Nuclear expression of N-cadherin correlates with poor prognosis of nasopharyngeal carcinoma

N-Cadherin Expression with Metastasis of Neck Lymph Nodes in Patients with Nasopharyngeal Carcinoma

Background

Lymph node (LN) metastases were one characteristic of negative progress of NPC patient despite its advanced therapeutic approaches. One mechanism for the occurrence of epithelial to mesenchymal transition (EMT)-mediated metastases is by increasing N-cadherin expression. The purpose of this research is to determine investigating N-cadherin expression against metastatic LN in NPC cases.

Methods

Samples were taken by unproportionate stratified random sampling. N-cadherin expression was examined using immunohistochemistry methods. N-cadherin expression was assessed visually by binocular light microscopy. We analyzed these data using Mann-Whitney U-test to examine N-cadherin expression and lymph node metastases.

Results

A strong expression was found in N3 group by 63.6%; 27.3% in the N2 group and 9.1% in the N1 group. In patients with NPC N0 or without lymph node metastases, N-cadherin expression is 0%. The expression of N-cadherin is indeed an indicator of the occurrence of lymph node metastases in NPC with a statistically significant analysis of p = 0.026 (p < 0.05).

Conclusion

There were correlations between N-cadherin expression and lymph node metastasis on NPC patients.

Epithelial-Mesenchymal Transition Associated with Head and Neck Squamous Cell Carcinomas: A Review

Head and neck squamous cell carcinomas (HNSCCs) are aggressive, recurrent, and metastatic neoplasms with a high occurrence around the world and can lead to death when not treated appropriately. Several molecules and signaling pathways are involved in the malignant conversion process. Epithelial-mesenchymal transition (EMT) has been described in HNSCCs, a major type of aggressive carcinoma. EMT describes the development of epithelial cells into mesenchymal cells, which depends on several molecular interactions and signaling pathways that facilitate mesenchymal conversion. This is related to interactions with the microenvironment of the tumor, hypoxia, growth factors, matrix metalloproteinases, and the presence of viral infections. In this review, we focus on the main molecules related to EMT, their interactions with the tumor microenvironment, plasticity phenomena, epigenetic regulation, hypoxia, inflammation, their relationship with immune cells, and the inhibition of EMT in the context of HNSCCs.

Epithelial to Mesenchymal Transition (EMT) in a Laryngeal Squamous Cell Carcinoma of a Horse: Future Perspectives

Simple Summary

Squamous cell carcinoma (SCC) is one of the most common cancers in horses, and it can arise at any site on the skin and mucosae. Recent studies associated equine papillomavirus type 2 (EcPV2) infections with this type of cancers of the oral tract and genitals. Larynx and pharynx are frequently recognized as sites of SCC. In humans, squamous cell carcinoma of the larynx (SCCL) is a common cancer associated with papilloma virus (PV) infection and epithelial to mesenchymal transition (EMT). EMT can occur under different biological conditions, upon the same programmed changes: embryogenesis and organ development fibrosis, wound healing, and cancer metastases. This work reports for the first time in a SCCL of a horse a wide immunohistochemical EMT characterization, by analyzing main epithelial markers (E-cadherin, β-catenin, and pan-cytokeratin AE3/AE1), main mesenchymal markers (N-cadherin and vimentin), and the main EMT-related transcription factors (TWIST-1, ZEB-1, and HIF-1α). This work illustrates an example of tumor cell adaptation during the metastatic process in the equine SCCL, taking also into consideration the potential influence provided by EcPV2 oncoproteins on the EMT process.

Abstract

Squamous cell carcinoma (SCC) is one of the most frequent tumors of skin and muco-cutaneous junctions in the horse. Equine papillomavirus type 2 (EcPV2) has been detected in equine SCC of the oral tract and genitals, and recently also in the larynx. As human squamous cell carcinoma of the larynx (SCCL), it is strongly etiologically associated with high-risk papillomavirus (h-HPV) infection. This study focuses on tumor cells behavior in a naturally occurring tumor that can undergo the so-called epithelial to mesenchymal transition (EMT). A SCCL in a horse was investigated by immunohistochemistry using antibodies against E-cadherin, pan-cytokeratin AE3/AE1, β-catenin, N-cadherin, vimentin, ZEB-1, TWIST, and HIF-1α. EcPV2 DNA detection and expression of oncogenes in SCC were investigated. A cadherin switch and an intermediate filaments rearrangement within primary site tumor cells together with the expression of the EMT-related transcription factors TWIST-1, ZEB-1, and HIF-1α were observed. DNA obtained from the tumor showed EcPV2 positivity, with E2 gene disruption and E6 gene dysregulation. The results suggest that equine SCCL might be a valuable model for studying EMT and the potential interactions between EcPV2 oncoproteins and the EMT process in SCCL.

ZEB and Snail expression indicates epithelial-mesenchymal transition in canine melanoma

Melanoma progression is associated with the epithelial-mesenchymal transition (EMT) when tumor cells reduce E-cadherin and increase N-cadherin expression resulting in an escape from the microenvironment via loss of cellular adhesion and gain of motility. Transcription factor proteins Snail and ZEB trigger EMT by repression of epithelial markers and activation of mesenchymal properties. This study evaluated E-cadherin, N-cadherin, Snail, ZEB1 and ZEB2 expression by IHC and investigated their relationship with morphological characteristics in cutaneous and oral canine melanoma. Results from melanoma cases demonstrated E-cadherin expression in 45% (9/20) of oral and 58% (22/38) of cutaneous tumors, while N-cadherin expression was observed in 95% (18/19) of oral and 92% (34/37) of cutaneous melanoma. Cytoplasmic and nuclear N-cadherin expression was positively correlated with ZEB1 expression, while the cell membrane N-cadherin expression was positively correlated with ZEB2. In addition, an increase in nuclear N-cadherin expression was associated with reduced Snail expression in cutaneous melanoma and an increase in Snail expression in oral melanoma, indicating that the correlation between N-cadherin and Snail expression is coincident with tumor location. Our data suggest that ZEB family protein is associated with N-cadherin translocation from cell membrane to the cytoplasm and nuclei, and may act as important transcription factors of EMT regulation in canine melanoma.

The Role of Carcinogenesis-Related Biomarkers in the Wnt Pathway and Their Effects on Epithelial-Mesenchymal Transition (EMT) in Oral Squamous Cell Carcinoma

As oral squamous cell carcinoma (OSCC) can develop from potentially malignant disorders (PMDs), it is critical to develop methods for early detection to improve the prognosis of patients. Epithelial-mesenchymal transition (EMT) plays an important role during tumor progression and metastasis. The Wnt signaling pathway is an intercellular pathway in animals that also plays a fundamental role in cell proliferation and regeneration, and in the function of many cell or tissue types. Specific components of master regulators such as epithelial cadherin (E-cadherin), Vimentin, adenomatous polyposis coli (APC), Snail, and neural cadherin (N-cadherin), which are known to control the EMT process, have also been implicated in the Wnt cascade. Here, we review recent findings on the Wnt signaling pathway and the expression mechanism. These regulators are known to play roles in EMT and tumor progression, especially in OSCC. Characterizing the mechanisms through which both EMT and the Wnt pathway play a role in these cellular pathways could increase our understanding of the tumor genesis process and may allow for the development of improved therapeutics for OSCC.

Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial cancer of the head and neck with high prevalence in southern China, which is accompanied by notable invasiveness and metastasis. Long noncoding RNAs (lncRNAs) participate in the progression of various cancers including NPC. Microarray-based analysis identified highly expressed lncRNA mothers against decapentaplegic homolog 5 (SMAD5)-antisense RNA 1 (AS1) related to NPC. Interestingly, it is found that SMAD5-AS1 competitively bound to microRNA (miR)-106a-5p to regulate SMAD5. Herein, the study aimed to clarify the role of SMAD5-AS1/miR-106a-5p/SMAD5 axis in the process of epithelial mesenchymal transition (EMT) in NPC. SMAD5-AS1 was highly expressed and miR-106a-5p was poorly expressed in NPC tissues and cell lines. The NPC cells were treated with a series of small interfering RNAs, mimics, or inhibitors to explore the effects of SMAD5-AS1, SMAD5, and miR-106a-5p on EMT, cell proliferation, migration, and invasion in NPC. Of note, SMAD5-AS1 silencing or miR-106a-5p overexpression reduced expression of N-cadherin, matrix metallopeptidase 9, Snail, and Vimentin while elevating E-cadherin expression, thus inhibiting EMT, cell proliferation, migration, and invasion in NPC by down-regulation of SMAD5. Moreover, SMAD5 silencing could reduce the ability of EMT induced by SMAD5-AS1 up-regulation. SMAD5-AS1 silencing or miR-106a-5p elevation inhibited tumorigenesis in nude mice. Taken together, SMAD5-AS1 silencing suppressed EMT, cell proliferation, migration, and invasion in NPC by elevating miR-106a-5p to down-regulate SMAD5, which provided a novel therapeutic target for NPC treatment.-Zheng, Y.-J., Zhao, J.-Y., Liang, T.-S., Wang, P., Wang, J., Yang, D.-K., Liu, Z.-S. Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma.

Detection and clinical significance of circulating tumor cells in patients with nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is the most common cancer type originating in the nasopharynx, and varies notably from other cancer types of the head and neck in its occurrence, causes, clinical behavior and treatment. Significant effort has been made into understanding the biological properties of circulating tumor cells (CTCs), with previous studies demonstrating the critical role CTCs serve in the metastatic spread of carcinoma. However, associations between NPC and CTCs have not been completely elucidated. Therefore, in the present study, the CanPatrol™ CTC-enrichment technique and classical in situ hybridization assay were utilized to acquire, identify and classify CTCs from patients with NPC. Subsequently, the correlation between CTCs and the clinical indexes, progression-free survival (PFS), N-cadherin gene expression and the response to therapy were investigated. The present study then determined whether the Wnt/β-catenin signaling pathway served a role in therapy for NPC cells. Collectively, the research demonstrated that CTCs could be detected in patients with NPC. Additionally, CTCs exhibited a statistically significant association with the Epstein-Barr virus infection prior to therapy and Eastern Cooperative Oncology Group score following therapy. Furthermore, co-treatment with cisplatin and paclitaxel significantly decreased the number of CTCs. In addition, mesenchymal CTCs may serve as a predictor of PFS. Finally, the present study demonstrated that cisplatin combined with paclitaxel induced apoptosis and decreased the tumor markers in NPC cells through the Wnt/β-catenin signaling pathway. In conclusion, these data indicated that CTCs may serve as a biomarker in monitoring the therapeutic efficacy of treatments for NPC. Furthermore, the Wnt/β-catenin signaling pathway served a therapeutic role in the treatment of NPC.

PD-L1 Expression with Epithelial Mesenchymal Transition of Circulating Tumor Cells Is Associated with Poor Survival in Curatively Resected Non-Small Cell Lung Cancer

In addition to the FDA-approved definition of a circulating tumor cell (CTC), various CTC phenotypes have been discovered. Epithelial-mesenchymal transition (EMT) of cancer cells is directly linked to PD-L1 upregulation. The goal of the study was to investigate PD-L1 expression and EMT in CTCs of non-small cell lung cancer (NSCLC) patients, and perform an outcome analysis. Prospectively, 7.5 mL peripheral blood was collected from 30 NSCLC patients that underwent surgery and 15 healthy controls. CTCs were enriched by size-based microfilter and immunofluorescence stainings performed (cytokeratin (CK) 8/18/19, EpCAM, CD45, PD-L1, EMT markers vimentin, and N-Cadherin, DAPI). Patient-matched NSCLC tissues were also stained. CTC staining intensity was quantified with a software and correlated with patient-matched NSCLC tissues and survival. PD-L1 and EMT markers were expressed at significantly higher proportions in CTCs than patient-matched NSCLC tissues (p < 0.05); ≥3 PD-L1^pos/EMT^posCTCs were associated with significantly poorer survival after curative surgery (p < 0.05). No CTCs were detected in 15 healthy controls. This study shows that PD-L1 expression and EMT of CTCs is a negative survival predictor for NSCLC patients. The therapeutic role of the molecular linkage of PD-L1 and EMT will need to be further investigated, as linked pathways could be targeted to improve NSCLC outcome.

Ginsenoside Rg3 Inhibits Migration and Invasion of Nasopharyngeal Carcinoma Cells and Suppresses Epithelial Mesenchymal Transition

Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic head and neck cancer. Distant metastasis becomes the predominant mode of treatment failure in NPC patients. Ginsenoside Rg3 (Rg3), an active pharmaceutical component extracted from traditional Chinese medicine ginseng, shows antitumor effects in various cancers. In this study, we aimed to determine whether Rg3 inhibits the migration and invasion activity of NPC cells and to explore the possible mechanisms. Our results revealed that Rg3 hampers cell migration and invasion in both HNE1 and CNE2 cell lines. A reduced level of matrix metalloproteinase-2 (MMP-2) and MMP-9 was induced by Rg3 treatment. In addition, Rg3 significantly altered the expression of epithelial mesenchymal transition (EMT) markers with increased E-cadherin but decreased Vimentin and N-cadherin expression. Transforming growth factor β- (TGF-β-) induced morphological transition and marker proteins change of EMT were reversed by Rg3. What is more, Rg3 suppressed the expression of EMT-related transcription factors, especially the Zinc Finger E-Box Binding Homeobox 1 (ZEB1). In summary, our data suggested that Rg3 could inhibit migration and invasion of NPC cells. This effect of Rg3 might be mediated through regulating MMP-2 and MMP-9 expressions and suppressing EMT. Thus, Rg3 may be a potentially effective agent for the treatment of NPC.

N-cadherin in cancer metastasis, its emerging role in haematological malignancies and potential as a therapeutic target in cancer

In many types of solid tumours, the aberrant expression of the cell adhesion molecule N-cadherin is a hallmark of epithelial-to-mesenchymal transition, resulting in the acquisition of an aggressive tumour phenotype. This transition endows tumour cells with the capacity to escape from the confines of the primary tumour and metastasise to secondary sites. In this review, we will discuss how N-cadherin actively promotes the metastatic behaviour of tumour cells, including its involvement in critical signalling pathways which mediate these events. In addition, we will explore the emerging role of N-cadherin in haematological malignancies, including bone marrow homing and microenvironmental protection to anti-cancer agents. Finally, we will discuss the evidence that N-cadherin may be a viable therapeutic target to inhibit cancer metastasis and increase tumour cell sensitivity to existing anti-cancer therapies.

FOXC1 plays a crucial role in the growth of pancreatic cancer

IGF-1R signaling controls various vital cellular functions and this signaling is deregulated in many cancers, including pancreatic cancer. Several efforts have mainly focused on inhibiting the IGF-1R signaling cascade. The outcomes of these focused preclinical studies have been positive, whereas clinical trials of IGF-1R inhibitors in pancreatic cancer have failed, raising the questions about this therapeutic approach. This necessitates a better understanding of the role of IGF-1R signaling in pancreatic cancer. We investigated the impact of IGF-1R signaling on crucial transcription factors and identified the FOXC1 as one of the crucial regulator of IGF-1R signaling. We employed genetic approaches to overexpress and silence FOXC1 in pancreatic cancer cells. Our results demonstrate that IGF-1R and FOXC1 seem to positively regulate each other. Further, FOXC1 increased the metastatic abilities of pancreatic cancer cells by enhancing cell proliferation, migration, invasion, epithelial-to-mesenchymal transition, and angiogenesis. The data from xenograft experiments further established the importance of FOXC1 in pancreatic tumorigenesis. In conclusion, FOXC1 is a potent oncogenic transcription factor, which promotes pancreatic cancer growth and metastasis. Thus, targeting FOXC1 could be a potential therapeutic strategy against pancreatic cancer.

Upregulated N-cadherin expression is associated with poor prognosis in epithelial-derived solid tumours: A meta-analysis

BACKGROUND

N-cadherin is an important molecular in epithelial-mesenchymal transition (EMT) and has been reported to be associated with aggressive behaviours of tumours. However, prognostic value of N-cadherin in solid malignancies remains controversially.

MATERIALS AND METHODS

The Pubmed/MELINE and EMBASE databases were used for a comprehensive literature searching. Pooled risk ratio (RR) and hazard ratio (HR) with their corresponding 95% confidence intervals (CIs) were employed to quantify the prognostic role.

RESULTS

Involving 36 studies with 5705 patients were performed to investigate relationships between N-cadherin upregulation and clinicopathological features, survival. Results suggested upregulated N-cadherin was associated with lymph node metastasis (RR = 1.16, 95% CI [1.00, 1.35]), higher histological grade (RR = 1.36, 95%CI [1.14, 1.62]), angiolymphatic invasion (RR = 1.19, 95% CI [1.06, 1.34]) and advanced clinical stage (RR = 1.32, 95% CI [1.06, 1.64]), while upregulated N-cadherin was apt to be associated with distant metastasis (RR = 1.43, 95% CI [0.99, 2.05]). Moreover, N-cadherin was correlated with poor prognosis of 3-year survival (HR = 1.78, 95% CI [1.51, 2.10]), 5-year survival (HR = 1.57, 95% CI [1.17, 2.10]) and overall survival (OS) (HR = 1.32, 95% CI [1.20, 1.44]). Subgroup analyses according to cancer types were also conducted for applying these conclusions to some tumours more properly. No publication bias was found except subgroup analysis of distant metastasis (P = .652 for Begg's test and 0.023 for Egger's test).

CONCLUSIONS

Taken together, upregulation of N-cadherin is associated with more aggressive behaviours of epithelial-derived solid malignancies and can be regarded as a predictor of poor survival.

Oxygen-dependent regulation of tumor growth and metastasis in human breast cancer xenografts

Background

Tumor hypoxia is relevant for tumor growth, metabolism, resistance to chemotherapy and metastasis. We have previously shown that hyperoxia, using hyperbaric oxygen treatment (HBOT), attenuates tumor growth and shifts the phenotype from mesenchymal to epithelial (MET) in the DMBA-induced mammary tumor model. This study describes the effect of HBOT on tumor growth, angiogenesis, chemotherapy efficacy and metastasis in a triple negative MDA-MB-231 breast cancer model, and evaluates tumor growth using a triple positive BT-474 breast cancer model.

Materials and methods

5 x 10⁵ cancer cells were injected s.c. in the groin area of NOD/SCID female mice. The BT-474 group was supplied with Progesterone and Estradiol pellets 2-days prior to tumor cell injection. Mice were divided into controls (1 bar, pO₂ = 0.2 bar) or HBOT (2.5 bar, pO₂ = 2.5 bar, 90 min, every third day until termination of the experiments). Treatment effects were determined by assessment of tumor growth, proliferation (Ki67-staining), angiogenesis (CD31-staining), metastasis (immunostaining), EMT markers (western blot), stromal components collagen type I, Itgb1 and FSP1 (immunostaining) and chemotherapeutic efficacy (5FU).

Results

HBOT significantly suppressed tumor growth in both the triple positive and negative tumors, and both MDA-MB-231 and BT-474 showed a decrease in proliferation after HBOT. No differences were found in angiogenesis or 5FU efficacy between HBOT and controls. Nevertheless, HBOT significantly reduced both numbers and total area of the metastastatic lesions, as well as reduced expression of N-cadherin, Axl and collagen type I measured in the MDA-MB-231 model. No change in stromal Itgb1 and FSP1 was found in either tumor model.

Conclusion

Despite the fact that behavior and prognosis of the triple positive and negative subtypes of cancer are different, the HBOT had a similar suppressive effect on tumor growth, indicating that they share a common oxygen dependent anti-tumor mechanism. Furthermore, HBOT significantly reduced the number and area of metastatic lesions in the triple negative model as well as a significant reduction in the EMT markers N-cadherin, Axl and density of collagen type I.

Overexpression of N-cadherin and β-catenin correlates with poor prognosis in patients with nasopharyngeal carcinoma

An increasing amount of evidence demonstrates that epithelial-mesenchymal transition (EMT) is important in tumor invasion and metastases. The cell-cell adhesion molecule N-cadherin and the Wnt/β-catenin cascade protein β-catenin are two biomarkers of EMT. The present study aimed to measure the expression levels of N-cadherin and β-catenin in samples from patients with nasopharyngeal carcinoma (NPC) and evaluate their prognostic significance. N-cadherin and β-catenin mRNA was evaluated using reverse transcription-quantitative polymerase chain reaction in 26 NPC tissue samples and 8 nasopharyngeal epithelium samples. Protein expression of N-cadherin and β-catenin was also detected using immunohistochemistry in 128 archival NPC paraffin-embedded specimens. Finally, associations between clinical pathological parameters and prognostic values in NPC were evaluated. The results demonstrated that both the mRNA and protein levels of N-cadherin and β-catenin were significantly increased in NPC tissues compared with the controls. Enhanced expression of N-cadherin and β-catenin protein was strongly correlated with the status of lymph node metastasis and clinical stages in patients with NPC. Notably, high expression of N-cadherin and β-catenin proteins was significantly correlated with lower overall survival (OS) rate in patients with NPC. Finally, multivariate analysis demonstrated that expression of N-cadherin protein and clinical stages were independent prognostic factors for patients with NPC. Therefore, the present study demonstrated that N-cadherin and β-catenin expression may be used as potential prognostic biomarkers for patients with NPC.

Targeted Disruption of miR-17-92 Impairs Mouse Spermatogenesis by Activating mTOR Signaling Pathway

The miR-17-92 cluster and its 6 different mature microRNAs, including miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1, and miR-92a, play important roles in embryo development, immune system, kidney and heart development, adipose differentiation, aging, and tumorigenicity. Currently, increasing evidence indicates that some members of miR-17-92 cluster may be critical players in spermatogenesis, including miR-17, miR-18a, and miR-20a. However, the roles and underlying mechanisms of miR-17-92 in spermatogenesis remain largely unknown. Our results showed that the targeted disruption of miR-17-92 in the testes of adult mice resulted in severe testicular atrophy, empty seminiferous tubules, and depressed sperm production. This phenotype is partly because of the reduced number of spermatogonia and spermatogonial stem cells, and the significantly increased germ cell apoptosis in the testes of miR-17-92-deficient mice. In addition, overactivation of the mammalian target of rapamycin signaling pathway and upregulation of the pro-apoptotic protein Bim, Stat3, c-Kit, and Socs3 were also observed in miR-17-92-deficient mouse testes, which might be, at least partially if not all, responsible for the aforementioned phenotypic changes in mutant testes. Taken together, these findings suggest that miR-17-92 is essential for normal spermatogenesis in mice.

MDK Protein Overexpression Correlates with the Malignant Status and Prognosis of Non-small Cell Lung Cancer

BACKGROUND AND AIMS

Midkine (MDK) is a heparin-binding growth factor and is overexpressed in various types of human cancer. However, little is known about the clinical significance of MDK in non-small cell lung cancer (NSCLC). The aim of this study was to measure MDK protein levels in patients with NSCLC and to explore its clinical significance.

METHODS

The expression status of MDK in NSCLC at Gene Expression Omnibus (GEO accession number: GSE19804) was observed. The expression of MDK mRNA and protein was examined in NSCLC tissues and normal lung tissues through real-time PCR and Western blot. Meanwhile, the relationship of MDK protein expression levels with clinical characteristics of 186 NSCLC patients was analyzed by immunohistochemistry.

RESULTS

MDK expression was increased in NSCLC tissues compared with paired normal lung tissues in microarray data (GSE19804). MDK mRNA and protein expression were obviously increased in NSCLC tissues than in paired adjacent normal lung tissues. Using immunohistochemistry, MDK protein overexpression was positively correlated with status of clinical stage, T classification, N classification, and M classification in NSCLC patients. In survival analysis, patients with higher MDK protein expression had a significantly shorter overall survival time than did patients with lower MDK protein expression. Multivariate analysis indicated that the MDK protein overexpression was an independent poor prognostic indicator for patients with NSCLC.

CONCLUSIONS

MDK plays an important role in NSCLC progression and prognosis and may act as a convincing prognostic indicator for NSCLC patients.

Epstein-Barr virus LMP1 induces focal adhesions and epithelial cell migration through effects on integrin-α5 and N-cadherin

Epstein–Barr virus (EBV) is a γ-herpesvirus associated with human epithelial and B-cell malignancies. The EBV latent membrane protein (LMP) 1 is expressed in nasopharyngeal carcinoma (NPC) and promotes oncogenic intracellular signaling mechanisms. LMP1 also promotes a pro-migratory phenotype through potential effects on cell surface proteins, as expression of LMP1 induces an epithelial–mesenchymal transition (EMT) in epithelial cell lines. In this study, LMP1 was examined for potential effects on cadherin and integrin surface interactions, and assessed for biological effects on adhesion and motility to fibronectin. Expression of LMP1 in the non-tumorigenic epithelial cell line MCF10a induced an EMT-associated cadherin switch. The induced N-cadherin was ligated and localized to the cell surface as determined by triton-solubility and immunofluorescence assays. In addition, LMP1 induced the assembly of focal adhesions (FAs) with increased production of fibronectin in MCF10a and NP460hTERT-immortalized nasopharyngeal cells. Biochemical enrichment of fibronectin-associated proteins indicated that LMP1 selectively promoted the recruitment of integrin-α5 and Src family kinase proteins to FA complexes. Neutralizing antibodies to N-cadherin and integrin-α5, but not integrin-αV, blocked the adhesion and transwell motility of MCF10a cells to fibronectin induced by LMP1. LMP1-induced transwell motility was also decreased by Src inhibition with the PP2 kinase inhibitor and short hairpin RNAs. These studies reveal that LMP1 has multiple mechanisms to promote the adhesive and migratory properties of epithelial cells through induction of fibronectin and modulation of cell surface interactions involving integrin-α5 and N-cadherin, which may contribute to the metastatic potential of NPC.

[Advances in the molecular mechanisms and prognostic significance of EMT in non-small cell lung cancer]

上皮细胞-间叶细胞转化（epithelial to mesenchymal transition, EMT）不仅在胚胎的发育过程中起着十分重要的作用，还参与非小细胞肺癌（non-small cell lung cancer, NSCLC）的转移过程。近期的研究发现，发生EMT的细胞不仅出现了形态的改变，还出现了相关表型的改变。既往有关EMT发生机制的研究多数是针对其他肿瘤的，因此很有必要研究NSCLC中是否有类似发生机制。随着研究的进展，EMT相关的基础研究逐渐被用于预测NSCLC的预后。本文将对NSCLC中EMT的发生机制及其临床应用的研究进展进行探讨。

Knockdown of c-Myc inhibits cell proliferation by negatively regulating the Cdk/Rb/E2F pathway in nasopharyngeal carcinoma cells

The proto-oncogene c-Myc encodes a transcription factor that is involved in the regulation of cellular proliferation, differentiation, and apoptosis. Several studies indicate that the over-expression of c-Myc is a frequent genetic abnormality in nasopharyngeal carcinoma (NPC). Therefore, specifically reducing its level by genetic means in established NPC cell lines helps to better understand its role in the pathogenesis of NPC. In this study, for the first time, we successfully established and characterized NPC 5-8F cell line with stably suppressed c-Myc expression by employing a DNA-based RNA interference approach. The suppression of c-Myc resulted in reduced cell growth, colony formation, and cell cycle progression in 5-8F cells. In vivo tumor formation assays revealed that the knockdown of c-Myc reduced the tumorigenic potential of 5-8F cells in nude mice. At the molecular level, we found that the knockdown of c-Myc could decrease the expression of several critical molecules involved in the Cdk/Rb/E2F pathway, including CDK4, cyclin D1, CDK2, pRb, E2F3, and DP2, and significantly reduced the promoter activity of cyclin D1. Taken together, these findings provide valuable mechanistic insights into the role of c-Myc in nasopharyngeal carcinogenesis and suggest that the knockdown of c-Myc may be a potential therapeutic approach for the treatment of NPC.

Nuclear p27 expression confers a favorable outcome for nasopharyngeal carcinoma patients

Objective. The purpose of the present study is to explore the correlation between nuclear expression of cyclin-dependent kinase inhibitor 1B (p27) and clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient survival. Methods. Immunohistochemistry was used to examine the expression of p27 in 130 primary NPC tissues. The relationship between the levels of p27 expression and clinicopathologic characteristics was analyzed. Survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. The significance of various survival variables was analyzed using multivariate Cox proportional hazards model. Results. p27 was expressed in both nuclear and cytoplasmic compartments. Nuclear expression of p27 was inversely correlated with T classification and clinical stage. Patients with nuclear p27 expression had better overall survival rates than those without nuclear expression of p27. Further, we observed that nuclear expression of p27 was positively associated with survival time of NPC patients not only in N0-1 and M0 classifications but also in radiotherapy and chemotherapy treatment groups. Finally, we found that nuclear expression of p27 was not an independent prognostic factor for patients with NPC. Conclusions. Our findings hint that nuclear expression of p27 is a potentially favorable factor in the progression and prognosis of NPC.

MMP-14 overexpression correlates with poor prognosis in non-small cell lung cancer

Matrix metalloproteinase-14 (MMP-14) has been demonstrated to play an important role in tumor progression. The aim of this study was to analyze the correlation between MMP-14 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). Immunohistochemical staining for MMP-14 protein was performed in 104 patients with NSCLC. High levels of MMP-14 protein were positively correlated with the status of clinical stage (I-II vs. III-IV; P < 0.001), N classification (N0-N1 vs. N2-N3; P < 0.001), distant metastasis (no vs. yes; P = 0.014), and differentiated degree (high vs. low or undifferentiated; P = 0.001). The patients with higher MMP-14 expression of protein had shorter survival time than patients with low MMP-14 expression. Multivariate analysis indicated that the level of MMP-14 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with NSCLC. In conclusion, MMP-14 is a potential unfavorable prognostic factor for patients with NSCLC.

Nuclear expression of CDK4 correlates with disease progression and poor prognosis in human nasopharyngeal carcinoma

AIMS

The purpose of this study was to examine the correlation between nuclear expression of cyclin-dependent kinase 4 (CDK4) and clinicopathological data in nasopharyngeal carcinoma (NPC), including patient survival.

METHODS AND RESULTS

Using real-time PCR and immunohistochemistry, the expression of CDK4 was examined in NPC and nasopharyngeal (NP) tissues. We observed that mRNA expression of CDK4 was elevated significantly in NPC tissues compared to NP tissues. Further, we found that CDK4 protein was expressed in both the nucleus and cytoplasm. Nuclear expression of CDK4 was correlated positively with clinical stage (P = 0.048), but not associated with other clinical features. Patients with tumours showing nuclear expression of CDK4 had poorer overall survival rates than those without nuclear tumour expression of CDK4. Nuclear expression of CDK4 was associated inversely with survival time for NPC patients in stages T1-2, stages N2-3 and clinical stages III-IV, and after treatment with radiotherapy or chemotherapy. Nuclear expression of CDK4 was an independent and unfavourable prognostic factor for patients with NPC.

CONCLUSIONS

Our findings suggest that nuclear expression of CDK4 is a potential marker for the progression and poor prognosis of NPC.

Decreased P27 protein expression is correlated with the progression and poor prognosis of nasopharyngeal carcinoma

Background

To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis.

Methods

Real-time PCR and immunohistochemistry were used to examine the mRNA and protein expressions of p27 in NPC and nasopharyngeal tissues. The relationship of p27 expression levels with clinical features and prognosis of NPC patients was analyzed.

Results

The expression level of p27 mRNA was markedly lower in NPC tissues than that in the nasopharyngeal tissues (P = 0.0006). Specific p27 protein staining by immunohistochemistry was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells but decreased expression was observed in NPC samples compared to normal epithelium samples (P = 0.002). In addition, low levels of p27 protein were inversely correlated with the status of T classification (p = 0.002) and clinical stage (p = 0.019) of NPC patients. Patients with lower p27 expression had a significantly shorter overall survival time than did patients with high p27 expression. Multivariate analysis suggested that the level of p27 expression was not an independent prognostic indicator (p = 0.682) for NPC survival.

Conclusion

Low level of p27 expression is a potential unfavorable prognostic factor for patients with NPC.

Virtual slides

The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1915282782109343.

Loss of cytoplasmic KLF4 expression is correlated with the progression and poor prognosis of nasopharyngeal carcinoma

AIMS

To examine, in nasopharyngeal carcinoma (NPC), the correlation of Krüppel-like factor 4 (KLF4) expression with clinicopathological features including patient prognosis.

METHODS AND RESULTS

Using real-time PCR and immunohistochemistry, expression of KLF4 mRNA and protein was examined in NPC and nasopharyngeal tissues. The relationship of KLF4 expression levels with clinical features and prognosis of NPC patients was analysed. mRNA expression was markedly lower in NPC than in the nasopharyngeal tissues. Using immunohistochemistry, staining for KLF4 protein was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells, but decreased cytoplasmic expression was observed in atypical hyperplasia and NPC samples compared to normal and squamous epithelium samples (P < 0.001). In addition, levels of cytoplasmic KLF4 protein were correlated inversely with the nodal (N) status (TNM classification; P = 0.002) and overall clinical stage (P < 0.001) of NPC patients. Patients with NPC showing lower cytoplasmic KLF4 expression had a significantly shorter overall survival time than those with high NPC KLF4 expression. Multivariate analysis suggested that the level of KLF4 expression was an independent prognostic indicator (P = 0.008) for NPC survival.

CONCLUSION

Low levels of cytoplasmic KLF4 expression are a potentially unfavourable prognostic factor for patients with NPC.

Loss of connective tissue growth factor as an unfavorable prognosis factor activates miR-18b by PI3K/AKT/C-Jun and C-Myc and promotes cell growth in nasopharyngeal carcinoma

Connective tissue growth factor (CTGF) has different roles in different types of cancer. However, the involvement and molecular basis of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC) have almost never been reported. In this study, we observed that downregulated CTGF expression was significantly associated with NPC progression and poor prognosis. Knockdown of CTGF markedly elevated the ability of cell proliferation in vivo and in vitro. Subsequently, we discovered that the reduction of CTGF increased the expression of miR-18b, an oncomir-promoting cell proliferation. Further, we discovered that attenuated CTGF-mediated upregulation of miR-18b was dependent on the increased binding of transcription factors Jun proto-oncogene (C-Jun) and v-Myc myelocytomatosis viral oncogene homolog (C-Myc) to miR-18b promoter region via phosphoinositide 3-kinase (PI3K)/AKT pathway. Finally, we further found that miR-18b directly suppressed the expression of CTGF in NPC. In clinical fresh specimens, miR-18b was widely overexpressed and inversely correlated with CTGF expression in NPC. Our studies are the first to demonstrate that reduced CTGF as an unfavorable prognosis factor mediates the activation of miR-18b, an oncomir directly suppresses CTGF expression, by PI3K/AKT/C-Jun and C-Myc and promotes cell growth of NPC.

Aldehyde dehydrogenase 1, a functional marker for identifying cancer stem cells in human nasopharyngeal carcinoma

Aldehyde dehydrogenase 1 (ALDH1) activity has now been employed successfully as a cancer stem cells (CSCs) marker in various tumors. We wanted to investigate whether ALDH1 can be used as a putative CSCs marker and a powerful prognostic factor in nasopharyngeal carcinoma (NPC). Here, we isolated ALDH1-positive cells from human NPC cell lines (5-8F and CNE2) and found that ALDH1-positive cancer cells grew faster and had higher clone formation efficiency (0.435±0.15; 0.431±0.025 vs. 0.131±0.007; 0.121±0.126), differentiation capability and had higher migration (233.00±5.29; 228.60±9.34 vs. 123.20±7.70 vs. 97.20±6.61) than those of ALDH1-negative cancer cells in vitro. In addition, ALDH1- positive cancer cells formed significantly more tumor spheres. Our in vivo experiments showed that only 5×10(3) ALDH1-positive NPC cells were required to induce tumors. Notably, ALDH1-positive cells are enriched in the side-population (SP) cells, and stem cells-like genes OCT4, BMI1, KLF4 and SOX2 are preferentially expressed in ALDH1-positive cells. Immunohistochemical results showed that the expression of ALDH1 correlated significantly with T classification (P=0.011), N classification (P=0.005), M classification (P=0.002) and clinical stage (P=0.001). Interestingly, ALDH1 expression in the tumor correlated significantly with epithelial-mesenchymal transition (EMT) markers including vimentin expression and loss of E-cadherin (P=0.003 and 0.008, respectively). Furthermore, multivariate analyses showed that ALDH1 expression was an independent prognostic indicator (P=0.032). Taken together, for the first time, we demonstrate that ALDH1 could be a novel stem cells marker and a valuable predictor of poor survival NPC.

Embryonic stem cells markers SOX2, OCT4 and Nanog expression and their correlations with epithelial-mesenchymal transition in nasopharyngeal carcinoma

Expression of embryonic stem cells (ESCs) markers (SOX2, OCT4, Nanog and Nestin) is crucial for progression of various human malignancies. The purpose of this study was to investigate the expression and prognostic impact of these molecules in nasopharyngeal carcinoma (NPC) patients by immunohistochemistry and immunofluorescence. In the present study, we found that the expression levels of SOX2, OCT4 and Nanog were highly expressed in NPC compared with the non-tumorous tissues. Furthermore, these proteins correlated significantly with several clinicalpathological factors and epithelial-mesenchymal transition (EMT)-associated indicators (E-cadherin/N-cadherin and Snail). In multivariate analyses, high expression of OCT4 (P = 0.013) and Nanog (P = 0.040), but not that of SOX2, was associated with worse survival and had strongly independent prognostic effects. Of note, OCT4 and Nanog were more frequently located at the invasive front of tumors, and correlated significantly with various aggressive behaviors including T classification, N classification, M classification and clinical stage. Furthermore, patients with co-expression of OCT4 and Nanog in the invasive front had significantly worse survival (P = 0.005). Interestingly, at the invasive front, these molecules correlated significantly with Nestin expression in endothelial cells (P<0.001). These findings provide evidence that ESCs biomarkers OCT4 and Nanog serves as independent prognostic factors for NPC. Additionally, cancer cells in the invasive front of NPC acquiring ESCs-like features should be maintained by vascular niches.

Tumour budding and the expression of cancer stem cell marker aldehyde dehydrogenase 1 in nasopharyngeal carcinoma

AIMS

To detect the prognostic significance of tumour budding and its expression of aldehyde dehydrogenase 1 (ALDH1) in nasopharyngeal carcinoma (NPC).

METHODS AND RESULTS

Tumour budding was investigated in 105 patients with NPC by immunohistochemistry for pan-cytokeratin (AE1/AE3). The intensity of budding correlated strongly with T classification (P=0.008), lymphatic invasion (P<0.001), vascular invasion (P=0.029), lymph node metastasis (P < 0.001), and clinical stage (P=0.010). Univariate analysis revealed that patients with high budding grade had poorer survival than those with low grade (P=0.002). Multivariate analysis showed that tumour budding was an independent predictor of survival (P=0.001). Furthermore, budding cells showed high-level expression of the cancer stem cell (CSC) marker ALDH1. Budding cells with high-level ALDH1 expression contributed to several aggressive behaviours and poor survival (P=0.000).

CONCLUSIONS

  We describe, for the first time, the presence of tumour budding and its correlation with aggressive tumour behaviour and poor patient survival in NPC. The degree of tumour budding could be a valuable predictive factor in NPC. In addition, we show, also for the first time, that budding cells in NPC might possess the invasive and metastatic properties of CSCs.

Aberrant expression of nuclear vimentin and related epithelial-mesenchymal transition markers in nasopharyngeal carcinoma

Expression of vimentin and the epithelial to mesenchymal transition (EMT) markers E-cadherin, β-catenin is essential for the progression of various human cancers. Our study aimed to investigate the aberrant localization E-cadherin, β-catenin and vimentin, and their prognostic significance in 122 nasopharyngeal carcinoma (NPC) patients by immunohistochemistry and immunofluorescence. Our results showed that both membranous and cytoplasmic localization of E-cadherin staining were associated with lymph node metastasis (p = 0.000 and 0.005, respectively) and clinical stage (p = 0.000 and 0.007, respectively). High cytoplasmic β-catenin correlated significantly with larger tumor size (p = 0.020), lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.036). However, no significant difference was observed between membranous β-catenin and clinicopathologic features (p ≥ 0.05). High nuclear vimentin expression correlated significantly with positive lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.000). Multivariate analysis showed that nuclear vimentin and cytoplasmic E-cadherin were independent prognostic factors (p = 0.016 and 0.001, respectively), as well as M classification (p = 0.001). More importantly, patients with high coexpression of nuclear vimentin and cytoplasmic E-cadherin had shorter survival time (p = 0.000). Furthermore, high coexpression of these two proteins was closely associated with lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.000). Our studies provide convincing evidence that EMT may play an important role in the biological progression of NPC, and nuclear vimentin and cytoplasmic E-cadherin might have independent prognostic value in NPC patients and serve as novel targets for prognostic therapeutics.

High expression of nuclear Snail, but not cytoplasmic staining, predicts poor survival in nasopharyngeal carcinoma

BACKGROUND

Transcription factor Snail has been shown to promote tumor progression and metastasis in various cancers. However, its clinical significance in nasopharyngeal carcinoma (NPC) is still scanty. We have explored the clinical significance of Snail expression and its association with patient outcome in NPC.

METHODS

Immunohistochemistry was used to examine the expression levels of Snail in 122 patients with NPC.

RESULTS

Cytoplasmic Snail was detected in 37.7 %, and nuclear staining was detected in 49.2 % of primary tumors, respectively. No significant associations were found between cytoplasmic Snail and the clinicopathologic variables except lymph node metastasis (P = 0.042). However, nuclear Snail was significantly associated with tumor stage (P = 0.003), T classification (P = 0.045), lymph node metastasis (P = 0.019), distant metastasis (P = 0.003), and reduced E-cadherin expression (P = 0.021). Patients with high nuclear Snail expression, but not cytoplasmic staining, had significantly shorter survival than those with low expression (P < 0.001). Significantly, nuclear Snail was an independent prognostic predictor for NPC (P < 0.001). Furthermore, the prognostic impact was largely limited to stage III-IV patients.

CONCLUSIONS

We demonstrated first that nuclear Snail, but not cytoplasmic staining, predicts worse outcome. In addition, the prognostic value in stage III-IV suggests that nuclear Snail could be a potential therapeutic target for late stage of NPC patients.