Biomarker For Nasopharyngeal Carcinoma Research Articles

Bioinformatic identification of candidate biomarkers and related transcription factors in nasopharyngeal carcinoma

BackgroundThe incidence of nasopharyngeal carcinoma (NPC) is rare, but a certain amount of mortality remains in NPC patients. Our study aimed to identify candidate genes as biomarkers for NPC screening, diagnosis, and therapy.MethodsWe investigated two microarray profile datasets GSE64634 and GSE12452 to screen the potential differentially expressed genes (DEGs) in NPC. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the DEGs were also performed. A protein-protein interaction (PPI) network of DEGs was constructed by STRING and visualized by Cytoscape software. The associated transcriptional factor regulatory network of the DEGs was also constructed.ResultsA total of 152 DEGs were identified from the GSE64634 and GSE12452 datasets, including 10 upregulated and 142 downregulated genes. Gene functional enrichment analysis indicated that these DEGs were enriched in the cilium movement, antimicrobial humoral response, O-glycan processing, mucosal immune response, carbohydrate transmembrane transporter activity, hormone biosynthetic process, neurotransmitter biosynthetic process, and drug metabolism-cytochrome P450 pathway. Five hub genes (DNALI1, RSPH4A, RSPH9, DNAI2, and ALDH3A1) and one significant module (score = 5.6) were obtained from the PPI network. Key transcriptional factors, such as SPI1, SIN3B, and GATA2, were identified with close interactions with these five hub DEGs from the gene-transcriptional factor network.ConclusionsWith the integrated bioinformatic analysis, numerous DEGs related to NPC were screened, and the hub DEGs we identified may be potential biomarkers for NPC.

MicroRNA-200c promotes tumor cell proliferation and migration by directly targeting dachshund family transcription factor 1 by the Wnt/β-catenin signaling pathway in nasopharyngeal carcinoma.

The purpose of the present study was to determine the crucial role of microRNAs (miRNAs/miRs) involved in the proliferation and migration of nasopharyngeal carcinoma (NPC) and to investigate their underlying mechanisms. In this study, we focused on the expression and function of miR-200c in NPC. First, we found the expression level of miR-200c in NPC cells and tissues was upregulated, and it was suggested that the high expression of miR-200c accelerated the proliferation and migration of NPC cells in vitro. Notably, a result of the present study was that the cell fate determination factor dachshund family transcription factor 1 (DACH1) was identified as a direct target of miR-200c. Suppression of miR-200c expression in NPC cells increased endogenous DACH1 mRNA and protein levels, which was negatively correlated with miR-200c. Meanwhile, DACH1 was shown to regulate the Wnt/β-catenin signaling pathway. Accordingly, it was concluded that miR-200c exerted a tumor-promoting role in NPC development by targeting DACH1, which may contribute to the increase in the rates of NPC proliferation and migration. miR-200c may be a potential diagnostic and prognostic biomarker for NPC.

Protocadherin 17 is a tumor suppressor and is frequently methylated in nasopharyngeal carcinoma.

PurposeSeveral PCDH genes were shown to be downregulated or silenced in carcinomas and act as candidate tumor suppressor genes. However, the functions of PCDH17 in nasopharyngeal carcinoma (NPC) remain unclear. Here, we investigated the PCDH17 promoter methylation status and its impact on the expression and functions of PCDH17 in NPC.Patients and methodsTo determine the mRNA levels and promoter methylation status of PCDH17 in NPC cell lines as well as 42 NPC patient specimens, we performed reverse transcription PCR, methylation-specific PCR, and bisulfite genome sequencing. The effects of ectopic PCDH17 expression in NPC cell lines were determined by colony formation, cell proliferation, wound healing, in vitro human umbilical vein endothelial cells tube formation, migration, invasion, cell cycle, and apoptosis assays and an in vivo subcutaneous tumor model.ResultsPCDH17 expression was almost absent or significantly reduced in 100% of the NPC cell lines (5/5). However, 5-aza-2′-deoxycytidine and trichostatin A treatment restored PCDH17 expression. Promoter methylation was involved in PCDH17 silencing. Ectopic expression of PCDH17 in silenced NPC cells reduced colony formation, cell migration, angiogenesis, VEGF secretion, and tumorigenicity.ConclusionPCDH17 plays a tumor suppressor role in NPC. PCDH17 methylation may be a tumor-specific event and can be used as an epigenetic biomarker for NPC.

NEAT1 is a potential prognostic biomarker for patients with nasopharyngeal carcinoma.

Nuclear paraspeckle assembly transcript 1 (NEAT1) has been found to be dysregulated and associated with clinical progression in various human cancers. The clinical and prognostic value of NEAT1 in nasopharyngeal carcinoma(NPC) was still controversial. The aim of our study was to provide more sufficient evidence that NEAT1 expression is correlated with overall survival in patients with NPC. NEAT1 expression was detected in NPC tissue samples, and the relationship between NEAT1 expression and clinical parameters, including prognosis, was analyzed. The meta-analysis was performed to further assess the prognostic significance of NEAT1 expression in patients with NPC. In our study, we found that the levels of NEAT1 expression were increased in NPC clinical tissue specimens, and associated with advanced M classification and clinical stages. Moreover, the Kaplan-Meier analysis suggested that the levels of NEAT1 expression were negatively associated with the overall survival of patients with NPC. Furthermore, univariate and multivariate Cox regression analyses showed that NEAT1 high-expression was an independent unfavorable prognostic factor in patients with NPC. Finally, we conducted a meta-analysis including 297 patients with NPC from the three studies, and found the pooled HR (95% confidence interval [CI]) was 1.64 (95% CI: 0.68-3.93) for the random effects model and 2.04 (95% CI: 1.42-2.95) for the fixed effect model. In conclusion, NEAT1 is a potential prognostic biomarker for NPC, but more studies are needed to further verify the prognostic value of NEAT1 in patients with NPC.

MiR-141 is up-regulated in biopsies from Vietnamese patients with nasopharyngeal carcinoma.

Novel biomarkers for screening, diagnosis and monitoring the treatment of nasopharyngeal carcinoma (NPC), one of the most common cancers in Vietnam, are urgently required. Increasing evidence suggests that microRNA-141 (miR-141) is associated with NPC, owing to its ability to affect the expression of genes that modulate tumorigenesis. Unfortunately, research on miR-141 expression in Vietnamese patients is limited. Therefore, the objective of the current study was to evaluate miR-141 expression and assess whether miR-141 might be a potential biomarker for diagnosis of NPC in Vietnamese patients. Total RNA isolated from 40 NPC biopsy samples and 37 non-cancerous samples was analyzed by quantitative reverse-transcription PCR. The miR-141 expression levels were compared between NPC biopsy and non-cancerous samples. The frequency of miR-141 detection was 37.50% and 10.80% in the NPC and non-cancerous samples, respectively (p = 0.0143). The miR-141 expression was 5.27 times higher in tumor samples than non-cancerous samples. Additionally, the RR (Relative risk) and OR (Odds ratio) were 1.83 (95%CI = 1.2576-2.6675, p = 0.0016) and 4.95 (95%CI = 1.4625-16.7541, p = 0.01), respectively. In conclusion, miR-141 was up-regulated in the biopsy samples and thus may be a potential biomarker for NPC in the Vietnamese population.

Plasma microRNA expression signature involving miR-548q, miR-630 and miR-940 as biomarkers for nasopharyngeal carcinoma detection.

Increasing studies have identified a series of circulating mircoRNAs (miRNAs) as biomarkers for disease detection due to their stability in the blood. The aim of the present study was to identify specific plasma miRNAs as potential biomarkers for nasopharyngeal carcinoma (NPC) detection. Relative public microarray data were obtained and analyzed for screening of the plasma differentially expressed miRNAs (DEMs) between NPC patients and controls. This study contained two phases: a screening phase and a validation one. Logistic regression and receiver operating characteristics curve (ROC) analyses were used to identify DEM signatures. Moreover, targeted genes of the selected DEMs were predicted and their functions were annotated by using bioinformatic analysis. Both the screening and the validation phases showed that three miRNAs (miR-548q, miR-630 and miR-940) in the plasma of NPC patients were up-regulated compared to those of controls. They can be used as biomarkers for discriminating NPC patients from non-cancerous controls. Moreover, we found a classifier including only two miRNAs (miR-548q and miR-940) that can be used as a diagnostic signature for NPC, achieving an area under curve (AUC) of 0.972, a sensitivity of 0.94, and a specificity of 0.925. The present study demonstrated that three miRNAs (miR-548q, miR-630 and miR940) might be novel and useful biomarkers for NPC detection. A two-miRNA signature (miR-548q and miR940) may be considered as a better biomarker for NPC detection with relatively high sensitivity and specificity. Future studies with large sample sizes are needed for further validation.

Placenta specific 8 gene induces epithelial-mesenchymal transition of nasopharyngeal carcinoma cells via the TGF-β/Smad pathway

The present study aimed to investigate the effects and mechanisms of PLAC8 on the epithelial-mesenchymal transition (EMT) of Nasopharyngeal carcinoma (NPC). The expression of PLAC8 in NPC and nasopharyngitis (NPG) tissues from 150 patients was determined using immunohistochemistry. The levels of PLAC8 in five NPC cell lines and nasopharyngeal permanent epithelial cell line were measured using western blotting. We then knocked out or overexpressed PLAC8 in CNE2 cells. Cell proliferation, wound healing, migration, and invasion assays were used to analyze the effects of PLAC8 on the proliferation, migration, and invasion in vivo and vitro. The results showed that the expression of PLAC8 was much higher in NPC tissues than in NPG tissues. The expression of PLAC8 was higher in all the cell lines than in the nasopharyngeal permanent epithelial cells. PLAC8 knockout resulted in significant decreases in cell proliferation, migration, and invasion; associated with lower protein levels of N-cadherin; and increased levels of E-cadherin. Overexpression of PLAC8 had the opposite effect. Furthermore, knockout of PLAC8 inactivated TGF-β/SMAD signaling pathway and suppressed the growth of NPC xenografts. PLAC8 may promote the carcinogenesis and EMT of NPC via the TGF-β/Smad pathway, which suggests that PLAC8 may be a potential biomarker for NPC.

Upregulation of circRNA_0000285 serves as a prognostic biomarker for nasopharyngeal carcinoma and is involved in radiosensitivity.

Despite significant medical advancement, nasopharyngeal carcinoma (NPC) remains one of the most difficult types of cancer to detect and treat. Circular RNA (circRNA) signatures may be used as prognostic and predictive factors for cancer. Previous studies indicated that the biological role of circular homeodomain interacting protein kinase 3 (HIPK3) has cancer type-specificity. The HIPK3 gene locus formats three circRNA isoforms: circRNA_100783, circRNA_0000285 and circRNA_100782. However, their roles in NPC remain unknown. In the present study, whether these circRNAs could be used as a biomarker for NPC diagnosis and predicting treatment response was investigated. Reverse transcription-quantitative polymerase chain reaction was performed to measure the levels of circRNA_100783, circRNA_0000285 and circRNA_100782 in NPC and adjacent tissues. In addition, the circRNA_0000285 levels were further confirmed in serum samples from patients with NPC and healthy controls. The results demonstrated that circRNA_0000285, but not circRNA_100782 and circRNA_100783, was significantly increased in NPC tissues and serum samples from patients with NPC, compared with adjacent tissues and serum samples from healthy controls, respectively. Furthermore, circRNA_0000285 expression was increased in patients with radioresistant NPC, compared with patients with radiosensitive NPC. Further analysis demonstrated that circRNA_0000285 was significantly associated with tumor size (P<0.001), differentiation (P=0.022), lymph node metastasis (P=0.035), distant metastasis (P=0.022) and Tumor-Node-Metastasis stage (P<0.001). Additionally, univariate and multivariate analyses indicated that circRNA_0000285 may be an independent prognostic factor for the outcome of patients with NPC. The present data indicated that circRNA_0000285 may be a novel biomarker for NPC and is involved in NPC radiosensitivity.

TIPE3 hypermethylation correlates with worse prognosis and promotes tumor progression in nasopharyngeal carcinoma

BackgroundIncreasing evidence recognizes that DNA methylation abnormalities play critical roles in cancer development. Our previous genome-wide methylation profile showed that tumor necrosis factor-alpha-induced protein 8 like 3 (TIPE3) was hypermethylated in nasopharyngeal carcinoma (NPC). However, the relationship between TIPE3 methylation and its mRNA expression, as well as its biological roles in NPC are unknown.MethodsBisulfite pyrosequencing and quantitative RT-PCR were performed to quantify the TIPE3 methylation and expression levels. Kaplan-Meier curves and Cox regression analysis were used to estimate the correlation between TIPE3 methylation levels and survival in two patient cohorts collected from two hospitals (n = 441). The MTT, colony formation, Transwell migration and invasion assays, and xenograft tumor growth and lung metastatic colonization models were used to identify the functions of TIPE3 on NPC cells.ResultsWe found that TIPE3 CpG island (CGI) was hypermethylated and its mRNA levels were downregulated in many cancers, including NPC. TIPE3 downregulation was associated with its CGI hypermethylation. Furthermore, NPC patients with high TIPE3 CGI methylation levels had poorer clinical outcomes than those with low methylation levels. The TIPE3 CGI methylation level was an independent prognostic factor. Moreover, restoring TIPE3 expression significantly inhibited NPC cell proliferation, migration and invasion in vitro, and suppressed tumor growth and lung metastatic colonization in vivo, while silencing TIPE3 acted in an opposite way.ConclusionsTIPE3 downregulation correlates with its CGI hypermethylation in several solid cancers. TIPE3 acts as a tumor suppressor in NPC, providing a further insight into NPC progression and representing a potential prognostic biomarker for NPC.

The sequence analysis of Epstein-Barr virus EBNA1 gene: could viral screening markers for nasopharyngeal carcinoma be identified?

Epstein-Barr virus (EBV) has been identified as a group 1 carcinogenic agent, particularly for nasopharyngeal carcinoma (NPC). The sequence diversity of EBV nuclear antigen 1 (EBNA1) reflects region-restricted polymorphisms, which may be associated with the development of certain malignancies. The aims of the present study were to evaluate EBV EBNA1 gene polymorphisms circulating in NPC, infectious mononucleosis, and isolates from patients with transplanted organs to determine if EBNA1 sequence specificities are useful as viral biomarkers for NPC. Forty biopsies of undifferentiated carcinoma of nasopharyngeal type (UCNT), 31 plasma samples from patients with mononucleosis syndrome, and 16 plasma samples from patients after renal transplantation were tested in this study. The EBNA1 gene was amplified by nested PCR. Further investigation included sequencing, phylogenetic, and statistical evaluations. Eighty-seven sequences were identified as one of the four EBNA1 subtypes, P-Ala, P-Thr, V-Val, and V-Ala, with further classification into ten subvariants. Of these, P-Thr-sv-1 and P-Thr-sv-3 have never been identified in Europe, while V-Val-sv-1 was newly discovered. Statistical analysis revealed significant differences in the distribution of EBNA1 P-Thr subvariants between the three groups of patients, with noticeable clustering of P-Thr-sv-5 in NPC isolates (p < 0.001). EBV EBNA1 showed no sequence specificity in primary infection. This research revealed a newly discovered EBNA1 subvariant. Importantly, EBNA1 P-Thr-sv-5 showed carcinoma-specific EBNA1 variability. Thus, identification of this subvariant should be considered as a viral screening marker for NPC or UCNT.

SOX2 recruits KLF4 to regulate nasopharyngeal carcinoma proliferation via PI3K/AKT signaling

AbstactSOX2 is a transcription factor that contributes to transcription modification and cancer, but the mechanism by which SOX2 regulates nasopharyngeal carcinoma cell proliferation is not well understood. Here, we identify a SOX2 signaling pathway that facilitates nasopharyngeal carcinoma, where it is upregulated. SOX2 expression was associated with nasopharyngeal carcinoma patient survival. SOX2 knockdown inhibited cell proliferation, colony formation, and tumorigenesis in an subcutaneous mouse xenograft model system. Six hundred and ninety-nine candidate SOX2 downstream dysregulated genes were identified in nasopharyngeal carcinoma cells through cDNA microarray analysis. SOX2 recruited the nuclear transcription factor KLF4 to bind to the PIK3CA promoter upregulate PIK3CA expression, acting to enhance PI3K/AKT signaling and tumorigenesis by upregulating PIK3CA expression. Besides, overexpressing activated AKT or PIK3CA rescued the growth inhibition of cells due to SOX2 knockdown. Together, our study suggest that SOX2 exhibits oncogenic properties and may be a reliable molecular biomarker in nasopharyngeal carcinoma. Targeting SOX2 might be a promising treatment strategy for nasopharyngeal carcinoma treatment.

MicroRNA‑122 acts as tumor suppressor by targeting TRIM29 and blocking the activity of PI3K/AKT signaling in nasopharyngeal carcinoma invitro.

Nasopharyngeal carcinoma (NPC) is endemic in the southern provinces of China and Southeast Asia. It has been reported that microRNA-122 (miR-122) and tripartite motif-containing protein 29 (TRIM29) serve important roles in many types of tumor. The present study aimed to evaluate the expression of miR-122 and TRIM29, and their clinical significance in NPC, and to examine the associated molecular mechanisms. It was observed that low expression of miR-122 and high expression of TRIM29 led to a low overall survival rate in patients with NPC, which was associated with tumor-node-metastasis (TNM) stage and distant metastasis of NPC. Low expression of miR-122 was correlated reciprocally with high expression of TRIM29 in NPC tissues, and the two were aggravated by radiation treatment in NPC cell lines. Through Cell Counting kit-8 and Transwell assays, miR-122 was demonstrated to be able to inhibit the proliferation, migration and invasion of NPC cells. Through reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analyses, the expression of metastasis-associated genes, including E-cadherin, metastatic tumor antigen 1, matrix metalloproteinase-2 and metalloproteinase inhibitor 2 were demonstrated to be regulated by miR-122 in NPC cells. Additionally, through a luciferase assay, RT-qPCR and western blot analysis, it was demonstrated that TRIM29 may be a direct target of miR-122. In addition, it was noted that miR-122 decreased the expression of phosphorylated (p) phosphatidylinositol 3-kinase (PI3K) and p-RAC-α serine/threonine-protein kinase (AKT). Collectively, the results of the present study demonstrated that miR-122 may exert its tumor suppressive role by targeting TRIM29 and inhibiting the activity of PI3K/AKT signaling. It was indicated that miR-122 and TRIM29 may be developed as biomarkers of NPC, and possible molecular targets for the prevention of metastasis in patients with NPC.

Prognostic values of hematological biomarkers in nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy

PurposeIn this study, we evaluated the prognostic values of hematological biomarkers in primary nasopharyngeal carcinoma (NPC) patients receiving definitive intensity-modulated radiotherapy (IMRT).MethodsThere were 427 NPC patients enrolled between January 2010 and March 2013 at Fudan University Shanghai Cancer Center. Pre-treatment absolute neutrophil count (ANC), platelet count (APC), lymphocyte count (ALC), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were collected as prognostic biomarkers. The Kaplan–Meier method and log-rank test were utilized to calculate progression-free survival (PFS) and overall survival (OS). The Cox proportional hazard models were applied to assess variables.ResultsANC, APC and ALC were declined, while NLR and PLR were elevated significantly after therapy (P < 0.001 each). On multivariate analysis, pre-treatment NLR ≥ 2.32 was associated with shortened OS (P = 0.048) and PFS (P = 0.008), whereas PLR ≥ 123.0 was related with inferior OS (P = 0.032), yet it was not correlated with PFS (P = 0.161).ConclusionsHigh pre-treatment NLR and PLR indicated poor survival in NPC patients treated with IMRT-based therapy. As easily accessible and economically feasible biomarkers, NLR and PLR can be applied into clinical practice, in combination with current TNM staging, to design a more personalized treatment in these patients.

Screening of nasopharyngeal carcinoma using plasma Epstein-Barr virus DNA for at-risk population

Nasopharyngeal carcinoma (NPC) is a prominent cancer in Southeast Asia. Decades of studies have shown that NPC is closely associated with infection of the human herpesvirus, Epstein-Barr virus (EBV). Quantitative real-time PCR-based technique was developed to detect circulating cell-free EBV DNA (cf-EBV DNA) as a biomarker for NPC in 1999 by a team led by Dr. Lo in Hong Kong (1).

P53R2 as a novel prognostic biomarker in nasopharyngeal carcinoma

Backgroundp53R2 is a target of p53 gene, which is essential for DNA repair, mitochondrial DNA synthesis, protection against oxidative stress, chromosomal instability, chronic inflammation and tumorigenesis. This study is aimed to investigate the expression of ribonucleotide reductase (RR) subunit p53R2 in nasopharyngeal carcinoma and its significance in the prognosis.MethodsThe expression levels of p53R2 in 201 patients with NPC were examined by immunohistochemical assay. The correlations of p53R2 expression and clinicopathological features of nasopharyngeal carcinoma patient were analysed by chi-square test. The Kaplan-Meier survival analysis and Cox multivariate regression model were used to analyze the prognostic significance of the patients with NPC.ResultsImmunohistochemical results showed that p53R2 was positively expressed in 92.5% (186/201) of nasopharyngeal carcinoma and the high expression rate was 38.3% (77/201). Further analysis observed that the negative correlation between expression of p53R2 and pT status had statistical significance (P < 0.05). Kaplan-Meier survival analysis found that the mean survival time of patients with high expression of p53R2 was 143.32 months, while the patients with low expression level of p53R2 was 121.63 months (P < 0.05). Cox regression analysis suggested that p53R2 protein expression could be used as an independent prognostic factor for nasopharyngeal carcinoma (P < 0.05).ConclusionsThis study drew a conclusion that p53R2 could be used as a prognostic biomarker indicative of the favorable outcome for patients with nasopharyngeal carcinoma.

Abnormally expressed microRNA as auxiliary biomarkers for nasopharyngeal carcinoma: A meta‑analysis

Aberrant expression of microRNA (miRNA) has been highlighted as a helpful indicator to aid in nasopharyngeal carcinoma (NPC) diagnosis. The present meta-analysis aimed to validate the efficacy of miRNA as potential biomarkers for NPC detection. Publication searches were conducted on the online PubMed and EMBASE databases from inception to June 2016. A bivariate meta-analysis was performed to generate the diagnostic parameters based on Meta-Disc 1.4 and Stata 12.0 programs. Sensitivity analysis and meta-regression tests were applied to trace heterogeneity sources among eligible studies. A total of six studies comprising 528 patients with NPC and 252 matched controls were enrolled. Results from the present meta-analysis demonstrated that miRNA testing achieved a pooled sensitivity of 0.78 [95% confidence interval (CI), 0.70-0.84] and specificity of 0.79 (95% CI, 0.73-0.84) in confirming NPC, corresponding to an area under the curve (AUC) value of 0.85. Additionally, the pooled diagnostic odds ratio was estimated to be 9.01 (95% CI, 5.62-14.44), along with a positive likelihood ratio of 2.81 (95% CI, 2.19-3.61) and negative likelihood ratio of 0.35 (95% CI, 0.28-0.44). Additionally, the stratified analyses revealed that paralleled testing of miRNA sustained a pooled accuracy superior compared with that of single miRNA testing (sensitivity, 0.88 vs. 0.70; specificity, 0.85 vs. 0.69; AUC, 0.95 vs. 0.75). Testing of miRNA harbors a moderate diagnostic efficacy and is acceptable as an auxiliary biomarker for NPC diagnosis.

Target-induced proximity ligation triggers recombinase polymerase amplification and transcription-mediated amplification to detect tumor-derived exosomes in nasopharyngeal carcinoma with high sensitivity

Tumor-derived exosomes (TEXs) are extracellular vesicles that are continuously released into the blood by tumor cells and carry specific surface markers of the original tumor cells. Substantial evidence has implicated TEXs as attractive diagnostic markers for cancer. However, the detection of TEXs in blood at an early tumor stage is challenging due to their very low concentration. Here, we established a method called PLA-RPA-TMA assay that allows TEXs to be detected with high sensitivity and specificity. Based on two proximity ligation assay (PLA) probes that recognize a biomarker on a TEX, we generated a unique surrogate DNA signal for the specific biomarker, which was synchronously amplified twice by recombinase polymerase amplification (RPA) coupled with transcription-mediated amplification (TMA), and then the products of the RPA-TMA reaction were quantitatively detected using a gold nanoparticle-based colorimetric assay. We established proof-of-concept evidence for this approach using TEXs from nasopharyngeal carcinoma (NPC) cells, with a detection limit of 102 particles/mL, and reported the measurement of plasma Epstein-Barr virus latent membrane protein 1 (LPM1)-positive (LMP1+, accuracy: 0.956) and epidermal growth factor receptor (EGFR)-positive (EGFR+, accuracy: 0.906) TEXs as potent early diagnostic biomarkers for NPC.

Promoter hypermethylation of SLIT2 is a risk factor and potential diagnostic biomarker for nasopharyngeal carcinoma

SLIT2 is a candidate tumor suppressor gene and recent studies have shown that SLIT2 expression is suppressed or reduced by hypermethylation in the promoter region in various cancers. The aim of this study was to investigate the association between SLIT2 promoter methylation and nasopharyngeal carcinoma (NPC) and its relative diagnostic ability for NPC. Bisulfite pyrosequencing technology was performed to measure methylation levels of the SLIT2 promoter in tissue and plasma samples from 61 NPC patients and 38 normal volunteers. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the diagnostic ability of SLIT2 methylation for diagnosing NPC. Our results showed that methylation levels of the SLIT2 promoter were significantly higher in NPC patients compared with individuals, both in tissue samples (P=2.57E−10) and plasma samples (plasma: P=3.86E−13). In addition, the frequency of SLIT2 promoter methylation markedly increased in the advanced stage (tissue: P=3.50E−05; plasma: P=1.14E−04) and advanced T classified (tissue: P=9.00E−06; plasma: P=3.80E−05), as well as in lymph node metastasis patients (tissue: P=1.82E−03; plasma: P=2.22E−03). In addition, the AUCs according to tissue and plasma samples were 0.846 and 0.866, respectively. When these two sample-types were combined, the AUC increased slightly to 0.874. Our study revealed that elevated SLIT2 promoter methylation contributed to the risk of NPC, as well as being involved in its progression and metastasis. Therefore, the methylated SLIT2 promoter could serve as a potential biomarker for diagnosing NPC.

MicroRNA profiling study reveals miR-150 in association with metastasis in nasopharyngeal carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that play a crucial role in pathogenesis of human cancers. Several miRNAs have been shown to involve in nasopharyngeal carcinoma (NPC) pathogenesis through alteration of gene networks. A global view of the miRNA expression profile of clinical specimens would be the best way to screen out the possible miRNA candidates that may be involved in disease pathogenesis. In this study, we investigated the expression profiles of miRNA in formalin-fixed paraffin-embedded tissues from patients with undifferentiated NPC versus non-NPC controls using a miRNA real-time PCR platform, which covered a total of 95 cancer-related miRNAs. Hierarchical cluster analysis revealed that NPC and non-NPC controls were clearly segregated. Promisingly, 10 miRNA candidates were differentially expressed. Among them, 9 miRNAs were significantly up-regulated of which miR-205 and miR-196a showed the most up-regulated in NPC with the highest incidence percentage of 94.1% and 88.2%, respectively, while the unique down-regulated miR-150 was further validated in patient sera. Finally, the in vitro gain-of-function and loss-of-function assays revealed that miR-150 can modulate the epithelial-mesenchymal-transition property in NPC/HK-1 cells and led to the cell motility and invasion. miR-150 may be a potential biomarker for NPC and plays a critical role in NPC tumourigenesis.

Analysis of Plasma Epstein–Barr Virus DNA to Screen for Nasopharyngeal Cancer

BackgroundCirculating cell-free Epstein–Barr virus (EBV) DNA is a biomarker for nasopharyngeal carcinoma. We conducted a prospective study to investigate whether EBV DNA in plasma samples would be useful to screen for early nasopharyngeal carcinoma in asymptomatic persons.MethodsWe analyzed EBV DNA in plasma specimens to screen participants who did not have symptoms of nasopharyngeal carcinoma. Participants with initially positive results were retested approximately 4 weeks later, and those with persistently positive EBV DNA in plasma underwent nasal endoscopic examination and magnetic resonance imaging (MRI).ResultsA total of 20,174 participants underwent screening. EBV DNA was detectable in plasma samples obtained from 1112 participants (5.5%), and 309 (1.5% of all participants and 27.8% of those who initially tested positive) had persistently positive results on the repeated sample. Among these 309 participants, 300 underwent endoscopic examination, and 275 underwent both endoscopic examination and MRI; of these participants, 34 had nasopharyngeal carcinoma. A significantly higher proportion of participants with nasopharyngeal carcinoma that was identified by screening had stage I or II disease than in a historical cohort (71% vs. 20%, P<0.001 by the chi-square test) and had superior 3-year progression-free survival (97% vs. 70%; hazard ratio, 0.10; 95% confidence interval, 0.05 to 0.18). Nine participants declined to undergo further testing, and 1 of them presented with advanced nasopharyngeal carcinoma 32 months after enrollment. Nasopharyngeal carcinoma developed in only 1 participant with negative EBV DNA in plasma samples within 1 year after testing. The sensitivity and specificity of EBV DNA in plasma samples in screening for nasopharyngeal carcinoma were 97.1% and 98.6%, respectively.ConclusionsAnalysis of EBV DNA in plasma samples was useful in screening for early asymptomatic nasopharyngeal carcinoma. Nasopharyngeal carcinoma was detected significantly earlier and outcomes were better in participants who were identified by screening than in those in a historical cohort. (Funded by the Kadoorie Charitable Foundation and the Research Grants Council of the Hong Kong government; ClinicalTrials.gov number, NCT02063399.)