Prognostic Significance of the Epstein-Barr Virus, p53, Bcl-2, and Survivin in Nasopharyngeal Cancer

The role of tertiary lymphoid structure and B cells in nasopharyngeal carcinoma: Based on bioinformatics and experimental verification

OBJECTIVE

Transcriptomic characteristics and prognosis of tertiary lymphoid structures (TLS) and infiltrating B cells in nasopharyngeal carcinoma (NPC) remain unclear. Here, NPC transcriptomic data and clinical samples were used to investigate the role of infiltrating B cells and TLS in NPC.

METHODS

We investigated the gene expression and infiltrating immune cells of NPC patients and further investigated the clinical relevance of B cell and TLS signatures. Transcriptional features of infiltrating B cell subsets were revealed by single-cell RNA sequencing (scRNA-seq) analysis. Immunohistochemical (IHC) and HE staining were performed to validate the clinical relevance of infiltrating B cells and TLS in NPC samples.

RESULTS

27 differentially expressed immune-related genes (IRGs) associated with prognosis were identified, including B cell marker genes CD19 and CD79B. The higher B cells and TLS signature scores were associated with better outcomes and early pathological staging in 88 NPC patients. ScRNA-seq identified five distinct B cell subsets in NPC, including the BC-4 cluster associated with poor outcomes and the BC-0 cluster associated with better outcomes. EBV infection was positively associated with the formation of TLS. Furthermore, experimental results showed that the infiltration of B cells in NPC tissues was higher than that of normal tissues, and the density of TLS in an early stage of NPC was higher than that in advanced-stage TLS.

CONCLUSION

Our findings demonstrate the functional importance of distinct B cell subsets in the prognosis of NPC. Additionally, we confirmed that B cells and TLS may serve as prognostic biomarkers of survival for NPC patients.

CD8+ Tumor-Infiltrating Lymphocyte Abundance Is a Positive Prognostic Indicator in Nasopharyngeal Cancer

PURPOSE

Tumor-infiltrating lymphocytes (TIL) are immune cell populations found within tumors, critical in the antigen-specific host immune response. In this study, we aimed to elucidate the prognostic significance of CD3+, CD4+, and CD8+ TILs in nasopharyngeal cancer (NPC).

EXPERIMENTAL DESIGN

Immune cell infiltration was quantified in NPC samples (n = 50) using RNA-sequencing (RNA-seq) data based on rearranged T-cell receptor (TCR) reads and the Estimation of Stromal and Immune cells in malignant tumors using expression data (ESTIMATE) immune score tool. The differential abundances of TIL subset populations were also characterized through IHC staining of formalin-fixed, paraffin-embedded samples from a training cohort (n = 35), which was a subset of the RNA-seq cohort (n = 50).

RESULTS

In the RNA-seq cohort, patients with higher rearranged TCR reads experienced superior 5- and 10-year overall survival (OS; P < 0.001), and disease-free survival (DFS; P < 0.001). Similarly, patients with higher ESTIMATE immune scores experienced superior 5- and 10-year OS (P = 0.024) and DFS (P = 0.007). In the training cohort, high abundances of CD8+ TILs were significantly associated with improved 5- and 10-year OS (P = 0.003) and DFS (P = 0.005). These findings were corroborated in an independent validation cohort (n = 84), and combined analysis of the training and validation cohorts [n = 119 (35+84)], which further demonstrated improved 5- and 10-year survival in terms of locoregional control (P < 0.001) and distant metastasis (P = 0.03).

CONCLUSIONS

Taken together, our study highlights the prognostic value of CD8+ TILs in NPC, and the potential of future investigations into cellular-based immunotherapies employing CD8+ lymphocytes.

Expression Profiles of tRNA-Derived Small RNAs and Their Potential Roles in Primary Nasopharyngeal Carcinoma

Introduction: tRNA-derived small RNAs (tsRNAs), a class of small non-coding RNAs, are divided into two categories: tRNA-related fragments (tRFs) and tRNA halves (tiRNAs). Abnormal expression of tsRNAs has been found in diverse cancers, which indicates that further understanding of the function of tsRNAs will help identify new biomarkers and potential therapeutic targets. Until now, the underlying roles of tsRNAs in primary nasopharyngeal carcinoma (NPC) are still unknown.

Methods: tRF and tiRNA sequencing was performed on four pairs of NPC tissues and healthy controls. Thirty pairs of NPC samples were used for quantitative real-time polymerase chain reaction (qRT-PCR) verification, and the ROC analysis was used to evaluate the diagnostic efficiency initially. Target prediction and bioinformatics analysis of validated tRFs and tiRNAs were conducted to explore the mechanisms of tsRNAs in NPC’s pathogenesis.

Results: A total of 158 differentially expressed tRFs and tiRNAs were identified, of which 88 are upregulated and 70 are downregulated in NPC. Three validated tRFs in the results of qRT-PCR were consistent with the sequencing data: two upregulations (tRF-1:28-Val-CAC-2 and tRF-1:24-Ser-CGA-1-M3) and one downregulation (tRF-55:76-Arg-ACG-1-M2). The GO and KEGG pathway enrichment analysis showed that the potential target genes of validated tRFs are widely enriched in cancer pathways. The related modules may play an essential role in the pathogenesis of NPC.

Conclusions: The tsRNAs may become a novel class of biological diagnostic indicators and possible targets for NPC.

Early risk-assessment of patients with nasopharyngeal carcinoma: the added prognostic value of MR-based radiomics

•

The current study extracted radiomics—a large quantitative data of imaging features—from magnetic resonance images of patients with nasopharyngeal carcinoma.

•

The survival model fitted with radiomic features showed good prognostic performance in predicting the progression-free survival of patients with nasopharyngeal carcinoma (integrated area under the curve, 0.71; 95% confidence interval, 0.71–0.72).

•

Addition of radiomics to clinical survival model improved the prognostication of progression-free survival in patients diagnosed with nasopharyngeal carcinoma (integrated area under the curve from 0.76 to 0.81, p<0.001).

Objectives

To assess the additive prognostic value of MR-based radiomics in predicting progression-free survival (PFS) in patients with nasopharyngeal carcinoma (NPC)

Methods

Patients newly diagnosed with non-metastatic NPC between June 2006 and October 2019 were retrospectively included and randomly grouped into training and test cohorts (7:3 ratio). Radiomic features (n=213) were extracted from T2-weighted and contrast-enhanced T1-weighted MRI. The patients were staged according to the 8^th edition of American Joint Committee on Cancer Staging Manual. The least absolute shrinkage and selection operator was used to select the relevant radiomic features. Univariate and multivariate Cox proportional hazards analyses were conducted for PFS, yielding three different survival models (clinical, stage, and radiomic). The integrated time-dependent area under the curve (iAUC) for PFS was calculated and compared among different combinations of survival models, and the analysis of variance was used to compare the survival models. The prognostic performance of all models was validated using a test set with integrated Brier scores.

Results

This study included 81 patients (training cohort=57; test cohort=24), and the mean PFS was 57.5 ± 43.6 months. In the training cohort, the prognostic performances of survival models improved significantly with the addition of radiomics to the clinical (iAUC, 0.72–0.80; p=0.04), stage (iAUC, 0.70–0.79; p=0.001), and combined models (iAUC, 0.76–0.81; p<0.001). In the test cohort, the radiomics and combined survival models were robustly validated for their ability to predict PFS.

Conclusion

Integration of MR-based radiomic features with clinical and stage variables improved the prediction PFS in patients diagnosed with NPC.

Prognostic Value of Survivin in Nasopharyngeal Carcinoma: A Systematic Review and Meta-analysis

Background: Previous studies have shown that survivin has potential prognostic value in nasopharyngeal carcinoma. However, the results remained controversial until now. Thus, to investigate the influence of survivin expression on prognosis and clinical characteristics in nasopharyngeal carcinoma, we performed this meta-analysis.

Methods: We searched PubMed, PMC, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure electronic databases from their establishment to 1 March 2021. The pooled hazard ratio (HR) and the pooled odds ratio (OR) were used to evaluate the prognostic and clinicopathological values of survivin in nasopharyngeal carcinoma. We used the I² statistic and the Q test to evaluate heterogeneity. Meta-regression, publication bias, and sensitivity analyses were also conducted.

Results: A total of 26 eligible studies with 2278 patients were included in our meta-analysis. We found that the expression of survivin is connected with poor overall survival (HR=1.94; 95% confidence interval (CI)=1.52-2.48; P<0.001), lymph node metastasis (OR=3.01; 95% CI=2.31- 3.91; P<0.001), local recurrence (OR=2.40; 95% CI=1.60-3.61, P<0.001), distant metastasis (OR=2.58; 95% CI=1.74-3.84, P<0.001), and a higher clinical stage (OR=4.58; 95% CI=2.81-7.47, P<0.001). However, no significant correlations were found between survivin expression and radio-sensitivity (OR=1.33; 95% CI=0.25-7.17, P=0.737) or gender (OR=1.02; 95% CI=0.75-1.39, P=0.887).

Conclusions: This meta-analysis indicates that survivin could be used as a biomarker for predicting prognosis in nasopharyngeal carcinoma.

The prognostic significance of survivin expression in patients with HNSCC: a systematic review and meta-analysis

Background

Survivin has been recently identified as a promising novel therapeutic target and prognostic marker in different types of cancer. Here we conducted a comprehensive meta-analysis to better clarify they the precise prognostic and diagnostic value of survivin in head and neck squamous cell carcinoma (HNSCC).

Methods

Database of PubMed (Medline), Embase, and Web of Science were systematically searched for related published literature up to September 2020. Pooled hazards ratios (HR) and related 95% confidence intervals (CI) were used to estimate the association of survivin expression and survival outcomes in HNSCC patients.

Results

Twenty eight studies with 4891 patients were finally included in this meta-analysis, the pooled analysis indicated that the survivin expression was significantly correlated with poorer overall survival (OS) (HR, 2.02; 95% CI, 1.65–2.47, P < 0.001), and poorer disease-free survival (DFS)/ disease-specific survival (DSS) (HR = 2.03, 95%CI: 1.64–2.52, P < 0.001; HR = 1.92, 95%CI: 1.41–2.60, P < 0.001, receptively). Similar results were observed in subgroup analysis stratified by different cancer types, such as laryngeal squamous cell carcinoma (LSCC) (HR = 1.35, 95%CI: 1.05–1.74, P < 0.001), oral squamous cell carcinomas (OSCC) (HR = 2.45, 95%CI: 1.89–3.17, P < 0.001), nasopharyngeal carcinoma (NPC) (HR = 2.53, 95%CI: 1.76–3.62, P < 0.001) and HNSCC (HR = 1.52, 95%CI: 1.25–1.86, P < 0.001). Furthermore, ethnicity-stratified analysis indicated that survivin was significantly associated with poorer OS among both Asian and Non- Asian HNSCC patients (HR = 2.16, 95%CI: 1.76–2.66; HR = 1.56, 95%CI: 1.33–1.82, respectively).

Conclusions

Our results suggested that survivin is predictors of worse prognosis in HNSCC patients. Hence, survivin is a potential therapeutic target for HNSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08170-3.

Prognostic significance of human papillomavirus and Epstein-Bar virus in nasopharyngeal carcinoma

BACKGROUND

The clinical significance of Epstein-Barr virus (EBV) and human papillomavirus (HPV) infection in nasopharyngeal carcinoma (NPC) is unclear.

METHODS

Three hundred and forty three patients with NPC diagnosed between 1998 and 2017 and treated at our institution were included. Chi-square was used to identify characteristics associated with viral status. Kaplan-Meier methods were used to estimate overall survival (OS) and Cox proportional regression was used to identify prognostic factors.

RESULTS

Patients with HPV-associated NPC were more likely to have a positive smoking history and to present at a higher T classification. At a median follow-up time of 59.9 months (range: 0.1-222.4 months), there were no differences in OS (P = .198), time to local failure (LF, P = .403), or time to distant metastasis (DM, P = .849) between the viral subgroups. Older age (hazard ratio [HR]: 2.242, 95% confidence interval [CI] 1.374-3.659, P = .001) and higher overall stage (HR: 2.047, 95% CI 1.235-3.391, P = .005) were prognostic for worse OS.

CONCLUSION

In our population, viral status was not prognostic for OS, LF, or DM.

Roles of β-catenin, TCF-4, and survivin in nasopharyngeal carcinoma: correlation with clinicopathological features and prognostic significance

Background

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck region with poorly understood progression and prognosis. The present study aims at exploring whether the expression of β-catenin, TCF-4, and survivin affects clinicopathological features and prognostic significance in NPC.

Methods

We enrolled 164 patients with NPC and 70 patients with chronic nasopharyngitis (CNP) in this study. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC) were conducted to evaluate the expression of β-catenin, TCF-4, and survivin. Spearman’s rank correlation analysis and Pearson correlation analysis were used to measure the correlation of β-catenin, TCF-4, and survivin. Risk factors for prognosis and survival conditions of NPC patients were analyzed by Cox proportional hazards model and Kaplan–Meier curves.

Results

The results obtained revealed that mRNA and protein expression of β-catenin, TCF-4, and survivin was higher in NPC tissues than in CNP tissues. Positive correlations amongst β-catenin, TCF-4, and survivin were identified by Spearman’s rank correlation analysis and Pearson correlation analysis. There was a significant correlation in expression of β-catenin, TCF-4, and survivin with EBV DNA, EBV-VCA-IgA, EBV-EA-IgA, T stage, N stage, and clinicopathological stages. Lower overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and disease-free survival (DFS) rates were detected in NPC patients with positive expression of β-catenin, TCF-4, and survivin, in contrast to those with negative expression. Cox proportional hazards model demonstrated that β-catenin, TCF-4, and survivin protein positive expression were independent risk factors for OS and DFS of NPC prognosis; there was an evident correlation between clinicopathological stages, TCF-4, and EBV-EA-IgA and OS, DMFS, LRFS, and DFS of NPC.

Conclusions

The aforementioned results indicate that β-catenin, TCF-4, and survivin proteins are highly expressed in NPC, which can be used as factors to predict the malignancy of NPC. In addition, positive expression of β-catenin, TCF-4, and survivin are potential risk factors that lead to an unfavorable prognosis of OS and DFS in NPC patients.

Predictive value of pretreatment MRI texture analysis in patients with primary nasopharyngeal carcinoma

Objectives

To determine the predictive value of pretreatment MRI texture analysis for progression-free survival (PFS) in patients with primary nasopharyngeal carcinoma (NPC).

Methods

Ethical approval by the institutional review board was obtained for this retrospective analysis. In 79 patients with primary NPC, texture analysis of the primary tumour was performed on pretreatment T2 and contrast-enhanced T1-weighted images (T2WIs and CE-T1WIs). The Cox proportional hazards model was used to determine the association of texture features, tumour volume and the tumour-node-metastasis (TNM) stage with PFS. Survival curves were plotted using the Kaplan-Meier method. The prognostic performance was evaluated with the receiver operating characteristic (ROC) analyses and C-index.

Results

Tumour volume (hazard ratio, 1.054; 95% confidence interval [CI], 1.016–1.093) and CE-T1WI-based uniformity (hazard ratio, 0; 95% CI, 0–0.001) were identified as independent predictors for PFS (p < 0.05). Kaplan-Meier analysis showed that smaller tumour volume (less than the cut-off value, 11.699 cm³) and higher CE-T1WI-based uniformity (greater than the cut-off value, 0.856) were associated with improved PFS (p < 0.05). The combination of CE-T1WI-based uniformity with tumour volume and the overall stage predicted PFS better (area under the curve [AUC], 0.825; Cindex, 0.794) than the tumour volume (AUC, 0.659; C-index, 0.616) or the overall stage (AUC, 0.636; C-index, 0.627) did (p < 0.05).

Conclusions

A texture parameter of pretreatment CE-T1WI-based uniformity improves the prediction of PFS in NPC patients.

Key Points

• Higher CE-T1WI-based uniformity and smaller tumour volume are predictive of improved PFS in NPC patients.

• The combination of CE-T1WI-based uniformity with tumour volume and the overall stage has a better predictive ability for PFS than the tumour volume or the overall stage alone.

• Pretreatment MRI texture analysis has a prognostic value for NPC patients.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5961-6) contains supplementary material, which is available to authorized users.

Breaking Bad: How Viruses Subvert the Cell Cycle

Interactions between the host and viruses during the course of their co-evolution have not only shaped cellular function and the immune system, but also the counter measures employed by viruses. Relatively small genomes and high replication rates allow viruses to accumulate mutations and continuously present the host with new challenges. It is therefore, no surprise that they either escape detection or modulate host physiology, often by redirecting normal cellular pathways to their own advantage. Viruses utilize a diverse array of strategies and molecular targets to subvert host cellular processes, while evading detection. These include cell-cycle regulation, major histocompatibility complex-restricted antigen presentation, intracellular protein transport, apoptosis, cytokine-mediated signaling, and humoral immune responses. Moreover, viruses routinely manipulate the host cell cycle to create a favorable environment for replication, largely by deregulating cell cycle checkpoints. This review focuses on our current understanding of the molecular aspects of cell cycle regulation that are often targeted by viruses. Further study of their interactions should provide fundamental insights into cell cycle regulation and improve our ability to exploit these viruses.

Is human papillomavirus and p16 expression associated with survival outcomes in nasopharyngeal cancer?: A systematic review and meta-analysis

INTRODUCTION

Human papillomavirus (HPV) is a known prognostic indicator in oropharyngeal cancer. Not much is known about the prognostic role of HPV in Nasopharyngeal cancer (NPC). Here, we performed a systematic review and meta-analysis of the literature to investigate if HPV status was a prognostic factor for NPC.

METHODS

PubMed (via the web), Embase, Scopus, and the Cochrane Library were searched. A systematic review and meta-analysis was done to generate the pooled Hazard Ratios (HR) for Overall Survival (OS).

RESULTS

A total of 7 studies from 2014 to 2018, reporting data on 2646 patients (range 43-1328) were included in this meta-analysis. The pooled data showed that HPV/p16 status was not associated with OS in NPC with HR of 0.77 (95% CI: 0.55-1.09, p = 0.14). The test for heterogeneity showed little to no heterogeneity of results (I² = 4%, p = 0.38). Subgroup analysis showed that in large sample sizes, HPV was significantly associated with survival.

CONCLUSION

Despite the finding in the pooled HR, we could not draw a definitive conclusion as to the prognostic significance of HPV in NPC. Recommendations for future research are given.

A Potential Role for Green Tea as a Radiation Sensitizer for Prostate Cancer

Prostate cancer (PCa) is the most common non-cutaneous cancer in the United States. There is currently a lack of safe and effective radiosensitizers that can enhance the effectiveness of radiation treatment (RT) for Pca. Clonogenic assay, PCNA staining, Quick Cell Proliferation assay, TUNEL staining and caspase-3 activity assay were used to assess proliferation and apoptosis in DU145 Pca cells. RT-PCR/IHC were used to investigate the mechanisms. We found that the percentage of colonies, PCNA staining intensity, and the optical density value of DU145 cells were decreased (RT/GT vs. RT). TUNEL + cells and the relative caspase-3 activity were increased (RT/GT vs. RT). Compared to RT, the anti-proliferative effect of RT/GT correlated with increased expression of the anti-proliferative molecule p16. Compared to RT, the pro-apoptotic effect of RT/GT correlated with decreased expression of the anti-apoptotic molecule Bcl-2. GT enhances RT sensitivity of DU145 by inhibiting proliferation and promoting apoptosis.

Zoledronic acid augments the radiosensitivity of cancer cells through perturbing S- and M-phase cyclins and p21CIP1 expression

Radiotherapy and adjuvant chemotherapy have become the standard treatments for multiple types of cancer. Although cancer cells are usually sensitive to radiotherapy, metastasis and local failure still occur mainly due to developed resistance to radiotherapy. Thus, it is critical to improve therapeutics for cancer treatment. The present study demonstrated that third-generation bisphosphonate zoledronic acid (ZOL), even at a low concentration, augments the radiosensitivity of cancer cells exposed to ionizing radiation (IR) by inducing S-phase arrest and subsequently promoting apoptosis. This function of ZOL was associated with elevated levels of cyclin A and cyclin B in the S and M phases, as well as decreased p21^CIP1 expression. In addition, ZOL also inhibited malignant the invasiveness of cancer cells. Notably, these effects could be enhanced concurrently with IR. The present data indicated that combined treatment with ZOL plus IR may be a novel technique to augment the radiosensitivity of cancer cells.

Cell-free Epstein-Barr virus-DNA in patients with nasopharyngeal carcinoma: Plasma versus urine

BACKGROUND

The purpose of this study was to explore urinary Epstein-Barr virus (EBV)-DNA as a potential biomarker in patients with nasopharyngeal carcinoma (NPC).

METHODS

EBV-DNA copies were estimated in plasma/urine of patients with NPC (n = 76) by real-time polymerase chain reaction (PCR) at baseline, during therapy, and at follow-up. Their correlation with EBV-RNA expression in tissues (n = 53) was used to assess sensitivity and specificity of plasma/urine EBV-DNA. Correlation of urine and plasma EBV-DNA with each other and with radiological response was evaluated.

RESULTS

This study demonstrated that urine EBV-DNA has high sensitivity (96%) at diagnosis and it correlates well with plasma EBV-DNA at baseline and after neoadjuvant chemotherapy. The EBV-DNA copies reduced significantly with therapy (plasma: p < .001; urine: p = .011). Patients with low EBV-DNA copies demonstrated improved survival (plasma: p = .023; urine: p = .083).

CONCLUSION

Plasma EBV-DNA is a good prognostic marker, whereas further study on a larger cohort may help in developing urine EBV-DNA as a surrogate prognostic marker for patients with NPC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1666-E1673, 2016.

Prognostic value of p16 expression in Epstein-Barr virus-positive nasopharyngeal carcinomas

BACKGROUND

Overexpression of p16 is associated with improved outcomes among patients with oropharyngeal carcinoma. However, its role in the outcomes of patients with nasopharyngeal cancer (NPC) remains unclear.

METHODS

Eighty-six patients with NPC treated at MD Anderson Cancer Center from 2000 to 2014 were identified. Epstein-Barr virus (EBV) and human papillomavirus (HPV) status were determined by in situ hybridization (ISH) and p16 by immunohistochemical staining.

RESULTS

EBV positivity was associated with extended overall survival (OS; median, 95.0 vs 44.9 months; p < .004), progression-free survival (PFS; median, 80.4 vs 28.1 months; p < .013), and locoregional control (median, 104.4 vs 65.5 months; p < .043). In patients with EBV-positive tumors, p16 overexpression correlated with improved PFS (median, 106.3 vs 27.1 months; p < .02) and locoregional control (median, 93.6 vs 64.5 months; p < .02).

CONCLUSION

P16 overexpression is associated with improved PFS and locoregional control in patients with EBV-positive NPC. P16 expression may complement EBV status in predicting treatment outcomes for patients with NPC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1459-E1466, 2016.

Identification of a microRNA signature associated with risk of distant metastasis in nasopharyngeal carcinoma

Purpose

Despite significant improvement in locoregional control in the contemporary era of nasopharyngeal carcinoma (NPC) treatment, patients still suffer from a significant risk of distant metastasis (DM). Identifying those patients at risk of DM would aid in personalized treatment in the future. MicroRNAs (miRNAs) play many important roles in human cancers; hence, we proceeded to address the primary hypothesis that there is a miRNA expression signature capable of predicting DM for NPC patients.

Methods and results

The expression of 734 miRNAs was measured in 125 (Training) and 121 (Validation) clinically annotated NPC diagnostic biopsy samples. A 4-miRNA expression signature associated with risk of developing DM was identified by fitting a penalized Cox Proportion Hazard regression model to the Training data set (HR 8.25; p < 0.001), and subsequently validated in an independent Validation set (HR 3.2; p = 0.01). Pathway enrichment analysis indicated that the targets of miRNAs associated with DM appear to be converging on cell-cycle pathways.

Conclusions

This 4-miRNA signature adds to the prognostic value of the current “gold standard” of TNM staging. In-depth interrogation of these 4-miRNAs will provide important biological insights that could facilitate the discovery and development of novel molecularly targeted therapies to improve outcome for future NPC patients.

Full-length single-cell RNA-seq applied to a viral human cancer: applications to HPV expression and splicing analysis in HeLa S3 cells

Background

Viral infection causes multiple forms of human cancer, and HPV infection is the primary factor in cervical carcinomas. Recent single-cell RNA-seq studies highlight the tumor heterogeneity present in most cancers, but virally induced tumors have not been studied. HeLa is a well characterized HPV+ cervical cancer cell line.

Result

We developed a new high throughput platform to prepare single-cell RNA on a nanoliter scale based on a customized microwell chip. Using this method, we successfully amplified full-length transcripts of 669 single HeLa S3 cells and 40 of them were randomly selected to perform single-cell RNA sequencing. Based on these data, we obtained a comprehensive understanding of the heterogeneity of HeLa S3 cells in gene expression, alternative splicing and fusions. Furthermore, we identified a high diversity of HPV-18 expression and splicing at the single-cell level. By co-expression analysis we identified 283 E6, E7 co-regulated genes, including CDC25, PCNA, PLK4, BUB1B and IRF1 known to interact with HPV viral proteins.

Conclusion

Our results reveal the heterogeneity of a virus-infected cell line. It not only provides a transcriptome characterization of HeLa S3 cells at the single cell level, but is a demonstration of the power of single cell RNA-seq analysis of virally infected cells and cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s13742-015-0091-4) contains supplementary material, which is available to authorized users.

Nasopharyngeal Cancer: Molecular Landscape

Nasopharyngeal carcinoma (NPC) is a unique epithelial malignancy arising from the superior aspect of the pharyngeal mucosal space, associated with latent Epstein-Barr virus infection in most cases. The capacity to characterize cancer genomes in unprecedented detail is now providing insights into the genesis and molecular underpinnings of this disease. Herein, we provide an overview of the molecular aberrations that likely drive nasopharyngeal tumor development and progression. The contributions of major Epstein-Barr virus–encoded factors, including proteins, small RNAs, and microRNAs, along with their interactions with pathways regulating cell proliferation and survival are highlighted. We review recent analyses that clearly define the role of genetic and epigenetic variations affecting the human genome in NPC. These findings point to the impact of DNA methylation and histone modifications on gene expression programs that promote this malignancy. The molecular interactions that allow NPC cells to evade immune recognition and elimination, which is crucial for the survival of cells expressing potentially immunogenic viral proteins, are also described. Finally, the potential utility of detecting host and viral factors for the diagnosis and prognosis of NPC is discussed. Altogether, the studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC, yet much remains to be uncovered. Emerging techniques for using and analyzing well-annotated biospecimens from patients with NPC will ultimately lead to a greater level of understanding, and enable improvements in precision therapies and clinical outcomes.

Prognostic utility of apoptosis index, Ki-67 and survivin expression in dogs with nasal carcinoma treated with orthovoltage radiation therapy

Apoptosis, Ki-67 and survivin expression have been reported as prognostic values in human cancer treated with radiation therapy. The aim of this study was to evaluate the correlation between the outcome of canine nasal carcinomas treated with radiation therapy and these cancer markers. The apoptotic index (AI) was evaluated with TUNEL assays, and an immunohistochemical evaluation was performed on Ki-67 and survivin in 33 biopsy samples taken before treatment. Median survival times were estimated using Kaplan-Meier curves and the log-rank method. The AI ranged from 0 to 0.7%, and the percentage of Ki-67-positive cells defined as the proliferative index (PI) ranged from 0.8 to 77% in all samples. Neither the AI nor the PI had a significant relationship with survival time (P=0.056 and 0.211). Survivin expression was detected in 84.9% of samples of canine nasal carcinoma. Dogs with high survivin expression were associated with poorer response to treatment and had shorter survival times (P=0.017 and 0.031). Advanced-stage tumors were also significantly associated with a high level of survivin (P=0.026). Overexpression of survivin was shown to be an unfavorable prognostic factor in dogs with nasal carcinomas treated with radiation therapy.

Transducin β-like 1 X-linked receptor 1 suppresses cisplatin sensitivity in nasopharyngeal carcinoma via activation of NF-κB pathway

Background

Transducin β-like 1 X-linked receptor 1 (TBL1XR1) is an important transcriptional cofactor involved in the regulation of many signaling pathways, and is associated with carcinogenesis and tumor progression. However, the precise role of TBL1XR1 in these processes is not well understood.

Methods

We detected the expression of TBL1XR1 protein and mRNA in nasopharyngeal carcinoma (NPC) cell lines and biopsies by western blotting, real-time PCR and immunohistochemical staining (IHC). Overexpression of TBL1XR1 in NPC enhanced chemoresistance to cisplatin using two NPC cell lines in vitro and in vivo.

Results

TBL1XR1 was upregulated in NPC cell lines and clinical samples. The expression of TBL1XR1 was correlated with several clinicopathological factors including clinical stage, T classification, N classification and patient survival. Univariate and multivariate analysis revealed that TBL1XR1 was an independent prognostic factor for patient survival. In vitro and in vivo studies demonstrated that TBL1XR1 high expression induced resistance to cisplatin-induced apoptosis in NPC cells. Furthermore, we found that TBL1XR1 activated the NF-κB pathway and promoted transcription of genes downstream of NF-κB, especially anti-apoptotic genes.

Conclusions

Upregulation of TBL1XR1 induces NPC cells resistance to cisplatin by activating the NF-κB pathway, and correlates with poor overall survival of NPC patients. TBL1XR1 has a pivotal role in NPC and could be a valuable prognostic factor as well as a novel biomarker for tailoring appropriate therapeutic regimes.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-195) contains supplementary material, which is available to authorized users.

Expression of Epstein-Barr virus-encoded latent membrane protein (LMP-1), p16 and p53 proteins in nonendemic nasopharyngeal carcinoma (NPC): a clinicopathological study

BACKGROUND AND AIMS

Although the latent membrane protein type 1 (LMP1) is frequently expressed in Epstein-Barr virus (EBV) malignancies, its contribution to the pathogenesis of nasopharyngeal carcinoma (NPC) is not fully defined. LMP1 functions as a viral mimic of the TNFR family member engaging a number of signaling pathways that induce morphological and phenotypic alterations. This study aimed to investigate the LMP1 expression and EBV infection in relation to clinical outcome and survival in a series of Mexican NPC patients. We also studied expression of p16 and p53 proteins.

METHODS

We analyzed in 25 tumor specimens the expression of LMP1, p16 and p53 by immunohistochemistry (IHC) and EBV presence by IHC/in situ hybridization. Differences in clinical outcome and survival in relation to protein expression were correlated through χ(2) statistics and Kaplan-Meier survival curves.

RESULTS

Our results showed a rate of 92% (23/25) of EBV infection. The expressions of LMP-1, p16 and p53 proteins were 40.0, 44.0 and 40.0%, respectively. LMP-1 immunoexpression was more common in older patients (>50 vs. <50 years old, p = 0.02) and with parapharyngeal space invasion (p = 0.02). The presence of metastatic disease at diagnosis (p = 0.03), distant recurrence disease (p = 0.006) and shorter distance recurrence-free survival (p = 0.05) was associated with lack of p16.

CONCLUSIONS

In our series, EBV infection rates are particularly high for nonendemic NPC, although without a statistically significant difference in overall survival, LMP1 and p16 expression was correlated with poorer clinical prognosis. Probably, LMP1 and p16 detection identify a worse clinical prognosis in NPC patient subgroup.

Improved survival of gastric cancer with tumour Epstein-Barr virus positivity: an international pooled analysis

BACKGROUND AND OBJECTIVE

About 9% of gastric carcinomas have Epstein-Barr virus (EBV) in the tumour cells, but it is unclear whether viral presence influences clinical progression. We therefore examined a large multicentre case series for the association of tumour EBV status with survival after gastric cancer diagnosis, accounting for surgical stage and other prognostic factors.

METHODS

We combined individual-level data on 4599 gastric cancer patients diagnosed between 1976 and 2010 from 13 studies in Asia (n=8), Europe (n=3), and Latin America (n=2). EBV positivity of tumours was assessed by in situ hybridisation. Mortality HRs for EBV positivity were estimated by Cox regression models stratified by study, adjusted for distributions of sex (71% male), age (mean 58 years), stage (52% tumour-node-metastasis stages III or IV), tumour histology (49% poorly differentiated, 57% Lauren intestinal-type), anatomic subsite (70% non-cardia) and year of diagnosis. Variations by study and continent were assessed using study-specific HRs for EBV positivity.

RESULTS

During median 3.0 years follow-up, 49% of patients died. Stage was strongly predictive of mortality, with unadjusted HRs (vs stage I) of 3.1 for stage II, 8.1 for stage III and 13.2 for stage IV. Tumour EBV positivity was 8.2% overall and inversely associated with stage (adjusted OR: 0.79 per unit change). Adjusted for stage and other confounders, EBV positivity was associated with lower mortality (HR, 0.72; 95% CI 0.61 to 0.86), with low heterogeneity among the study populations (p=0.2). The association did not significantly vary across patient or tumour characteristics. There was no significant variation among the three continent-specific HRs (p=0.4).

CONCLUSIONS

Our findings suggest that tumour EBV positivity is an additional prognostic indicator in gastric cancer. Further studies are warranted to identify the mechanisms underlying this protective association.

Immunohistochemical expression of latent membrane protein 1 (LMP1) and p53 in nasopharyngeal carcinoma: Moroccan experience

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor intimately associated with Epstein-Barr virus (EBV). NPC is a characteristic tumor displaying epidemiological, genetic and regional distribution properties that makes it unique by its natural behavior.

OBJECTIVES

To assess the expression pattern of LMP1 and p53 proteins in the different histological types of NPC in a sample of the Moroccan population and to define any association between the expression of those proteins with the sex, the age and the histological types of NPC.

METHODS

Archival formalin-fixed, paraffin-embedded NPC biopsies were evaluated in 23 Moroccan patients for the presence of LMP1 and p53 using immunohistochemistry (IHC).

RESULTS

No LMP1 expression was observed whereas 8 of 23 cases (34. 7%) had detectable p53 protein in the nuclei of tumor cells. After statistical analysis according to the Fisher's exact probability test, no significant association between p53 expression and histological type, age and sex distributions was demonstrated (p>0.05).

CONCLUSION

This study confirms that p53 overexpression is present in a subset of Moroccan NPC patients. Our results are consistent with those reported by other studies concerning the same NPC endemic risk area and provide original data concerning Morocco.

Efficient CD44-targeted magnetic resonance imaging (MRI) of breast cancer cells using hyaluronic acid (HA)-modified MnFe2O4 nanocrystals

Targeted molecular imaging with hyaluronic acid (HA) has been highlighted in the diagnosis and treatment of CD44-overexpressing cancer. CD44, a receptor for HA, is closely related to the growth of cancer including proliferation, metastasis, invasion, and angiogenesis. For the efficient detection of CD44, we fabricated a few kinds of HA-modified MnFe2O4 nanocrystals (MNCs) to serve as specific magnetic resonance (MR) contrast agents (HA-MRCAs) and compared physicochemical properties, biocompatibility, and the CD44 targeting efficiency. Hydrophobic MNCs were efficiently phase-transferred using aminated polysorbate 80 (P80) synthesized by introducing spermine molecules on the hydroxyl groups of P80. Subsequently, a few kinds of HA-MRCAs were fabricated, conjugating different ratios of HA on the equal amount of phase-transferred MNCs. The optimized conjugation ratio of HA against magnetic content was identified to exhibit not only effective CD44 finding ability but also high cell viability through in vitro experiments. The results of this study demonstrate that the suggested HA-MRCA shows strong potential to be used for accurate tumor diagnosis.

microRNA-16 represses colorectal cancer cell growth in vitro by regulating the p53/survivin signaling pathway

Dysregulated expression of microRNAs (miRNA) is a hallmark of cancer. miR-16 has been reported to be downregulated and to act as a tumor suppressor in different cancer types. In the present study, we sought to investigate the possible roles and mechanisms of miR-16 and its relationship with p53 and survivin in CRC cells. We showed that miR-16 was downregulated in 67% of CRC tissues and was correlated with the degree of histological differentiation. Experiments in vitro showed that overexpression of miR-16 inhibited the proliferation and induced apoptosis of CRC cells through the intrinsic apoptosis pathway. We further showed that miR-16 repressed survivin expression at both the mRNA and protein levels and the survivin gene was a direct target of miR-16. In addition, miR-16 reduced p53 expression and p53 increased miR-16 levels, with downregulation of miR-16 targets survivin, cyclin D1 and CDK6. Our findings suggest that miR-16 represses colorectal cancer cell growth in vitro by regulating the p53/survivin signaling pathway. Our findings provide further evidence for the involvement of dysregulated miRNAs in CRC, and miR-16 could serve as a molecular target for CRC therapy.

A Phase II trial of erlotinib as maintenance treatment after gemcitabine plus platinum-based chemotherapy in patients with recurrent and/or metastatic nasopharyngeal carcinoma

BACKGROUND

Despite the efficacy of gemcitabine-platinum regimen, the outcome of patients with recurrent and/or metastatic nasopharyngeal carcinoma (RM NPC) is poor. A phase II trial was conducted to determine the efficacy of erlotinib, given as maintenance therapy after gemcitabine-platinum chemotherapy in patients with RM NPC.

PATIENTS AND METHODS

Patients were treated with gemcitabine 1000 mg/m on days 1 and 8 as well as cisplatin 70 mg/m on day 1 (or carboplatin area under curve 5 on day 1, if contraindication to cisplatin) 3 weeks. After 6 chemotherapy cycles (or before in case of progression), patients were switched to erlotinib 150 mg/d 4 weeks. Primary end point was time to progression in patients without progressive disease after 6 chemotherapy cycles and treated with maintenance erlotinib. Epstein-Barr virus DNA plasma levels, measured using quantitative real-time polymerase chain reaction, were correlated with outcome.

RESULTS

Of 20 enrolled patients, 19 patients received 96 chemotherapy cycles. Fifteen patients were switched to erlotinib and received 36 cycles (range: 1 to 6 cycles). Safety profiles observed with the chemotherapy combination and erlotinib were those expected. Of 12 patients evaluable for response to erlotinib, all progressed except 3 patients (25%) who had stable disease for 3, 4, and 7 months, respectively. Median time to progression was 6.9 months for 13 patients without progressive disease after 6 chemotherapy cycles and treated with erlotinib. No correlation was identified between Epstein-Barr virus DNA plasma levels and clinical outcome.

CONCLUSIONS

Maintenance or second-line therapy with erlotinib after chemotherapy was not effective in RM NPC. Historical comparison with patients treated with the same chemotherapy alone until progression suggests that it may be detrimental to stop chemotherapy after 6 cycles if disease did not progress.

Nasopharyngeal carcinoma signaling pathway: an update on molecular biomarkers

Nasopharyngeal carcinoma (NPC) is an uncommon cancer, which has a distinctive ethnic and geographic distribution. Etiology of NPC is considered to be related with a complex interaction of environmental and genetic factors as well as Epstein-Barr virus infection. Since NPC is located in the silent painless area, the disease is usually therefore diagnosed at the advanced stages; hence early detection of NPC is difficult. Furthermore, understanding in molecular pathogenesis is still lacking, pondering the identification of effective prognostic and diagnostic biomarkers. Dysregulation of signaling molecules in intracellular signal transduction, which regulate cell proliferation, apoptosis, and adhesion, underlines the basis of NPC pathogenesis. In this paper, the molecular signaling pathways in the NPC are discussed for the holistic view of NPC development and progression. The important insights toward NPC pathogenesis may offer strategies for identification of novel biomarkers for diagnosis and prognosis.

Epstein-Barr virus oncoprotein LMP1 mediates survivin upregulation by p53 contributing to G1/S cell cycle progression in nasopharyngeal carcinoma

Latent membrane protein 1 (LMP1) is an important oncogenic protein encoded by Epstein-Barr virus (EBV) and plays an important role in the development of nasopharyngeal carcinoma (NPC). Our previous study has shown that p53 protein was accumulated and phosphorylated in NPC, implying its transcription factor activity in NPC tumorigenesis. However, the biological function and potential downstream target of p53 mediated by LMP1 in NPC remain unknown. In this study, we found that LMP1 simultaneously induced upregulation of both p53 and survivin at the protein level, as well as their phosphorylation. Knockdown of p53 by siRNA revealed that LMP1 increased survivin expression by p53 directly. Furthermore, we found that LMP1 upregulated survivin by p53 at the transcriptional level by increasing p53-mediated survivin promoter activity and DNA binding activity. Moreover, LMP1 induced the co-localization of p53 and survivin in the nucleus, conferring to their related functions in NPC tumorigenesis. We further found that p53 promoted G1/S cell cycle progression, but did not induce apoptosis in LMP1-positive NPC cells. Collectively, these findings suggest that p53 acting as a transcription factor promotes the transcriptional activity of survivin, and further increases its protein expression and phosphorylation in the regulation of LMP1, thus, leading to G1/S cell cycle progression with no effect on apoptosis in NPC tumorigenesis.

Deciphering the molecular genetic basis of NPC through molecular, cytogenetic, and epigenetic approaches

Nasopharyngeal carcinoma (NPC) is consistently associated with EBV infection and prevalence in southern China and Southeast Asia. In addition to EBV, the development of NPC involves cumulative genetic and epigenetic changes influenced by predisposing genetic factors and environmental carcinogens. Over the past two decades, knowledge of genetic and epigenetic alterations of NPC has rapidly accumulated. Multiple chromosomal abnormalities (e.g. copy number changes on chromosomes 3p, 9p, 11q, 12p, and 14q), gene alterations (e.g. p16 deletion and LTBR amplification), and epigenetic changes (e.g. RASSF1A and TSLC1 methylation) have been identified by various genome-wide approaches, such as allelotyping, CGH, and microarray analysis. In this review, we will discuss the critical genetic events that contribute to the initiation and progression of NPC. Studies on the precancerous lesions and in vitro immortalized nasopharyngeal epithelial cell models provide important evidence for the involvement of genetic alterations and EBV infection in early development of this cancer. A hypothetical model describing the role of EBV latent infection and multiple genetic changes in NPC tumorigenesis is proposed.

Eight-Signature Classifier for Prediction of Nasopharyngeal Carcinoma Survival

Purpose

Currently, nasopharyngeal carcinoma (NPC) prognosis evaluation is based primarily on the TNM staging system. This study aims to identify prognostic markers for NPC.

Patients and Methods

We detected expression of 18 biomarkers by immunohistochemistry in NPC tumors from 209 patients and evaluated the association between gene expression level and disease-specific survival (DSS). We used support vector machine (SVM) –based methods to develop a prognostic classifier for NPC (NPC-SVM classifier). Further validation of the NPC-SVM classifier was performed in an independent cohort of 1,059 patients.

Results

The NPC-SVM classifier integrated patient sex and the protein expression level of seven genes, including Epstein-Barr virus latency membrane protein 1, CD147, caveolin-1, phospho-P70S6 kinase, matrix metalloproteinase 11, survivin, and secreted protein acidic and rich in cysteine. The NPC-SVM classifier distinguished patients with NPC into low- and high-risk groups with significant differences in 5-year DSS in the evaluated patients (87% v 37.7%; P < .001) in the validation cohort. In multivariate analysis adjusted for age, TNM stage, and histologic subtype, the NPC-SVM classifier was an independent predictor of 5-year DSS in the evaluated patients (hazard ratio, 4.9; 95% CI, 3.0 to 7.9) in the validation cohort.

Conclusion

As a powerful predictor of 5-year DSS among patients with NPC, the newly developed NPC-SVM classifier based on tumor-associated biomarkers will facilitate patient counseling and individualize management of patients with NPC.

Inhibition of NOTCH3 signalling significantly enhances sensitivity to cisplatin in EBV-associated nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an EBV-associated epithelial malignancy which is prevalent in south-east Asia and southern China. Despite the multiple genetic and epigenetic changes reported, the contribution of dysregulated signalling pathways to this distinct type of head and neck cancer is not well understood. Here we demonstrate the up-regulation of NOTCH ligands (JAG1 or DLL4) and effector (HEY1) in the majority of EBV-positive tumour lines and primary tumours. Among the NOTCH receptors, NOTCH3 was over-expressed in all EBV-positive tumour lines and 92.5% of primary tumours. Aberrant activation of NOTCH3 signalling was consistently detected in all these samples. These findings imply that NOTCH3 may play an crucial role in the development of NPC. By NOTCH3 specific siRNA, NOTCH3 signalling was suppressed and thereby significant growth inhibition and apoptosis induction occurred in NPC cells. Down-regulation of a number of targets involved in cell proliferation, eg CCND1, C-MYC,NFKB1, and survival, eg BCL2, BCL-XL, SURVIVIN, was confirmed in the NOTCH3 knockdown NPC cells. Importantly, NOTCH3 knockdown highly enhanced the sensitivity of NPC cells to cisplatin treatment. Furthermore, we revealed that the ability of NPC cells to form spheroids in vitro and tumours in nude mice was also significantly decreased after knockdown of NICD3 expression. These findings indicate that activation of NOTCH3 pathway is a critical oncogenic event in NPC tumourigenesis. Targeting NOTCH3 signalling may serve as a potential therapeutic approach for treating patients suffering from EBV-associated NPC.

MiR-218 suppresses nasopharyngeal cancer progression through downregulation of survivin and the SLIT2-ROBO1 pathway

Nasopharayngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Here we report frequent downregulation of the microRNA miR-218 in primary NPC tissues and cell lines where it plays a critical role in NPC progression. Suppression of miR-218 was associated with epigenetic silencing of SLIT2 and SLIT3, ligands of ROBO receptors that have been previously implicated in tumor angiogenesis. Exogenous expression of miR-218 caused significant toxicity in NPC cells in vitro and delayed tumor growth in vivo. We used an integrated trimodality approach to identify targets of miR-218 in NPC, cervical, and breast cell lines. Direct interaction between miR-218 and the 3'-untranslated regions (UTR) of mRNAs encoding ROBO1, survivin (BIRC5), and connexin43 (GJA1) was validated in a luciferase-based transcription reporter assay. Mechanistic investigations revealed a negative feedback loop wherein miR-218 regulates NPC cell migration via the SLIT-ROBO pathway. Pleotropic effects of miR-218 on NPC survival and migration were rescued by enforced expression of miR-218-resistant, engineered isoforms of survivin and ROBO1, respectively. In clinical specimens of NPC (n=71), ROBO1 overexpression was significantly associated with worse overall (P=0.04, HR=2.4) and nodal relapse-free survival (P=0.008, HR=6.0). Our findings define an integrative tumor suppressor function for miR-218 in NPC and further suggest that restoring miR-218 expression in NPC might be useful for its clinical management.

Functional polymorphism -31C/G in the promoter of BIRC5 gene and risk of nasopharyngeal carcinoma among chinese

Background

Baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5, also called as survivin) is a member of the inhibitor of apoptosis protein (IAP) family, which plays an important role in the occurrence and progression of cancer. Recently, a polymorphism in the promoter of BIRC5, -31C/G (rs9904341), was shown to influence BIRC5 expression.

Methods

We examined whether the -31C/G was related to the risk of developing nasopharyngeal carcinoma (NPC) in a case-control population from Guangxi province in southern China, which consists of 855 patients with NPC and 1036 controls. This polymorphism was genotyped by TaqMan assay. The genetic associations with the occurrence and progression of NPC were estimated by logistic regression.

Results

We observed a statistically significant increased occurrence of NPC associated with the CC genotype (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.13–1.73; P = 0.0020) compared with the genotypes containing G allele (CG + GG genotype). However, no significant association was observed for the -31C/G with the severity of NPC (as measured by tumor-node-metastasis staging system).

Conclusion

Our findings suggest that the functional polymorphism -31C/G in the promoter of BIRC5 gene may play a role in mediating the susceptibility to NPC among Chinese.

Detection of EBV in nasopharyngeal carcinoma by quantum dot fluorescent in situ hybridization

AIMS

Nasopharyngeal carcinoma (NPC) is a common cancer in Southeast Asia and is frequently associated with Epstein-Barr virus (EBV) infection. The primary aim of this study was to improve the method of EBV detection by exploring quantum dots in FISH detection, and compare QD-based FISH with conventional ISH.

MATERIALS AND METHODS

Biopsy specimens were retrospectively retrieved from 35 NPC patients as paraffin-embedded tissue blocks. QD-FISH was developed to detect the presence of EBV encoded small RNA (EBER) using biotin-labeled EBER oligonucleotide probe indirectly labeled with streptavidin-conjugated quantum dots. Conventional ISH was also performed using a commercial kit to assess concordance between the two methods.

RESULTS

All the 35 NPC cases were nonkeratinizing carcinoma (7 differentiated and 28 undifferentiated subtypes). EBER-positive signals were detected in 91.43% (32/35) and 80% (28/35) cases by QD-FISH and ISH, respectively. There was no significant difference in the number of EBER-positive cases by the two methods. A moderate concordance was found between QD-FISH and ISH for EBER status (κ=0.55). Four EBER-negative cases by ISH showed EBER-positive signals when detected by QD-FISH.

CONCLUSIONS

EBV is closely associated with NPC in Chinese patients. QD-FISH is a novel effective method for EBER detection, and has a moderate concordance with conventional ISH.

Chk1 inhibitor Gö6976 enhances the sensitivity of nasopharyngeal carcinoma cells to radiotherapy and chemotherapy in vitro and in vivo

Nasopharyngeal carcinoma (NPC) is a malignant tumor. This type of carcinoma has a low 5-year patient survival rate. Thus, there is a need for improved therapeutics. We determined that the Chk1 inhibitor Gö6976 enhanced the sensitivity of CNE1 and CNE2 cells to ionizing radiation (IR) or cisplatin by abrogating S and G(2)/M arrest and subsequently promoting apoptosis. Furthermore, Gö6976 appeared to sensitize NPC xenografts in nude mice to IR or cisplatin treatment. This is the first report to show that the Chk1 inhibitor Gö6976 sensitizes NPC cells to treatment using in vitro and in vivo models.

Prognostic significance of clinical parameters and Epstein-Barr virus infection in non-endemic undifferentiated carcinoma of nasopharyngeal type: a Serbian report

Undifferentiated carcinoma of nasopharyngeal type (UCNT) is very rare tumour in Serbia, like in most of the countries of Europe, with incidence less than 0.5 per 100,000 people per year. The aim of this study was to assess the presence of Epstein-Barr virus (EBV) in the UCNT of a non-endemic population in Serbia and identify the main clinical parameters that interfere with patients' survival rate. This study included 102 patients with UCNT who were diagnosed between 1996 and 2003. Biopsies were analysed for EBV-encoded RNA (EBER) by in situ hybridization of tumour tissue microarray. Of 102 patients, 76 were men and 26 were women with ages ranging between 18 and 82 years (median 52.5, mean 53.0±14.1). Survival rates were 80, 39 and 31% for one, three and five years, respectively. Ninety-three of 102 cases were EBER positive (92%). Factors with unfavourable prognostic values were age over 50 years at the time of diagnosis, advanced clinical stage, therapy other than chemoradiotherapy and EBER negative status. In regard to the clinical data, EBER expression in UCNT was shown to be a strong independent predictor of overall and progression-free survival. To our knowledge, the current report constitutes the largest European non-endemic series of UCNT samples from a single institution with correlation between survival and clinical parameters/EBER status.

Significance of Plk1 regulation by miR-100 in human nasopharyngeal cancer

Polo-like kinase 1 (Plk1) is a critical regulator of many stages of mitosis; increasing evidence indicates that Plk1 overexpression correlates with poor clinical outcome, yet its mechanism of regulation remains unknown. Hence, a detailed evaluation was undertaken of Plk1 expression in human nasopharyngeal cancer (NPC), the cellular effects of targeting Plk1 using siRNA in combination with ionizing radiation (RT) and potential upstream microRNAs (miRs) that might regulate Plk1 expression. Using immunohistochemistry, Plk1 was observed to be overexpressed in 28 of 40 (70%) primary NPC biopsies, which in turn was associated with a higher likelihood of recurrence (p = 0.018). SiPlk1 significantly inhibited Plk1 mRNA and protein expression, and decreased Cdc25c levels in NPC cell lines. This depletion resulted in cytotoxicity of C666-1 cells, enhanced by the addition of RT, mediated by G2/M arrest, increased DNA double-strand breaks, apoptosis, and caspase activation. Immunofluorescence demonstrated that the G2/M arrest was associated with aberrant spindle formation, leading to mitotic arrest. In vivo, transfection of C666-1 cells and systemic delivery of siPlk1 decreased tumour growth. MicroRNA-100 (miR-100) was predicted to target Plk1 mRNA, which was indeed underexpressed in C666-1 cells, inversely correlating with Plk1 expression. Using luciferase constructs containing the 3'-UTR of Plk1 sequence, we document that miR-100 can directly target Plk1. Hence, our data demonstrate for the first time that underexpressed miR-100 leads to Plk1 overexpression, which in turn contributes to NPC progression. Targeting Plk1 will cause mitotic catastrophe, with significant cytotoxicity both in vitro and in vivo, underscoring the important therapeutic opportunity of Plk1 in NPC.

The pathogenic role of Epstein-Barr virus (EBV) in sclerosing polycystic adenosis

Sclerosing polycystic adenosis (SPA) is a pathology of the salivary gland which occurs infrequently and has a controversial etiology. In this study, we investigated the possible roles of HPV and EBV in the pathogenesis of SPA. Archived cases of salivary gland lesions were retrieved, and their diagnoses were re-evaluated; cases that fit the diagnosis of SPA were selected and subjected to Alcian Blue-Periodic Acid Schiff's histochemical staining and immunohistochemical staining for HPV-1, EBV, S-100, and Bcl-2 proteins in addition to the proliferative marker Ki-67. In addition, RNA extracted from formalin-fixed, paraffin-embedded tissues was subjected to RT-PCR to confirm any positive immunohistochemical results. Co-localization of EBV and Bcl-2 in lesional cells was the most striking finding; Ki-67 was expressed in basal cells, while no expression was seen in the adjacent salivary gland cells. Our EBV (+) ve immunostaining results were confirmed by RT-PCR using RNA extracted from paraffin sections. Our results suggest a significant pathogenic role of EBV in SPA. Moreover, they provide new evidence on the neoplastic nature of SPA.

Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes

BACKGROUND

Tumor-specific cytotoxic T cells and infiltrating lymphocytes are frequently found in tumor tissues in patients with nasopharyngeal carcinoma (NPC). Most patients with NPC, however, especially those with advanced stages, have a poor clinical prognosis despite conventional immunotherapy. The aim of this work was to examine the effect of indoleamine 2,3-dioxygenase (IDO), an immunosuppressive enzyme, on the lymphocyte function in NPC.

METHODS

The NPC cell line CNE2 was treated by interferon-gamma (IFNgamma) and the levels of IDO expression was analyzed by Western blotting and reverse phase high-performance liquid chromatography (HPLC). Lymphocytes from health human exposed to the milieu created by IDO-positive CNE2 cells and the lymphocyte cytotoxicity to target tumor cells was analyzed by standard lactate dehydrogenase (LDH) release assay. Additionally, expression of IDO was determined by Immunohistochemical assay in the tumor tissues form clinically evaluated NPC.

RESULTS

IDO expression was acutely induced in the NPC cell line CNE2 by low dose interferon-gamma (IFNgamma) or by co-incubation with activated lymphocytes. Exposure to the milieu created by IDO-positive CNE2 cells did not promote lymphocyte death, but lymphocyte cytotoxicity against target tumor cells was impaired. The suppression of lymphocyte cytotoxic function was fully restored when the conditioned medium was replaced by fresh medium for 24 h. In additionally, the IDO-positive cells were found scattered in the tumor tissues from patients with NPC.

CONCLUSION

Altogether, these findings suggest that IDO-mediated immunosuppression may be involved in the tumor immune evasion, and that blocking IDO activity in tumor cells may help to re-establish an effective anti-tumor T cell response in NPC.

Comparative prognostic value of HPV16 E6 mRNA compared with in situ hybridization for human oropharyngeal squamous carcinoma

PURPOSE

A significant proportion of oropharyngeal squamous cell carcinomas (OSCC) are associated with the human papilloma virus (HPV), particularly HPV16. The optimal method for HPV determination on archival materials however, remains unclear. We compared a quantitative real-time polymerase chain reaction (qRT-PCR) assay for HPV16 mRNA to a DNA in situ hybridization (ISH) method, and evaluated their significance for overall (OS) and disease-free (DFS) survival.

PATIENTS AND METHODS

Matched, archival biopsies from 111 patients with OSCC were evaluated for HPV16 using a qRT-PCR for E6 mRNA and ISH for DNA. Immunohistochemistry for p16, p53, and epidermal growth factor receptor were also performed.

RESULTS

HPV16 E6 mRNA was positive in 73 (66%) of 111 samples; ISH was positive in 62 of 106 samples (58%), with 86% concordance. P16 was overexpressed in 72 samples (65%), which was strongly associated with HPV16 status by either method. E6 mRNA presence or p16 overexpression were significantly associated with superior OS; E6 mRNA, HPV16 ISH, or p16 were all significantly associated with DFS. On multivariate analysis adjusted for age, stage, and treatment, positive E6 mRNA was the only independent predictor for superior OS; for DFS, p16 expression or HPV16 status determined by either method was significant.

CONCLUSION

The prevalence of HPV16 in OSCC ranges from 58% to 66%, in a recently treated Canadian cohort. Classification of HPV-positivity by HPV16 E6 mRNA, HPV16 ISH or p16 immunohistochemistry (IHC) is associated with improved DFS. However, the latter two assays are technically easier to perform; hence, HPV16 ISH or p16 IHC should become standard evaluations for all patients with OSCC.