Direct interaction between miR-203 and ZEB2 suppresses epithelial-mesenchymal transition signaling and reduces lung adenocarcinoma chemoresistance

miR-203 is a tumor suppressor which participates in the pathogenesis of many tumors including lung adenocarcinoma. However, the role of miR-203 in suppressing chemotherapy resistance to cisplatin (cis-diamminedichloroplatinum; DDP) as well as its molecular mechanism is still to be determined in lung adenocarcinoma. In this study, we found that miR-203 decreased lung cancer cell migration and invasion, and that increased miR-203 expression sensitized lung adenocarcinoma cells to DDP in vitro Furthermore, ZEB2 was found to be a direct target of miR-203, which induces epithelial-mesenchymal transition (EMT) signal. Knock-down of ZEB2 significantly increased DDP chemosensitivity in lung adenocarcinoma. More interestingly, we also demonstrated that ZEB2 could directly bind to E-box of the miR-203 promoter and suppress its expression in lung adenocarcinoma. Our data reveal that miR-203 serves as a negative feedback by directly suppressing the upstream ZEB2 gene, which inhibits EMT signaling and reduces chemoresistance of DDP. Together, these results highlight a feedback loop between miR-203 and ZEB2, which participates in the pathogenesis of lung adenocarcinoma.

Melatonin suppresses TPA-induced metastasis by downregulating matrix metalloproteinase-9 expression through JNK/SP-1 signaling in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), a disease common in the South-East Asian population, has high lymph node metastatic ability. Melatonin, an endogenously produced substance present in animals, plants, fungi, and bacteria, has oncostatic activity via several mechanisms. The molecular mechanisms involved in melatonin-mediated tumor inhibitory potential are not completely defined. Here, we show that melatonin treatment inhibits TPA-induced cell motility by regulating the matrix metalloproteinase-9 (MMP-9) expression in NPC. We also identified the signaling cascade through which melatonin inhibits MMP-9 expression; this involves melatonin regulating the binding activity of the transcription factor specificity protein-1 (SP-1)-DNA. Our mechanistic analysis further reveals that the c-Jun N-terminal kinase/mitogen-activated protein kinase pathway is involved in the melatonin-mediated tumor suppressor activity. Furthermore, the findings indicate a functional link between melatonin-mediated MMP-9 regulation and tumor suppressing ability and provide new insights into the role of melatonin-induced molecular and epigenetic regulation of tumor growth. Thus, we conclude that melatonin suppresses the motility of NPC by regulating TPA-induced MMP-9 gene expression via inhibiting SP-1-DNA binding ability. The results provide a functional link between melatonin-mediated SP-1 regulation and the antimetastatic actions of melatonin on nasopharyngeal carcinoma.

The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells

NANOG is a transcription factor that is involved in the self-renewal of embryonic stem cells (ES) and is a critical factor for the maintenance of the undifferentiated state of pluripotent cells. Extensive data in the literature show that the NANOG gene is aberrantly expressed during the development of malignancy in cancer cells. ES and cancer stem cells (CSCs), a subpopulation of cancer cells within the tumor, are thought to share common phenotypic properties. This review describes the role of NANOG in cancer cell proliferation, epithelial-mesenchymal transition (EMT), apoptosis and metastasis. In addition, this paper illustrates a correlation between NANOG and signal transducer and activator of transcription 3 (STAT3) in the maintenance of cancer stem cell properties and multidrug resistance. Together, the available data demonstrate that NANOG is strictly involved in the process of carcinogenesis and is a potential prognostic marker of malignant tumors.

Long non-coding RNA XIST exerts oncogenic functions in human nasopharyngeal carcinoma by targeting miR-34a-5p

Long non-coding RNA (lncRNA) X inactivate-specific transcript (XIST) has been verified as an oncogenic gene in several human malignant tumors, and its dysregulation was closed associated with tumor initiation, development and progression. Nevertheless, whether the aberrant expression of XIST in human nasopharyngeal carcinoma (NPC) is corrected with malignancy, metastasis or prognosis has not been elaborated. Here, we discovered that XIST was up-regulated in NPC tissues and higher expression of XIST contributed to a markedly poorer survival time. In addition, multivariate analysis demonstrated XIST was an independent risk factor for prognosis. XIST over-expression enhanced, while XIST silencing hampered the cell growth in NPC. Additionally, mechanistic analysis revealed that XIST up-regulated the expression of miR-34a-5p targeted gene E2F3 through acting as a competitive 'sponge' of miR-34a-5p. Taking all into account, we concluded that XIST functioned as an oncogene in NPC through up-regulating E2F3 in part through 'spongeing' miR-34a-5p.

Functional and molecular characterization of cancer stem-like cells in bladder cancer: a potential signature for muscle-invasive tumors

Striking evidence associates cancer stem cells (CSCs) to the high recurrence rates and poor survival of patients with muscle-invasive bladder cancer (BC). However, the prognostic implication of those cells in risk stratification is not firmly established, mainly due to the functional and phenotypic heterogeneity of CSCs populations, as well as, to the conflicting data regarding their identification based on a single specific marker. This emphasizes the need to exploit putative CSC-related molecular markers with potential prognostic significance in BC patients.

This study aimed to isolate and characterize bladder CSCs making use of different functional and molecular approaches. The data obtained provide strong evidence that muscle-invasive BC is enriched with a heterogeneous stem-like population characterized by enhanced chemoresistance and tumor initiating properties, able to recapitulate the heterogeneity of the original tumor. Additionally, a logistic regression analysis identified a 2-gene stem-like signature (SOX2 and ALDH2) that allows a 93% accurate discrimination between non-muscle-invasive and invasive tumors.

Our findings suggest that a stemness-related gene signature, combined with a cluster of markers to more narrowly refine the CSC phenotype, could better identify BC patients that would benefit from a more aggressive therapeutic intervention targeting CSCs population.

MiR-17-5p promotes cancer cell proliferation and tumorigenesis in nasopharyngeal carcinoma by targeting p21

MicroRNAs (miRNAs) may act as either tumor suppressors or oncogenes in various types of cancers. Previous studies have indicated that miR‐17‐5p is involved in the initiation and development of human tumors. However, its mechanism and function in nasopharyngeal carcinoma (NPC) remain largely unclear. In this study, we evaluated the expression profiles of miR‐17‐5p and p21 in NPC cell lines and tissues by quantitative real‐time PCR (qRT‐PCR). For the analysis, we have established a stable overexpression or depletion of miR‐17‐5p NPC cell lines for analyzing the effects of cell proliferation by MTT, colony formation, and cell cycle assay. A nude mice xenograft model was used to verify the tumor growth in vivo. MiR‐17‐5p was overexpressed, whereas the expression of p21 was downregulated in NPC cell lines and tissues. The miR‐17‐5p expression level was inversely correlated with the p21 mRNA level in NPC samples. Furthermore, analysis of 2^−ΔΔCt value in 81 NPC patients suggested that the elevated expression level of miR‐17‐5p or the downregulated expression level of p21 was significantly correlated with tumor size (T classification) and tumor stage, and Kaplan–Meier survival analysis revealed a correlation between miR‐17‐5p or p21 expression level and overall survival times in 81 NPC patients. MiR‐17‐5p promoted cell growth in vivo and in vitro by directly targeting p21. Our results indicate that miR‐17‐5p can promote the occurrence of NPC and it may serve as a potential novel diagnostic maker or therapeutic target for NPC in the future.

Downregulation of long non-coding RNA MEG3 in nasopharyngeal carcinoma

In our previous whole-transcriptome sequencing analysis, downregulation of a long non-coding RNA, maternally expressed gene 3 (MEG3), was identified in NPC samples. This finding suggests the possible role of MEG3 as a tumor suppressor in this distinctive disease. In the present study, two MEG3 variants, AF119863 (MEG3-AF) and BX247998 (MEG3-BX), were found abundantly expressed in a normal nasopharyngeal epithelial cell line, NP69. Significant downregulation of MEG3-AF was further verified in a panel of NPC samples including xenografts and primary biopsies. MEG3 is an imprinted gene located within chromosome 14q32, a common deleted region in NPC. Both DNA copy number loss and aberrant promoter methylation contributed to MEG3 inactivation. Interestingly, MEG3 expression could successfully be rescued by the treatment of a demethylation agent. Besides, ectopic expression of MEG3 in NPC cell lines resulted in considerable repression of in vitro anchorage-independent growth and in vivo tumorigenicity, in addition to significant inhibition in cell proliferation, colony formation, and induction of cell cycle arrest. Finally, we revealed the association between MEG3 activity and the p53 signaling cascade. Our findings characterize MEG3 as a tumor suppressive long non-coding RNA in NPC and encourage the development of precise long non-coding RNA-targeted epigenetic therapy against this malignancy. © 2016 Wiley Periodicals, Inc.

Circulating Epstein-Barr virus-encoded micro-RNAs as potential biomarkers for nasal natural killer/T-cell lymphoma

Nasal natural killer/T-cell lymphoma (NNKTL) is an Epstein-Barr virus (EBV)-associated malignancy and is characterized by local invasion and widespread dissemination, with a consequent poor prognosis. Micro-RNAs (miRNAs) play roles in the pathogenesis of several malignancies by regulating gene expression and have been recently identified as stable entities in serum. Here, we investigated the value of circulating EBV-miRNAs as biomarkers for NNKTL. Sera of patients with NNKTL were subjected to miRNA polymerase chain reaction (PCR)-array analysis, after which serum EBV-miRNA levels were verified using quantitative PCR. The latter analysis revealed high miR-BART2-5p, miR-BART7-3p, miR-BART13-3p, and miR-BART1-5p expression levels in sera of patients with NNKTL and indicated accurate values for discriminating patients with NNKTL from healthy controls. Levels of these 4 EBV-miRNAs, which were secreted from NNKTL cells, significantly decreased after treatment compared with those before treatment. Furthermore, a high circulating miR-BART2-5p level was associated with disease progression and poor prognosis in patients with NNKTL. Our findings demonstrate that circulating EBV-miRNAs, particularly miR-BART2-5p, may serve as potential diagnostic and prognostic biomarkers in patients with NNKTL.

Protein Markers Associated with an ALDH Sub-Population in Colorectal Cancer

ALDH has been shown to be a marker that denotes a sub-population of cancer stem cells in colorectal and other cancers. This sub-population of cells shows an increased risk for tumor initiation, metastasis, and resistance to chemotherapy and radiation resulting in recurrence and death. It is thus essential to identify the important signaling pathways related to ALDH1+ CSCs in colon cancer. The essential issue becomes to isolate pure sub-populations of cells from heterogeneous tissues for further analysis. To achieve this goal, tissues from colorectal cancer Stage III patients were immuno-stained with ALDH1 antibody. Target ALDH1+ and ALDH1- cells from the same tissue were micro-dissected using Laser Capture Microdissection (LCM). Captured cells were lysed and analyzed using LC-MS/MS where around 20,000 cells were available for analysis. This analysis resulted in 134 proteins which were differentially expressed between ALDH1+ and ALDH1- cells in three patient sample pairs. Based on these differentially expressed proteins an IPA pathway analysis was performed that showed two key pathways in cell to cell signaling and organismal injury and abnormalities. The IPA analysis revealed β-catenin, NFκB (p65) and TGFβ1 as important cancer-related proteins in these pathways. A TMA validation using immunofluorescence staining of tissue micro-arrays including 170 cases was used to verify that these key proteins were highly overexpressed in ALDH1+ cells in colon cancer tissues compared to ALDH1- cells.

MiR-155 Enhances Insulin Sensitivity by Coordinated Regulation of Multiple Genes in Mice

miR-155 plays critical roles in numerous physiological and pathological processes, however, its function in the regulation of blood glucose homeostasis and insulin sensitivity and underlying mechanisms remain unknown. Here, we reveal that miR-155 levels are downregulated in serum from type 2 diabetes (T2D) patients, suggesting that miR-155 might be involved in blood glucose control and diabetes. Gain-of-function and loss-of-function studies in mice demonstrate that miR-155 has no effects on the pancreatic β-cell proliferation and function. Global transgenic overexpression of miR-155 in mice leads to hypoglycaemia, improved glucose tolerance and insulin sensitivity. Conversely, miR-155 deficiency in mice causes hyperglycemia, impaired glucose tolerance and insulin resistance. In addition, consistent with a positive regulatory role of miR-155 in glucose metabolism, miR-155 positively modulates glucose uptake in all cell types examined, while mice overexpressing miR-155 transgene show enhanced glycolysis, and insulin-stimulated AKT and IRS-1 phosphorylation in liver, adipose tissue or skeletal muscle. Furthermore, we reveal these aforementioned phenomena occur, at least partially, through miR-155-mediated repression of important negative regulators (i.e. C/EBPβ, HDAC4 and SOCS1) of insulin signaling. Taken together, these findings demonstrate, for the first time, that miR-155 is a positive regulator of insulin sensitivity with potential applications for diabetes treatment.

Ectopic expression of Cripto-1 in transgenic mouse embryos causes hemorrhages, fatal cardiac defects and embryonic lethality

Targeted disruption of Cripto-1 in mice caused embryonic lethality at E7.5, whereas we unexpectedly found that ectopic Cripto-1 expression in mouse embryos also led to embryonic lethality, which prompted us to characterize the causes and mechanisms underlying embryonic death due to ectopic Cripto-1 expression. RCLG/EIIa-Cre embryos displayed complex phenotypes between embryonic day 14.5 (E14.5) and E17.5, including fatal hemorrhages (E14.5-E15.5), embryo resorption (E14.5-E17.5), pale body surface (E14.5-E16.5) and no abnormal appearance (E14.5-E16.5). Macroscopic and histological examination revealed that ectopic expression of Cripto-1 transgene in RCLG/EIIa-Cre embryos resulted in lethal cardiac defects, as evidenced by cardiac malformations, myocardial thinning, failed assembly of striated myofibrils and lack of heartbeat. In addition, Cripto-1 transgene activation beginning after E8.5 also caused the aforementioned lethal cardiac defects in mouse embryos. Furthermore, ectopic Cripto-1 expression in embryonic hearts reduced the expression of cardiac transcription factors, which is at least partially responsible for the aforementioned lethal cardiac defects. Our results suggest that hemorrhages and cardiac abnormalities are two important lethal factors in Cripto-1 transgenic mice. Taken together, these findings are the first to demonstrate that sustained Cripto-1 transgene expression after E11.5 causes fatal hemorrhages and lethal cardiac defects, leading to embryonic death at E14.5-17.5.

EBV-miR-BART10-3p facilitates epithelial-mesenchymal transition and promotes metastasis of nasopharyngeal carcinoma by targeting BTRC

Epstein-Barr virus (EBV) infection is closely associated with tumorigenesis and development of nasopharyngeal carcinoma (NPC), but the underlying molecular mechanisms remain poorly understood. It has been recently reported that EBV encodes 44 mature miRNAs, some of which were found to promote tumor development by targeting virus-infected host genes or self-viral genes. However, few targets of EBV encoded-miRNAs that are related to NPC development have been identified to date. In this study, we revealed that in NPC cells, EBV-miR-BART10-3p directly targets BTRC gene that encodes βTrCP (beta-transducin repeat containing E3 ubiquitin protein ligase). We found that EBV-miR-BART10-3p expression in clinical samples from a cohort of 106 NPC patients negatively correlated with BTRC expression levels. Over-expression of EBV-miR-BART10-3p and down-regulation of BTRC were associated with poor prognosis in NPC patients. EBV-miR-BART10-3p promoted the invasion and migration cabilities of NPC cells through the targeting of BTRC and regulation of the expression of the downstream substrates β-catenin and Snail. As a result, EBV-miR-BART10-3p facilitated epithelial-mesenchymal transition of NPC. Our study presents an unreported mechanism underlying EBV infection in NPC carcinogenesis, and provides a potential novel biomarker for NPC diagnosis, treatment and prognosis.

Overexpression of IGFBP3 is associated with poor prognosis and tumor metastasis in nasopharyngeal carcinoma

Insulin-like growth factor-binding protein-3 (IGFBP3) is an N-linked glycosylated, phosphorylated protein, which has been reported to regulate cancer progression and metastasis. However, the role of IGFBP3 in tumor metastasis remains under debate. Nasopharyngeal carcinoma (NPC) is a highly metastatic head and neck cancer. And it fails to achieve the desired therapeutic efficacy in patients with metastasis, while the role of IGFBP3 in NPC is still unclear. In this study, we first used immunohistochemistry to explore the expression of IGFBP3 in NPC tissues. We found that IGFBP3 was significantly elevated in NPC and its expression level was correlated with N classification, distant metastasis, and TNM clinical stage (all P < 0.05). Patients with high expression of IGFBP3 had poorer survival rate (P < 0.05). In addition, we found that downregulation of IGFBP3 inhibited cell migration and adhesion by Transwell migration assay, wounding healing assay, and cell adhesion assays in vitro. Besides, NPC cells stimulated with recombinant IGFBP3 accelerated migration and adhesion. These data suggest overexpression of IGFBP3 promotes tumor metastasis in NPC, which makes it a potential therapeutic target.

Antigen Presenting Properties of a Myeloid Dendritic-Like Cell in Murine Spleen

This paper distinguishes a rare subset of myeloid dendritic-like cells found in mouse spleen from conventional (c) dendritic cells (DC) in terms of phenotype, function and gene expression. These cells are tentatively named “L-DC” since they resemble dendritic-like cells produced in longterm cultures of spleen. L-DC can be distinguished on the basis of their unique phenotype as CD11b^hiCD11c^loMHCII^-CD43⁺Ly6C^-Ly6G^-Siglec-F^- cells. They demonstrate similar ability as cDC to uptake and retain complex antigens like mannan via mannose receptors, but much lower ability to endocytose and retain soluble antigen. While L-DC differ from cDC by their inability to activate CD4⁺ T cells, they are capable of antigen cross-presentation for activation of CD8⁺ T cells, although less effectively so than the cDC subsets. In terms of gene expression, CD8^- cDC and CD8⁺ cDC are quite distinct from L-DC. CD8⁺ cDC are distinguishable from the other two subsets by expression of CD24a, Clec9a, Xcr1 and Tlr11, while CD8^- cDC are distinguished by expression of Ccnd1 and H-2Eb2. L-DC are distinct from the two cDC subsets through upregulated expression of Clec4a3, Emr4, Itgam, Csf1r and CD300ld. The L-DC gene profile is quite distinct from that of cDC, confirming a myeloid cell type with distinct antigen presenting properties.

MicroRNA-1275 suppresses cell growth, and retards G1/S transition in human nasopharyngeal carcinoma by down-regulation of HOXB5

Through analysis of a reported microarray-based high-throughput examination, we found that miR-1275 was significantly down-regulated in nasopharyngeal carcinoma (NPC). While its role and mechanism participated in NPC progression are still little known. Here, we explored the effect of miR-1275 on the progression of NPC. Results demonstrated that miR-1275 was markedly down-regulated in NPC tissues and cell lines. MiR-1275 markedly repressed cell growth as confirmed by CCK8 and colony formation assay, via inhibition of HOXB5 in NPC cell lines. Moreover, miR-1275 suppressed G1/S transition via inhibition of HOXB5. Further, oncogene HOXB5 was evidenced to be a potential target of miR-1275, and its expression was conversely correlated with miR-1275 expression in NPC. Collectively, our study indicated that miR-1275, a tumor suppressor, played a critical effect on NPC progression via inhibition of cell growth, and suppression of G1/S transition by targeting oncogenic HOXB5.

Stemness-related transcriptional factors and homing gene expression profiles in hepatic differentiation and cancer

Stem cell transcriptional signature activation is an essential event in the development of cancer. This study aimed to investigate the differential expression profile of three pluripotency-associated genes (OCT4, NANOG, and SOX2), G-protein-coupled chemokine receptor 4 (CXCR4) and the ligand (CXCL2), and alpha feto-protein (AFP) in hepatogenic differentiated stem cells and in sera of hepatitis C virus (HCV) and HCV-induced hepatocellular carcinoma (HCC) patients. Mesenchymal stem cells derived from umbilical cord blood were differentiated using hepatogenic differentiation media. Serum specimens were collected from 96 patients (32 cirrhotic HCV, 32 early HCC, and 32 late HCC) and 96 controls. Real-time quantitative reverse transcription polymerase chain reaction was performed for relative quantification of the 6 target genes using LIVAC method. In silico network analysis was also executed to explore the pluripotency and tumorigenic regulatory circuits in liver cancer. The expression levels of all genes declined gradually during the stages of stem cell differentiation. On univariate and multivariate analyses, NANOG, CXCR4 and AFP were significantly up-regulated in HCC patients with late clinical stage. In contrast, SOX2 and CXCL2 were markedly over-expressed in cirrhotic patients and could be used for clear demarcation between cirrhotic and HCC patients in our cases. In conclusion, our data highlight the potential role of SOX2 stem cell marker and CXCL2 chemokine in liver cell degeneration and fibrogenesis in HCV-induced hepatic cirrhosis in our sample of the Egyptian population. In addition, the significant association of NANOG and CXCR4 high-expression with late HCC, could contribute to the acquisition of stem cell-like properties in hepatic cancer and dissemination in late stages, respectively. Taken together, our results could have a potential application in HCC prognosis and treatment.

Epstein-Barr virus-encoded miR-BART6-3p inhibits cancer cell metastasis and invasion by targeting long non-coding RNA LOC553103

Epstein-Barr virus (EBV) infection is causatively related to a variety of human cancers, including nasopharyngeal carcinoma (NPC) and gastric cancer (GC). EBV encodes 44 mature miRNAs, a number of which have been proven to promote carcinogenesis by targeting host genes or self-viral genes. However, in this study, we found that an EBV-encoded microRNA, termed EBV-miR-BART6-3p, inhibited EBV-associated cancer cell migration and invasion including NPC and GC by reversing the epithelial-mesenchymal transition (EMT) process. Using microarray analysis, we identified and validated that a novel long non-coding RNA (lncRNA) LOC553103 was downregulated by EBV-miR-BART6-3p, and LOC553103 knockdown by specific siRNAs phenocopied the effect of EBV-miR-BART6-3p, while LOC553103 overexpression promoted cancer cell migration and invasion to facilitate EMT. In conclusion, we determined that EBV-miR-BART6-3p, a microRNA encoded by oncogenic EBV, inhibited EBV-associated cancer cell migration and invasion by targeting and downregulating a novel lncRNA LOC553103. Thus, our study presents an unreported mechanism underlying EBV infection in EBV-associated cancer carcinogenesis, and provides a potential novel diagnosis and treatment biomarker for NPC and other EBV-related cancers.

HNSCC cells resistant to EGFR pathway inhibitors are hypermutated and sensitive to DNA damaging substances

Despite remarkable successes with targeted therapies in the treatment of cancer, resistance can occur which limits the clinical outcome. In this study, we generated and characterized resistant cell clones derived from two different head and neck squamous cell carcinoma (HNSCC) cell lines (Cal27, UD-SCC-5) by long-term exposure to five targeted- and chemotherapeutics (afatinib, MK2206, BEZ235, olaparib and cisplatin). The resistant tumor cell clones showed an increased ERK1/2 expression and an altered expression of the stem-cell markers CD44, ALDH1, Oct4, Sox2, Nanog and Bmi1. None of the single markers alone was predictive for resistance to all five targeted- and chemotherapeutics. Furthermore, long-term exposure of tumor cells to these five drugs resulted in an eightfold increase in the mutational rate compared to untreated cells. Interestingly, targeted- and chemotherapy resistant cell clones remained sensitive to irradiation. Lastly, clones that were resistant to afatinib, MK2206 or BEZ235 showed cross-resistance to further treatment with therapeutics that affect the same signaling pathway, but remained sensitive to those affecting different pathways such as cisplatin and olaparib. In contrast, cell clones which were once resistant to cisplatin or olaparib were found to be multidrug-resistant. These data might indicate that patients with HNSCC benefit more by a first line targeted therapy followed by cisplatin as a second line therapy.

Cytokine-induced killer cells efficiently kill stem-like cancer cells of nasopharyngeal carcinoma via the NKG2D-ligands recognition

Cancer stem cells (CSCs) are considered to be the root cause for cancer treatment failure. Thus, there remains an urgent need for more potent and safer therapies against CSCs for curing cancer. In this study, the antitumor activity of cytokine-induced killer (CIK) cells against putative CSCs of nasopharyngeal carcinoma (NPC) was fully evaluated in vitro and in vivo. To visualize putative CSCs in vitro by fluorescence imaging, and image and quantify putative CSCs in tumor xenograft-bearing mice by in vivo bioluminescence imaging, NPC cells were engineered with CSC detector vector encoding GFP and luciferase (Luc) under control of Nanog promoter. Our study reported in vitro intense tumor-killing activity of CIK cells against putative CSCs of NPC, as revealed by percentage analysis of side population cells, tumorsphere formation assay and Nanog-promoter-GFP-Luc reporter gene strategy plus time-lapse recording. Additionally, time-lapse imaging firstly illustrated that GFP-labeled or PKH26-labeled putative CSCs or tumorspheres were usually attacked simultaneously by many CIK cells and finally killed by CIK cells, suggesting the necessity of achieving sufficient effector-to-target ratios. We firstly confirmed that NKG2D blockade by anti-NKG2D antibody significantly but partially abrogated CIK cell-mediated cytolysis against putative CSCs. More importantly, intravenous infusion of CIK cells significantly delayed tumor growth in NOD/SCID mice, accompanied by a remarkable reduction in putative CSC number monitored by whole-body bioluminescence imaging. Taken together, our findings suggest that CIK cells demonstrate the intense tumor-killing activity against putative CSCs of NPC, at least in part, by NKG2D-ligands recognition. These results indicate that CIK cell-based therapeutic strategy against CSCs presents a promising and safe approach for cancer treatment.

Inflammation-Related DNA Damage and Cancer Stem Cell Markers in Nasopharyngeal Carcinoma

Nitrative and oxidative DNA damage plays an important role in inflammation-related carcinogenesis. To investigate the involvement of stem cells in Epstein-Barr virus infection-related nasopharyngeal carcinoma (NPC), we used double immunofluorescence staining to examine several cancer stem/progenitor cell markers (CD44v6, CD24, and ALDH1A1) in NPC tissues and NPC cell lines. We also measured 8-nitroguanine formation as an indicator of inflammation-related DNA lesions. The staining intensity of 8-nitroguanine was significantly higher in cancer cells and inflammatory cells in the stroma of NPC tissues than in chronic nasopharyngitis tissues. Expression levels of CD44v6 and ALDH1A1 were significantly increased in cancer cells of primary NPC specimens in comparison to chronic nasopharyngitis tissues. Similarly, more intense staining of CD44v6 and ALDH1A1 was detected in an NPC cell line than in an immortalized nasopharyngeal epithelial cell line. In the case of CD24 staining, there was no significant difference between NPC and chronic nasopharyngitis tissues. 8-Nitroguanine was detected in both CD44v6- and ALDH1A1-positive stem cells in NPC tissues. In conclusion, CD44v6 and ALDH1A1 are candidate stem cell markers for NPC, and the increased formation of DNA lesions by inflammation may result in the mutation of stem cells, leading to tumor development in NPC.

ZEB1 expression is increased in IDH1-mutant lower-grade gliomas

Transcription factors that induce epithelial-mesenchymal transition (EMT) promote invasion, chemoresistance and a stem-cell phenotype in epithelial tumors, but their roles in central nervous system tumors are not well-understood. We hypothesized these transcription factors have a functional impact in grades II-III gliomas. Using the National Cancer Institute (NCI) Repository for Molecular Brain Neoplasia Data (REMBRANDT) and the Cancer Genome Atlas (TCGA) Lower-Grade Glioma (LGG) data, we determined the impact of EMT-promoting transcription factors (EMT-TFs) on overall survival in grades II-III gliomas, compared their expression across common genetic subtypes and subsequently validated these findings in a set of 31 tumors using quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. Increased expression of the gene coding for the transcriptional repressor Zinc Finger E box-binding Homeobox 1 (ZEB1) was associated with a significant increase in overall survival (OS) on Kaplan-Meier analysis. Genetic subtype analysis revealed that ZEB1 expression was relatively increased in IDH1/2-mutant gliomas, and IDH1/2-mutant gliomas expressed significantly lower levels of many ZEB1 transcriptional targets. Similarly, IDH1/2-mutant tumors expressed significantly higher levels of targets of microRNA 200C (MIR200C), a key regulator of ZEB1. In a validation study, ZEB1 mRNA was significantly increased in IDH1-mutant grades II-III gliomas, and ZEB1 protein expression was more pronounced in these tumors. Our findings demonstrate a novel relationship between IDH1/2 mutations and expression of ZEB1 and its transcriptional targets. Therapy targeting ZEB1-associated pathways may represent a novel therapeutic avenue for this class of tumors.

The small noncoding RNAs (sncRNAs) of murine gammaherpesvirus 68 (MHV-68) are involved in regulating the latent-to-lytic switch in vivo

The human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV), which are associated with a variety of diseases including tumors, produce various small noncoding RNAs (sncRNAs) such as microRNAs (miRNAs). Like all herpesviruses, they show two stages in their life cycle: lytic replication and latency. During latency, hardly any viral proteins are expressed to avoid recognition by the immune system. Thus, sncRNAs might be exploited since they are less likely to be recognized. Specifically, it has been proposed that sncRNAs might contribute to the maintenance of latency. This has already been shown in vitro, but the respective evidence in vivo is very limited. A natural model system to explore this question in vivo is infection of mice with murine gammaherpesvirus 68 (MHV-68). We used this model to analyze a MHV-68 mutant lacking the expression of all miRNAs. In the absence of the miRNAs, we observed a higher viral genomic load during late latency in the spleens of mice. We propose that this is due to a disturbed regulation of the latent-to-lytic switch, altering the balance between latent and lytic infection. Hence, we provide for the first time evidence that gammaherpesvirus sncRNAs contribute to the maintenance of latency in vivo.

Karyopherinβ1 regulates proliferation of human glioma cells via Wnt/β-catenin pathway

Karyopherinβ1 (KPNB1), one of the cytosolic factors involved in the selective protein transport across nucleus, docked at nuclear pore complex and transported through nuclear envelope in an ATP-dependent style, assisting proteins to be recognized as import substrates. It has been reported to be bound up with the origination and progress of lung cancer, cervical cancer, head and neck cancer and hepatocellular carcinoma. In current study, we demonstrated for the first time that the role of KPNB1 in human glioma. KPNB1 was over-expressed as the well-known trend of Ki-67(p < 0.01) and tightly closed to poor prognosis, as an independent prognostic factor. In vitro, up-regulation of KPNB1 was accompanied by certain rising levels of proliferation markers, employing U251 and U87MG cells as serum-starve models. Silencing KPNB1 in U251 and U87MG led to G1 phase arrested directly via flow cytometry analysis. In the nucleus of KPNB1-depletion cell models, the decreasing expression of KPNB1 and β-catenin was detected respectively, which indicated that KPNB1 functioned via β-catenin signal. Besides, the interaction between KPNB1 and β-catenin was proved clearly by immunoprecipitation. Taken together, it showed that KPNB1 might enhance human glioma proliferation via Wnt/β-Catenin Pathway.

Effects of RECQ1 helicase silencing on non-small cell lung cancer cells

RECQ1, the most abundant one of the human RecQ helicases family, has been identified as a prometastasis gene in breast and cervical cancers. However, the effects of RECQ1 on non-small cell lung cancer (NSCLC) and the underlying molecular mechanisms are still unclear. In the present study, RECQ1 expression (in three NSCLC cell lines and one bronchial epithelial cell line) was detected by real-time quantitative PCR (RT-qPCR). Expression of RECQ1 in A549 cells was knocked down by lentivirus-mediated RNA interference technique (RNAi). The effects of RECQ1 knockdown on cell proliferation, migration and invasion were assessed by Cell Counting Kit-8 (CCK-8) assay and transwell assays. Epithelial-mesenchymal transition (EMT)-associated proteins (E-cadherin, N-cadherin as well as vimentin) were detected by RT-qPCR and western blotting analyses. We found that RECQ1 expression was significantly higher in three NSCLC cell lines than that in a normal human bronchial epithelial cell line. Knocking down RECQ1 significantly suppressed A549 cell proliferation, migration and invasion. The expressions of the epithelial marker, E-cadherin were elevated in both mRNA and protein levels, whereas the expressions of the mesenchymal markers, N-cadherin and vimentin were decreased. Taken together, our findings suggest that RECQ1 may act as an important mediator in promoting lung cancer progression via modulation of the EMT. RECQ1 might represent a potential therapeutic target in NSCLC.

Identification of genes involved in Epstein-Barr virus-associated nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is the most common cancer originating from the nasopharynx, and can be induced by infection with Epstein-Barr virus (EBV). To study the mechanisms of EBV-associated NPC, a microarray of the GSE12452 dataset was analyzed. GSE12452 was downloaded from Gene Expression Omnibus and consisted of 31 NPC samples and 10 normal healthy nasopharyngeal tissue samples. The differentially-expressed genes (DEGs) were screened using the linear models for microarray data package in R. Using Database for Annotation, Visualization and Integrated Discovery software, potential functions of the DEGs were predicted by Gene Ontology and pathway enrichment analyses. With the information from the Search Tool for the Retrieval of Interacting Genes/Proteins database, the protein-protein interaction (PPI) network was visualized by Cytoscape. Furthermore, modules of the PPI network were searched using ClusterONE in Cytoscape. A total of 951 DEGs were screened in the NPC samples compared with the normal healthy nasopharyngeal tissue samples. Function enrichment indicated that the upregulated genes were associated with the cell cycle, cytoskeleton organization and DNA metabolism. Meanwhile, the downregulated genes were mainly associated with cell differentiation, hormone metabolism, inflammatory response and immune response. PPI networks for the DEGs suggested that upregulated mitotic arrest deficient 2-like 1 (MAD2L1; degree=133), proliferating cell nuclear antigen (PCNA; degree=125) and cyclin B1 (CCNB1; degree=115), and downregulated member A1 of aldehyde dehydrogenase 1 (ALDH1A1; degree=15) may be of great importance as they exhibited higher degrees on interaction. Mucin 1 (MUC1) was a key node of module 4. Overall, the study indicated that MAD2L1, CCNB1, PCNA, ALDH1A1 and MUC1 may have a correlation with EBV-associated NPC.

Silencing expression of the NANOG gene and changes in migration and metastasis of urinary bladder cancer cells

INTRODUCTION

It has been proved that expression of the NANOG gene is observed not only in embryonic-derived malignancies, but also in breast cancer, ovarian cancer, cervix cancer and bladder cancer. NANOG overexpression is correlated with high activity of MMP-2 and MMP-9. The aim of the study was to evaluate the changes in the malignant phenotype of T24 bladder cancer cells with modulated expression of the NANOG gene.

MATERIAL AND METHODS

Human urinary bladder cancer cells T24 (HTB-4) were cultivated under standard conditions. Transfection of the cells with silencing constructions was performed with the application of Lipofectamine 2000 (Invitrogen) reagent. Evaluation of changes in the expression level of individual genes was performed using qRTPCR. Changes in the protein level were evaluated using the Human ELISA Kit (Abcam). The invasion capability of transfected cells was tested using Matrigel Invasion Chambers (BD Biosciences). The changes in cell migration were assessed with a wound-healing assay.

RESULTS

The qRTPCR evaluation showed that silencing the NANOG gene in T24 cells led to the decrease of mRNA for the MMP-2 gene to the level of 62.4% and the MMP-9 gene to the level of 76%. The cells with modulated expression of the NANOG gene migrated slower in the Matrigel invasion assay and in the wound-healing assay. The immunoenzymatic test showed a decrease in the protein level of MMP-9.

CONCLUSIONS

The transcriptional activity of the NANOG gene might be connected with some aspects of bladder cancer cell metastasis in vitro and has an influence on MMP-2 and MMP-9 expression levels.

DNA methylome changes by estradiol benzoate and bisphenol A links early-life environmental exposures to prostate cancer risk

Developmental exposure to endocrine-disrupting chemicals (EDCs), 17β-estradiol-3-benzoate (EB) and bisphenol A (BPA), increases susceptibility to prostate cancer (PCa) in rodent models. Here, we used the methylated-CpG island recovery assay (MIRA)-assisted genomic tiling and CpG island arrays to identify treatment-associated methylome changes in the postnatal day (PND)90 dorsal prostate tissues of Sprague-Dawley rats neonatally (PND1, 3, and 5) treated with 25 µg/pup or 2,500 µg EB/kg body weight (BW) or 0.1 µg BPA/pup or 10 µg BPA/kg BW. We identified 111 EB-associated and 86 BPA-associated genes, with 20 in common, that have significant differentially methylated regions. Pathway analysis revealed cancer as the top common disease pathway. Bisulfite sequencing validated the differential methylation patterns observed by array analysis in 15 identified candidate genes. The methylation status of 7 (Pitx3, Wnt10b, Paqr4, Sox2, Chst14, Tpd52, Creb3l4) of these 15 genes exhibited an inverse correlation with gene expression in tissue samples. Cell-based assays, using 5-aza-cytidine-treated normal (NbE-1) and cancerous (AIT) rat prostate cells, added evidence of DNA methylation-mediated gene expression of 6 genes (exception: Paqr4). Functional connectivity of these genes was linked to embryonic stem cell pluripotency. Furthermore, clustering analyses using the dataset from The Cancer Genome Atlas revealed that expression of this set of 7 genes was associated with recurrence-free survival of PCa patients. In conclusion, our study reveals that gene-specific promoter methylation changes, resulting from early-life EDC exposure in the rat, may serve as predictive epigenetic biomarkers of PCa recurrence, and raises the possibility that such exposure may impact human disease.

Roles of Signaling Pathways in the Epithelial-Mesenchymal Transition in Cancer

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor β(TGF-β), Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

Down-regulation of miR-192-5p protects from oxidative stress-induced acute liver injury

miR-192-5p has gained increasing relevance in various diseases, however, its function in acute liver injury is currently unknown. We analysed miR-192-5p serum levels and hepatic miR-192-5p expression in mice after hepatic ischaemia and reperfusion (I/R) as well as in toxic liver injury. On a functional level, miRNA levels were analysed in the different hepatic cell-compartments and in the context of tumour necrosis factor (TNF)-dependent liver cell death. We detected increased serum levels of miR-192-5p after hepatic I/R- and carbon tetrachloride (CCl4)-induced liver injury. miR-192-5p levels correlated with the degree of liver damage and the presence of hepatic cell death detected by TUNEL stainings (terminal deoxynucleotidyltransferase-mediated dUTP biotin nick-end labelling stainings). Moreover, expression of miR-192-5p was increased in a hypoxia/reoxygenation (H/R) model of in vitro hepatocyte injury, supporting that the passive release of miR-192-5p represents a surrogate for hepatocyte death in liver injury. In critically ill patients, miR-192-5p levels were elevated selectively in patients with liver injury and closely correlated with the presence of hepatic injury. In contrast with up-regulated miR-192-5p in the serum, we detected a down-regulation of miR-192-5p in both injured mouse and human livers. Deregulation of miR-192-5p in livers was dependent on stimulation with TNF. Functional experiments confirmed a protective effect of down-regulation of miR-192-5p in hepatocytes, suggesting a role of miR-192-5p in limiting liver injury. Finally, we identified Zeb2, an important regulator of cell death, as a potential target gene mediating the function of miR-192-5p. Our data suggest that miR-192-5p is involved in the regulation of liver cell death during acute liver injury and might represent a potent marker of hepatic injury.

Higher methylation intensity induced by EBV LMP1 via NF-κB/DNMT3b signaling contributes to silencing of PTEN gene

Phosphatase and tensin homolog (PTEN) is a major tumor suppressor and usually silenced via the deletion, insertion and mutation. We previously discovered its inactivation via aberrant CpG island methylation. Here, we provide further evidence that EBV latent membrane protein 1(LMP1) can induce a higher intensity of DNA methylation at PTEN CpG islands, inactivating PTEN at the cellular and molecular level. Initially, increased methylation intensity of PTEN CpG islands was observed in EBV-infected nasopharyngeal carcinoma (NPC) cells, accompanied by decreased PTEN expression. In NPC tissue samples showing the methylation at PTEN promoter, LMP1 was highly expressed in higher methylation intensity group relative to lower intensity group, and DNA methyltransferase 3b (DNMT3b) expression was positively correlated with LMP1 expression. Moreover, transfection of LMP1 gene into EBV-negative NPC cells demonstrated that LMP1 up-regulated DNMT3b expression, leading to a higher intensity of PTEN CpG island methylation. Mechanistically, computational prediction and luciferase reporter assay identified a functional NF-κB binding site on DNMT3b promoter and the mutated NF-κB binding site abolished LMP1-mediated DNMT3b activation. Chromatin immunoprecipitation displayed that NF-κB p65 subunit constitutively bound to DNMT3b promoter, supporting the activation of DNMT3b by EBV LMP1 via NF-κB signaling. Furthermore, the expression level of DNMT3b was observed to be increased in the nuclei of LMP1-expressing NPC cells, and a NF-κB inhibitor, PDTC, counteracted LMP1-mediated DNMT3b overexpression. Thus, this study first reports that LMP1-mediated NF-κB can up-regulate DNMT3b transcription, thereby leading to relatively higher methylation intensity at PTEN CpG islands, and ultimately silencing major tumor suppressor PTEN.

Decreasing the ratio of matriptase/HAI‑1 by downregulation of matriptase as a potential adjuvant therapy in ovarian cancer

Tumor invasion and metastasis are complex biological processes. Matriptase and its endogenous inhibitor, hepatocyte growth factor activator inhibitor‑1 (HAI‑1) are involved in invasion and metastasis. To evaluate the ratio of matriptase/HAI‑1 and their potential therapeutic value in ovarian cancer, HO‑8910 human ovarian cancer cells and the homologous high‑metastatic HO‑8910PM cells were used as in vitro cellular models ovarian cancer. The invasive and metastatic abilities, and the expression of matriptase and HAI‑1 in these cells were detected using scratch assays, Transwell chamber assays, reverse transcription‑quantitative polymerase chain reaction, western blotting and fluorescent immunocytochemistry. Following infection with lentivirus‑mediated matriptase‑targeting small interfering RNA (siRNA), cell cycle progression and apoptosis were also analyzed. The migration distance and number of invading HO‑8910PM cells were significantly increased compared with HO‑8910 cells. HO‑8910PM cells exhibited a significantly higher ratio of matriptase/HAI‑1 mRNA levels compared with HO‑8910 cells (0.51 vs. 0.24, ~2.2 fold increase). Compared with HO‑8910 cells, the matriptase mRNA level was increased by ~3.6 fold in HO‑8910PM cells, whereas the HAI‑1 mRNA level was increased by ~1.7 fold. Similar increases in protein expression levels were also observed in HO‑8910PM cells compared with HO‑8910 cells. Migration and invasiveness were positively correlated with matriptase expression level (r=0.994, P<0.01) and the ratio of matriptase/HAI‑1 (r=0.929, P<0.01). Downregulation of matriptase using siRNA resulted in inhibition of the invasive and metastatic abilities of HO‑8910PM cells, cell cycle arrest in the G0/G1 phase and increased apoptosis. The present study demonstrated that ovarian cancer cell metastasis and invasion were more dependent on upregulation of matriptase levels than downregulation of HAI‑1. Matriptase may be a potential adjuvant therapeutic target for inhibiting ovarian cancer invasion and metastasis.

MicroRNA-92a promotes metastasis of nasopharyngeal carcinoma by targeting the PTEN/AKT pathway

MicroRNAs have been confirmed to be a group of important regulators during the pathogenesis of nasopharyngeal carcinoma (NPC). This study confirmed that the expression of microRNA-92a (miR-92a) was significantly upregulated in NPC as compared to noncancerous nasopharyngeal epithelial tissues. Furthermore, high expression of miR-92a was observed in all NPC cell lines, especially in high metastatic cell lines. Clinical analysis indicated that high expression of miR-92a was associated with adverse clinicopathological features including the advanced tumor-node-metastasis stage and distant metastasis, and conferred poor prognosis of patients. In vitro assays showed that miR-92a overexpression potentiated the migration and invasion of 6-10B cells, and miR-92a silencing reduced the number of migrated and invaded 5-8F cells. Phosphatase and tensin homolog (PTEN) was confirmed as a direct downstream target of miR-92a in NPC cells. Otherwise, alteration of miR-92a expression regulated PTEN/AKT pathway in NPC cells. Mechanistically, miR-92a exerted its promoting effects on the metastatic behaviors of NPC cells through suppressing PTEN/AKT pathway. Taken together, this study demonstrates that miR-92a is a promising prognostic biomarker for patients with NPC, and may be a potential therapeutic target to prevent the metastasis of NPC.

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

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

miR-374a-CCND1-pPI3K/AKT-c-JUN feedback loop modulated by PDCD4 suppresses cell growth, metastasis, and sensitizes nasopharyngeal carcinoma to cisplatin

miR-374a has been reported to function as an oncogene during tumor pathogenesis. In this study, miR-374a is observed to reduce nasopharyngeal carcinoma (NPC) cell proliferation, migration, invasion, metastasis and cisplatin (DDP) resistance in vitro and in vivo. Mechanistic analyses indicate that miR-374a directly targets CCND1 to inactivate pPI3K/pAKT/c-JUN forming a negative feedback loop, as well as suppressing downstream signals related to cell cycle progression and epithelial-mesenchymal transition (EMT). Interestingly, we also observed that miR-374a direct targeting of CCND1 is modulated by tumor suppressor PDCD4 via suppressing pPI3K/pAKT/c-JUN signaling. In clinical specimens, miR-374a was positively and negatively correlated with expression of PDCD4 and CCND1, respectively. Our studies are the first to demonstrate that the miR-374a-CCND1-pPI3K/AKT-c-JUN feedback loop induced by PDCD4 supresses NPC cell growth, metastasis and chemotherapy resistance.

The Role of microRNAs in the Pathogenesis of Herpesvirus Infection

MicroRNAs (miRNAs) are small non-coding RNAs important in gene regulation. They are able to regulate mRNA translation through base-pair complementarity. Cellular miRNAs have been involved in the regulation of nearly all cellular pathways, and their deregulation has been associated with several diseases such as cancer. Given the importance of microRNAs to cell homeostasis, it is no surprise that viruses have evolved to take advantage of this cellular pathway. Viruses have been reported to be able to encode and express functional viral microRNAs that target both viral and cellular transcripts. Moreover, viral inhibition of key proteins from the microRNA pathway and important changes in cellular microRNA pool have been reported upon viral infection. In addition, viruses have developed multiple mechanisms to avoid being targeted by cellular microRNAs. This complex interaction between host and viruses to control the microRNA pathway usually favors viral infection and persistence by either reducing immune detection, avoiding apoptosis, promoting cell growth, or promoting lytic or latent infection. One of the best examples of this virus-host-microRNA interplay emanates from members of the Herperviridae family, namely the herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2), human cytomegalovirus (HCMV), human herpesvirus 8 (HHV-8), and the Epstein–Barr virus (EBV). In this review, we will focus on the general functions of microRNAs and the interactions between herpesviruses, human hosts, and microRNAs and will delve into the related mechanisms that contribute to infection and pathogenesis.

Gold nano-particles (AuNPs) carrying anti-EBV-miR-BART7-3p inhibit growth of EBV-positive nasopharyngeal carcinoma

Epstein-Barr virus (EBV) infection is a major etiological factor for nasopharyngeal carcinoma (NPC). Several EBV-encoded BART miRNAs have been associated with viral latency, immune escape, cell survival, cell proliferation and apoptosis. Here, we report that EBV-miR-BART7-3p, an EBV-encoded BART miRNA highly expressed in NPC, was correlated with cell-cycle progression in vitro and increased tumor formation in vivo. This viral miRNA stimulated the PTEN/PI3K/Akt pathway and induced c-Myc and c-Jun. Knockdown of PTEN mimicked EBV-miR-BART7-3p-induced tumorigenic phenotype. Based on these results, we conducted a therapeutic experiment by using gold nano-particles (AuNPs) carrying anti-EBV-miR-BART7-3p. Silencing of EBV-miR-BART7-3p reduced tumor growth in animal model. We conclude that EBV-miR-BART7-3p favors carcinogenesis, representing a potential target for miRNA-based therapy.

URG4 expression is a novel prognostic factor for the progression of nasopharyngeal carcinoma and overall survival of patient

URG4, a novel oncogene, is involved in the development and progression of various tumors. This study investigated the clinicopathological significance of URG4 in nasopharyngeal carcinoma (NPC). We used five NPC tissues and adjacent normal nasopharyngeal tissues to determine URG4 expression and found that URG4 was upregulated in NPC tissues. Immunohistochemistry analysis found URG4 was expressed positively in 97.1% (99/102) of NPC samples and highly expressed in 41.2% (42/102) of NPC samples. Its level was positively correlated with advancing clinical stage. Kaplan–Meier analysis with the log-rank test found that patients with high URG4 expression had poor outcome and patients with low URG4 expression had better survival. Statistical analysis showed that there was a significant correlation between URG4 expression and clinical stage, larger tumor size, and lymph node involvement. Cox-regression analysis showed that URG4 expression could serve as a prognostic factor for NPC patients. In summary, this study showed that URG4 was upregulated in NPC tissues, patients with high URG4 expression had poor outcome, and URG4 was found to be a valuable biomarker for NPC progression.

miR-154 inhibits migration and invasion of human non-small cell lung cancer by targeting ZEB2

Emerging evidence suggests that microRNAs (miRs) play critical roles in the development and progression of non-small cell lung cancer (NSCLC). In a previous study, the present authors demonstrated that miR-154 acts as a tumor suppressor in NSCLC; however, its underlying molecular mechanism and target in NSCLC remain poorly understood. In the present study, ectopic expression of miR-154 remarkably suppressed cell migration and invasion in NSCLC cells. Zinc finger E-box binding homeobox 2 (ZEB2) was identified as a direct target of miR-154 in NSCLC cells. Furthermore, overexpression of miR-154 could decrease the expression of ZEB2 at the messenger RNA and protein levels. Ectopic expression of miR-154 also increased the levels of E-cadherin, an epithelial marker, and decreased the levels of vimentin, a mesenchymal marker, which contributed to suppress epithelial-mesenchymal transition (EMT) and to inhibit cell migration and invasion. In addition, downregulation of ZEB2 exerted similar effects to those caused by miR-154 overexpression on NSCLC cell migration and invasion, while upregulation of ZEB2 could significantly reverse the inhibitory effects on migration and invasion caused by miR-154 on NSCLC cells. These findings demonstrated that miR-154 inhibited migration and invasion of NSCLC cells by regulating EMT through targeting ZEB2, suggesting that miR-154 may be a potential anticancer therapeutic target for NSCLC.

Distribution and clinical significance of circulating tumor cells in nasopharyngeal carcinoma

OBJECTIVE

Nasopharyngeal carcinoma is one of the leading malignancies with obscure etiology. Circulating tumor cells have been showed to intimately correlate with characteristics in different kinds of cancer. But links between circulating tumor cells and nasopharyngeal carcinoma were still lacking. Therefore, we explored circulating tumor cells' distribution in nasopharyngeal carcinoma and their possible associations with nasopharyngeal carcinoma.

METHODS

Firstly, we found that the positive ratio of circulating tumor cells is extremely high in four stages of nasopharyngeal carcinoma. Meanwhile, positive ratios of mesenchymal circulating tumor cells were higher in early stages of nasopharyngeal carcinoma. Apart from epithelial circulating tumor cells, total, hybrid and mesenchymal circulating tumor cells were correlated with nasopharyngeal carcinoma clinical stage.

RESULTS

Our results showed that hybrid and mesenchymal circulating tumor cells were associated with nasopharyngeal carcinoma metastasis (both distant and lymph node) and smoking. Meanwhile, hybrid circulating tumor cells expressed the highest Epstein-Barr virus proteins and deoxyribonucleic acid in three types of circulating tumor cells. Moreover, we found that Epstein-Barr virus proteins viral-caspid antigen-immunoglobulin A (VCA/IgA) and early antigen-immunoglobulin A (EA/IgA), but not Epstein-Barr virus-deoxyribonucleic acid, had a closed association with nasopharyngeal carcinoma metastasis. However, Epstein-Barr virus hallmarks failed to associate with other nasopharyngeal carcinoma characteristics. Furthermore, we confirmed that matrix metalloproteinase 9 existed in circulating tumor cells and expressed most in mesenchymal circulating tumor cells. In addition, matrix metalloproteinase 9-expressed extent in hybrid circulating tumor cells is somewhat different from epithelial and mesenchymal circulating tumor cells in matrix metalloproteinase 9-positive circulating tumor cells. Nevertheless, matrix metalloproteinase 9 had no relationship with other nasopharyngeal carcinoma characteristics. Finally, our results showed that circulating tumor cells were decreased in patients after therapies.

CONCLUSION

Taken together, circulating tumor cells were tightly correlated with nasopharyngeal carcinoma characteristics. In addition, Epstein-Barr virus was associated with nasopharyngeal carcinoma metastasis. Of note, decreased circulating tumor cells indicated a favorable curative effect in nasopharyngeal carcinoma patients.

NDRG1 Controls Gastric Cancer Migration and Invasion through Regulating MMP-9

The purpose of this study is to detect the clinical significance of NDRG1 and its relationship with MMP-9 in gastric cancer metastatic progression. 101 cases of gastric cancer specimens were utilized to identify the protein expression of NDRG1 and MMP-9 by immunohistochemistry, their clinical significance was also analyzed. The suppression by siRNA-NDRG1 was employed to detect the role of NDRG1 in gastric cancer progression and its relationship with MMP-9. NDRG1 expression was correlated inversely with the degree of tumor cell differentiation (p < 0.01), invasion depth (p < 0.05), lymph node metastasis (p < 0.05) and TNM stage (p < 0.05), whereas MMP-9 was positive correlated with the degree of tumor cell differentiation (p < 0.01), lymph node metastasis (p < 0.05) and TNM stage (p < 0.05), but not correlated with invasion depth (p>0.05). Furthermore, cell proliferation and invasion effect were remarkably enhanced when NDRG1 was silencing, but MMP-9 expression was increased. NDRG1 silencing enhances gastric cancer cells progression through upregulating MMP-9. It suggests that NDRG1 may inhibit the metastasis of gastric cancer via regulating MMP-9.

The effects of cordycepin on the cell proliferation, migration and apoptosis in human lung cancer cell lines A549 and NCI-H460

OBJECTIVES

Our study aimed to evaluate the effect of cordycepin on human lung cancer cell lines A549 and NCI-H460.

METHODS

Human lung cancer A549 cells and NCI-H460 cells were treated with different concentrations of cordycepin for different times. Cells incubated without cordycepin were defined as a control. The cell proliferation, migration and apoptosis were, respectively, determined by MTT assay, transwell migration assay and flow cytometry. Additionally, the expression levels of related proteins associated with cell cycle, epithelial-mesenchymal transition (EMT) and apoptosis were examined.

KEY FINDINGS

The survival rate of A549 cells and NCI-H460 cells treated with cordycepin significantly decreased compared with untreated cells in a concentration-dependent manner, while the apoptosis rate increased. The migration number of cells treated with cordycepin significantly decreased as the increase in concentration. qRT-PCR and Western blot analysis showed that the aberrant expression of related molecules associated with cell cycle, migration and apoptosis was observed in the lung cancer cells, such as cyclin B, cyclin E, MMP-9, caspase-3 and Bcl-2.

CONCLUSIONS

Cordycepin may exert inhibitory effects on the development of human lung cancer via inhibiting cell proliferation, suppressing migration and inducing apoptosis, suggesting that cordycepin may have therapeutic potential for the treatment of this disease.

Tumor Budding: The Name is EMT. Partial EMT

Tumor budding is a histological phenomenon encountered in various cancers, whereby individual malignant cells and/or small clusters of malignant cells are seen in the tumor stroma. Postulated to be mirror epithelial-mesenchymal transition, tumor budding has been associated with poor cancer outcomes. However, the vast heterogeneity in its exact definition, methodology of assessment, and patient stratification need to be resolved before it can be routinely used as a standardized prognostic feature. Here, we discuss the heterogeneity in defining and assessing tumor budding, its clinical significance across multiple cancer types, and its prospective implementation in clinical practice. Next, we review the emerging evidence about partial, rather than complete, epithelial-mesenchymal phenotype at the tumor bud level, and its connection with tumor proliferation, quiescence, and stemness. Finally, based on recent literature, indicating a co-expression of epithelial and mesenchymal markers in many tumor buds, we posit tumor budding to be a manifestation of this hybrid epithelial/mesenchymal phenotype displaying collective cell migration.

miR-3188 regulates nasopharyngeal carcinoma proliferation and chemosensitivity through a FOXO1-modulated positive feedback loop with mTOR-p-PI3K/AKT-c-JUN

The biological role of miR-3188 has not yet been reported in the context of cancer. In this study, we observe that miR-3188 not only reduces cell-cycle transition and proliferation, but also significantly prolongs the survival time of tumour-bearing mice as well as sensitizes cells to 5-FU. Mechanistic analyses indicate that miR-3188 directly targets mTOR to inactivate p-PI3K/p-AKT/c-JUN and induces its own expression. This feedback loop further suppresses cell-cycle signalling through the p-PI3K/p-AKT/p-mTOR pathway. Interestingly, we also observe that miR-3188 direct targeting of mTOR is mediated by FOXO1 suppression of p-PI3K/p-AKT/c-JUN signalling. In clinical samples, reduced miR-3188 is an unfavourable factor and negatively correlates with mTOR and c-JUN levels but positively correlates with FOXO1 expression. Our studies demonstrate that as a tumour suppressor, miR-3188 directly targets mTOR to stimulate its own expression and participates in FOXO1-mediated repression of cell growth, tumorigenesis and NPC chemotherapy resistance.

Although miR-related mechanisms have been implicated in nasopharyngeal carcinoma (NPC), a precise role for miR-3188 has not been reported in this context. Here, Zhao et al. show that FOXO1-induced miR-3188 acts as a tumour suppressor in NPC by regulating the axis mTOR/PI3K/Akt/c-Jun.

Clinical relevance of the tumor microenvironment and immune escape of oral squamous cell carcinoma

BACKGROUND

Changes in the tumor microenvironment and immune surveillance represent crucial hallmarks of various kinds of cancer, including oral squamous cell carcinoma (OSCC), and a close crosstalk of hypoxia regulating genes, an activation of chemokines and immune cells has been described.

METHODS

A review about the pivotal role of HIF-1, its crosstalk to various cornerstones in OSCC tumorigenesis is presented.

RESULTS

Hypoxia is a frequent event in OSCC and leads to a reprogramming of the cellular metabolism in order to prevent cell death. Hypoxic OSCC cells induce different adaptive changes such as anaerobic glycolysis, pH stabilisation and alterations of the gene and protein expression profile. This complex metabolic program is orchestrated by the hypoxia inducible factor (HIF)-1, the master regulator of early tumor progression. Hypoxia-dependent and -independent alterations in immune surveillance lead to different immune evasion strategies, which are partially mediated by alterations of the tumor cells, changes in the frequency, activity and repertoire of immune cell infiltrates and of soluble and environmental factors of the tumor micromilieu with consecutive generation of an immune escape phenotype, progression of disease and poor clinical outcome of OSCC patients.

CONCLUSIONS

This review focusses on the importance of HIF-1 in the adaption and reprogramming of the metabolic system to reduced oxygen values as well as on the role of the tumor microenvironment for evasion of OSCC from immune recognition and destruction.

Dietary Fatty Acids from Leaves of Clerodendrum Volubile Induce Cell Cycle Arrest, Downregulate Matrix Metalloproteinase-9 Expression, and Modulate Redox Status in Human Breast Cancer

The antiproliferative effect of the fatty acid components of Clerodendrum volubile leaves as well as its antioxidant effect on MCF-7 and MDA-MB-231 human breast cancer cell lines were investigated. Fatty acids extracted from C. volubile leaf oil were subjected to gas chromatography mass spectrometry (GCMS) analysis. The cells were cultured and treated with the fatty acids for 48 h, after which the antiproliferation effect was ascertained via MTT assay and cell viability analysis using BD fluorescence activated cells sorting (FACS) Calibur. Cell cycle was analyzed by flow cytometry on FACS Calibur. Western blotting was used in determining expression of proteins in the cell lines. The treated cell lines were assessed for reduced glutathione level, catalase, superoxide dismutase, and lipid peroxidation. The fatty acids significantly inhibited cell proliferation, arrested G0/G1 phase, downregulated the expression of MMP-9, and attenuated oxidative stress in of MCF-7 cell lines but had little or no effect on MDA-MB-231 cell lines. These results indicate the therapeutic potential of the fatty acids components of the leaves of C. volubile on human breast cancer, which may be explored further in drug development.

KITENIN promotes glioma invasiveness and progression, associated with the induction of EMT and stemness markers

KITENIN (KAI1 COOH-terminal interacting tetraspanin) promotes tumor invasion and metastasis in various cancers. This study assessed the association between KITENIN expression and advanced glioma grade in patients. In vitro assays revealed that KITENIN knockdown inhibited the invasion and migration of glioma cells, whereas KITENIN overexpression promoted their invasion and migration. In orthotopic mouse tumor models, mice transplanted with KITENIN-transfected glioma cells had significantly shorter survival than mice transplanted with mock-transfected cells. Patients with low KITENIN expression showed a significantly longer progression-free survival than patients with high KITENIN expression. KITENIN induced the expression of the epithelial-mesenchymal transition (EMT) markers (N-cadherin, ZEB1, ZEB2, SNAIL and SLUG) as well as the glioma stemness markers (CD133, ALDH1 and EPH-B1). Taken together, these findings showed that high levels of KITENIN increased glioma invasiveness and progression, associated with the up-regulation of EMT and stemness markers.