Marker For Nasopharyngeal Carcinoma Research Articles

Dosage des marqueurs tumoraux CYFRA 21-1 et ACE dans le cancer du nasopharynx en Algérie

Summary Nasopharyngeal cancer is one of the most important cancers in our country. It is characterized by the influence of different etiologic factors: viral, genetic and environmental. Its diagnosis is delayed by lack of specific tumor markers. The aim of this study was to evaluate the importance of the use of CYFRA 21-1 and ACE markers in nasopharyngeal carcinoma (NPC). Our prospective study interested 164 patients (132 M, 32 F) with a mean age of 47 years (13 to 70) with 24 of them aged less than 30 years, presenting a nasopharyngeal carcinoma histologically confirmed and 180 healthy controls without evident neoplasm. Undifferentiated forms represent 93% of cases. A blood sample was collected from each patient and control before any treatment, as well as controls to measure CYFRA 21-1 and ACE by immunoenzymatic assay. The results showed that the mean serum CYFRA 21-1 values were significantly higher in patients with NPC than those in controls (P ± 0.001). A significant correlation was found only between the serum CYFRA 21-1 level before treatment and the clinical outcome of patients (P ± 0.0009). Seric level of CYFRA 21-1 at diagnosis of NPC may play a predictive role to evaluate the risk of metastatic disease and prognosis.

Early detection of nasopharyngeal carcinoma by plasma Epstein‐Barr virus DNA analysis in a surveillance program

Nasopharyngeal carcinoma (NPC) is prevalent in Southeast Asia. Over the last decade, plasma Epstein-Barr virus (EBV) DNA has been developed as a tumor marker for NPC. In this study, the authors investigated whether plasma EBV DNA analysis is useful for NPC surveillance. In total, 1318 volunteers ages 40 to 60 years were prospectively recruited. Plasma EBV DNA and serology for viral capsid antigen immunoglobulin A (IgA) were measured. Participants who had detectable plasma EBV DNA or positive IgA serology underwent nasal endoscopic examination and a follow-up plasma EBV DNA analysis in approximately 2 weeks. All participants were followed for 2 years to record the development of NPC. Three individuals with NPC were identified at enrolment. All of them were positive for EBV DNA and remained positive in follow-up analysis. Only 1 of those patients was positive for EBV serology. In 1 patient who had NPC with a small tumor confined to the mucosa, the tumor was not detectable on endoscopic examination. Because of a 2-fold increase in plasma EBV DNA on the follow-up analysis, that patient underwent magnetic resonance imaging, which revealed the tumor. Among the participants who did not have NPC but had initially positive plasma EBV DNA results, approximately 66% had negative EBV DNA results after a median of 2 weeks. Plasma EBV DNA analysis proved useful for detecting early NPC in individuals without a clinical suspicion of NPC. Repeating the test in those who had initially positive results differentiated those with NPC from those who had false-positive results. Cancer 2013. © 2013 American Cancer Society.

Fatty acid synthase overexpression confers an independent prognosticator and associates with radiation resistance in nasopharyngeal carcinoma

Fatty acid synthase (FASN) is overexpressed in many human cancers and associated with poor prognosis. However, the role of FASN in nasopharyngeal carcinoma (NPC) has not been studied. We evaluated the expression of FASN immunohistochemically in 124 NPC specimens, stratified them into two groups (FASN-high and FASN-low), and examined the correlation with various clinicopathological parameters. In two NPC cell lines, HONE1 and TW01, we targeted the FASN transcript by shRNAi and evaluated the effect on cell proliferation by WST-1 assay and radiation-induced apoptosis by measuring caspase-3 and caspase-7 activation. NPC with high FASN immunoexpression was correlated with advanced pT disease status and worse prognosis in terms of disease-specific survival, metastasis-free survival and local recurrence-free survival, compared to FASN-low group in both univariate and multivariate analyses. In the two NPC cell lines, endogenous FASN expression was significantly higher than the non-tumor keratinocyte, DOK. When the expression of FASN was suppressed by shRNAi, the tumor cells showed decreased cell proliferation and increased apoptosis after radiation. Our results supported FASN as an adverse prognostic marker in NPC, possibly by conferring cell growth advantage and resistance to radiation-induced apoptosis on tumor cells. The inhibition of FASN expression might be investigated as an adjunct in treatment, especially in radiation resistant NPC.

Long‐term survival analysis of nasopharyngeal carcinoma by plasma Epstein‐Barr virus DNA levels

The objective of this study was to confirm the relation between plasma Epstein-Barr virus (EBV) DNA (pEBV DNA) load and treatment outcomes after long-term follow-up in patients with nasopharyngeal carcinoma (NPC). In total, 210 patients with NPC were enrolled, including 99 previously reported patients and 111 new patients. They prospectively received treatment with induction chemotherapy plus radiotherapy and were followed for at least 6 years. In these patients, pEBV DNA levels were measured before treatment and 1 week after treatment. The plasma viral load was correlated with treatment outcomes in the group of new patients and in the entire group. By using previously defined pEBV DNA cutoff values (1500 copies/mL pretreatment and 0 copies/mL post-treatment), there was a significant correlation between the pEBV DNA value and relapse-free survival, overall survival, and subsequent relapse rates in the new, independent patient cohort. Outcome analyses for the entire group revealed a higher relapse rate (45.6% vs 21.5% [P = .0037] or 76.7% vs 26.1% [P < .0001]), a worse relapse-free survival rate (56.5% vs 79.3% [P < .0001] or 23.3% vs 75.6% [P < .0001]), and poorer overall survival (59.2% vs 86% [P = .0003] or 33.3% vs 79.4% [P < .0001]) in patients who had high pretreatment or persistently detectable post-treatment pEBV DNA levels, respectively, versus their respective counterparts. Multivariate Cox analysis also confirmed these results. In this expanded study, the prognostic significance of pEBV DNA was confirmed using predefined cutoff values in an independent patient group, and pEBV DNA was identified as an independent prognostic marker for NPC.

221P - Methylation Marker has a Complementary Value to Epstein-Barr Virus-Based Tests in Early Detection of Nasopharyngeal Carcinoma

ABSTRACT Undifferentiated nasopharyngeal carcinoma (NPC) is strongly linked to Epstein-Barr virus (EBV) infection. The presence of aberrant antibodies against EBV and high viral DNA load can be predictive for the disease and have been proposed for screening tools. Beside the EBV-based markers, analysis of aberrant methylation in gene promoter of tumor suppressor gene (TSG) may have potential value in identifying NPC at early stage. This study determined methylation status of multiple TSGs and evaluated whether it may improve NPC early detection using EBV-based assays. Association between EBV-encoded latent membrane protein 1 (LMP1) and methylation status was also tested. Nasopharyngeal brushings and sera were obtained from 53 NPC cases, 22 high risk individuals and 25 healthy EBV carriers. In all sera the detection of antibody against EBV was performed using EBV-IgA ELISA. EBV DNA load was measured by a quantitative light-cycler PCR on nasopharyngeal brushing samples. For methylation analysis, DNA was modified using bisulfite treatment and amplified by methylation-specific PCR (MSP) or quantitative MSP to target region within promoter of eleven TSGs. The expression of LMP1 was tested using immunohistochemistry. NPC samples demonstrated frequent methylation for individual TSGs (DAPK1 79%, CDH13 77%, DLC1 77%, RASSF1A 76%, CADM1 70%, p16 66%, WIF1 61%, CHFR 59%, RIZ1 57% and RASSF2A 29%). High risk individuals showed high frequency of four methylated genes, low methylation of two TSGs and undetectable methylation of another four TSGs. Healthy subjects had similar pattern as high risk individuals. Because not all of methylated genes allowed good discrimination between NPC and healthy individuals, a panel of markers (RASSF1A, p16, WIF1, CHFR and RIZ1) was determined and combined analysis revealed a detection rate of 98%. Quantitative analysis of MAL gene, TSG that has never been tested in NPC, showed promising result for NPC marker. The expression of LMP1 was observed to associate with methylated RASSF1A. In conclusion, methylation analysis has a complementary value to EBV-based assays for NPC risk assessment. The association of EBV oncogene to methylation status underlined the role of EBV in epigenetic event during oncogenesis. Disclosure All authors have declared no conflicts of interest.

Comparative serum proteomic analysis involving liver organ-specific metastasis-associated proteins of nasopharyngeal carcinoma

Metastasis is the main cause of cancer-related mortality; patients with liver metastases (LM) have the worst prognosis among patients with nasopharyngeal carcinoma (NPC). However, at present, few biomarkers for detecting organ-specific metastasis have been identified. Proteomics, an ultra-sensitive analytical technique, can detect molecular changes before organ-specific metastasis occurs. Analysis with matrix-assisted, laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS), combined with magnetic chemical affinity beads is a new technique for evaluating protein separation. We sought to identify potential liver-specific, metastasis-associated proteomic printing in patients with NPC. We examined 64 serum samples from 50 patients who had pathologically confirmed NPC and 14 who had pathologically confirmed non-NPC with LM using MALDI-TOF-MS with weak cation bead protein chips. During follow-up of at least 37 months (maximum, 176 months) following radiotherapy, we confirmed 16 cases of LM (LM NPC), 16 cases without LM (non-LM NPC) and 18 cases without metastasis (non-M NPC). Using comparison analysis, 4 protein mass peaks, 4155.34, 4194.87, 4210.78 and 4249.56 m/z were identified as liver-specific, metastasis-associated protein peaks in NPC and two of them (4155 and 4249 m/z) met two different statistical criteria in both ClinProt software analyses and discriminant analyses. Models based on the 4 potential serum markers of NPC discriminated between LM NPC, non-LM NPC, non-M NPC and non-NPC LM analyzed with sieved markers. The recognition capability and cross-validation of these models for differentiating the above 4 groups are all approximately 80%. MALDI-TOF-MS combined with tree analysis models may provide a clinical diagnostic platform for detecting potential liver-specific, metastasis-associated proteomic printing in NPC. However, markedly differential proteins still need to be identified.

Integrated Analysis of Multiple Gene Expression Profiling Datasets Revealed Novel Gene Signatures and Molecular Markers in Nasopharyngeal Carcinoma

To identify the novel gene signatures and molecular markers of nasopharyngeal carcinoma (NPC) by integrated bioinformatics analysis of multiple gene expression profiling datasets. Seven published gene expression profiling studies and one of our unpublished works were reanalyzed to identify the common significantly dysregulated (CSD) genes in NPC. Overrepresentation analysis of cytogenetic bands, Gene Ontology (GO) categories, pathways were used to explore CSD genes functionally associated with carcinogenesis. The protein expressions of selected CSD genes were examined by immunohistochemistry on tissue microarrays, and the correlations of their expressions with clinical outcomes were evaluated. Using the criteria (genes reported deregulated in more than one study), a total of 962 genes were identified as the CSD genes in NPC. Four upregulated (BUB1B, CCND2, CENPF, and MAD2L1) and two downregulated (LTF and SLPI) genes were markedly reported in six studies. The enrichments of chromosome aberrations were 2q23, 2q31, 7p15, 12q15, 12q22, 18q11, and 18q12 in upregulated genes and 14q32 and 16q13 in downregulated genes. The activated GO categories and pathways related to proliferation, adhesion, invasion, and downregulated immune response had been functionally associated with NPC. SLPI significantly downregulated in nasopharyngeal adenocarcinoma. Furthermore, the high expression of BUB1B or CENPF was associated with poor overall survival of patients. It was first clearly identified the dysregulated expression of BUB1B and SLPI in NPC tissues. Further studies of the CSD genes as gene signatures and molecular markers of NPC might improve the understanding of the disease and identify new therapeutic targets.

Expression of Human Leukocyte Antigen G is associated with Prognosis in Nasopharyngeal Carcinoma

Human leukocyte antigen G (HLA-G) has multiple immune regulatory functions including the induction of immune tolerance in malignancies. The roles of HLA-G have not been investigated in nasopharyngeal carcinoma (NPC). This study is aimed to evaluate the role of HLA-G as prognostic factor for NPC patients as well as its role in the immune regulation. Western assays showed high HLA-G expression in NPC cell lines, but low in the immortalized nasopharyngeal epithelial cell line NP69. HLA-G protein was further detected in 79.2% of 552 NPC specimens with immunohistochemistry (IHC), but not in normal nasopharyngeal epithelium tissue. Moreover, high expression of HLA-G predicted poor survival of NPC patients and positively correlated with tumor N classification and recurrence or metastasis. Multivariate analysis indicated that HLA-G was an independent and unfavorable prognostic factor. Furthermore, the presence of CD68+macrophages and IL-10 were also examined, which are two prognostic markers of NPC and important factors for regulating immune surveillance. The correlations of HLA-G with these two immune factors were revealed in NPC tissues. Taken together, our results suggest that HLA-G is an independent biomarker for NPC prognosis, and HLA-G might contribute to NPC progression, which might jointly regulate immune surveillance in NPC together with macrophages and IL-10.

Expression and prognosis of FOXO3a and HIF-1α in nasopharyngeal carcinoma

The Forkhead Box O3a transcription factor (FOXO3a) and hypoxia-inducible factor-1α (HIF-1α) have been reported to play important roles in the development and prognosis of human cancers. However, their exact roles are not clear. Therefore, we investigated the expression status and clinical significance of FOXO3a and HIF-1α expression in nasopharyngeal carcinoma. The expression of FOXO3a and HIF-1α proteins was detected in nasopharyngeal carcinoma tissues and normal nasopharyngeal tissues by immunohistochemistry and western blot. Furthermore, we analyzed the association of FOXO3a and HIF-1α expression with various clinicopathologic factors including survival status of nasopharyngeal carcinoma patients. FOXO3a was low expressed and HIF-1α was high expressed in nasopharyngeal carcinoma tissues, compared with normal nasopharyngeal tissues (both P < 0.05). The low expression of FOXO3a was significantly correlated with clinical stage (P = 0.003), T stage (P = 0.011), lymph node metastasis (P = 0.003), and distant metastasis (P = 0.030), and over expression of HIF-1α was significantly correlated with T stage (P = 0.026), lymph node metastasis (P = 0.002), and distant metastasis (P = 0.010). The Spearman analysis indicated that FOXO3a expression was inversely correlated with HIF-1α expression(rs = -0.598, P < 0.001). Overall survival curves estimated by Kaplan-Meier showed that tumor patients with low FOXO3a or high HIF-1α expression had significantly poorer prognosis compared with patients with high FOXO3a or low HIF-1α levels (P < 0.001, and P = 0.012, respectively). In addition, multivariate Cox regression analysis showed that T stage, distant metastasis, and FOXO3a were significant independent prognostic factors for overall survival (P = 0.011, P = 0.008, and P = 0.047, respectively). Our results suggested that FOXO3a and HIF-1α may be considered to be important prognostic markers in nasopharyngeal carcinoma.

To build a prognostic score model containing indispensible tumour markers for metastatic nasopharyngeal carcinoma in an epidemic area

Background and objectiveThe survival outcomes of patients with metastatic nasopharyngeal carcinoma (NPC) differ significantly between individuals. The aim of this study is to build a prognostic score model (PSM) incorporating circulating tumour markers for metastatic NPC in an epidemic area. MethodsSeven hundred and ninety-nine patients with disseminated NPC were analysed retrospectively. Univariate and multivariable analyses were conducted using the Cox proportion hazards model. Factors analysed included patients, characteristics (gender, age group, performance status), circulating tumour-marker characteristics (Epstein–Barr virus (EBV) DNA level, EBV VCA-IgA level, lactate dehydrogenase (LDH) level, alkaline phosphatase (ALP) level), basic laboratory characteristics (leucocyte count, haemoglobin level, albumin level), and disease characteristics (presence of metastasis at presentation, disease-free interval, number of metastatic sites, specific metastatic sites). The PSM was built according to numerical score derived from the regression coefficients of each independent prognostic variable. The prognostic score of each patient was calculated by totalling up the scores of each independent variable. ResultsIndependent prognostic factors included performance status, age, haemoglobin level, LDH level, ALP level and EBV DNA level. Three prognostic groups based on PSM were obtained: low risk (total score=0–4); intermediate risk (5–8); high risk (9–12). Median survivals of the three groups were 25.5, 15.1 and 7months, respectively, (P<0.001). ConclusionClinical and laboratory characteristics can help guide the prognostication of patients with metastatic NPC in epidemic areas.

Eight-Signature Classifier for Prediction of Nasopharyngeal Carcinoma Survival

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

Novel potential markers of nasopharyngeal carcinoma for diagnosis and therapy

Objective To search for markers of nasopharyngeal carcinoma (NPC) for diagnosis. Design and methods Using gas chromatography and mass spectrometry, we evaluated 51 serum metabolites in 49 NPC, 37 throat cancer patients and 40 healthy controls. High metabolites were selected and confirmed in NPC tissues. Sensitivity and specificity were appraised for 53 NPC diagnoses. Results Metabolic profiling revealed that kynurenine, N-acetylglucosaminylamine, N-acetylglucosamine and hydroxyphenylpyruvate increased in NPC patient sera. Their sensitivity and specificity were respectively 79% and 71%, 78% and 69%, 83% and 68%, 84% and 73% for NPC diagnosis. These increases were confirmed in NPC cells. Four metabolites gradually increased from stage I to stage III. After radiotherapy, four metabolites decreased gradually, and tended to a normal level, and were associated with rate of tumor reduction. Conclusion The results reveal that kynurenine, N-acetylglucosaminylamine, N-acetylglucosamine and hydroxyphenylpyruvate are potentially markers of NPC for diagnosis and therapy.

Identification of candidate molecular markers of nasopharyngeal Carcinoma by tissue microarray and in situ hybridization

To scan differentially expressed genes and to identify candidate molecular markers in nasopharyngeal carcinoma (NPC), we analyzed cDNA microarray data by GenMAPP to find specifically expressed genes in NPC and used tissue microarray and in situ hybridization techniques to confirm our microarray results. Our cDNA microarray results showed that TSPAN-1 and DPP10 genes were down-expressed in NPC, and COX7B and RFC2 genes were over-expressed in NPC. Real-time quantitative reverse transcription-PCR and in situ hybridization (ISH) techniques confirmed that TSPAN-1 and DPP10 genes had only 40.72 and 40.70% positive expression in NPC, but had high positive expression in chronic inflammation of nasopharyngeal mucosa (P < 0.01). However, COX7B and RFC2 genes were high positive rate in NPC (84.24 and 64.53%, respectively) than in normal control tissues. The data suggested that TSPAN-1, DPP10, COX7B and RFC2 genes might be the putative molecular markers of NPC.

Immunohistochemical study identifying prognostic biomolecular markers in nasopharyngeal carcinoma treated by radiotherapy

We evaluated the predictive significance of 14 reported markers using immunohistochemical study in nasopharyngeal carcinoma. Immunohistochemical stainings were done in 38 patients for Met, cyclooxygenase-2 (COX-2), nm23-H1, epidermal growth factor receptor (EGFR), p63, early growth response factor 1 (Egr1), chromosome segregation 1-like (CSE1L), cathepsin-D (aspartyl protease), C-erbB2, p53, signal transducers and activators of transcription (STAT3/STAT5), CD138 (Syndecan-1), and LIN28 with the usual methods. The median follow-up time was 30 months (11-83 months). High Met and CD138 expression were statistically significant negative prognostic factors on survival. The expression of Egr1 had a positive prognostic effect on survival. The combined score of these 3 markers, Met plus CD138 minus Egr1, was a strong prognostic factor. The median survival curve was distinctly separated in accord with this combined score. No prognostic value was revealed in COX-2, nm23-H1, EGFR, p63, CSE1L, cathepsin-D, C-erbB2, p53, STAT3, STAT5, and LIN28. The combined score of these markers could be used to stratify biomolecular risk groups.

Identification of Galectin-1 as a novel biomarker in nasopharyngeal carcinoma by proteomic analysis

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in southern China and Southeast Asia. It is characterized as a multistep process involved in multiple genetic and epigenetic events. The mechanism of carcinogenesis still needs to be further clarified. In this study, two-dimensional gel electrophoresis, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), RT-PCR, Western blot and immunohistochemical (IHC) analyses were used to detect Galectin-1 expression in NPC compared with normal nasopharyngeal epithelial tissues (NNET). We found that Galectin-1 was expressed at a significantly higher level in NPC compared with NNET. Our results indicated that high expression level of Galectin-1 might correlate with the development of NPC and Galectin-1 may serve as a potential diagnostic marker or therapeutic target for NPC.

Elevated Beclin 1 expression is correlated with HIF-1α in predicting poor prognosis of nasopharyngeal carcinoma

Recent studies have suggested that autophagy plays a pivotal role in regulation of cancer development and progression. High expression of the autophagy-related Beclin 1 protein predicted favorable patient outcome in several tumors. Here, a randomized controlled trial (RCT)-derived 128 nasopharyngeal carcinoma (NPC) patients were subjected to analysis of Beclin 1 expression and survival probability. In this RCT, 61 patients treated with induction chemotherapy plus concurrent chemoradiotherapy were used as a training set to generate a Beclin 1 cutoff score for patient outcome by receiver operating characteristic (ROC) curve analysis. For validation, the ROC-derived cutoff point was subjected to analysis of the association of Beclin 1 expression with patient outcome and clinical characteristics in testing set. The testing set comprised of 67 patients received induction chemotherapy plus radiotherapy. In the testing set and overall patients, our univariate and multivariate analysis showed that higher Beclin 1 expression, defined by the training set ROC analysis-generated cutoff score, predicted poorer overall survival, progression-free survival and distant metastasis-free survival. However, we failed to detect a correlation between Beclin 1 and local failure-free survival. Moreover, a positive relationship between Beclin 1 and HIF-1α expression was found. Importantly, among patients with elevated HIF-1α expression, a subset with lower Beclin 1 expression displayed a significant overall survival advantage than those with higher expression (p = 0.036). Contrary to previous studies, our results demonstrated that high autophagic Beclin 1 expression was an inferior prognostic marker for NPC. HIF-1α-associated Beclin 1 high expression might facilitate NPC cells surviving from chemoradiotherapy, suggesting a novel therapeutic molecular target for NPC.

The Association Between Epstein-Barr Virus with Nasopharyngeal Carcinoma in Patients from Southwestern Region of Iran

The aimed to evaluate the plasma level of Viral Capsid Antigen (VCA)-IgA and IgG in family members of Nasopharyngeal Carcinoma (NPC) patient in comparison to healthy controls in Southwestern of Iran. Total 60 NPC patients were compared with 60 sex, age and ethnically matched healthy controls. The obtained serum samples participants were tested for VCA-IgA, VCA-IgG, Early Antigen (EA), IgG, EBNA-IgG by ELIZA. There was no significant difference in all EBV antibodies between patients and control groups (p>0.05). The serological of three IgG antibody meant that 66.6 of two groups had the past infection; of NPC families 6.6 and from controls 1.6 were susceptible to infection with EBV. 3.3 in members of NPC families had reactivation infection. The sex of the patients in case group had positive correlation with VCA-IgA, EBNA-IgG, EA-IgG and negative correlation with VCA-IgG. The age of the patients also showed positive correlation with EBNA-IgG, EA-IgG, VCA-IgG and negative correlation with VCA-IgA. None of the EBV antibodies had significant correlation with age and sex of the patients. Because of no statistical difference between VCA-IgA mean titr from members of NPC families and controls, there is the not higher risk for members of NPC families to controls for NPC. The cause that had positive VCA-IgA also had positive EBNA-IgG and VCA-IgG. Anti-EBV antibodies can be used as diagnostic markers of NPC in Southwestern region of Iran. The combined use of two or more markers marginally improved the discriminating power but that has to take into consideration the higher costs. © 2010 Academic Journals Inc.

The antiapoptotic protein, FLIP, is regulated by heterogeneous nuclear ribonucleoprotein K and correlates with poor overall survival of nasopharyngeal carcinoma patients

Heterogeneous nuclear ribonucleoprotein K (hnRNP K) mediates antiapoptotic activity in part by inducing downstream antiapoptotic genes. To systematically identify hnRNP K targets in nasopharyngeal carcinoma (NPC), affymetrix chips were used to identify genes that were both overexpressed in primary NPC and downregulated by hnRNP K knockdown in NPC-TW02 cells. The resulting gene set included the antiapoptotic gene, FLIP, which was selected for further study. In cells treated with hnRNP K siRNA, TRAIL-induced apoptosis was enhanced and the FLIP protein level was reduced. Promoter, DNA pull-down and chromatin-immunoprecipitation assays revealed that hnRNP K directly interacts with the poly(C) element on the FLIP promoter, resulting in transcriptional activation. Through iTRAQ-mass spectrometric identification of proteins differentially associated with the poly(C) element or its mutant, nucleolin was determined to be a cofactor of hnRNP K for FLIP activation. Furthermore, FLIP was highly expressed in tumor cells, and this high-level expression was significantly correlated with high-level hnRNP K expression (P=0.002) and poor overall survival (P=0.015) as examined in 67 NPC tissues. A multivariate analysis confirmed that FLIP was an independent prognostic factor for NPC. Taken together, these findings indicate that FLIP expression is transcriptionally regulated by hnRNP K and nucleolin, and may be a potential prognostic and therapeutic marker for NPC.

Cell Secretome Analysis Using Hollow Fiber Culture System Leads to the Discovery of CLIC1 Protein as a Novel Plasma Marker for Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in Southeast Asia. Unfortunately, most NPC victims have had metastasis when first diagnosed due to its deep location and vague symptoms. To date, discovery of sensitive and specific biomarkers for improving detection of NPC remains a challenge. Our previous study established a strategy for cell secretome analysis using a hollow fiber culture (HFC) system combined with liquid chromatography mass spectrometry. Herein, the above platform was used to collect NPC secretome for the discovery of relevant clinical biomarkers. Among 66 identified proteins, chloride intracellular channel 1 (CLIC1) was sieved out for intended use as a potential NPC biomarker candidate. Approximately 75% of NPC tissue specimens showed positive CLIC1 staining by IHC. The plasma levels of CLIC1 in NPC patients (N = 70), as presented by sandwich ELISA, were significantly higher than those in the healthy controls (N = 74) (mean +/- SD, 16.38 +/- 26.53 vs 2.39 +/- 5.32 microg/mL; p = 0.00005). Using a cutoff point of 2.58 microg/mL, CLIC1 successfully discriminated NPC from the benign healthy control group with a sensitivity of 63% and a specificity of 77%. The area under the receiver operating characteristic curve was determined to be 0.74 (95% CI, 0.652-0.818). The statistical analysis of CLIC1 level in plasma shows that CLIC1 could be applied as a marker for early detection of NPC. This is the first report for the detection of CLIC1 as a plasma marker. Our results indicate that the analytical platform could provide a feasible strategy to profile tumor cell secretome for identifying cancer biomarkers, and CLIC1 may be a novel plasma tumor marker for NPC.

Genetic polymorphism of Interleukin-16 and risk of nasopharyngeal carcinoma

Background Common genetic variants in inflammatory cytokine genes can affect the risk of developing nasopharyngeal carcinoma (NPC). Interleukin-16 (IL-16), a pro-inflammatory cytokine, plays a pivotal role in inflammatory diseases as well as in the pathogenesis of tumors. Methods We analyzed rs4778889 T/C, rs11556218 T/G, and rs4072111 C/T polymorphisms of IL-16 in 206 patients with NPC and 373 healthy controls in a Chinese population, using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy and DNA sequencing methods. Results The rs11556218 T/G polymorphism of IL-16 gene was significantly associated with the susceptibility to NPC. The TG genotype was associated with a significantly higher risk of NPC as compared with the TT genotype (OR = 1.67; 95% CI, 1.18–2.36). Patients carrying the G allele had a significantly higher risk for developing NPC compared to individuals carrying the T allele (OR = 1.36; 95% CI, 1.03–1.78). Conclusions This study shows an association between IL-16 gene polymorphisms and the risk of NPC, and our data suggests that IL-16 gene polymorphisms may be useful as genetic susceptibility markers for NPC.