ABSTRACT
In this study, we aimed to use the combined detection of multiple antibodies against Epstein-Barr virus (EBV) antigens to develop a model for screening and diagnosis of nasopharyngeal carcinoma (NPC). Samples of 300 nasopharyngeal carcinoma patients and 494 controls, including 294 healthy subjects (HC), 99 non-nasopharyngeal carcinoma cancer patients (NNPC), and 101 patients with benign nasopharyngeal lesions (BNL), were incubated with the EUROLINE Anti-EBV Profile 2, and band intensities were used to establish a risk prediction model. The nasopharyngeal carcinoma risk probability analysis based on the panel of VCAgp125 IgA, EBNA-1 IgA, EA-D IgA, EBNA-1 IgG, EAD IgG, and VCAp19 IgG displayed the best performance. When using 26.1% as the cutoff point in ROC analysis, the AUC value and sensitivity/specificity were 0.951 and 90.7%/86.2%, respectively, in nasopharyngeal carcinoma and all controls. In nasopharyngeal carcinoma and controls without the non-nasopharyngeal carcinoma and BNL groups, the AUC value and sensitivity/specificity were 0.957 and 90.7%/88.1%, respectively. The diagnostic specificity and sensitivity of the EUROLINE Anti-EBV Profile 2 assay for both nasopharyngeal carcinoma and early-stage nasopharyngeal carcinoma were higher than that of mono-antibody detection by immune-enzymatic assay and real-time PCR (EBV DNA). In the VCA-IgA-negative group, 82.6% of nasopharyngeal carcinoma patients showed high probability for nasopharyngeal carcinoma, and the negative predictive value was 97.1%. In the VCA-IgA-positive group, 73.3% of healthy subjects showed low probability. The positive predictive value reached 98.2% in this group. The nasopharyngeal carcinoma risk probability value determined by the EUROLINE Anti-EBV Profile 2 might be a suitable tool for nasopharyngeal carcinoma screening. Cancer Prev Res; 10(9); 542-50. ©2017 AACR.
Subject(s)
Antigens, Viral/immunology , Carcinoma/diagnosis , Cell-Free Nucleic Acids/isolation & purification , DNA, Viral/isolation & purification , Early Detection of Cancer/methods , Epstein-Barr Virus Nuclear Antigens/immunology , Herpesvirus 4, Human/immunology , Nasopharyngeal Neoplasms/diagnosis , Adult , Carcinoma/virology , Cell-Free Nucleic Acids/blood , China/epidemiology , DNA, Viral/blood , Enzyme-Linked Immunosorbent Assay , Female , Herpesvirus 4, Human/genetics , Humans , Male , Mass Screening/methods , Middle Aged , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/virology , Predictive Value of Tests , ROC Curve , Real-Time Polymerase Chain Reaction , Risk Assessment , Risk Factors , Serologic Tests/methodsABSTRACT
OBJECTIVES: This study was designed to establish an ELISA method, as well as the cut-off value, for IgA against Epstein-Barr virus (EBV) viral capsid antigen (VCA), as a screening assay for nasopharyngeal carcinoma (NPC) in southern China. In addition, the correlation between relative optical density (rOD) values from ELISA and titers from the immunoenzymatic assay (IEA) was also evaluated. METHODS: Two hundred and fifty-eight NPC cases, 33 non-NPC head and neck cancer patients, and 1156 healthy controls were recruited for this study. VCA-IgA and early antigen (EA)-IgA were measured by ELISA kits and IEA in parallel. RESULTS: The total precision of the VCA-IgA ELISA achieved a level of <13.0% coefficient of variation. An rOD value of 1.60 for the VCA-IgA ELISA was determined as the cut-off point for southern China, and the sensitivity and specificity for NPC diagnosis when using this cut-off value were 93.0% and 92.4%, respectively. The area under the receiver operating characteristic curve (ROC-AUC) value was 0.969. The correlation coefficient between titers and rOD values was 0.957. rOD values were correlated with NPC overall stage and lymph node involvement. CONCLUSIONS: The cut-off level established in our study could be used to facilitate more accurate diagnosis of NPC in southern China. The rOD value might be an index for NPC prognosis, since it shows a good correlation with the titer from IEA.
Subject(s)
Antibodies, Viral/immunology , Antigens, Viral/immunology , Capsid Proteins/immunology , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human/immunology , Immunoglobulin A/immunology , Nasopharyngeal Neoplasms/diagnosis , Nasopharyngeal Neoplasms/etiology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , Carcinoma , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin A/blood , Male , Middle Aged , Nasopharyngeal Carcinoma , Neoplasm Staging , ROC Curve , Reagent Kits, Diagnostic , Reference Values , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
Retinoic acid-inducible protein I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are cytosolic viral RNA sensors that induce type I interferon production (IFN). In this study, we found that MDA5 undergoes inducible SUMOylation by small ubiquitin-like modifier-1 (SUMO-1) in response to polyI:C stimulation. Enhanced SUMOylation of MDA5 by exogenously expressed SUMO-conjugating enzyme Ubc9 correlated with upregulation of IFN expression and repressed virus replication. Conversely, overexpression of a SUMOylation-deficient mutant of Ubc9 or knockdown of endogenous Ubc9 reduced IFN production. Furthermore, we showed that PIAS2ß, a SUMOylation E3 ligase, could specifically interact with and enhance the SUMOylation of MDA5. Consequently, PIAS2ß knockdown reduced the SUMOylation of MDA5 and the IFN production. Collectively, these findings suggest that SUMO-1 modification of MDA5 possibly via PIAS2ß may play a role in the MDA5-mediated IFN response to viral infections.
Subject(s)
DEAD-box RNA Helicases/metabolism , Interferon Type I/metabolism , Protein Inhibitors of Activated STAT/metabolism , Signal Transduction , Sumoylation , Up-Regulation , Cell Line , DEAD-box RNA Helicases/chemistry , Gene Knockdown Techniques , Humans , Interferon-Induced Helicase, IFIH1 , Poly I-C/metabolism , Protein Binding , UbiquitinationABSTRACT
Retinoic acid-inducible gene-I (RIG-I) functions as an intracellular pattern recognition receptor (PRR) that recognizes the 5'-triphosphate moiety of single-stranded RNA viruses to initiate the innate immune response. Previous studies have shown that Lys63-linked ubiquitylation is required for RIG-I activation and the downstream anti-viral type I interferon (IFN-I) induction. Herein we reported that, RIG-I was also modified by small ubiquitin-like modifier-1 (SUMO-1). Functional analysis showed that RIG-I SUMOylation enhanced IFN-I production through increased ubiquitylation and the interaction with its downstream adaptor molecule Cardif. Our results therefore suggested that SUMOylation might serve as an additional regulatory tier for RIG-I activation and IFN-I signaling.
