the current review we summarize the evidence for EMT in the common gynaecological epithelial malignancies, and discuss the morphological and immunohistochemical changes occurring at the invasive tumour front that may represent EMT-like processes. The possibility that carcinosarcomas represent a variant type of EMT with 'fixed' mesenchymal differentiation is also considered. Diagnostic histopathologists are ideally placed to critically evaluate the role of EMT in gynaecological and other types of malignancy.

Reduced CTGF expression promotes cell growth, migration, and invasion in nasopharyngeal carcinoma

Background

The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC).

Experimental design

CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored.

Results

NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC.

Conclusion

Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.

Flow induces epithelial-mesenchymal transition, cellular heterogeneity and biomarker modulation in 3D ovarian cancer nodules

Seventy-five percent of patients with epithelial ovarian cancer present with advanced-stage disease that is extensively disseminated intraperitoneally and prognosticates the poorest outcomes. Primarily metastatic within the abdominal cavity, ovarian carcinomas initially spread to adjacent organs by direct extension and then disseminate via the transcoelomic route to distant sites. Natural fluidic streams of malignant ascites triggered by physiological factors, including gravity and negative subdiaphragmatic pressure, carry metastatic cells throughout the peritoneum. We investigated the role of fluidic forces as modulators of metastatic cancer biology in a customizable microfluidic platform using 3D ovarian cancer nodules. Changes in the morphological, genetic, and protein profiles of biomarkers associated with aggressive disease were evaluated in the 3D cultures grown under controlled and continuous laminar flow. A modulation of biomarker expression and tumor morphology consistent with increased epithelial-mesenchymal transition, a critical step in metastatic progression and an indicator of aggressive disease, is observed because of hydrodynamic forces. The increase in epithelial-mesenchymal transition is driven in part by a posttranslational up-regulation of epidermal growth factor receptor (EGFR) expression and activation, which is associated with the worst prognosis in ovarian cancer. A flow-induced, transcriptionally regulated decrease in E-cadherin protein expression and a simultaneous increase in vimentin is observed, indicating increased metastatic potential. These findings demonstrate that fluidic streams induce a motile and aggressive tumor phenotype. The microfluidic platform developed here potentially provides a flow-informed framework complementary to conventional mechanism-based therapeutic strategies, with broad applicability to other lethal malignancies.

Epigenetic deregulation of the anaplastic lymphoma kinase gene modulates mesenchymal characteristics of oral squamous cell carcinomas

DNA hypermethylation of promoter CpG islands is associated with epigenetic silencing of tumor suppressor genes in oral squamous cell carcinomas (OSCCs). We used a methyl-CpG-binding domain protein capture method coupled with next-generation sequencing (MBDCap-seq) to survey global DNA methylation patterns in OSCCs with and without nodal metastasis and normal mucosa (total n = 58). Of 1462 differentially methylated CpG islands identified in OSCCs relative to normal controls, MBDCap-seq profiling uncovered 359 loci linked to lymph node metastasis. Interactive network analysis revealed a subset of these loci (n = 23), including the anaplastic lymphoma kinase (ALK) gene, are potential regulators and effectors of invasiveness and metastatic progression. Promoter methylation of ALK was preferentially observed in OSCCs without node metastasis, whereas relatively lower methylation levels were present in metastatic tumors, implicating an active state of ALK transcription in the latter group. The OSCC cell line, SCC4, displayed reduced ALK expression that corresponded to extensive promoter CpG island methylation. SCC4 treatment with demethylating agents induced ALK expression and increased invasion and migration characteristics. Inhibition of ALK activity in OSCC cells with high ALK expression (CAL27, HSC3 and SCC25), decreased cell growth and resulted in changes in invasive potential and mesenchymal marker expression that were cell-line dependent. Although ALK is susceptible to epigenetic silencing during oral tumorigenesis, overwriting this default state may be necessary for modulating invasive processes involved in nodal metastases. Given the complex response of OSCC cells to ALK inhibition, future studies are required to assess the feasibility of targeting ALK to treat invasive OSCCs.

Recombinant Erdr1 suppresses the migration and invasion ability of human gastric cancer cells, SNU-216, through the JNK pathway

Erythroid differentiation regulator 1 (Erdr1) suppressed cell motility in vitro and has anti-metastatic effect in vivo on melanoma. The current study investigated the effect of recombinant Erdr1 on the migration and invasion ability of SNU-216 cell, a gastric cancer cell line. The expression of Erdr1 is inversely correlated with IL-18 expression, which has a pro-cancer effect in gastric cancer. Treatment with rErdr1 markedly suppressed the ability of SNU-216 cells to migrate and invade, indicating that recombinant Erdr1 inhibited the motility of gastric cancer cells. E-cadherin expression levels were measured to determine the factor involved in the rErdr1-suppressed motility. E-cadherin is a representative of the cadherin family, known as cell motility enhancement adhesion molecule. Our results revealed that E-cadherin levels were increased by rErdr1 treatment, suggesting the involvement of E-cadherin in rErdr1-reduced cell migration. The cells were treated with specific MAPK inhibitors such as SP600125, SB203580 or PD98059 to identify the signaling mechanism involved with rErdr1 suppressed cell migration. The results indicated that the rErdr1 inhibited migration was primarily reversed by SP600125, a JNK inhibitor. In addition, the level of JNK phosphorylation was markedly increased by recombinant Erdr1. Taken together, these findings suggest that rErdr1 suppressed the ability of gastric cancer cells to metastasis by up regulating E-cadherin through a JNK pathway activation. Furthermore, it can be suggested that the inhibitory effect of recombinant Erdr1 on SNU-216 cell's metastatic potential was through cell motility suppression.

TACC3 promotes epithelial-mesenchymal transition (EMT) through the activation of PI3K/Akt and ERK signaling pathways

Transforming acidic coiled-coil protein 3 (TACC3) is a member of the TACC family, essential for mitotic spindle dynamics and centrosome integrity during mitosis. Mounting evidence suggests that deregulation of TACC3 is associated with various types of human cancer. However, the molecular mechanisms by which TACC3 contributes to the development of cancer remain largely unknown. Here, we propose a novel mechanism by which TACC3 regulates epithelial-mesenchymal transition (EMT). By modulating the expression of TACC3, we found that overexpression of TACC3 leads to changes in cell morphology, proliferation, transforming capability, migratory/invasive behavior as well as the expression of EMT-related markers. Moreover, phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated protein kinases (ERKs) signaling pathways are critical for TACC3-mediated EMT process. Notably, depletion of TACC3 is sufficient to suppress EMT phenotype. Collectively, our findings identify TACC3 as a driver of tumorigenesis as well as an inducer of oncogenic EMT and highlight its overexpression as a potential therapeutic target for preventing EMT-associated tumor progression and invasion.

TGF-beta induces serous borderline ovarian tumor cell invasion by activating EMT but triggers apoptosis in low-grade serous ovarian carcinoma cells

Apoptosis in ovarian surface epithelial (OSE) cells is induced by transforming growth factor-beta (TGF-β). However, high-grade serous ovarian carcinomas (HGC) are refractory to the inhibitory functions of TGF-β; their invasiveness is up-regulated by TGF-β through epithelial-mesenchymal transition (EMT) activation. Serous borderline ovarian tumors (SBOT) have been recognized as distinct entities that give rise to invasive low-grade serous carcinomas (LGC), which have a relatively poor prognosis and are unrelated to HGC. While it is not fully understood how TGF-β plays disparate roles in OSE cells and its malignant derivative HGC, its role in SBOT and LGC remains unknown. Here we demonstrate the effects of TGF-β on cultured SBOT3.1 and LGC-derived MPSC1 cells, which express TGF-β type I and type II receptors. TGF-β treatment induced the invasiveness of SBOT3.1 cells but reduced the invasiveness of MPSC1 cells. The analysis of apoptosis, which was assessed by cleaved caspase-3 and trypan blue exclusion assay, revealed TGF-β-induced apoptosis in MPSC1, but not SBOT3.1 cells. The pro-apoptotic effect of TGF-β on LGC cells was confirmed in another immortalized LGC cell line ILGC. TGF-β treatment led to the activation of Smad3 but not Smad2. The specific TβRI inhibitor SB431542 and TβRI siRNA abolished the SBOT3.1 invasion induced by TGF-β, and it prevented TGF-β-induced apoptosis in MPSC1 cells. In SBOT3.1 cells, TGF-β down-regulated E-cadherin and concurrently up-regulated N-cadherin. TGF-β up-regulated the expression of the transcriptional repressors of E-cadherin, Snail, Slug, Twist and ZEB1. In contrast, co-treatment with SB431542 and TβRI depletion by siRNA abolished the effects of TGF-β on the relative cadherin expression levels and that of Snail, Slug, Twist and ZEB1 as well. This study demonstrates dual TGF-β functions: the induction of SBOT cell invasion by EMT activation and apoptosis promotion in LGC cells.