TGFßR2 is a major target of miR-93 in nasopharyngeal carcinoma aggressiveness.

BACKGROUND: MiR-17-92 cluster and its paralogues have emerged as crucial regulators of many oncogenes and tumor suppressors. Transforming growth factor-ß receptor II (TGFßR2), as an important tumor suppressor, is involved in various cancer types. However, it is in cancer that only two miRNAs of this cluster and its paralogues have been reported so far to regulate TGFßR2. MiR-93 is oncogenic, but its targetome in cancer has not been fully defined. The role of miR-93 in nasopharyngeal carcinoma (NPC) still remains largely unknown. METHODS: We firstly evaluated the clinical signature of TGFßR2 down-regulation in clinical samples, and next used a miRNA expression profiling analysis followed by multi-validations, including Luciferase reporter assay, to identify miRNAs targeting TGFßR2 in NPC. In vitro and in vivo studies were performed to further investigate the effects of miRNA-mediated TGFßR2 down-regulation on NPC aggressiveness. Finally, mechanism studies were conducted to explore the associated pathway and genes influenced by this miRNA-mediated TGFßR2 down-regulation. RESULTS: TGFßR2 was down-regulated in more than 50% of NPC patients. It is an unfavorable prognosis factor contributing to clinical NPC aggressiveness. A cluster set of 4 TGFßR2-associated miRNAs was identified; they are all from miR-17-92 cluster and its paralogues, of which miR-93 was one of the most significant miRNAs, directly targeting TGFßR2, promoting cell proliferation, invasion and metastasis in vitro and in vivo. Moreover, miR-93 resulted in the attenuation of Smad-dependent TGF-ß signaling and the activation of PI3K/Akt pathway by suppressing TGFßR2, further promoting NPC cell uncontrolled growth, invasion, metastasis and EMT-like process. Impressively, the knockdown of TGFßR2 by siRNA displayed a consentaneous phenocopy with the effect of miR-93 in NPC cells, supporting TGFßR2 is a major target of miR-93. Our findings were also substantiated by investigation of the clinical signatures of miR-93 and TGFßR2 in NPC. CONCLUSION: The present study reports an involvement of miR-93-mediated TGFßR2 down-regulation in NPC aggressiveness, thus giving extended insights into molecular mechanisms underlying cancer aggressiveness. Approaches aimed at blocking miR-93 may serve as a promising therapeutic strategy for treating NPC patients.

EBV-miR-BART1 is involved in regulating metabolism-associated genes in nasopharyngeal carcinoma.

EBV-miR-BART1 has been found to be highly expressed in some cancers including nasopharyngeal carcinoma (NPC), but its exact roles in the pathogenesis of NPC remain unclear. Here, we did RNA deep sequencing to compare the gene expression profile between EBV-miR-BART1-expressing CNE1 cells and the control cells to determine the possible effects of EBV-miR-BART1 in NPC. Gene expression profiling analysis unexpectedly showed a significant number of up- and down-modulated metabolism-associated genes, such as G6PD, SAT1, ASS1, PAST1, FUT1, SGPL1, DHRS3, B4GALT1, PHGDH, IDH2, PISD, UGT8, LDHB and GALNT1, in EBV-miR-BART1-expressing NPC cells, which were next confirmed by RT-qPCR. Moreover, of these metabolism-genes, PSAT1 and PHGDH expression levels were significantly upregulated and most of other genes were obviously up-expressed in NPC specimens compared with chronic nasopharyngitis (CNP) tissues. Collectively, we for the first time found the effects of EBV-miR-BART1 on the expression of mechanism-associated genes in NPC, suggesting a novel role of EBV-miR-BART1 in cancer metabolism, which remains to be fully elucidated.

Author Correction: Epstein-Barr virus-encoded microRNA BART1 induces tumour metastasis by regulating PTEN-dependent pathways in nasopharyngeal carcinoma.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Extracranial head and neck schwannomas: a clinical analysis of 33 patients.

OBJECTIVE: To study the clinical features, diagnosis, and management of the extracranial head and neck schwannomas. STUDY DESIGN: Retrospective study. METHODS: The clinical data of 33 patients with schwannoma of the head and neck from 1996 to 2006 were studied retrospectively. RESULTS: Extracranial head and neck schwannomas usually presented as solitary and well-demarcated lesions with insidious course. Although benign, the lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, relevant to location of the lesion. Fine needle aspiration cytology, computed tomography scans, and magnetic resonance imaging may provide limited implications in the diagnosis of schwannomas, whereas postoperative pathologic examination establishes the final diagnosis. CONCLUSIONS: Complete surgical excisions with appropriate approaches have proven to be efficient and successful in the treatment of head and neck schwannomas.

Epstein-Barr virus-encoded microRNA BART1 induces tumour metastasis by regulating PTEN-dependent pathways in nasopharyngeal carcinoma.

Epstein-Barr virus (EBV), aetiologically linked to nasopharyngeal carcinoma (NPC), is the first human virus found to encode many miRNAs. However, how these viral miRNAs precisely regulate the tumour metastasis in NPC remains obscure. Here we report that EBV-miR-BART1 is highly expressed in NPC and closely associated with pathological and advanced clinical stages of NPC. Alteration of EBV-miR-BART1 expression results in an increase in migration and invasion of NPC cells in vitro and causes tumour metastasis in vivo. Mechanistically, EBV-miR-BART1 directly targets the cellular tumour suppressor PTEN. Reduction of PTEN dosage by EBV-miR-BART1 activates PTEN-dependent pathways including PI3K-Akt, FAK-p130(Cas) and Shc-MAPK/ERK1/2 signalling, drives EMT, and consequently increases migration, invasion and metastasis of NPC cells. Reconstitution of PTEN rescues all phenotypes generated by EBV-miR-BART1, highlighting the role of PTEN in EBV-miR-BART-driven metastasis in NPC. Our findings provide new insights into the metastasis of NPC regulated by EBV and advocate for developing clinical intervention strategies against NPC.

Hes1 is involved in the self-renewal and tumourigenicity of stem-like cancer cells in colon cancer.

A small subpopulation of cancer cells with stem cell-like features might be responsible for tumour generation, progression, and chemoresistance. Hes1 influences the maintenance of certain stem cells and progenitor cells and the digestive systems. We found upregulated Hes1 in poorly differentiated cancer samples compared with well-differentiated tumour samples, and most of the adenocarcinomas exhibited significantly higher levels of Hes1 mRNA compared with that observed in matched normal colon samples. Moreover, Hes1 expression was found to be correlated with the expression of stem cell markers in colon cancer samples, and Hes1 upregulates the expression of stemness-related genes in colon cancer cells. In addition, Hes1 enhances the self-renewal properties of the stem-like cells by increasing the sizes of CD133+ cells and SP cells and the ability of tumour sphere formation. Additionally, the Hes1-overexpressing cells formed significantly larger and higher number of colonies, as determined through the colony and the soft agar assays. More importantly, Hes1 enhances the tumourigenicity of colon cancer cell lines in nude mice and exhibits a strong tumour-formation ability at a cell density of 1 × 10(3). Taken together, our data indicate that Hes1 induces stem-like cell self-renewal and increases the number of tumour-initiating cells in colon cancer.

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

BACKGROUND: The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC). EXPERIMENTAL DESIGN: CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored. RESULTS: NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC. CONCLUSION: Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.

Water bath hyperthermia reduces stemness of colon cancer cells.

OBJECTIVES: Researchers have proposed that cancer stem cells (CSCs) are the driving force of tumorigenesis, recurrence, and metastases, contributing to the failure of some cancer treatments. Water bath hyperthermia, a novel treatment for cancer, can be highly effective when combined with chemotherapy, radiotherapy, or immunotherapy. Side population (SP) cells are part of a subpopulation of cells that have stem cell-like characteristics. In preliminary experiments, we discovered a decrease in SP cells in heat-treated colon cancer cells, which encouraged us to investigate whether hyperthermia had in fact played a role in regulating the stemness of colon cancer cells. DESIGN AND METHODS: We determined the number of SP cells and CD133-positive cells using flow cytometry; surveyed the expression of stemness-related genes and proteins by using quantitative reverse transcriptase-polymerase chain reaction and Western blot analysis, respectively; and evaluated tumor formation ability by using the tumor sphere formation assay. RESULTS: We found that water bath hyperthermia at 40 °C results in a decreased percentage of SP cells (i.e. decreased from 0.6% to 0.0% and 1.1% to 0.1% among heat-treated HCT116 cells and SW620 cell respectively) and CD133-positive cells (i.e. decreased from 25.1 ± 1.2% to 18.7 ± 1.3% and 33.6 ± 3.2% to 23.5 ± 2.5% among heat-treated HCT116 cells and SW620 cell separately), weakens stem cell self-renewal properties (i.e., tumor colony formation ability), and downregulates the expression of stem-like cellular markers in colon cancer cells. CONCLUSIONS: All the findings indicate that hyperthermia has an important effect on the stemness of colon cancer cells.

CA-125-indicated asymptomatic relapse confers survival benefit to ovarian cancer patients who underwent secondary cytoreduction surgery.

BACKGROUND: There is no consensus regarding the management of ovarian cancer patients, who have shown complete clinical response (CCR) to primary therapy and have rising cancer antigen CA-125 levels but have no symptoms of recurrent disease. The present study aims to determine whether follow-up CA-125 levels can be used to identify the need for imaging studies and secondary cytoreductive surgery (CRS). METHODS: We identified 410 ovarian cancer patients treated at The University of Texas MD Anderson Cancer Center between 1984 and 2011. These patients had shown CCR to primary therapy. Follow-up was conducted based on the surveillance protocol of the MD Anderson Cancer Center. We used the Cox proportional hazards model and log-rank test to assess the associations between the follow-up CA-125 levels and secondary CRS and survival duration. RESULTS: The CA-125 level of 1.68 × nadir was defined as the indicator of recurrent disease (p < 0.001). The specificity and sensitivity of this criterion were 82.9% and 85.6%, respectively, and the median lead-time of the CA-125 biochemical progression prior to clinically-defined relapse was 31 days (ranging from 1 to 391 days). The median number of the negative imaging studies for the clinical relapse findings in patients with a CA-125 level of < 1.68 × nadir was 3 (ranging from 0 to 24 times). The increase of CA-125 level at relapse was an independent predictor of overall and progression free survival in patients who had shown CCR to primary therapy (p = 0.04 and 0.02 respectively). The overall and progression free survival durations in patients with a CA-125 level ≤ 1.68 × nadir at relapse (69.4 and 13.8 months) were longer than those with a CA-125 level > 1.68 × nadir at relapse (55.7 and 10.4 months; p = 0.04 and 0.01, respectively). The overall and progression free survival duration of patients with asymptomatic relapse and underwent a secondary CRS was longer than that of patients with symptomatic relapse (p = 0.02 and 0.04 respectively). CONCLUSIONS: The increase of serum CA-125 levels is an early warning of clinical relapse in ovarian cancer. Using CA-125 levels in guiding the treatment of patients with asymptomatic recurrent ovarian cancer, who have shown CCR to primary therapy, can facilitate optimal secondary CRS and extend the survival duration of the patients.

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.

Paclitaxel inhibits ovarian tumor growth by inducing epithelial cancer cells to benign fibroblast-like cells.

Paclitaxel is commonly used to treat multiple human malignancies, but its mechanism of action is still poorly defined. Human ovarian cancer SKOV3 cells (parental SKOV3) were treated with paclitaxel (1µM) for 2days, and the morphologic changes in the cells were monitored for more than 4months. Parental SKOV3 underwent a markedly morphologic transition from the epithelial to fibroblast-like phenotype following treatment with paclitaxel; the resulting cells were designated as SKOV3-P. The SKOV3-P cells' proliferative ability was assessed via a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. The molecular characteristics of these cells were assessed via immunocytochemical staining and Western blot analysis. Their invasiveness and tumor formation ability was evaluated via wound-scratch and colony formation assays. The tumorigenicity of SKOV3-P cells was assessed in vivo after subcutaneous injection of tumor cells between injections of parental and paclitaxel-treated cells in nude mice. SKOV3-P cells have decreased the proliferation and invasion ability, decreased colony-forming ability when cultured in Matrigel and lost their tumor formation as compared with parental SKOV3 cells when injected in nude mice. SKOV3-P cells have decreased expression of E-cadherin, cytokeratin, Snail, PI3K, and P-Akt-Ser473, and increased expression of fibronectin, vimentin, Slug, P27, and PTEN. These results demonstrated that paclitaxel can inhibit tumor growth by inducing ovarian cancer epithelial cells toward a benign fibroblast-like phenotype through dysregulation of previously known pathways involved in the regulation of epithelial to mesenchymal transition (EMT), which may represent a novel mechanism for paclitaxel-induced tumor suppression.

[Establishment of a nasopharyngeal carcinoma cell line CNE1 stably overexpressing ebv-miR-BART7 mediated by lentivirus].

OBJECTIVE: To establish a nasopharyngeal carcinoma (NPC) cell line CNE1-pLVTHM/BART7 with stable ebv-miR-BART7 overexpression. METHODS: The recombinant lentivirus pLVTHM/BART7 expression plasmid was packaged into mature lentivirus by 293FT cells and used to infect CNE1 cells. Flow cytometry was employed for sorting the GFP(+) cells. The efficiency of ebv-miR-BART7 overexpression was determined using qRT-PCR. RESULTS: The recombinant lentivirus plasmid pLVTHM/BART7 was successfully constructed and verified by PCR and sequencing. The expression of ebv-miR-BART7 in CNE1 cells infected with the lentivirus pLVTHM/BART7 was significantly increased as compared with the negative control and the blank control cells. CONCLUSION: The recombinant lentivirus vector pLVTHM/BART7 results in high and stable expression of ebv-miR-BART7 in infected CNE1 cells, which provides a useful cell model for further studies of the role of ebv-miR-BART7 in nasopharyngeal carcinoma.

Potential tumor suppressor NESG1 as an unfavorable prognosis factor in nasopharyngeal carcinoma.

BACKGROUND: Recently we identified nasopharyngeal epithelium specific protein 1 (NESG1) as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the involvement of NESG1 in tumor progression and prognosis of human NPC. METHODOLOGY/PRINCIPAL FINDINGS: NESG1 protein expression in NPC was examined. Survival analysis was performed using Kaplan-Meier method. The effect of NESG1 on cell proliferation, migration, and invasion were also investigated. RESULTS: NESG1 expression was downregulated in atypical hyperplasia and NPC samples compared to normal and squamous nasopharynx tissues. Reduced protein expression was negatively associated with the status of NPC progression. Patients with lower NESG1 expression had a shorter overall survival and disease-free time than did patients with higher NESG1 expression. Multivariate analysis suggested NESG1 expression as an independent prognostic indicator for NPC patient survival. Proliferation, migration, and invasion ability were significantly increased in cell lines following lentiviral-mediated shRNA suppression of NESG1 expression. Microarray analysis indicated that NESG1 participated in multiple pathways, including MAPK signaling and cell cycle regulation. Finally, DNA methylation microarray examination revealed a lack of hypermethylation at the NESG1 promoter, suggesting other mechanisms are involved in suppressing NESG1 expression in NPC. CONCLUSION: Our studies are the first to demonstrate that decreased NESG1 expression is an unfavorable prognostic factor for NPC.