As a distinct type of head and neck cancer, non-keratinizing nasopharyngeal carcinoma (NPC) is closely associated with EBV infection and massive lymphoid infiltration. The unique histological features suggest that local inflammation plays an important role in NPC tumourigenesis. We comprehensively characterized NF-κB signalling, a key inflammatory pathway which might contribute to the tumourigenesis of this EBV-associated cancer. By EMSA, western blotting, and immunohistochemical staining, constitutive activation of distinct NF-κB complexes, either p50/p50/Bcl3 or p50/RelB, was found in almost all EBV-positive NPC tumours. siRNA or chemical inhibition of NF-κB signalling significantly inhibited the growth of EBV-positive NPC cells C666-1. Gene expression profiling identified a number of NF-κB target genes involved in cell proliferation, apoptosis, immune response, and transcription. We further confirmed that p50 signals modulate the expression of multiple oncogenes (MYB, BCL2), chemokines, and chemokine receptors (CXCL9, CXCL10, CX3CL1, and CCL20). The findings support a crucial role of these constitutively activated NF-κB signals in NPC tumourigenesis and local inflammation. In addition to expression of the viral oncoprotein LMP1, genetic alteration of several NF-κB regulators (eg TRAF3, TRAF2, NFKBIA, A20) also contributes to the aberrant NF-κB activation in EBV-associated NPC. Except for LMP1-expressing C15 cells, all NPC tumour lines harbour at least one of these genetic alterations. Importantly, missense mutations of TRAF3, TRAF2, and A20 were also detected in 3/33 (9.1%) primary tumours. Taken together with the reported LTBR amplification in 7.3% of primary NPCs, genetic alterations in NF-κB pathways occurred in at least 16% of cases of this cancer. The findings indicate that distinct NF-κB signals are constitutively activated in EBV-positive NPC cells by either multiple genetic changes or EBV latent genes.

Purpose: Nasopharyngeal cancer (NPC) is a common cancer in Hong Kong, and relapse can occur frequently. Using protein chip profiling analysis, we aimed to identify serum biomarkers that were useful in the diagnosis of relapse in NPC.Experimental Design: Profiling analysis was performed on 704 sera collected from 42 NPC patients, 39 lung cancer patients, 30 patients with the benign metabolic disorder thyrotoxicosis (TX), and 35 normal individuals (NM). Protein profile in each NPC patient during clinical follow up was correlated with the relapse status.Results: Profiling analysis identified two biomarkers with molecular masses of 11.6 and 11.8 kDa, which were significantly elevated in 22 of 31 (71%) and 21 of 31 (68%) NPC patients, respectively, at the time of relapse (RP) as compared with 11 patients in complete remission (CR; RP versus CR, P ‫؍‬ 0.009), 30 TX (RP versus TX, P < 0.001), or 35 NM (RP versus NM, P < 0.001). The markers were also elevated in 16 of 39 (41%) lung cancer patients at initial diagnosis. By tryptic digestion, followed by tandem mass spectrometry fragmentation, the markers were identified as two isoforms of serum amyloid A (SAA) protein. Monitoring the patients longitudinally for SAA level both by protein chip and immunoassay showed a dramatic SAA increase, which correlated with relapse and a drastic fall correlated with response to salvage chemotherapy. Serum SAA findings were compared with those of serum Epstein-Barr virus DNA in three relapsed patients showing a similar correlation with relapse and chemo-response.Conclusions: SAA could be a useful biomarker to monitor relapse of NPC.

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Background: A new strain of coronavirus (CoV) has caused an outbreak of severe acute respiratory syndrome (SARS), with 8098 individuals being infected and 774 deaths worldwide. We carried out protein chip array profiling analysis in an attempt to identify biomarkers that might be useful in monitoring the clinical course of SARS patients. Methods: We performed surface-enhanced laser desorption ionization time-of-flight mass spectrometry on 89 sera collected from 28 SARS patients, 72 sera from 51 control patients with various viral or bacterial infections, and 10 sera from apparently healthy individuals. Results: Nine significantly increased and three significantly decreased serum biomarkers were discovered in the SARS patients compared with the controls. Among these biomarkers, one (11 695 Da) was identified to be serum amyloid A (SAA) protein by peptide mapping

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.