Novel therapy for nasopharyngeal carcinoma--where are we

Analysis of the clinical efficacy and safety of anti-PD-1 immune checkpoint inhibitors in locally advanced nasopharyngeal cancer

OBJECTIVE

To analyze the efficacy and adverse effects of anti-PD-1 immune checkpoint inhibitors aimed at nasopharyngeal carcinoma (NPC).

METHODS

During the first stage of the study, using 40 patients with stage III/IVa NPC treated with anti-PD-1 immune checkpoint inhibitors in combination with chemoradiotherapy as a first-line treatment (observation group) and 70 patients with NPC treated with chemoradiotherapy alone (control group). In the second stage of the study, 88 patients with NPC treated with immune checkpoint inhibitors were grouped according to the number of lines of immunotherapy, the number of times, and the types of application.

RESULTS

Observation of the short-term effects in the first stage indicated that the objective response rate (ORR) of the observation group and the control group against primary foci of NPC was 75.0% versus 40.0%; the mortality rate of the observation group was much lower than that of the control group. The overall first-line treatment evaluation of the observation vs. control groups were as follows: ORR (67.5% vs. 38.6%); median PFS (17.52 vs. 17.21 months); and median OS (18.68 vs. 18.14 months), respectively (p < 0.05). The second stage of the study had an ORR of 53.4%, and the efficacy of immunotherapy was related to staging, timing, and frequency.

CONCLUSION

Anti-PD-1 immune checkpoint inhibitors combined with chemoradiotherapy as the first-line treatment for nasopharyngeal carcinoma may improve patient outcomes significantly. Timing, frequency, and the type of immunotherapy exerted an effect on the efficacy of immunotherapy. Adverse effects that occurred during treatment were tolerable and controllable.

Study on the value of Inhibin B in the diagnosis of nasopharyngeal carcinoma and its correlation with traditional Chinese medicine syndromes: An observational study

To investigate the expression of Inhibin B between various clinical stages, Chinese medicine dialectic typing, and in nasopharyngeal carcinoma (NPC) tissues and serum, and to evaluate the potential of Inhibin B as a new biomarker for NPC. Paraffin specimens of pathologically confirmed NPC tissues and paracancerous tissues were retrospectively collected, and the expression of Inhibin α (INHA) and Inhibin βB (INHBB) was detected by SP method, and their relationship with clinicopathological indexes was analyzed; in addition, patients with NPC who had received radiotherapy were included as the study subjects, and Epstein-Barr virus DNA (EBV-DNA), INHA, and INHBB in patients were detected by using the fluorescence quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and chemiluminescent immuno-sandwiching method, respectively. EBV-DNA, EBV-viral capsid antigen-immunoglobulin A (VCA IgA), INHA, and INHBB were detected in the patients, respectively, and their relationships with traditional Chinese medicine (TCM) patterns were also analyzed. The expression of INHA and INHBB in NPC tissues was lower than that in paracancerous tissues, and the expression of INHA in NPC patients was correlated with lymphatic metastasis, clinical staging, and TCM staging; the levels of EBV-DNA and VCA IgA were higher than that of healthy populations in NPC patients and were higher than that of patients with stage III + IV than that of patients with stage I + II, and the levels of INHA and INHBB were lower than those of healthy populations and were lower than those of patients with stage III + IV than that of patients with stage I + II. The levels of INHA and INHBB in nasopharyngeal cancer patients were lower than those in healthy people, and the levels in stage III + IV patients were lower than those in stage I + II patients. The levels of EBV-DNA and VCA IgA in nasopharyngeal cancer patients were correlated with the Chinese medicine patterns, and had different patterns. The expression of Inhibin B may be related to the progression of NPC, and it has certain typing significance for different TCM syndromes of NPC, which is helpful for TCM typing diagnosis.

AURKA, as a potential prognostic biomarker, regulates autophagy and immune infiltration in nasopharyngeal carcinoma

BACKGROUND

Dysfunction of Aurora A (AURKA) plays crucial role in tumorigenesis and development of many types of cancer. However, the role of AURKA in nasopharyngeal carcinoma (NPC) has not been investigated yet.

MATERIALS AND METHODS

Two independent NPC cohorts (GSE61218 and GSE102349) were enrolled from public database to investigate the expression level of AURKA between NPC and nasopharyngitis samples, the association of AURKA expression level with prognosis in NPC, and the potential mechanism of AURKA in NPC by using bioinformatics analyses. The expression level of AURKA protein in 62 paired NPC and nasopharyngitis tissues was evaluated by immunohistochemistry (IHC). Two NPC cell lines (SUNE-1 and CNE-2) were enrolled and the expression levels of AURKA in the NPC cells were inhibited by RNA interference. The expression levels of mRNAs were tested by qPCR and western-blotting. CCK-8 assay was applied to measure the cell growth. Cell migration was measured by using wound healing assays.

RESULTS

AURKA was highly expressed in NPC samples compared to nasopharyngitis samples in GSE61218, which was confirmed by IHC. High expression of AURKA was associated with worse prognosis in GSE102349. Notably, silencing of AURKA was associated with significantly decreased cell growth and migration in NPC. Moreover, we found that the differentially expressed genes between high and low AURKA expression groups in GSE102349 were majorly enriched in both autophagy-related and immune-related pathways. Additionally, the expression level of AURKA was associated with the expression levels of autophagy-related genes and the infiltration of immune cells.

CONCLUSION

AURKA overexpressed in NPC, which was associated with poor prognosis. Silencing of AURKA inhibited the proliferation and migration of NPC cells. Besides, AURKA might participate in the regulation of both autophagy and immunity in NPC.

Enhanced motility and interaction of nasopharyngeal carcinoma with epithelial cells in confined microwells

The three-dimensional (3D) structure of the extracellular matrix and cell-cell contacts are two important cues to altering cell migration behavior and the tumor formation process. In this work, we designed and fabricated microwell arrays with a grating-patterned bottom in polydimethylsiloxane platforms to systematically study the effects of confinement, changes in topography, and cell-cell contacts on the migration behavior of nasopharyngeal carcinoma (NPC43) and immortalized nasopharyngeal epithelial (NP460) cells by time-lapse imaging. When two types of cells were co-cultured in microwells, the migration speed and spreading area of NPC43 cells were significantly increased, which might be attributed to the heterotypic cell-cell contacts with NP460 cells. On a flat surface, NPC43 cells could not form clusters due to the frequent interruptions by the active movements of NP460 cells. However, in 3D microwell arrays, clusters of NPC43 cells formed on the bottom surface while the majority of NP460 cells migrated onto the sidewalls. These cell clusters could be further processed to form spheroids for drug screening. These results also revealed that the 3D microenvironments and cell-cell contacts could have significant implications for NPC cell migration and initiation of tumor formation, which will provide insight for NPC progression and dissemination.

A Microfluidic Platform Revealing Interactions between Leukocytes and Cancer Cells on Topographic Micropatterns

Immunoassay for detailed analysis of immune-cancer intercellular interactions can achieve more promising diagnosis and treatment strategies for cancers including nasopharyngeal cancer (NPC). In this study, we report a microfluidic live-cell immunoassay integrated with a microtopographic environment to meet the rising demand for monitoring intercellular interactions in different tumor microenvironments. The developed assay allows: (1) coculture of immune cells and cancer cells on tunable (flat or micrograting) substrates, (2) simultaneous detection of different cytokines in a wide working range of 5-5000 pg/mL, and (3) investigation of migration behaviors of mono- and co-cultured cells on flat/grating platforms for revealing the topography-induced intercellular and cytokine responses. Cytokine monitoring was achieved on-chip by implementing a sensitive and selective microbead-based sandwich assay with an antibody on microbeads, target cytokines, and the matching fluorescent-conjugated detection antibody in an array of active peristaltic mixer-assisted cytokine detection microchambers. Moreover, this immunoassay requires a low sample volume down to 0.5 μL and short assay time (30 min) for on-chip cytokine quantifications. We validated the biocompatibility of the co-culture strategy between immune cells and NPC cells and compared the different immunological states of undifferentiated THP-1 monocytic cells or PMA-differentiated THP-1 macrophages co-culturing with NP460 and NPC43 on topographical and planar substrates, respectively. Hence, the integrated microfluidic platform provides an efficient, broad-range and precise on-chip cytokine detection approach, eliminates the manual sampling procedures and allows on-chip continuous cytokine monitoring without perturbing intercellular microenvironments on different topographical ECM substrates, which has the potential of providing clinical significance in early immune diagnosis, personalized immunotherapy, and precision medicine.

A Phase II Study of Nivolumab plus Gemcitabine in Patients with Recurrent or Metastatic Nasopharyngeal Carcinoma (KCSG HN17-11)

PURPOSE

Although programmed death 1/programmed death ligand 1 (PD-1/PD-L1) inhibitors are promising agents for recurrent or metastatic nasopharyngeal carcinoma (NPC), PD-1/PD-L1 inhibitor monotherapy has shown modest efficacy. This study evaluated the efficacy and safety of nivolumab plus gemcitabine in patients with NPC who failed prior platinum-based chemotherapy.

PATIENTS AND METHODS

This is a phase II, multicenter, open-label, single-arm study. Patients with recurrent or metastatic NPC received nivolumab 3 mg/kg and gemcitabine 1,250 mg/m2 every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS). The secondary endpoints included objective response rate (ORR), overall survival (OS), and safety. To identify potential biomarkers, whole-exome sequencing, whole-transcriptome sequencing, and immune phenotype analysis based on Lunit SCOPE IO, an artificial intelligence-powered spatial tumor-infiltrating lymphocyte analyzer, were performed.

RESULTS

Thirty-six patients were enrolled between June 2018 and June 2019. The ORR was 36.1% and disease control rate was 97.2%. With median follow-up of 22.0 months, median PFS was 13.8 months [95% confidence interval (CI), 8.6-16.8 months]. Median OS was not reached, and OS rate at 6 months was 97.0% (95% CI, 80.4%-99.6%). The grade ≥3 treatment-related adverse events were hypertension (2.8%) and anemia (2.8%). In multivariate analysis of mutation of chromatin modifier gene, tumor mutational burden (≥ 2.1 mut/Mb), and somatic copy-number alteration (SCNA) level, the group with high SCNA (> 3 points; HR, 7.0; 95% CI, 1.3-37.9; P = 0.02) had independently associated with poor PFS. Immune phenotype analysis showed that tumors with high proportion of immune-excluded immune phenotype was significantly correlated with poor PFS (HR, 4.4; 95% CI, 1.2-16.2; P = 0.018).

CONCLUSIONS

Nivolumab plus gemcitabine showed promising efficacy with favorable toxicity profiles in patients with advanced NPC in whom platinum-based combination chemotherapy failed.

Noninvasive Diagnosis of Nasopharyngeal Carcinoma Based on Phenotypic Profiling of Viral and Tumor Markers on Plasma Extracellular Vesicles

Nasopharyngeal carcinoma (NPC) is a malignant tumor commonly associated with Epstein-Barr virus (EBV) infection, and its early diagnosis as well as its differentiation from nasopharyngitis (NPG) remains challenging due to the insufficient sensitivity of routine screening methods in clinical practice. To date, circulating extracellular vesicles (EVs, 40-1000 nm) have shown appealing potential in liquid biopsy for cancer diagnosis and prognosis. Herein, nanoflow cytometry (nFCM) capable of single EV analysis was applied to examine the expression of surface proteins with very low copy numbers on individual EVs as small as 40 nm. The particle concentrations of five EV subsets exposing EBV-encoded latent membrane proteins (LMP1 and LMP2A) and tumor markers (PD-L1, EGFR, and EpCAM) in plasma were determined rapidly via single-particle enumeration. We identified a five-marker panel named EV^SUM5 (an unweighted sum of the concentration of the five individual EV subsets) that significantly surpassed the traditional VCA-IgA assay in discriminating NPC patients from both healthy donors and NPG patients with accuracies of 96.3 and 83.1%, respectively. Moreover, EV^SUM2 (an unweighted sum of virus-specific LMP1- and LMP2A-positive EVs) could achieve the diagnosis of NPG with an accuracy of 82.6%. Collectively, the work presented a rapid, reliable, and noninvasive method as well as two diagnostic markers to help more accurately differentiate NPC from NPG patients and healthy donors in clinical practice.

Long noncoding RNA LINC00930 promotes PFKFB3-mediated tumor glycolysis and cell proliferation in nasopharyngeal carcinoma

Background

Metabolic reprogramming is a hallmark of cancer. However, the roles of long noncoding RNAs (lncRNAs) in cancer metabolism, especially glucose metabolism remain largely unknown.

Results

In this study, we identified and functionally characterized a novel metabolism-related lncRNA, LINC00930, which was upregulated and associated with tumorigenesis, lymphatic invasion, metastasis, and poor prognosis in nasopharyngeal carcinoma (NPC). Functionally, LINC00930 was required for increased glycolysis activity and cell proliferation in multiple NPC models in vitro and in vivo. Mechanistically, LINC00930 served as a scaffold to recruit the RBBP5 and GCN5 complex to the PFKFB3 promoter and increased H3K4 trimethylation and H3K9 acetylation levels in the PFKFB3 promoter region, which epigenetically transactivating PFKFB3, and thus promoting glycolytic flux and cell cycle progression. Clinically, targeting LINC00930 and PFKFB3 in combination with radiotherapy induced tumor regression.

Conclusions

Collectively, LINC00930 is mechanistically, functionally and clinically oncogenic in NPC. Targeting LINC00930 and its pathway may be meaningful for treating patients with NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02282-9.

Nasopharyngeal Carcinoma: Clinical Achievements and Considerations Among Treatment Options

Nasopharyngeal carcinoma (NPC) is a severe malignancy arising from the nasopharyngeal epithelium and is southern China's third most common cancer. With the advancement of treatment methods, early-stage NPC patients usually have a better prognosis and more prolonged survival period than those with other malignant tumors. Most treatment failures are due to distant metastasis or a locally advanced stage of NPC in the initial diagnosis. In addition, approximately 10% of patients develop local recurrence, and 10%-20% of patients experience distant metastasis after treatment. These patients have a poor prognosis, with a median survival of only approximately 10-15 months. In the rapid development of treatment options, the efficacy and safety of some treatments have been validated and approved for first-line treatment, while those of other treatments remain unclear. The present study aims to provide a comprehensive overview of recent advances in NPC treatment and explain the various therapeutic possibilities in treating locally advanced, recurrent, and metastatic NPC patients.

The clinical prognostic value of PD-L1 after concurrent chemoradiotherapy in Chinese nasopharyngeal carcinoma patients

Background

Although immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of nasopharyngeal carcinoma (NPC), it is still the second- or third-line treatment after the failure of radiotherapy or chemotherapy. In this study, we aimed to investigate the impact of concurrent chemoradiotherapy (CCRT) on programmed death-ligand 1 (PD-L1) protein expression in NPC patients.

Methods

We enrolled 24 NPC patients treated with intensity-modulated radiation therapy (IMRT) combined with cisplatin CCRT. PD-L1 expression was evaluated by immunohistochemistry, and next-generation sequencing and annotation were performed to determine the genetic alteration after CCRT.

Results

Our results showed that patients with a high expression of PD-L1 were more inclined to a complete response (CR) to chemoradiotherapy, as opposed to a partial response (PR) (P<0.05). Moreover, the mean values of the tumor mutation burden (TMB) and the tumor neoantigen burden (TNB) in the PD-L1 positive group were significantly lower than that of the PD-L1 negative group in our cohort.

Conclusions

We confirmed that the TMB and TNB may be potential clinical indicators in NPC treatment, and PD-L1 expression may be a clinical biomarker in NPC chemoradiotherapy. Finally, through next-generation sequencing and annotation, we found that the most frequent driver gene mutations in NPC were TET2, TP53, and MAPK.

Identifying distinct risks of treatment failure in nasopharyngeal carcinoma: A study based on the dynamic changes in peripheral blood lymphocytes, monocytes, N classification, and plasma Epstein-Barr virus DNA

BACKGROUND

To evaluate the prognostic value of the dynamic change in absolute lymphocyte counts (ALCs) and absolute monocyte counts (AMCs) and identify patients with N stage and plasma Epstein-Barr virus (EBV) DNA levels in nasopharyngeal carcinoma (NPC) who are at risk of treatment failure.

METHODS

A total of 1124 eligible patients with Stage II-IVb NPC treated with concurrent chemoradiotherapy (CCRT) were enrolled. Percentage changes in the ALC (ΔALC%) and AMC (ΔAMC%) were calculated.

RESULTS

Patients with high ΔALC% were correlated with poorer 5-year overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) rates than those with low ΔALC%. Likewise, high ΔAMC% was significantly associated with worse outcome than low ΔAMC% (OS, p = 0.001; PFS, p = 0.001; DMFS, p = 0.034). Multivariate analyses revealed that ΔALC% (p = 0.046), ΔAMC% (p = 0.019), and EBV DNA level (p < 0.001) were independent prognostic factors for OS. With respect to PFS, ΔALC% (p = 0.036), ΔAMC% (p = 0.011), N classification (p = 0.016), and EBV DNA level (p < 0.001) were also independent prognosticators. Based on the aforementioned independent risk factors (ΔALC% ≥ 83.33%, ΔAMC% ≥ 40.00%, Stage N2-3, EBV DNA ≥ 4000 copies/ml), patients were divided into three different risk groups (low-risk group [with <1 risk factor], intermediate risk group [with 1-3 risk factors], and high-risk group [with 4 risk factors]) that correlated with disparate risks of death (p < 0.001), disease progression (p < 0.001), and distant metastasis (p < 0.001).

CONCLUSIONS

High ΔALC% and ΔAMC% were correlated with poor prognosis in patients with NPC. Risk stratification based on ΔALC%, ΔAMC%, N classification, and plasma EBV DNA levels could provide potential utility for risk-adapted therapeutic strategies for NPC.

Human papillomavirus E6 and E7: What remains?

Decades of research on the human papillomavirus oncogenes, E6 and E7, have given us huge amounts of data on their expression, functions and structures. We know much about the very many cellular proteins and pathways that they influence in one way or another. However, much of this information is quite discrete, referring to one activity examined under one condition. It is now time to join the dots to try to understand a larger picture: how, where and when do all these interactions occur... and why? Examining these questions will also show how many of the yet obscure cellular processes work together for cellular and tissue homeostasis in health and disease.

Biopsy of distant metastasis is not a significant prognostic factor for synchronous metastatic nasopharyngeal carcinoma: a propensity score-matched analysis from the Surveillance Epidemiology and End-Results Registry

Introduction: Biopsy is essential for some patients with suspected distant metastasis, so we aim to figure out whether biopsy of distant metastasis is associated with impaired survival in NPC.

Methods: A total of 743 synchronous metastatic NPC patients from 2004 to 2016 were analyzed from the population-based Surveillance, Epidemiology, and End Results program. Propensity score matching was used to control confounders and create a well-balanced cohort. Five-year survival rate estimates and Kaplan-Meier survival curves were calculated. Cox proportional hazard ratios (HRs) were used to identify independent prognostic factors for survival.

Results: Of 743 eligible patients, 194 (26.11%) underwent biopsy of distant metastasis. After control for demographic and clinicopathologic characteristics, patients with biopsy of distant metastasis achieved comparable 5-year overall survival (OS) (20.3% vs 24.7%; P = 0.41) and 5-year cancer specific survival (CSS) (31.0% vs 33.6%; P = 0.35) with patients without biopsies. Multivariate analysis further confirmed that biopsy of distant metastasis was not associated with impaired OS (HR = 1.03, 95% CI = 0.84-1.25; P = 0.80) or CSS (HR = 1.07, 95% CI = 0.86-1.34; P = 0.54).

Conclusions: Biopsy of distant metastasis was not associated with impaired survival outcomes for synchronous metastatic NPC patients. Biopsy of distant metastasis could be another diagnosed choice for patients with suspected distant metastasis.

Foxq1 promotes metastasis of nasopharyngeal carcinoma by inducing vasculogenic mimicry via the EGFR signaling pathway

In nasopharyngeal carcinoma (NPC), the treatment of tumor metastasis and recurrence is challenging and is associated with poor clinical efficacy. Vasculogenic mimicry (VM) is a new blood-supply model of malignant tumor that is closely related to tumors’ distant metastasis. Our previous study demonstrated that miR-124 could target Foxq1 to inhibit NPC metastasis. Whether Foxq1 affects metastasis through vasculogenic mimicry is worth consideration. In this study, we show that VM formation positively correlates with the expression of Foxq1, and EGFR, and the TNM stage in 114 NPC patient samples. Meanwhile, we show that VM-positive NPC patients have a poor prognosis. Furthermore, using in vitro and vivo approaches, we confirm that Foxq1 has a significant effect on NPC metastasis through promoting VM formation, which could be effectively inhibited by EGFR inhibitors (Nimotuzumab or Erlotinib). Also a synergistic efficacy of anti-EGFR and anti-VEGF drugs has been found in NPC inhibition. Mechanistically, the luciferase reporter gene and CHIP assays show that Foxq1 directly binds to the EGFR promoter region and regulates EGFR transcription. In conclusion, our results show that Foxq1 is regulated by miR-124 and that it promotes NPC metastasis by inducing VM via the EGFR signaling pathway. Overall, these results provide a new theoretical support and a novel target selection for anti-VM therapy in the treatment of nasopharyngeal carcinoma.

Migration of immortalized nasopharyngeal epithelia and carcinoma cells through porous membrane in 3D platforms

In the present study, 3D biomimetic platforms were fabricated with guiding grating to mimic extracellular matrix topography, porous membrane to resemble the epithelial porous interface and trenches below to represent blood vessels as an in vitro tissue microenvironment. Fabrication technologies were developed to integrate the transparent biocompatible polydimethylsiloxane platforms with preciously controlled dimensions. Cell migration behaviors of an immortalized nasopharyngeal epithelial cell line (NP460) and a nasopharyngeal carcinoma cell line (NPC43) were studied on the 2D and 3D platforms. The NP460 and NPC43 cells traversing through the porous membrane and migrating in the trenches below were studied by time-lapse imaging. Before traversing through the pores, NP460 and NPC43 cells migrated around the pores but NPC43 cells had a lower migration speed with less lamellipodia spreading. After traversing to trenches below, NPC43 cells moved faster with an alternated elongated morphology (mesenchymal migration mode) and round morphology (amoeboid migration mode) compared with only mesenchymal migration mode for NP460 cells. The cell traversing probability through porous membrane on platforms with 30 μm wide trenches below was found to be the highest when the guiding grating was perpendicular to the trenches below and the lowest when the guiding grating was parallel to the trenches below. The present study shows important information on cell migration in complex 3D microenvironment with various dimensions and could provide insight for pathology and treatment of nasopharyngeal carcinoma.

Induction chemotherapy plus nimotuzumab followed by concurrent chemoradiotherapy for advanced nasopharyngeal carcinoma

INTRODUCTION

This study investigated the best mode for the application of nimotuzumab (Nimo) in combination with chemoradiotherapy to treat nasopharyngeal carcinoma (NPC).

MATERIAL AND METHODS

Data were prospectively collected from 168 patients with NPC from September 2009 to February 2014. One hundred twelve patients received 2-3 cycles of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT), and 56 patients with well-matched propensity scores received IC + CCRT + Nimo. Patients were divided into 3 subgroups according to the application schedule of Nimo: group A, IC + CCRT; group B: IC (combined with Nimo) + CCRT; and group C: IC + CCRT (combined with Nimo). The 5-year overall survival (OS) and progression-free survival (PFS) and adverse events were investigated.

RESULTS

With a median follow-up of 61.4 months (range: 1.7-96.5 months), the 5-year OS and PFS for group A vs. groups B + C were 74.8 ±4.1% versus 87.0 ±4.6% (p = 0.043) and 72.7 ±4.3% vs. 83.1 ± 5.1% (p = 0.243), respectively. The 5-year OS of group B was significantly improved over that of group A (93.0 ±4.8% vs. 74.8 ±4.1%, p = 0.038); however, there was no benefit to the 5-year PFS (89.3 ±5.9% vs. 72.7 ±4.3%, p = 0.144). The 5-year OS and PFS for group C were 80.4 ±7.9% and 76.4 ±8.5%, respectively, and there was no statistically significant difference from group A (p = 0.257 and p = 0.611, respectively). No significant increase in toxicities was observed with the addition of Nimo.

CONCLUSIONS

Nimo administered with chemoradiotherapy is effective for NPC. Nimo concurrent with IC followed by CCRT could be the optimal mode of sequential treatment.

Traversing behavior of tumor cells in three-dimensional platforms with different topography

Three-dimensional polydimethylsiloxane platforms were developed to mimic the extracellular matrix with blood vessels by having scaffolds with micropatterns, porous membrane and trenches. Precisely controlled physical dimensions, layouts, and topography as well as different surface chemical treatments were applied to study their influences on nasopharyngeal carcinoma cell (10-15 μm in diameter) migration in mimicked platforms over 15-hour of time-lapse imaging. By placing the pores at different distance from the edges of the trenches, pores with different trench sidewall exposures and effective sizes were generated. Pores right next to the trench sidewalls showed the highest cell traversing probability, most likely related to the larger surface contact area with cells along the sidewalls. Straight grating oriented perpendicular to trenches below the top layer increased cell traversing probability. Pore shape as well as pore size influenced the cell traversing probability and cells could not traverse through pores that were 6 μm or less in diameter, which is much smaller than the cell size. Trench depth of 15 μm could induce more cells to traverse through the porous membrane, while shallower trenches impeded cell traversing and longer time was needed for cells to traverse because 3 and 6 μm deep trenches were much smaller than cell size which required large cell deformation. Hydrophobic surface coating on the top layer and fibronectin in pores and trenches increased the cell traversing probability and reduced the pore size that cells could traverse from 8 to 6 μm, which indicated that cells could have larger deformation with certain surface coatings.

Microenvironmental topographic cues influence migration dynamics of nasopharyngeal carcinoma cells from tumour spheroids

Tumour metastasis is a complex process that strongly influences the prognosis and treatment of cancer. Apart from intracellular factors, recent studies have indicated that metastasis also depends on microenvironmental factors such as the biochemical, mechanical and topographical properties of the surrounding extracellular matrix (ECM) of tumours. In this study, as a proof of concept, we conducted tumour spheroid dissemination assay on engineered surfaces with micrograting patterns. Nasopharyngeal spheroids were generated by the 3D culture of nasopharyngeal carcinoma (NPC43) cells, a newly established cell line that maintains a high level of Epstein–Barr virus, a hallmark of NPC. Three types of collagen I-coated polydimethylsiloxane (PDMS) substrates were used, with 15 μm deep “trenches” that grated the surfaces: (a) 40/10 μm ridges (R)/trenches (T), (b) 18/18 μm (R/T) and (c) 50/50 μm (R/T). The dimensions of these patterns were designed to test how various topographical cues, different with respect to the size of tumour spheroids and individual NPC43 cells, might affect dissemination behaviours. Spreading efficiencies on all three patterned surfaces, especially 18/18 μm (R/T), were lower than that on flat PDMS surface. The outspreading cell sheets on flat and 40/10 μm (R/T) surfaces were relatively symmetrical but appeared ellipsoid and aligned with the main axes of the 18/18 μm (R/T) and 50/50 μm (R/T) grating platforms. Focal adhesions (FAs) were found to preferentially formed on the ridges of all patterns. The number of FAs per spheroid was strongly influenced by the grating pattern, with the least FAs on the 40/10 μm (R/T) and the most on the 50/50 μm (R/T) substrate. Taken together, these data indicate a previously unknown effect of surface topography on the efficiency and directionality of cancer cell spreading from tumour spheroids, suggesting that topography, like ECM biochemistry and stiffness, can influence the migration dynamics in 3D cell culture models.

Investigation of collective migration of nasopharyngeal carcinoma cells from tumour spheroids on micro-engineered platforms that induced asymmetrical tumour shape.

Integration of biochemical and topographic cues for the formation and spatial distribution of invadosomes in nasopharyngeal epithelial cells

Invadosomes are invasive protrusions generated by cells which can secrete matrix metalloproteinases for focal digestion of extracellular matrix. They also aid invasive cancer cells in their transmigration through vascular endothelium. However, how the physical and chemical cues in a three-dimensional (3D) system signal the spatial localization of invadosomes remains largely unknown. Here we study the topographic guidance of invadosome formation in invasive nasopharyngeal cells under the stimulation of an inflammatory cytokine, TGF-β1, using engineered gratings with different width and depth. We first report that TGF-β1 can act as an external signal to upregulate the formation of invadosomes with a random distribution on a plane 2D surface. When the cells were seeded on parallel 3D gratings of 5 µm width and 1 µm depth, most of the invadosomes aligned to the edges of the gratings, indicating a topographic cue to the control of invadosome localization. While the number of invadosomes per cell were not upregulated when the cells were seeded on 3D topography, guidance of invadosomes localization to edges is correlated with cell migration directionality on 1 µm deep gratings. Invadosomes preferentially form at edges when the cells move at a lower speed and are guided along narrow gratings. The invadosomes forming at 3D edges also have a longer half-life than those forming on a plane surface. These data suggest that there are integrated biochemical and 3D geometric cues underlying the spatial regulation of invasive structures so as to elicit efficient invasion or metastasis of cells. STATEMENT OF SIGNIFICANCE: Nasopharyngeal cells were integrated with the biological cues and matrix topography to govern the activity and spatial distribution of invadosomes. The biochemical induction of invadosome formation by TGF-β1 in nasopharyngeal cells was observed. When the cells were seeded on parallel 3D gratings, most of the invadosomes aligned to the edges of the gratings due to topographical induced invadosome localization. While the number of invadosomes per cell were not upregulated, guidance of invadosomes localization to edges is correlated with cell migration directionality on 1 µm deep gratings. Invadosomes preferentially form at edges with a higher stability when the cells are guided along narrow gratings. The integrated biochemical and 3D geometric cues could elicit efficient invasion or metastasis of cells.

Human blood test based on surface-enhanced Raman spectroscopy technology using different excitation light for nasopharyngeal cancer detection

Nasopharyngeal carcinoma (NPC), a kind of squamous cell carcinoma, occurs in the top and the side wall of nasopharyngeal, which harms human health and life. In this study, a novel blood test (SERS) was carried out for 30 NPC patients and 30 normal ones. Using multi-variate statistical analysis for spectral data, the diagnostic sensitivities of 89.3% (50/56) and 85.7% (48/56) can be achieved for 633 and 785 nm exciting wavelength, respectively. Also corresponding specificities are 71.4% (41/56) and 78.6% (44/56), respectively. These results demonstrated that the two kinds of excitation wavelength all have the feasibility of obtaining high-quality SERS spectra to differentiate cancer from normal samples. Furthermore, the performance of the SERS test with 785 nm wavelength excitation is nearly equal to the SERS experimental effect under 633 nm wavelength excitation for NPC detection.

Structural Basis for Cooperative Binding of EBNA1 to the Epstein-Barr Virus Dyad Symmetry Minimal Origin of Replication

Epstein-Barr virus is associated with several human malignancies, including nasopharyngeal carcinoma, gastric cancer, and lymphoma. Latently infected cells carry a circularized EBV episome where the origin of replication (oriP) is comprised of two elements: the family of repeats (FR) and dyad symmetry (DS). The viral protein Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) binds to FR and DS to promote EBV episome maintenance and DNA replication during latent infection in proliferating cells. EBNA1 binding to the DS constitutes a minimal origin of DNA replication. Here we report the crystal structure of two EBNA1 DNA-binding domain dimers bound to a DS half-site. This structure shows that the DNA is smoothly bent, allowing for stabilizing interactions between the dimers. The dimer-dimer interface requires an intricate hydrogen bonding network involving residues R491 and D581. When this interface is disrupted, we note loss of stable dimer-dimer complex formation on the DNA, compromised oriP-containing plasmid replication in cells, and impaired recruitment of the MCM3 complex to the oriP Surface conservation analysis reveals that these residues are part of a larger conserved surface that may be critical for recruitment of replication machinery to the oriP Our results reveal a new region of EBNA1 critical for its activity and one that may be exploited by targeted small molecules to treat EBV-associated disease.IMPORTANCE Epstein-Barr virus (EBV) is a causative agent of various malignancies and may also contribute to autoimmune disease. The latent and episomal form of the virus is known to drive EBV-associated oncogenesis. Persistence of the viral episome in proliferating tumor cells requires the interaction of Epstein-Barr virus nuclear antigen 1 (EBNA1) with the viral origin of plasmid replication (oriP). The dyad symmetry (DS) element in oriP is the essential minimal replicator of oriP Here we report the X-ray crystal structure of EBNA1 bound to DS. The structure reveals a previous unrecognized interface formed between dimers of EBNA1 necessary for cooperative DNA binding, recruitment of cellular replication machinery, and replication function. These findings provide new insights into the mechanism of EBNA1 function at the replication origin and new opportunities to inhibit EBV latent infection and pathogenesis.

Palliative chemotherapy with or without anti-EGFR therapy for de novo metastatic nasopharyngeal carcinoma: a propensity score-matching study

Objective

We aimed to investigate the efficacy and safety of cetuximab (CTX) or nimotuzumab (NTZ) on the addition of palliative chemotherapy (PCT) in patients with de novo metastatic nasopharyngeal carcinoma (NPC).

Materials and methods

From 2007 to 2016, 451 eligible patients with de novo metastatic NPC were enrolled in the study. With propensity score matching technique, we created a well-balanced cohort by matching patients who received CTX/NTZ plus PCT (62 patients) with those receiving PCT alone (248 patients) in a ratio of 1:4. The primary endpoint was overall survival (OS). All potential prognostic factors were involved in the multivariate analysis with the Cox regression hazards model. Kaplan-Meier curves were used to compare the survival status, and log-rank test to measure the significance.

Results

The median follow-up time was 27.7 months (range, 1-126 months). No significant difference in survival was observed between the CTX/NTZ plus PCT group and PCT group. (3-year OS: 63.0% vs 58.1%; P=0.485). The administration of CTX/NTZ was not found to be an independent prognostic factor in multivariate analysis. With regard to toxicity, the development of a G3-4 skin reaction and mucositis was more common in patients receiving CTX plus PCT. Interaction effects analysis did not show any significant interaction effects on OS between the treatment regimen and prognostic factors (P>0.05).

Conclusion

The efficacy of CTX/NTZ and PCT is comparable to single PCT treatment in terms of survival outcomes among de novo metastatic NPC patients. Moreover, the application of CTX exacerbated skin reactions and mucositis.

Modified Anoikis Assay That Functionally Segregates Epstein-Barr Virus LMP1 Strains into Two Groups

Nasopharyngeal carcinoma (NPC) is a metastatic Epstein-Barr virus (EBV)-associated cancer that expresses the viral oncogenic protein, latent membrane protein 1 (LMP1). During epithelial metastasis, detached cells must overcome anoikis-induced cell death and gain the ability to reattach and restore growth potential. Anoikis assays have revealed cell survival mechanisms during suspension, but few studies have tracked the fate of cells surviving anoikis-inducing conditions. In this study, a modified anoikis assay was used to examine if the expression of LMP1 confers the recovery of epithelial cells from anoikis. Cells expressing LMP1 mutants and strains were evaluated for distinguishing properties in survival during suspension, reattachment, and outgrowth potential. Expression of LMP1 promoted the outgrowth of the NPC cell line HK1 following anoikis induction that was not attributed to enhanced cell survival in suspension or reattachment. The mechanism of LMP1-induced outgrowth required Akt signaling and the conserved PXQXT motif on LMP1, which activates Akt. Deletion of any of the three LMP1 C-terminal activation regions (CTAR) abrogated anoikis recovery, suggesting that additional LMP1-regulated signaling pathways are likely involved. Of the seven LMP1 strains, only B958, China1, and Med⁺ promoted HK1 outgrowth from anoikis. This distinguishing biological property segregates LMP1 strains into two categories (anoikis recovering and nonrecovering) and suggests that LMP1 strain-specific sequences may be important in determining metastatic outgrowth potential in NPC tumors.IMPORTANCE LMP1 is one of the most divergent sequences in the EBV genome and phylogenetically segregates into seven LMP1 strains. The LMP1 strains differ in geographical distribution and NPC tumor prevalence, but the molecular basis for this potential selection is not clear. While there are signaling motifs conserved in all LMP1 sequences from circulating EBV isolates, phylogenetic studies of NPC also suggest that there may be sequence selection for tumor-associated LMP1 strains and polymorphisms. The present study describes a modified anoikis assay that can distinguish LMP1 strains into two groups by biological properties. The pleiotropic LMP1 signaling properties and sequence diversity may offer a unique opportunity to illuminate the complex mechanisms of metastasis. Although the host genomic landscape is variable between NPC tumors, the present functional-mapping studies on LMP1 support the notion that viral proteins could serve as molecular tool kits and potentially reveal sequence-associated risk factors in NPC metastatic progression.

ABT-199-mediated inhibition of Bcl-2 as a potential therapeutic strategy for nasopharyngeal carcinoma

BACKGROUND

Aberrant overexpression of Bcl-2 protein has been detected in 80% of nasopharyngeal carcinoma (NPC), and Bcl-2 family proteins are implicated in both NPC oncogenesis and chemotherapy resistance. Previous studies have shown that while treatment of NPC cells with Bcl-2 family inhibitors alone is rarely effective, concomitant treatment with a cytotoxic reagent such as cisplatin can increase efficacy through a synergistic effect. The aim of the current work was to determine how we might increase the efficacy of Bcl-2 family inhibitors in the absence of cytotoxic reagents, which are associated with negative side effect profiles.

METHODS

We assessed cell proliferation in Bcl-2 high-expressing NPC cells by CCK-8 assay after treatment with the Bcl-2 inhibitor ABT-199 and/or the Mcl-1 inhibitor S63845. Apoptotic induction by ABT-199 was evaluated by Annexin V-FITC and PI double staining. We also evaluated Bcl-2 family protein expression (Bim, Mcl-1, Bcl-xL, Noxa) after treatment with ABT-199 by western blotting. Finally, xenografted Balb/c nude mice were used to test ABT-199 efficacy in vivo, H&E and immunohistochemistry assay were used to analyze tumor samples.

RESULTS

ABT-199 effectively induced NPC cell apoptosis in vitro and in the xenograft model. Following ABT-199 treatment in NPC cells, upregulation of Mcl-1 and Bcl-xL can lead to drug resistance, while concomitant Noxa overexpression partially neutralized the Mcl-1-caused resistance. Given that ABT-199 induces apoptosis in NPC cells through the Bcl-2/Noxa/Mcl-1 axis, treatment avenues further targeting this pathway should be promising. Indeed, the newly developed Mcl-1 inhibitor S63845 in combination with ABT-199 had a synergistic effect on NPC cell apoptosis.

CONCLUSION

Bcl-2 inhibition in NPC cells with ABT-199 triggers apoptosis through the Bcl-2/Noxa/Mcl-1 axis, and dual inhibition of the anti-apoptotic Bcl-2 family proteins Bcl-2 and Mcl-1 provided a strong synergistic effect without the need for adjunctive cytotoxic agent treatment with cisplatin.

VEGF Upregulation in Viral Infections and Its Possible Therapeutic Implications

Several viruses are recognized as the direct or indirect causative agents of human tumors and other severe human diseases. Vascular endothelial growth factor (VEGF) is identified as a principal proangiogenic factor that enhances the production of new blood vessels from existing vascular network. Therefore, oncogenic viruses such as Kaposi’s sarcoma herpesvirus (KSHV) and Epstein-Barr virus (EBV) and non-oncogenic viruses such as herpes simplex virus (HSV-1) and dengue virus, which lack their own angiogenic factors, rely on the recruitment of cellular genes for angiogenesis in tumor progression or disease pathogenesis. This review summarizes how human viruses exploit the cellular signaling machinery to upregulate the expression of VEGF and benefit from its physiological functions for their own pathogenesis. Understanding the interplay between viruses and VEGF upregulation will pave the way to design targeted and effective therapeutic approaches for viral oncogenesis and severe diseases.

Optimization of Formulations Consisting of Layered Double Hydroxide Nanoparticles and Small Interfering RNA for Efficient Knockdown of the Target Gene

Layered double hydroxide (LDH) nanoparticles (NPs) are safe and effective vectors for small interfering RNA (siRNA) delivery. However, it is unclear whether there are optimal parameters for the efficient delivery of functional siRNA using LDH NPs. In this research, we comprehensively examined the effect of parameters, such as the mixing method and LDH/siRNA mass ratio on siRNA silencing capability. We first noted that the best way for loading gene segments (25 bp dsDNA and siRNA) is to add gene molecules to 100 nm LDH and then diluting in Dulbecco's modified Eagle's medium. Very interestingly, the optimal LDH/gene mass ratio is around 20:1 in terms of cellular uptake amount of gene segments, whereas this ratio is shifted to around 5:1 in terms of target gene silencing efficacy, which has been reasonably explained. The optimization for LDH NP-based gene delivery system may provide the guidance for more efficient in vitro and in vivo siRNA delivery using the optimal parameters.

Sunitinib Induces NK-κB-dependent NKG2D Ligand Expression in Nasopharyngeal Carcinoma and Hepatoma Cells

Multitargeted tyrosine kinase inhibitors (MTKIs) have been shown to combine with natural killer (NK) cell adoptive transfer for the treatment in various cancers. MTKIs sensitize cancer cells to NK cell therapy through upregulation of nature killer group 2 member D ligands (NKG2DLs) on tumor cells. However, the molecular mechanism of MTKIs-mediated upregulation of NKG2DLs is still unknown. In this study, we confirmed sunitinib induced downregulation of its targets, such as vascular endothelial growth factor, platelet-derived growth factor, and c-kit in multiple-drug-resistant nasopharyngeal carcinoma cell line CNE2/DDP and hepatoma cell line HepG2. Then, we further showed sunitinib induced cell proliferation inhibition, apoptosis, and DNA damage in CNE2/DDP and HepG2 cells. Coculture experiments showed that sunitinib-treated CNE2/DDP and HepG2 cells were able to increase the activation and cytotoxicity of NK cells. Quantitative polymerase chain reaction results showed that sunitinib upregulated NKG2DLs, apoptotic genes, DNA damage repair genes, and nuclear factor (NF)-κβ family genes. Silencing of NF-κβ1, NF-κβ2, or RelB (NF-κβ pathway) inhibited sunitinib-induced upregulation of NKG2DLs. Taken together, we concluded that sunitinib upregulated NKG2DLs through NF-κβ signaling noncanonical pathway which might mediate higher cytotoxic sensitivity of CNE2/DDP and HepG2 cells to NK cells.

High pretreatment serum gamma-glutamyl transpeptidase predicts an inferior outcome in nasopharyngeal carcinoma

Background

Gamma-glutamyl transpeptidase (GGT) which plays an important role in tumor initiation, invasion, drug resistance is strongly associated with poor prognosis in patients with cancers. This study was designed to estimate whether pretreatment serum GGT could predict the clinical outcome of nasopharyngeal carcinoma (NPC) patients.

Results

An optimal cutoff value was identified as 23 U/L for GGT. Univariate analysis and multivariate analysis demonstrated that elevated GGT was correlated with shorter local recurrence-free survival (LRFS) (HR, 4.163; 95% CI, 1.690-10.251; p=0.023), progression-free survival (PFS) (HR, 3.119; 95% CI, 1.955-4.976; p=0.031) and overall survival (OS) (HR, 2.811; 95% CI, 1.614-4.896; p=0.007).

Materials and Methods

We retrospectively analyzed data from 374 patients with NPC. Kaplan–Meier method was used to calculate and compare the prognosis. The Cox proportional hazards model was applied to carry out univariate and multivariate analyses.

Conclusion

Pretreatment GGT can be a novel and independent prognostic biomarker for patients with NPC.

Phage-display screening identifies LMP1-binding peptides targeting the C-terminus region of the EBV oncoprotein

Latent membrane protein 1 (LMP1), a major oncoprotein of Epstein Barr Virus (EBV) is responsible for transforming B lymphocytes in vitro. LMP1 is overexpressed in several EBV-associated malignancies, and different approaches have been developed to reduce its level and accordingly its oncogenic function in tumor tissues. This study aimed to use phage display peptide library to obtain peptides which could specifically bind to the cytoplasmic region of LMP1 to prevent its interaction with signaling proteins. The LMP1 C-terminus region was produced in bacterial E. coli and used as target for the phage library panning. After 3 rounds, 20 phage clones were randomly selected and 8 showed high binding affinity to the recombinant C-terminus LMP1 protein. The most interesting candidates are the FO5 "QPTKDSSPPLRV" and NO4 "STTSPPAVPHNN" peptides since both bind the C-terminus LMP1 as showed by molecular docking. Furthermore, sequence alignment revealed that the FO5 peptide shared sequence similarity with the Death Receptor 4 which belongs to the tumor necrosis factor-related apoptosis-inducing receptor which plays key role in anti-tumor immunity.

The other side of the coin: Leveraging Epstein-Barr virus in research and therapy

Epstein-Barr virus is (EBV) a ubiquitous virus prevalent in 90% of the human population. Transmitted through infected saliva, EBV is the causative agent of infectious mononucleosis (IM) and is further implicated in malignancies of lymphoid and epithelial origins. In the past few decades, research efforts primarily focused on dissecting the mechanism of EBV-induced oncogenesis. Here, we present an alternate facet of the oncovirus EBV, on its applications in research and therapy. Finally, discussions on the prospective utilization of EBV in nasopharyngeal carcinoma (NPC) diagnosis and therapy will also be presented.

Tolfenamic Acid Inhibits the Proliferation, Migration, and Invasion of Nasopharyngeal Carcinoma: Involvement of p38-Mediated Down-Regulation of Slug

PURPOSE

Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to exhibit antitumor effects in various cancers apart from nasopharyngeal cancer (NPC). NPC exhibits high invasiveness, as well as metastatic potential, and patients continue to suffer from residual, recurrent, or metastatic disease even after chemoradiation therapy. Therefore, new treatment strategies are needed for NPC. In this study, we investigated the efficacy and molecular mechanisms of TA in NPC treatment.

MATERIALS AND METHODS

TA-induced cell death was detected by cell viability assay in the NPC cell lines, HNE1 and HONE1. Wound healing assay, invasion assay, and Western blot analysis were used to evaluate the antitumor effects of TA in NPC cell lines.

RESULTS

Treatment with TA suppressed the migration and invasion of HNE1 and HONE1 cells. Hepatocyte growth factor enhanced the proliferation, migration, and invasion abilities of NPC cells. This enhancement was successfully inhibited by TA treatment. Treatment with TA increased phosphorylation of p38, and the inhibition of p38 with SB203580 reversed the cytotoxic, anti-invasive, and anti-migratory effects of TA treatment in NPC cell lines. Moreover, inhibition of p38 also reversed the decrease in expression of Slug that was induced by TA treatment.

CONCLUSION

In conclusion, the activation of p38 plays a role in mediating TA-induced cytotoxicity and inhibition of invasion and migration via down-regulation of Slug.

Chemotherapeutic effect of a novel temozolomide analog on nasopharyngeal carcinoma in vitro and in vivo

BACKGROUND

Many patients with nasopharyngeal carcinoma (NPC) face poor prognosis. Due to its hidden anatomical location, the tumor is usually diagnosed quite late, and despite initially successful treatment with radiation and cisplatin, many patients will relapse and succumb to the disease. New treatment options are urgently needed. We have performed preclinical studies to evaluate the potential NPC therapeutic activity of a newly developed analog of temozolomide (TMZ), an alkylating agent that is the current chemotherapeutic standard of care for patients with malignant glioma.

RESULTS

TMZ was covalently conjugated to the natural monoterpene perillyl alcohol (POH), creating the novel fusion compound NEO212. Its impact on two NPC cell lines was studied through colony formation assays, cell death ELISA, immunoblots, and in vivo testing in tumor-bearing mice. In vitro, NEO212 effectively triggered tumor cell death, and its potency was significantly greater than that of its individual components, TMZ or POH alone. Intriguingly, merely mixing TMZ with POH also was unable to achieve the superior potency of the conjugated compound NEO212. Treatment of NPC cells with NEO212 inactivated the chemoprotective DNA repair protein MGMT (O6-methylguanine methyltransferase), resulting in significant chemosensitization of cells to a second round of drug treatment. When tested in vivo, NEO212 reduced tumor growth in treated animals.

CONCLUSION

Our results demonstrate anticancer activity of NEO212 in preclinical NPC models, suggesting that this novel compound should be evaluated further for the treatment of patients with NPC.

EBV oncogene N-LMP1 induces CD4 T cell-mediated angiogenic blockade in the murine tumor model

Antivascular immunity may provide long-term protection by preventing neovascularization that precedes tumor progression. Although the tumorigenesis promoted by EBV-encoded oncogene latent membrane protein 1 derived from Taiwanese nasopharyngeal carcinoma (N-LMP1) has been demonstrated, the potential of N-LMP1 for inducing immune surveillance remains elusive. In this article, we describe the immunogenicity of N-LMP1 (1510) and its induction of antivascular immunity in a transplantable tumor model in immunocompetent BALB/c mice. The immunogenicity of N-LMP1 was evaluated on the basis of tumor rejection following immunization. The impact of the immunization on the dynamics of tumor angiogenesis was assessed by temporal noninvasive dynamic contrast-enhanced magnetic resonance imaging and was further confirmed by histologic study and vascular count. Through the experiments of in vivo depletion and adoptive transfer, CD4 T cells were identified as effectors that depend on IFN-γ for tumor prevention. The response was further verified by the identification of an MHC H-2 I-E(d)-restricted peptide derived from N-LMP1 and by the immunization of mice with N-LMP1 peptide-loaded dendritic cells. These studies provide insight into N-LMP1-specific immunity in vivo, which suggests that CD4 T cells may play an important role in angiogenic surveillance against LMP1-associated cancer via tumor stroma targeting.

Therapeutic implications of Epstein-Barr virus infection for the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly endemic in certain regions including the People’s Republic of China and Southeast Asia. Its etiology is unique and multifactorial, involving genetic background, epigenetic, and environment factors, including Epstein–Barr virus (EBV) infection. The presence of EBV in all tumor cells, aberrant pattern of antibodies against EBV antigens in patient sera, and elevated viral DNA in patient circulation as well as nasopharyngeal site underline the role of EBV during NPC development. In NPC tumors, EBV expresses latency type II, where three EBV-encoded proteins, Epstein–Barr nuclear antigen 1, latent membrane protein 1 and 2 (LMP1, 2), are expressed along with BamH1-A rightward reading frame 1, Epstein–Barr virus-encoded small nuclear RNAs, and BamH1-A rightward transcripts. Among all encoded proteins, LMP1 plays a central role in the propagation of NPC. Standard treatment of NPC consists of radiotherapy with or without chemotherapy for early stage, concurrent chemoradiotherapy in locally advanced tumors, and palliative systemic chemotherapy in metastatic disease. However, this standard care has limitations, allowing recurrences and disease progression in a certain proportion of cases. Although the pathophysiological link and molecular process of EBV-induced oncogenesis are not fully understood, therapeutic approaches targeting the virus may increase the cure rate and add clinical benefit. The promising results of early phase clinical trials on EBV-specific immunotherapy, epigenetic therapy, and treatment with viral lytic induction offer new options for treating NPC.