Treatment for metastatic nasopharyngeal carcinoma. Eur Ann Otorhinolaryngol Head Neck Dis. 2011;128:79-85. [PMID: 21177151 DOI: 10.1016/j.anorl.2010.10.003]

CFTR is a potential marker for nasopharyngeal carcinoma prognosis and metastasis

While there is an increasing interest in the correlation of cystic fibrosis transmembrane conductance regulator (CFTR) and cancer incidence, the role of CFTR in nasopharyngeal carcinoma (NPC) development remains unknown. In this study, we aimed to explore the prognostic value of CFTR in NPC patients. The expression of CFTR was determined in NPC cell lines and tissues. Statistical analysis was utilized to evaluate the correlation between CFTR expression levels and clinicopathological characteristics and prognosis in 225 cases of NPC patients. The results showed that CFTR was down-regulated in NPC tissues and cell lines. Low expression of CFTR was correlated with advanced stage (p = 0.026), distant metastasis (p < 0.001) and poor prognosis (p < 0.01). Multivariate analysis identified CFTR as an independent prognostic factor (p = 0.003). Additionally, wound healing and transwell assays revealed that overexpression of CFTR inhibited NPC cell migration and invasion, whereas knockdown of CFTR promoted cell migration and invasion. Thus, the current study indicates that CFTR, as demonstrated to play an important role in tumor migration and invasion, may be used as a potential prognostic indicator in NPC.

XIAP Limits Autophagic Degradation of Sox2 and Is A Therapeutic Target in Nasopharyngeal Carcinoma Stem Cells

Rationale: Nasopharyngeal carcinoma (NPC) is the most frequent head and neck tumor in South China. The presence of cancer stem cells (CSCs) in NPC contributes to tumor maintenance and therapeutic resistance, while the ability of CSCs to escape from the apoptosis pathway may render them the resistant property to the therapies. Inhibitor of apoptosis proteins family proteins (IAPs), which are overexpressed in nasopharyngeal carcinoma stem cells, may play an important role in maintaining nasopharyngeal cancer stem cell properties. Here, we develop a novel CSC-targeting strategy to treat NPC through inhibiting IAPs.

Methods: Human NPC S-18 and S-26 cell lines were used as the model system in vitro and in vivo. Fluorescence activated cell sorting (FACS) assay was used to detect nasopharyngeal SP cells and CD44+ cells. The characteristics of CSCs were defined by sphere suspension culture, colony formation assay and cell migration. The role of XIAP on the regulation of Sox2 protein stability and ERK1-mediated phosphorylation of Sox2 signaling pathway were analyzed using immunoblotting, immunoprecipitation, immunofluorescence, phosphorylation mass spectrometry, siRNA silencing and plasmid overexpression. The correlation between XIAP and Sox2 in NPC biopsies and their role in prognosis was performed by immunohistochemistry. APG-1387 or chemotherapies-induced cell death and apoptosis in S-18 and S-26 were determined by WST, immunoblotting and flow cytometry assay.

Results: IAPs, especially X chromosome-linked IAP (XIAP), were elevated in CSCs of NPC, and these proteins were critically involved in the maintenance of CSCs properties by enhancing the stability of Sox2. Mechanistically, ERK1 kinase promoted autophagic degradation of Sox2 via phosphorylation of Sox2 at Ser251 and further SUMOylation of Sox2 at Lys245 in non-CSCs. However, XIAP blocked autophagic degradation of Sox2 by inhibiting ERK1 activation in CSCs. Additionally, XIAP was positively correlated with Sox2 expression in NPC tissues, which were associated with NPC progression. Finally, we discovered that a novel antagonist of IAPs, APG-1387, exerted antitumor effect on CSCs. Also, the combination of APG-1387 with CDDP /5-FU has a synergistic effect on NPC.

Conclusion: Our study highlights the importance of IAPs in the maintenance of CSCs in NPC. Thus, XIAP is a promising therapeutic target in CSCs and suggests that NPC patients may benefit from a combination treatment of APG-1387 with conventional chemotherapy.

Knockdown of GRP78 enhances cell death by cisplatin and radiotherapy in nasopharyngeal cells

Radiotherapy and adjuvant cisplatin chemotherapy are the mainstream approaches in the treatment of nasopharyngeal carcinoma (NPC). These have been shown to effectively improve the outcome and reduce tumor recurrence. However, radiotherapy and chemotherapy resistance during the course of treatment has become more common recently, resulting in the failure of NPC therapy. Therefore, new therapeutic strategies or adjuvant drugs are urgently needed. The current study was designed to look for new treatment strategies or auxiliary drugs in the treatment of NPC. Two human NPC cell lines, HNE1 and HNE1/DDP, were used to examine the relationship between endoplasmic reticulum stress and cell resistance to ionizing radiation (IR) and cisplatin (DDP). Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Meanwhile, propidium iodide (PI) staining and PI/Annexin V staining were used to observe cell apoptosis. Finally, western blot was used to detect the endogenous expression of glucose-regulated protein 78 (GRP78) and other apoptosis-related proteins. GRP78 small interference RNA was transfected using Lipofectamine 2000. Compared with HNE1/DDP, IR and DDP increased the cell apoptosis and inhibited the cell proliferation of HNE1. Inhibition of GRP78 can reverse IR and DDP resistance in NPC cells by PI/Annexin V staining. Knockdown of GRP78 upregulates the expression of pro-apoptotic proteins and downregulates the expression of antiapoptotic proteins. These results indicate that HNE1 is more sensitive to DDP and IR than HNE1/DDP. Knockdown GRP78 can reverse IR and DDP resistance in NPC cells. Inhibition of GRP78 gives us a new target to overcome resistance to radiotherapy and chemotherapy of NPC cells. Thus, this study should be further explored in vivo and assessed for possible clinical applications.

Prognostic factors of nasopharyngeal carcinoma patients in a tertiary referral hospital: a retrospective cohort study

Background

Nasopharyngeal carcinoma (NPC) exhibits a distinctive racial and geographic distribution. Many studies have reported varied significant prognostic factors affect the survival of NPC patients. Hence, this current study aimed to identify the prognostic factors of NPC patients registered in a tertiary referral hospital.

Methods

The records of one hundred and thirty-four NPC cases confirmed by histopathology in Hospital Universiti Sains Malaysia (USM) between 1st January 1998 and 31st December 2007 that fulfilled the inclusion and exclusion criteria were retrospectively reviewed. Simple and multiple Cox proportional hazard regression analyses were performed to determine the significant prognostic factors affect the survival of NPC patients.

Results

The mean (SD) age of patients diagnosed with NPC was 48.12 (15.88) years with Malay was the largest ethnic group compared to other ethnicities. Most of patients had locally advanced stage IV (40.6%) and stage III (39.1%) of NPC. The overall median survival time of NPC patients was 31.30 months (95% CI 23.76, 38.84). The significant prognostic factors that influenced the survival of NPC patients were older age (HR 1.03, 95% CI 1.01, 1.04), metastases (HR 2.52, 95% CI 1.01, 6.28) and stage IV disease (HR 4.50, 95% CI 1.66, 9.88).

Conclusion

Older age, the presence of metastases and late stage are significant prognostic factors that influence the survival of NPC. Therefore, it is important to provide education to public and to raise awareness to diagnose NPC at an earlier stage and before the presence of metastases.

Long non-coding RNA LOC100129148 functions as an oncogene in human nasopharyngeal carcinoma by targeting miR-539-5p

Emerging studies have shown that long noncoding RNAs (lncRNAs) play critical roles in carcinogenesis and progression, including human nasopharyngeal carcinoma (NPC). The correlation between lncRNAs expression and NPC development has not been well identified in the recent literature. Recently, high-through put analysis reveals that LOC100129148 is highly expressed in NPC. However, whether the aberrant expression of LOC100129148 in NPC is corrected with tumorigenesis or prognosis has not been investigated. Herein, we identified that LOC100129148 was up-regulated in NPC tissues and cell lines, and higher expression of LOC100129148 resulted in a markedly poorer survival time. Over-expressed LOC100129148 favored, but silenced LOC100129148 hampered cell proliferation in NPC cells. Additionally, LOC100129148 enhanced the KLF12 expression through functioning as a competitive 'sponge' for miR-539-5p. Thus, our study reports a novel mechanism underlying NPC carcinogenesis, and provides a potential novel diagnosis and treatment biomarker for NPC.

High YBX1 expression indicates poor prognosis and promotes cell migration and invasion in nasopharyngeal carcinoma

Y-box binding protein-1 (YBX1) is a multifunctional protein and often acts as an indicator of poor prognosis in cancers. Increasing evidence has shown that the levels of YBX1 protein were closely associated with multidrug resistance, relapse, metastasis and poor prognosis in cancers. However, its role in nasopharyngeal carcinoma (NPC) metastasis remains unknown. In our study, we discovered that the expression of YBX1 was increased in nasopharyngeal carcinoma tissues. YBX1 protein levels positively correlated with T stage and metastasis of NPC patients. Moreover, expression of YBX1 was negatively correlated with membrane E-cadherin levels and positively correlated with Vimentin expression. In vitro, the expression of YBX1 was closely related to the invasive and migratory ability of nasopharyngeal carcinoma cells. Knockdown of YBX1 inhibited migration and invasion in 5-8F cells, and over-expression of YBX1 promoted CNE1 cells migration and invasion. Transforming growth factor-β1 (TGF-β1) treatment led to epithelial-to-mesenchymal transition (EMT) in CNE1 cells accompanied by elevated YBX1 expression. On the contrary, knockdown of YBX1 partially inhibited the TGF-β1-induced CNE1 cell migration, together with changes of EMT-associated markers. Our study revealed that TGF-β1/YBX1 signaling might be one of novel mechanisms mediating EMT in NPC, providing a new target for the treatment of nasopharyngeal carcinoma.

STAT3 mediates resistance to anoikis and promotes invasiveness of nasopharyngeal cancer cells

Nasopharyngeal carcinoma (NPC), a tumor arising from the epithelial cells of the nasopharynx, is endemic in Southeast Asia and Taiwan. The prognosis of NPC patients with local recurrence and metastasis is poor. Resistance to anoikis is a primary characteristic of tumor cells that metastasize. However, the mechanism through which NPC cells resist anoikis and are able to metastasize has not been fully elucidated. In the present study, the acquisition of anoikis resistance was analyzed in the TW01 and TW06 human NPC cell lines growing under anchorage-independent conditions. A considerable number of TW01 and TW06 cells was found to be resistant to anoikis and exhibited a higher capability of migration and invasion. These anoikis-resistant NPC cells exhibited significantly increased expression of signal transducer and activation of transcription 3 (Stat3) compared with adherent cells. Furthermore, blockade of STAT3 expression by STAT3 inhibitors or STAT3 silencing significant increased anoikis in anoikis-resistant NPC cells. Moreover, silencing STAT3 not only reduced the capacity of NPC cells to resist anoikis, but also reversed their invasive properties. The expression of epithelial‑to-mesenchymal transition‑related proteins and CD44 was also significantly decreased following STAT3 knockdown. The results of the present study established that STAT3 mediates anoikis resistance, with enhanced cell migration and invasion of NPC cells, and that activation of STAT3 may increase metastatic capacity, indicating the crucial role of STAT3 in conferring anoikis resistance and enhanced invasive properties to NPC cells.

Cardamonin induces ROS-mediated G2/M phase arrest and apoptosis through inhibition of NF-κB pathway in nasopharyngeal carcinoma

Cardamonin has been demonstrated to have an inhibitory effect in many cancers, but its underlying mechanism remains elusive. Here, we studied, for the first time, the mechanism of cardamonin-induced nasopharyngeal carcinoma cell death both in vitro and in vivo. In our study, we showed that cardamonin inhibited cancer cell growth by inducing G2/M phase cell cycle arrest and apoptosis via accumulation of ROS. NF-κB activation was involved in breaking cellular redox homeostasis. Therefore, our results provided new insight into the mechanism of the antitumor effect of cardamonin, supporting cardamonin as a prospective therapeutic drug in nasopharyngeal carcinoma by modulating intracellular redox balance.

Propensity score matching analysis of a phase II study on simultaneous modulated accelerated radiation therapy using helical tomotherapy for nasopharyngeal carcinomas

Background

Using propensity score matching method (PSM) to evaluate the feasibility and clinical outcomes of simultaneous modulated accelerated radiation therapy (SMART) using helical tomotherapy (HT) in patients with nasopharyngeal carcinoma (NPC).

Methods

Between August 2007 and January 2016, 381 newly diagnosed NPC patients using HT were enrolled in pre-PSM cohort, including 161 cases in a prospective phase II study (P67.5 study, with a prescription dose of 67.5Gy in 30 fractions to the primary tumour and positive lymph nodes) and 220 cases in a retrospective study (P70 study, with a prescription dose of 70Gy in 33 fractions to the primary tumour and positive lymph nodes). Acute and late toxicities were assessed according to the established RTOG/EORTC criteria and Common Terminology Criteria for Adverse Events (CTCAE) V 3.0. Survival rate were assessed with Kaplan-Meier method, log-rank test and Cox regression.

Results

After matching, 148 sub-pairs of 296 patients were generated in post-PSM cohort. The incidence of grade 3–4 leukopenia, thrombocytopenia and anemia in the P67.5 group was significantly higher than in the P70 study, but no significant different was found in other acute toxicities or late toxicities between the two groups. The median follow-up was 33 months in the P67.5 and P70 group, ranging 12–54 months and 6–58 months, respectively. No significant differences in 3-year local-regional recurrence free survival (LRRFS), distant metastasis-free survival (DMFS), disease free survival (DFS) and overall survival (OS) were observed between the 2 groups. Univariate analysis showed that age, T stage, clinical stage were the main factors effecting survival. Cox proportional hazards model showed that 67.5Gy/30F pattern seemed superior in 3-year OS (HR = 0.476, 95% CI: 0.236-0.957).

Conclusions

Through increasing fraction dose and shortening treatment time, the P67.5 study achieved excellent short-term outcomes and potential clinical benefits, with acceptable acute and late toxicities.

Trial registration

The trial was registered at Chinese Clinical Trial Registry on 5 July 2014 with a registration code of ChiCTRONC-14,004,895.

18F-Fluorodeoxyglucose-positron Emission Tomography/Computed Tomography Imaging of Metastatic Nasopharyngeal Cancer with Emphasis on the Distribution of Bone Metastases

Distant metastases change the prognosis of patients with nasopharyngeal carcinoma (NPC) which most commonly metastasizes to the bone. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is reported as useful in imaging NPC metastases. Our study assesses the incidence and distribution of bone metastases detected by ¹⁸F-FDG PET/CT in NPC. 717 ¹⁸F-FDG PET/CT scan reports of histologically proven NPC patients imaged in Singapore General Hospital, Singapore, between 2003 and 2009 were reviewed for the total number of metastases (scanned from vertex to mid-thigh) and analyzed for distribution. Of the 709 FDG avid metastases in these reports, 357/709 (50.35%) were locoregional nodal metastasis and 352/709 (49.65%) were distant metastases of which 192/709 (27.08%) of total metastases and 54.54% of distant metastases (192/352) were in the bones. The majority of the bone lesions 125/192 (65.1%) were in the axial skeleton with 109/192 (56.77%) in the lower skeleton (thoracolumbar spine, sacrum, and pelvis). The incidence of bone metastases in our study (27.08%) was higher than that reported in other studies, for example, 15% by Liu et al. and 11% (230 patients) by Caglar et al. Bone metastases have been reported in the femurs and the feet and as such some metastases may have been outside the field of view of the scans. In our study, 27% of FDG avid NPC metastases are in the bones.

Elevation of MiR-9-3p suppresses the epithelial-mesenchymal transition of nasopharyngeal carcinoma cells via down-regulating FN1, ITGB1 and ITGAV

MicroRNAs had been proved to be pivotal regulators in nasopharyngeal carcinoma (NPC) by regulating a large amount of genes' expression. In our research, we aim to explore the functions of miR-9-3p on the metastases of NPC and figure out the potential mechanisms. First, we revealed downregulation of miR-9-3p and upregulation of fibronectin 1 (FN1), β1 integrin (ITGB1) and α5 integrin (ITGAV) expression in NPC tissues and cells compared with the normal using RNA-seq analysis, RT-qPCR, western blot and immunohistochemistry. By transfection of miR-9-3p mimics in CNE-1, CNE-2 and HONE-1 cells, we confirmed tumor-suppressing roles of miR-9-3p via suppressing EMT process by MTT, wound scratch, transwell assay and western blot. After constructing luciferase reporting plasmids and transient transfection in HEK 293T cells, we proved that FN1, ITGB1 and ITGAV were all targets of miR-9-3p. Then we manipulated the expression of miR-9-3p, FN1, ITGB1 and ITGAV in HONE-1 cells, verifying the tumor-promoting effect of FN1, ITGB1 and ITGAV on cell proliferation and metastases via facilitating EMT process of cells. Additionally, these functions of FN1, ITGB1 and ITGAV could be efficiently abrogated by overexpression of miR-9-3p. Taken together, we demonstrated that elevation of miR-9-3p suppresses the proliferation and metastases of NPC via downregulating FN1, ITGB1, ITGAV and inhibiting the EMT process, which provided a series of therapeutic targets for the treatment of NPC.

Celastrol-induced apoptosis in human nasopharyngeal carcinoma is associated with the activation of the death receptor and the mitochondrial pathway

Nasopharyngeal carcinoma (NPC) is a cancer that arises from the epithelium of the nasopharynx. Celastrol is a triterpene from traditional Chinese medicine, which demonstrates anti-proliferative activity in several cancer cell lines. However, the effect of celastrol on human NPC and the underlying mechanisms are not yet elucidated. The present study investigated whether celastrol induced apoptosis in human NPC cells, and the underlying molecular mechanisms were explored. Celastrol decreased the viability of HONE-1 and NPC-039 cells in a dose-dependent manner, and induced G1 and G2/M phase cell cycle arrest. The level of cleaved caspases-3, -8, and -9 and poly (ADP-ribose) polymerase 1 increased in cells treated with celastrol. There was an increase in active Bcl-2-like 11 isoform S, Bcl-2-associated X, Bcl-2 antagonist/killer and truncated BH3-interacting death antagonist, and the levels of the anti-apoptotic Bcl-2 and Bcl-2-like 1 decreased. Celastrol induced an increase in Fas, Fas-associated via death domain, TNF receptor superfamily members (TNRSF) 1A and 10B, and TNFRSF1A associated via death domain, and induced a dose-dependent reduction in mitochondrial membrane potential. Celastrol inhibited activation of mitogen-activated protein kinase (MAPK) 1/3 and 14, and induced MAPK 8/9 activation. The results indicated that celastrol induced apoptosis through the death receptor and the mitochondrial pathway in human NPC cells, and is a promising candidate in the development of drugs against NPC.

The Ratio of C-Reactive Protein/Albumin is a Novel Inflammatory Predictor of Overall Survival in Cisplatin-Based Treated Patients with Metastatic Nasopharyngeal Carcinoma

The C-reactive protein/albumin (CRP/Alb) ratio has been recently identified as a prognostic factor in various cancers, whereas its role remains unclear in metastatic nasopharyngeal carcinoma (NPC). The current study retrospectively analyzed 148 patients with metastatic NPC who underwent cisplatin-based chemotherapy and further evaluated the prognostic value of the CRP/Alb ratio and its association with clinical characteristics in these patients. The optimal cut-off value was 0.189 for the CRP/Alb ratio. The high CRP/Alb ratio was significantly associated with elevated NLR, platelet-to-lymphocyte ratio (PLR), and EBV-DNA levels and decreased haemoglobin level (all p < 0.05). The results of multivariate analysis showed that the CRP/Alb ratio was an independent prognostic factor of overall survival. Patients with a high CRP/Alb ratio (≥0.189) had a 1.867 times (p = 0.024, 95% CI = 1.085–3.210) greater risk of mortality compared with those with a low CRP/Alb ratio (<0.189). In addition, combining the CRP/Alb ratio with GPS could accurately discriminate the prognosis of our patients. Our results suggested that the CRP/Alb ratio is a feasible and inexpensive tool for predicting survival outcomes and is a valuable coadjutant for the GPS to further identify differences in survivals of patients with metastatic NPC.

Unusual presentation of nasopharyngeal carcinoma with rectal metastasis

Nasopharyngeal carcinoma (NPC) is a rare tumour that mainly metastasizes in lymph nodes, bones, lungs and liver. Colorectal metastases of NPC are extremely rare phenomenon and associated with a poor prognosis. We reported here a case of NPC with rectal metastasis, we discussed the treatment modalities and the prognosis after reviewing the similar cases described in the literature.

Unusual axillary metastasis of recurrent nasopharyngeal cancer: A case report

RATIONALE

Nasopharyngeal carcinoma (NPC) has a high propensity of metastasis. The most commonly described sites of distant metastasis are the bones, lungs, and liver, whereas axillary metastasis is seldom reported.

PATIENT CONCERNS

We hereby present the case of a 66-year-old man with NPC, cT2N2M0, at diagnosis. He had completed chemoradiotherapy and been disease-free for 7 years.

DIAGNOSES

After that period, late recurrence in the form of a solitary axillary lymph node metastasis was detected and confirmed by core-needle biopsy.

INTERVENTIONS

The lesion was chemoresistant but responded to salvage radiotherapy at a dose of 65 Gy in 21 fractions.

OUTCOMES

Post-radiotherapy positron emission tomography scan showed no evidence of disease.

LESSONS

We suggested that long-term follow-up of NPC patients is important because a late relapse may occur at an unusual site. Aggressive management of solitary metastasis may achieve good outcome.

NEDD4 is involved in acquisition of epithelial-mesenchymal transition in cisplatin-resistant nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a highly invasive head-neck cancer derived from the nasopharyngeal epithelium, mainly prevalent in southern China and Southeast Asia. Radiotherapy and adjuvant cisplatin (DDP) chemotherapy are standard administrations applied in the treatment of NPC. However, resistance to chemotherapeutic drugs has recently become more common, resulting in worse treatment outcome for NPC therapy. To elucidate the underlying molecular basis of drug resistance to DDP in NPC cells, we examined the morphocytology, cell motility and molecular changes in DDP-resistant NPC cells with respect to epithelial-mesenchymal transition (EMT) features. We found that EMT is closely associated with DDP-induced drug resistance in NPC cells, as DDP-resistant cells displayed morphological and molecular markers changes consistent with EMT. Wound healing and Transwell Boyden chamber assays revealed an enhanced migration and invasion potential in DDP-resistant NPC cells. Mechanistically, upregulation of NEDD4 was observed to relate to EMT in DDP-resistant cells. More importantly, depletion of NEDD4 in resistant cells led to a partial reversion of EMT phenotypes to MET characteristics. These data suggest that NEDD4 is largely involved in EMT features and chemoresistance of NPC cancer cells. NEDD4 could be a novel therapeutic target to overcome drug resistance in successful administrations of NPC.

A generic RNA pulsed DC based approach for developing therapeutic intervention against nasopharyngeal carcinoma

The recurrent nasopharyngeal carcinoma of head-and-neck cancers pathology showed unique symptoms and clinical characteristics. The complexity of pathology poses challenges for developing therapeutic interventional approaches against nasopharyngeal carcinoma (NPC). The conventional treatment regimens offer limited local control and survival, which, leads to adverse delayed complications. Our study present a generic monocyte derived dendritic cell (MoDC) vaccine strategy for NPC in which RNA is used as a source of tumor-associated antigens (TAAgs). The RNA extracted from well-characterized highly immunogenic NPC cells (C666-1) was transfected into MoDCs. The formulated and characterized cationic liposomes were used to achieving efficient RNA transfection of immature DCs. Further, DCs were forcibly matured with a cytokine cocktail to achieve greater expression of MHC and co-stimulatory molecules. Moreover, our results did not see any effect of RNA or lipids on MoDCs phenotype or cytokine expression. RNA loaded DCs derived from HLA-A2-positive donors were shown to activate effector memory cytotoxic T lymphocytes (CTLs) specific for TAAg ligand expressed by C666-1 cells. Our results show the comparison of cytotoxic response mounted against RNA-loaded DCs with those directly stimulated by C666-1 tumor cells. Our findings suggest that DCs expressing tumor cell RNA primed naïve T cells show T cells priming with lesser cytotoxicity and cytokine secretion when exposed with with C666-1 tumor cells. These results surface the potential of DCs to deliver RNA in NPCs, sufficient presentation of RNA to provoke perdurable immune responses against nasopharyngeal carcinoma. Our results implies that DC based vaccine approach may be useful to develop therapeutic interventional approach in the form of vaccine to address NPCs.

Depletion of NFBD1/MDC1 Induces Apoptosis in Nasopharyngeal Carcinoma Cells Through the p53-ROS-Mitochondrial Pathway

NFBD1, a signal amplifier of the p53 pathway, is vital for protecting cells from p53-mediated apoptosis and the early phase of DNA damage response under normal culture conditions. Here we investigated its expression in patients with nasopharyngeal carcinoma (NPC), and we describe the biological functions of the NFBD1 gene. We found that NFBD1 mRNA and protein were more highly expressed in NPC tissues than in nontumorous tissues. To investigate the function of NFBD1, we created NFBD1-depleted NPC cell lines that exhibited decreased cellular proliferation and colony formation, an increase in their rate of apoptosis, and an enhanced sensitivity to chemotherapeutic agents compared with in vitro controls. However, N-acetyl cysteine (NAC) and downregulation of p53 expression could partially reverse the apoptosis caused by the loss of NFBD1. Further analysis showed that loss of NFBD1 resulted in increased production of intracellular reactive oxygen species (ROS) depending on p53, which subsequently triggered the mitochondrial apoptotic pathway. Using a xenograft model in nude mice, we showed that silencing NFBD1 also significantly inhibited tumor growth and led to apoptosis. Taken together, our data suggest that inhibition of NFBD1 in NPC could be therapeutically useful.

Exome Sequencing Identifies Potentially Druggable Mutations in Nasopharyngeal Carcinoma

In this study, we first performed whole exome sequencing of DNA from 10 untreated and clinically annotated fresh frozen nasopharyngeal carcinoma (NPC) biopsies and matched bloods to identify somatically mutated genes that may be amenable to targeted therapeutic strategies. We identified a total of 323 mutations which were either non-synonymous (n = 238) or synonymous (n = 85). Furthermore, our analysis revealed genes in key cancer pathways (DNA repair, cell cycle regulation, apoptosis, immune response, lipid signaling) were mutated, of which those in the lipid-signaling pathway were the most enriched. We next extended our analysis on a prioritized sub-set of 37 mutated genes plus top 5 mutated cancer genes listed in COSMIC using a custom designed HaloPlex target enrichment panel with an additional 88 NPC samples. Our analysis identified 160 additional non-synonymous mutations in 37/42 genes in 66/88 samples. Of these, 99/160 mutations within potentially druggable pathways were further selected for validation. Sanger sequencing revealed that 77/99 variants were true positives, giving an accuracy of 78%. Taken together, our study indicated that ~72% (n = 71/98) of NPC samples harbored mutations in one of the four cancer pathways (EGFR-PI3K-Akt-mTOR, NOTCH, NF-κB, DNA repair) which may be potentially useful as predictive biomarkers of response to matched targeted therapies.

Albumin-to-Alkaline Phosphatase Ratio: A Novel Prognostic Index of Overall Survival in Cisplatin-based Chemotherapy-treated Patients with Metastatic Nasopharyngeal Carcinoma

The Albumin-to-Alkaline Phosphatase Ratio (AAPR) has been recently revealed as a prognostic index for hepatocellular carcinoma, whereas its role in metastatic nasopharyngeal cancer (NPC) remains unclear. The aim of this study was to evaluate the clinical value of AAPR in patients with metastatic NPC. We retrospectively reviewed 209 metastatic NPC patients treated with cisplatin-based regimens. Survival data were calculated using the Kaplan-Meier method and were compared using the log-rank test. Univariate and multivariate survival analyses were conducted using the Cox proportional hazards regression methodology. The optimal cutoff level of AAPR for assessing overall survival (OS) was 0.447, which was determined by R software. An AAPR less than 0.447 was significantly associated with a higher lactate dehydrogenase (LDH) level (273 vs. 185 U/L, P = 0.004), a higher EBV DNA viral load (5.59×105 vs. 3.49×104 copies/ml, P = 0.001), and more liver and bone metastases (P = 0.005 and P = 0.001, respectively). Additionally, patients with an AAPR < 0.447 had a shorter overall survival and progression-free survival (hazard ratio: 3.269, 95% confidence interval: 1.710-6.248; HR: 2.295, 95% confidence interval: 1.217-4.331, respectively) than those with an AAPR ≥ 0.447. Our study suggested that the AAPR might be a novel prognostic factor in metastatic NPC patients treated with cisplatin-based regimens. However, a prospective study to validate its prognostic value is needed, and the mechanisms underlying the low AAPR and poor survival in metastatic NPC need to be further investigated.

miR-185-3p regulates the invasion and metastasis of nasopharyngeal carcinoma by targeting WNT2B in vitro

MicroRNAs (miRs) have been recognised as important regulators of malignant behaviour in different types of human cancer, including nasopharyngeal carcinoma (NPC). A previous study by our group revealed that miR-185-3p regulates the radioresistance of NPC cells. The present study aimed to investigate the effect of miR-185-3p on NPC invasion and metastasis. Human NPC CNE-2 and 5-8F cell lines were transfected with a miR-185-3p mimic and miR-185-3p inhibitor, respectively, and their effects on the invasion and metastasis of these cells was assessed using a wound healing assay and Matrigel invasion assay. The target gene of miR-185-3p, Wnt family member 2B (WNT2B) was silenced in 5-8F cells using siRNA in order to investigate its function in NPC. Data from the present study demonstrated that the expression of miR-185-3p was the highest in 5-8F and lowest in CNE-2 cells out of a range of NPC cell lines. Following the transfection of miR-185-3p mimic into CNE-2 cells, the wound healing and Matrigel invasion assays indicated that the migration and invasion ability of CNE-2 cells was significantly reduced compared with the negative control group. In addition, the inhibition of miR-185-3p in 5-8F cells significantly increased the capacity for migration and invasion. Furthermore, silencing WNT2B expression resulted in a significant reduction in the invasion and metastasis in 5-8F cells. The inhibition of miR-185-3p, which promotes invasion and metastasis, could be reversed through the silencing of WNT2B in 5-8F cells. The results of the present study indicate that miR-185-3p mediates the invasion and metastasis of NPC by targeting WNT2B in vitro.

Plasma Fibrinogen Correlates with Metastasis and is Associated with Prognosis in Human Nasopharyngeal Carcinoma

Background: The purpose of this observational study was to evaluate the prognostic significance of the pre-treatment plasma fibrinogen level for survival outcomes in nasopharyngeal carcinoma (NPC).

Methods: A total of 998 patients with NPC treated at a single centre in China were retrospectively enrolled, of whom 182 (18.2%) developed distant metastasis during follow-up. Survival analyses were performed by the Kaplan-Meier method and Cox regression modelling to measure 3-year overall survival (OS) and distant metastasis-free survival (DMFS).

Results: Median OS for the entire cohort was 37.8 months. Using the cut-off value of 3.345 g/L identified in receiver operating curve analysis for fibrinogen, a high pre-treatment plasma fibrinogen level were associated with older age (P = 0.034), advanced TNM stage (P = 0.004) and development of distant metastasis (P < 0.001; Chi-square test). Multivariate Cox proportional hazard analysis demonstrated the pre-treatment plasma fibrinogen level was an independent significant prognostic factor for OS and DMFS in both the entire cohort and also among patients who developed distant metastasis during follow-up.

Conclusions: This study suggests the pre-treatment plasma fibrinogen level may serve as an independent prognostic marker to predict the survival outcomes of patients with NPC, including patients with metastatic disease.

Cyclin-Dependent Kinase Inhibitor 3 Promotes Cancer Cell Proliferation and Tumorigenesis in Nasopharyngeal Carcinoma by Targeting p27

Nasopharyngeal carcinoma (NPC) is a common malignancy of the head and neck that arises from the nasopharynx epithelium and is highly invasive. Cyclin-dependent kinase inhibitor 3 (CDKN3) belongs to the dual-specificity protein phosphatase family, which plays a key role in regulating cell division. Abnormal expression of CDKN3 has been found in numerous types of cancer. In the current study, we explored the possible role of CDKN3 in cell proliferation, ability to invade, and radiosensitivity in NPC cells. We reported that CDKN3 was upregulated and p27 was downregulated in NPC tissues and is associated with a worse prognosis for patients. In addition, downregulation of CDKN3 and upregulation of p27 decreased cell proliferation, induced cell cycle arrest, increased apoptosis, decreased cell invasion, and enhanced radiosensitivity. Silencing of p27 significantly inhibited the effects of the knockdown of CDKN3. Moreover, downregulation of CDKN3 and upregulation of p27 inhibited the increase in tumor volume and weight in implanted tumors, decreased the phosphorylation of Akt, and increased the expression of cleaved caspase 3 in tumors. CDKN3 expression was also inversely correlated with p27 expression in NPC patients. Knockdown of CDKN3 increased p27 expression. Silencing of p27 markedly inhibited the effects of CDKN3 on cell proliferation, cell cycle progression, apoptosis, invasion, and radiosensitivity. These results demonstrate that upregulation of p27 is involved in the knockdown of CDKN3-induced decrease in cell proliferation, increase in cell cycle arrest and apoptosis, decrease in invasion, and increase in radiosensitivity. The results demonstrate that the CDKN3/p27 axis may be a novel target in the treatment of NPC.

miR-324-3p suppresses migration and invasion by targeting WNT2B in nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck with strong ability of invasion and metastasis. Our previous study indicated that miR-324-3p, as a tumor-suppressive factor, could regulate radioresistance of NPC cells by targeting WNT2B. The purpose of this study is to investigate the role of miR-324-3p on migration and invasion in NPC cells.

Methods

Quantitative real time PCR was applied to measure the expression level of miR-324-3p and WNT2B mRNA in both cells and tissues, and the expression level of WNT2B protein was determined by western blotting. The capacity of migration and invasion were tested by using wound healing and transwell invasion assay.

Results

Ectopic expression of miR-324-3p or silencing its target gene WNT2B could dramatically suppress migration and invasion capacity of NPC cells. Meanwhile, the alterations of miR-324-3p in NPC cells could influence the expression level of the biomarkers of epithelial-mesenchymal transition (EMT), including E-cadherin and Vimentin. Moreover, the expression of miR-324-3p was obviously downregulated and WNT2B was significantly upregulated in NPC tissues. The expression levels of miR-324-3p and WNT2B were closely correlated with T stage, clinic stage and cervical lymph node metastasis of NPC (P < 0.05).

Conclusion

miR-324-3p could suppress the migration and invasion of NPC by targeting WNT2B and the miR-324-3p/WNT2B pathway possibly provide new potential therapeutic clues for NPC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0372-8) contains supplementary material, which is available to authorized users.

Therapeutic effect of TMZ-POH on human nasopharyngeal carcinoma depends on reactive oxygen species accumulation

Nasopharyngeal carcinoma (NPC) is a common head and neck malignancy without efficient chemotherapeutic agents for it. In our current study, we demonstrated the cytotoxicity effects of a newly patented compound temozolomide–perillyl alcohol (TMZ-POH) on NPC in vitro and in vivo, and the possible mechanisms involved. Human NPC cell lines CNE1, CNE2, HNE2, and SUME-α were treated with control (DMSO), TMZ, POH, TMZ plus POH, and TMZ-POH. Our data indicated that TMZ-POH could inhibit NPC cell proliferation, cause G₂/M arrest and DNA damage. TMZ-POH triggered apoptosis in NPC cells via significant activation of caspase-3 and poly(ADP-ribose) polymerase (PARP). Importantly, TMZ-POH-induced cell death was found to be associated with (i) the loss of inner mitochondrial membrane potential (ΔΨm) and release of mitochondrial Cytochrome c, (ii) the increase in ROS generation, and (iii) the activation of stress-activated protein kinases (SAPK)/c-Jun N-terminal kinases (JNK) signaling pathway. The generation of ROS in response to TMZ-POH seems to play a crucial role in the cell death process since the blockage of ROS production using the antioxidant N-acetyl-L-cysteine or catalase reversed the TMZ-POH-induced JNK activation, DNA damage, and cancer cell apoptosis. These results provide the rationale for further research and preclinical investigation of the antitumor effect of TMZ-POH against human NPC.

Knockdown of TKTL1 additively complements cisplatin-induced cytotoxicity in nasopharyngeal carcinoma cells by regulating the levels of NADPH and ribose-5-phosphate

BACKGROUND

Transketolase-like 1 (TKTL1) plays an important role in pentose phosphate pathway (PPP) branch, the main pathway generating nicotinamide adenine dinucleotide phosphate (NADPH) and nucleotides for DNA synthesis. TKTL1 is closely related to DNA damage and has a close relationship with incidence and progression of cancers. Cisplatin is the main chemotherapeutic drug by inducing DNA damage. Whether TKTL1 knockdown additively complements cisplatin-induced cytotoxicity in nasopharyngeal carcinoma cells, however, remains largely undefined.

METHODS

Lipofectamine 2000 was used to transfect si-TKTL1s with different sequences into the CNE2 and HONE1 cells. The mRNA and protein levels of TKTL1 were determined by qRT-PCR and western blot, respectively. MTT assay and flow cytometry were used to access the viability and apoptosis of CNE2 and HONE1 cells. The NADPH and ribose-5-phosphate levels in both CNE2 and HONE1 cells were determined by NADPH examination kit and HPCE analysis, respectively. The effect of TKTL1 knockdown and NADPH/ribose-5-phosphate supplement on DNA damage was assessed by using Comet assay.

RESULTS

TKTL1 knockdown significantly decreased TKTL1 level in CNE2 and HONE1 cells. A significant decrease in cell viability and an obvious increase in cell apoptosis rate were found in si-TKTL1+cisplatin group compared with si-TKTL1 group or si-control+cisplatin group. The levels of NADPH and ribose-5-phosphate in CNE1 and HONE1 cells were dramatically decreased in si-TKTL1 group compared with si-control group. TKTL1 knockdown additively complemented cisplatin-induced cytotoxicity, which was partly reversed by the supplements of NADPH and ribose-5-phosphate, including the increased survival rate, decreased apoptosis and DNA damage.

CONCLUSIONS

Knockdown of TKTL1 additively complements cisplatin-induced cytotoxicity in the nasopharyngeal carcinoma cells by inhibiting the levels of NADPH and ribose-5-phosphate, indicating that TKTL1 may be a promising target to improve the therapeutic effect combining with cisplatin for the patients with nasopharyngeal carcinoma.

Circulating tumor cells in the blood of poorly differentiated nasal squamous cell carcinoma patients: correlation with treatment response

CONCLUSION

The results implied that CTCs were common even in early TNM stages and might become a potential parameter in evaluating therapeutic effects of radio and chemotherapies.

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a head and neck malignancy with an extraordinary high incidence in Southern China and a high metastasis rate. Analysis of circulating tumor cells (CTCs) in peripheral blood is a relatively new prognostic marker for cancer patients.

PATIENTS AND METHODS

This retrospective study included data from 38 nasopharyngeal patients with poorly differentiated squamous cell carcinoma in TNM stage I (n = 2), TNM stage II (n = 12), TNM stage III (n = 8), and TNM stage IV (n = 16). CTCs in peripheral blood of all patients were counted before and 1 week as well as 1 months after radiotherapy.

RESULTS

The data showed that in 52.6% of the patients CTCs could be detected in peripheral blood and the numbers were significantly decreased 1 month after radiotherapy treatment (p < 0.001). There was no correlation between CTC number or positivity and TNM stages or other clinical parameters.

Overweight/obese status associates with favorable outcome in patients with metastatic nasopharyngeal carcinoma: a 10-year retrospective study

Background

Although the prognostic impact of body mass index (BMI) in patients with non-metastatic nasopharyngeal carcinoma (NPC) had been extensively studied, its effect among metastatic NPC patients remains unknown. The purpose of this study was to evaluate the prognostic effect of BMI in patients with metastatic NPC.

Methods

We retrospectively studied 819 patients who were diagnosed with distant metastasis from NPC and received treatment between 1998 and 2007. The patients were divided into three subgroups according to the World Health Organization classifications for Asian populations: underweight (BMI <18.5 kg/m²), normal weight (BMI 18.5–22.9 kg/m²), and overweight/obese (BMI ≥23.0 kg/m²). The associations of BMI with overall survival (OS) and progression-free survival (PFS) were determined by Cox regression analysis.

Results

Of the 819 patients, 168 (20.5%) were underweight, 431 (52.6%) were normal weight, and 220 (26.9%) were overweight/obese. Multivariate analysis adjusted for covariates showed that overweight/obese patients had a longer OS than underweight patients [hazard ratio (HR), 0.64; 95% confidence interval (CI), 0.49–0.84] and normal weight patients (HR, 0.72; 95% CI, 0.57–0.90); no significant difference in PFS was observed among these three groups (P = 0.407). Moreover, in stratified analysis, no statistically significant differences in the effect of overweight/obese status among different subgroups were observed.

Conclusion

For patients with metastatic NPC, overweight/obese status was associated with longer OS but not longer PFS compared with underweight or normal weight status.

Phase I/II dose-finding study of nanoparticle albumin-bound paclitaxel (nab®-Paclitaxel) plus Cisplatin as Treatment for Metastatic Nasopharyngeal Carcinoma

BACKGROUND

This phase I/II study aimed to determine the maximum tolerated dose (MTD) of nanoparticle albumin-bound paclitaxel (nab (®)-paclitaxel) plus cisplatin as treatment for metastatic nasopharyngeal carcinoma (NPC).

METHODS

Patients were enrolled into 1 of 3 dose cohorts, each with 21-day treatment cycles: 1) intravenous (IV) nab-paclitaxel 260 mg/m(2) on day 1; 2) IV nab-paclitaxel 140 mg/m(2) on days 1 and 8; 3) IV nab-paclitaxel 100 mg/m(2) on days 1, 8, and 15. All patients received IV cisplatin 75 mg/m(2) on day 1. Treatment continued for 4-6 cycles, or until progression or unacceptable toxicity. If more than one-third of the patients in a cohort experienced a dose-limiting toxicity (DLT), the dose used in the previous cohort would be designated the MTD. Secreted protein acidic and rich in cysteine (SPARC) expression was detected by immunohistochemistry staining.

RESULTS

Sixty-nine patients were enrolled, of whom 64 and 67 were eligible for efficacy and safety analysis, respectively. Two DLTs occurred in cohort 1 (grade 4 febrile neutropenia, grade 3 myalgia), none occurred in cohort 2, and 2 occurred in cohort 3 (both grade 3 fatigue). The MTD was not reached. Partial responses were achieved by 42 patients, 15 had stable disease, and 7 had progressive disease, giving an overall response rate of 66 %. Median progression-free survival was 9 months (95 % CI, 6-12 months). Grade ≥ 3 adverse events were mainly hematologic. There was no significant difference between the 3 cohorts with respect to efficacy or safety. Biomarker analyses indicated that stromal, rather than tumoral, SPARC may predict the response to nab-paclitaxel in NPC.

CONCLUSIONS

Our findings suggest that nab-paclitaxel plus cisplatin is a highly active regimen with moderate toxicity for the treatment of metastatic NPC, which warrants further investigation in a phase III study.

TRIAL REGISTRATIONS

ClinicalTrials.gov ID: NCT01735409 . The trial was registered on November 20th, 2012.

Cetuximab in combination with chemoradiotherapy in the treatment of recurrent and/or metastatic nasopharyngeal carcinoma

The aim of the study was to assess the efficacy and toxicity of cetuximab in the combined treatment for patients with recurrent and/or metastatic nasopharyngeal carcinoma (R/M NPC). Between March 2007 and November 2011, a total of 30 R/M NPC patients treated with comprehensive therapy including cetuximab were retrospectively enrolled. Intensity-modulated radiation therapy was delivered in recurrent disease with a median dose of 60 Gy. Chemotherapy regimens included TP/TPF (docetaxel 60-75 mg/m d1+DDP 25 mg/m d1-3±5-FU 500 mg/m/day with 120-h infusion), GP (gemcitabine 1.0 g/m d1, d8+DDP 25 mg/m d1-3), and PC (paclitaxel 60 mg/m/week d1+carboplatin AUC 2/week d1). Acute and late toxicities were documented by the radiation oncologists. The median age of the patients was 44 years (range 26-62). A total of 21 patients (70%) achieved response (CR+PR). The median survival time, time to progression, and 2-year overall survival were 23.6, 12.2 months, and 53.3%, respectively. Cetuximab appears to be effective and well tolerated when combined with chemoradiation therapy for the treatment of R/M NPC.

Multimodality Treatment May Improve the Survival Rate of Patients with Metastatic Nasopharyngeal Carcinoma with Good Performance Status

The aim of the present study was to evaluate the benefit of chemotherapy, combined with palliative radiotherapy (PRT) and other local treatments to the metastatic sites, for patients with metastatic nasopharyngeal carcinoma (NPC) who had a performance status 0-2. We conducted a retrospective review of available data from 197 biopsy-proven NPC patients who developed metastasis after their initial definitive treatment. These patients were grouped into three categories according to the different treatment paths that were followed: the best supportive care (64 patients), chemotherapy alone (55 patients), and multimodality treatment with chemotherapy combined with PRT and other local treatments to metastatic sites (78 patients). The 2-year metastatic survival rate of patients in the multimodality treatment group was 57.7%, which was significantly better than that of the patients in both the chemotherapy alone group and the best supportive care group (32.7% and 1.6%, respectively). The independent significant factors affecting survival were the disease-free interval prior to the detection of metastatic disease, the number of metastases, the number of chemotherapy cycles and the biological effective dose of PRT. In conclusion, multimodality treatment may improve survival of select patients with recurrent NPC with distant metastases.

Protein N-arginine methyltransferase 5 promotes the tumor progression and radioresistance of nasopharyngeal carcinoma

Radiotherapy resistance is the main cause of the the poor prognosis of some nasopharyngeal carcinoma (NPC) patients. Yet, the exact mechanism is still elusive. In the present study, we explored the clinical and biological role of protein arginine methyltransferase 5 (PRMT5) in NPC. Our results revealed that PRMT5 was overexpressed in NPC tissues when compared with that in adjacent non-tumor tissues by quantitative RT-PCR and immunoblotting. High expression of PRMT5 was correlated with adverse outcomes of NPC patients as determined by the scoring of a tissue microarray. Silencing of PRMT5 promoted the radiosensitivity of 5-8F and CNE2 cells as determined by cell proliferation and colony formation assays. Furthermore, fibroblast growth factor receptor 3 (FGFR3) was identified as one of the downstream targets of PRMT5, and the silencing of PRMT5 decreased the mRNA and protein levels of FGFR3 in the 5-8F and CNE2 cells. Silencing of FGFR3 induced similar phenotypes as the inhibition of PRMT5, and re-expression of FGFR3 in 5-8F/shPRMT5 and CNE2/shPRMT5 cells restored the proliferation and colony formation ability induced by irradiation exposure. Our results indicate that PRMT5 is a marker of poor prognosis in NPC patients. PRMT5 promoted the radioresistance of NPC cells via targeting FGFR3, at least partly if not totally. PRMT5 and its downstream effector FGFR3 may be potential targets for anticancer strategy.

Distant metastasis risk and patterns of nasopharyngeal carcinoma in the era of IMRT: long-term results and benefits of chemotherapy

PURPOSE

To report the distant metastasis (DM) risk and patterns for nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT) and to analyze the benefits of chemotherapy based on DM risk.

MATERIALS AND METHODS

576 NPC patients were analyzed. The DM rates were calculated using the Kaplan-Meier method, and the log-rank test was used to compare differences. The patients were divided into different risk subclassifications according to DM hazard ratios.

RESULTS

91 patients developed DM after treatment, with bone as the most common metastatic sites. 82.4% of DMs occurred within 3 years of treatment. Patients were classified as low-risk, intermediate-risk and high-risk, and the corresponding 5-year DM rates were 5.1%, 13.1% and 32.4%, respectively (P < 0.001). Chemotherapy failed to decrease the DM rate in the low-risk subclassification, but decreased the DM risk in the intermediate-risk subclassification (P = 0.025). In the high-risk subclassification, the DM rate was 31.9% though chemotherapy was used, which was significantly higher than that of other two subclassifications.

CONCLUSIONS

DM is the dominant treatment failure in NPC treated by IMRT, with similar occurrence times and distributions to those that occurred in the era of conventional radiotherapy. Further studies on treatment optimization are needed in high-risk patients.

Silencing NFBD1/MDC1 enhances the radiosensitivity of human nasopharyngeal cancer CNE1 cells and results in tumor growth inhibition

NFBD1 functions in cell cycle checkpoint activation and DNA repair following ionizing radiation (IR). In this study, we defined the NFBD1 as a tractable molecular target to radiosensitize nasopharyngeal carcinoma (NPC) cells. Silencing NFBD1 using lentivirus-mediated shRNA-sensitized NPC cells to radiation in a dose-dependent manner, increasing apoptotic cell death, decreasing clonogenic survival and delaying DNA damage repair. Furthermore, downregulation of NFBD1 inhibited the amplification of the IR-induced DNA damage signal, and failed to accumulate and retain DNA damage-response proteins at the DNA damage sites, which leaded to defective checkpoint activation following DNA damage. We also implicated the involvement of NFBD1 in IR-induced Rad51 and DNA-dependent protein kinase catalytic subunit foci formation. Xenografts models in nude mice showed that silencing NFBD1 significantly enhanced the antitumor activity of IR, leading to tumor growth inhibition of the combination therapy. Our studies suggested that a combination of gene therapy and radiation therapy may be an effective strategy for human NPC treatment.

Risk factors and prediction-score model for distant metastasis in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

The objective of this study is to identify the risk factors and construct a prediction-score model for distant metastasis (DM) in nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT). A total of 520 nonmetastatic NPC patients were analysed retrospectively. The independent risk factors for DM were tested by multivariate Cox regression analysis. The prediction-score model was established according to the regression coefficient. The median follow-up was 88.4 months. The 5-year DM rate was 15.1%. N2-3, primary tumour volume of nasopharynx (GTVnx) >24.56 cm(3), haemoglobin change after treatment (ΔHGB) >25.8 g/L, albumin-globulin ratio (AGR) ≤1.34, pretreatment neutrophil-lymphocyte ratio (NLR) >2.81 and pretreatment serum lactate dehydrogenase (LDH) >245 U/L were significantly adverse independent predictive factors for DM. Three subgroups were defined based on the prediction-score model: low risk (0-2), intermediate risk (3-4) and high risk (5-8). The 5-year DM rates were 4.6, 21.8 and 50.8%, respectively (P < 0.001). The areas under the curve for DM in the prediction-score model and the UICC/AJCC staging system seventh edition were 0.748 and 0.627, respectively (P < 0.001). The scoring model is useful in evaluating the risk of DM in IMRT-treated NPC patients and guiding future therapeutic trials. Further prospective study is needed.

Serum alkaline phosphatase predicts survival outcomes in patients with skeletal metastatic nasopharyngeal carcinoma

OBJECTIVE

Bone metastasis is frequently associated with nasopharyngeal carcinoma. The diagnosis and follow-up of bone metastatic patients usually relies on skeletal X-ray and bone scintigraphy, which are time-consuming and costly. This study aimed to evaluate whether serum alkaline phosphatase offers clinical value in predicting the clinical response and survival outcome for skeletal metastatic nasopharyngeal carcinoma.

METHODS

Serum alkaline phosphatase was measured at baseline and then before each cycle of treatment in 416 nasopharyngeal carcinoma patients with bone metastasis. The correlations between the pre-treatment and post-treatment alkaline phosphatase levels and the treatment efficacy were analyzed using the chi-square test. Survival was analyzed using the Kaplan-Meier method and then compared using the log-rank test.

RESULTS

Patients with elevated pre-treatment alkaline phosphatase (>110 IU/L) had significantly worse progression-free survival (P<0.001) and overall survival (P<0.001) than those with a normal level of this marker (≤110 IU/L). Patients with elevated post-treatment alkaline phosphatase had worse progression-free survival (P<0.001) and overall survival (P<0.001) compared with those with a normal level. Patients with normal pre-treatment and post-treatment alkaline phosphatase showed the most favorable prognosis. The Cox multivariate analysis revealed that only the pre-treatment and post-treatment alkaline phosphatase levels were independent prognostic factors for progression-free survival (HR ϝ 1.656, P<0.001; HR ϝ 2.226, P<0.001) and for overall survival (HR ϝ 1.794, P<0.001; HR ϝ 2.657, P<0.001).

CONCLUSIONS

Serum alkaline phosphatase appears to be a significant independent prognostic index in patients with skeletal metastatic nasopharyngeal carcinoma, which could reflect the short-term treatment response of palliative chemotherapy and the long-term survival outcomes.

M1 stage subdivision and treatment outcome of patients with bone-only metastasis of nasopharyngeal carcinoma

BACKGROUND

The current M1 stage in nasopharyngeal carcinoma (NPC) does not differentiate patients based on metastatic site and number of metastases. This study aims to subdivide the M1 stage of NPC patients with bone-only metastases and to identify the patients who may benefit from combined chemoradiotherapy (CRT).

METHODS

Between 1998 and 2007, 312 patients diagnosed with bone-only metastasis at Sun Yat-sen University Cancer Center were enrolled. Various possible subdivisions of M1 stage were considered, including by the time order of metastasis (synchronous vs. metachronous), involvement of specific bone metastatic site, the number of metastatic sites, and the number of metastases. The correlation of the subdivisions of M1 stage with overall survival (OS) was determined by Cox regression.

RESULTS

The median OS was 23.4 months. Patients with more than three metastatic sites had significantly poorer OS than patients with three or fewer metastatic sites (16.2 vs. 32.4 months; p < .001). Metastasis to the spine was significantly associated with unfavorable OS (20.4 vs. 37.9 months; p < .001). Multivariate analysis showed that number of metastatic sites (more than three vs. three or fewer), spine involvement (present vs. absent), and treatment modality (CRT vs. chemotherapy or radiotherapy only) were independent prognostic factors for OS. In stratified analysis, compared with chemotherapy or radiotherapy alone, combined chemoradiotherapy could significantly benefit the patients with single bone metastasis (hazard ratio: 0.21; 95% confidence interval: 0.09-0.50).

CONCLUSION

Metastasis to the spine and having more than three bone metastatic sites are independent unfavorable predictors for OS in NPC patients with bone-only metastasis. Combined chemoradiotherapy should be considered for patients with single bone metastasis.

Parthenolide inhibits cancer stem-like side population of nasopharyngeal carcinoma cells via suppression of the NF-κB/COX-2 pathway

Cancer stem cells play a central role in the pathogenesis of nasopharyngeal carcinoma and contribute to both disease initiation and relapse. In this study, cyclooxygenase-2 (COX-2) was found to regulate cancer stem-like side population cells of nasopharyngeal carcinoma cells and enhance cancer stem-like cells' characteristics such as higher colony formation efficiency and overexpression of stemness-associated genes. The regulatory effect of COX-2 on cancer stem-like characteristics may be mediated by ABCG2. COX-2 overexpression by a gain-of-function experiment increased the proportion of side population cells and their cancer stemness properties. The present study also demonstrated that in contrast to the classical chemotherapy drug 5-fluorouracil, which increased the proportion of side population cells and upregulated the expression of COX-2, parthenolide, a naturally occurring small molecule, preferentially targeted the side population cells of nasopharyngeal carcinoma cells and downregulated COX-2. Moreover, we found that the cancer stem-like cells' phenotype was suppressed by using COX-2 inhibitors NS-398 and CAY10404 or knocking down COX-2 with siRNA and shRNA. These findings suggest that COX-2 inhibition is the mechanism by which parthenolide induces cell death in the cancer stem-like cells of nasopharyngeal carcinoma. In addition, parthenolide exhibited an inhibitory effect on nuclear factor-kappa B (NF-κB) nucler translocation by suppressing both the phosphorylation of IκB kinase complex and IκBα degradation. Taken together, these results suggest that parthenolide may exert its cancer stem cell-targeted chemotherapy through the NF-κB/COX-2 pathway.

The Glasgow Prognostic Score predicts poor survival in cisplatin-based treated patients with metastatic nasopharyngeal carcinoma

BACKGROUND

Several inflammation-based prognostic scoring systems, including Glasgow Prognostic Score (GPS), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) have been reported to predict survival in many malignancies, whereas their role in metastatic nasopharyngeal carcinoma (NPC) remains unclear. The aim of this study is to evaluate the clinical value of these prognostic scoring systems in a cohort of cisplatin-based treated patients with metastatic NPC.

METHODS

Two hundred and eleven patients with histologically proven metastatic NPC treated with first-line cisplatin-based chemotherapy were retrospectively evaluated. Demographics, disease-related characteristics and relevant laboratory data before treatment were recorded. GPS, NLR and PLR were calculated as described previously. Response to first-line therapy and survival data were also collected. Survival was analyzed in Cox regressions and stability of the models was examined by bootstrap resampling. The area under the receiver operating characteristics curve (AUC) was calculated to compare the discriminatory ability of each scoring system.

RESULTS

Among the above three inflammation-based prognostic scoring systems, GPS (P<0.001) and NLR (P = 0.019) were independently associated with overall survival, which showed to be stable in a bootstrap resampling study. The GPS consistently showed a higher AUC value at 6-month (0.805), 12-month (0.705), and 24-month (0.705) in comparison with NLR and PLR. Further analysis of the association of GPS with progression-free survival showed GPS was also associated independently with progression-free survival (P<0.001).

CONCLUSIONS

Our study demonstrated that the GPS may be of prognostic value in metastatic NPC patients treated with cisplatin-based palliative chemotherapy and facilitate individualized treatment. However a prospective study to validate this prognostic model is still needed.

A recombinant modified vaccinia ankara vaccine encoding Epstein-Barr Virus (EBV) target antigens: a phase I trial in UK patients with EBV-positive cancer

PURPOSE

Epstein-Barr virus (EBV) is associated with several cancers in which the tumor cells express EBV antigens EBNA1 and LMP2. A therapeutic vaccine comprising a recombinant vaccinia virus, MVA-EL, was designed to boost immunity to these tumor antigens. A phase I trial was conducted to demonstrate the safety and immunogenicity of MVA-EL across a range of doses.

EXPERIMENTAL DESIGN

Sixteen patients in the United Kingdom (UK) with EBV-positive nasopharyngeal carcinoma (NPC) received three intradermal vaccinations of MVA-EL at 3-weekly intervals at dose levels between 5 × 10(7) and 5 × 10(8) plaque-forming units (pfu). Blood samples were taken at screening, after each vaccine cycle, and during the post-vaccination period. T-cell responses were measured using IFNγ ELISpot assays with overlapping EBNA1/LMP2 peptide mixes or HLA-matched epitope peptides. Polychromatic flow cytometry was used to characterize functionally responsive T-cell populations.

RESULTS

Vaccination was generally well tolerated. Immunity increased after vaccination to at least one antigen in 8 of 14 patients (7/14, EBNA1; 6/14, LMP2), including recognition of epitopes that vary between EBV strains associated with different ethnic groups. Immunophenotypic analysis revealed that vaccination induced differentiation and functional diversification of responsive T-cell populations specific for EBNA1 and LMP2 within the CD4 and CD8 compartments, respectively.

CONCLUSIONS

MVA-EL is safe and immunogenic across diverse ethnicities and thus suitable for use in trials against different EBV-positive cancers globally as well as in South-East Asia where NPC is most common. The highest dose (5 × 10(8) pfu) is recommended for investigation in current phase IB and II trials.

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.

LASSO NTCP predictors for the incidence of xerostomia in patients with head and neck squamous cell carcinoma and nasopharyngeal carcinoma

To predict the incidence of moderate-to-severe patient-reported xerostomia among head and neck squamous cell carcinoma (HNSCC) and nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT). Multivariable normal tissue complication probability (NTCP) models were developed by using quality of life questionnaire datasets from 152 patients with HNSCC and 84 patients with NPC. The primary endpoint was defined as moderate-to-severe xerostomia after IMRT. The numbers of predictive factors for a multivariable logistic regression model were determined using the least absolute shrinkage and selection operator (LASSO) with bootstrapping technique. Four predictive models were achieved by LASSO with the smallest number of factors while preserving predictive value with higher AUC performance. For all models, the dosimetric factors for the mean dose given to the contralateral and ipsilateral parotid gland were selected as the most significant predictors. Followed by the different clinical and socio-economic factors being selected, namely age, financial status, T stage, and education for different models were chosen. The predicted incidence of xerostomia for HNSCC and NPC patients can be improved by using multivariable logistic regression models with LASSO technique. The predictive model developed in HNSCC cannot be generalized to NPC cohort treated with IMRT without validation and vice versa.

Activation of Akt/mTOR pathway is associated with poor prognosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor of the head and neck region, which frequently occurs in Southeast Asia, especially in the south of China. It is known that the mammalian target of rapamycin (mTOR) pathway plays a central role in regulating cellular functions, including proliferation, growth, survival, mobility, and angiogenesis. Aberrant expression of the mTOR signaling pathway molecules has been found in many types of cancer. However, whether the alterations of p-Akt, p-p70S6K and p-4EBP1 protein expression are associated with clinicopathological features and prognostic implications in NPC have not been reported. The purposes of the present study are to investigate the association between the expression of p-Akt, p-p70S6K and p-4EBP1 proteins and clinicopathological features in NPC by immunohistochemistry. The results showed that the positive percentage of p-Akt, p-p70S6K and p-4EBP1 proteins expression in NPC (47.2%, 73.0% and 61.7%, respectively) was significantly higher than that in the non-cancerous nasopharyngeal control tissue (33.3%, 59.1% and 47.0%, respectively). There was a significantly higher positive expression of p-Akt in undifferentiated non-keratinizing nasopharyngeal carcinoma than that in differentiated non-keratinizing nasopharyngeal carcinoma (P = 0.014). Additionally, positive expression of p-p70S6K and p-4EBP1 proteins, and positive expression of either of p-Akt, p-p70S6K and p-4EBP1 were significantly correlated inversely with overall survival rates of NPC patients (P = 0.023, P = 0.033, P = 0.008, respectively). Spearman’s rank correlation test showed that expression of p-Akt in NPC was significantly associated with expression of p-p70S6K (r = 0.263, P<0.001) and p-4EBP1(r = 0.284, P<0.001). Also there was an obviously positive association between expression of p-p70S6K and p-4EBP1 proteins in NPC (r = 0.286, P<0.001). Multivariate Cox regression analysis further identified positive expression of p-4EBP1 and p-p70S6K proteins were the independent poor prognostic factors for NPC (P = 0.043, P = 0.027, respectively). Taken together, high expression of p-p70S6K and p-4EBP1 proteins may act as valuable independent biomarkers to predict a poor prognosis of NPC.

MiR-124 suppresses tumor growth and metastasis by targeting Foxq1 in nasopharyngeal carcinoma

Background

The molecular mechanisms underlying dysregulation of microRNAs have been documented in nasopharyngeal carcinoma (NPC). Our previous study demonstrated that plasma miR-124 was down-regulated in NPC using microarray analysis and quantitative PCR validation. Though growing studies showed that down-regulated miR-124 was closely related to tumourigenesis in various types of cancers, the role of miR-124 in NPC remains largely unknown.

Methods

The expression level of miR-124 was evaluated in NPC cell lines and patient specimens using quantitative reverse transcription-PCR (Real-time qPCR). The clinicopathological significance of the resultant data was later analyzed. Then, we explored the role of miR-124 in NPC tumorigenesis by in vitro and in vivo experiments. Homo sapiens forkhead box Q1 (Foxq1) was confirmed as a novel direct target gene of miR-124 by the dual-luciferase assay and western bolt.

Results

We found that miR-124 was commonly down-regulated in NPC specimens and NPC cell lines. The expression of miR-124 was inversely correlation with clinical stages and marked on T stages. Then, the ectopic expression of miR-124 dramatically inhibited cell proliferation, colony formation, migration and invasion in vitro, as well as tumor growth and metastasis in vivo. Furthermore, we identified Foxq1 as a novel direct target of miR-124. Functional studies showed that knockdown of Foxq1 inhibited cell growth, migration and invasion, whereas Foxq1 overexpression partially rescued the suppressive effect of miR-124 in NPC. In clinical specimens, Foxq1 was commonly up-regulated in NPC, and the level increased with clinical stages and T stages. Additionally, the level of Foxq1 was inversely correlated with miR-124.

Conclusions

Our results demonstrate that miR-124 functions as a tumor-suppressive microRNA in NPC, and that its suppressive effects are mediated chiefly by repressing Foxq1 expression. MiR-124 could serve as an independent biomarker to identify patients with different clinical characteristics. Therefore, our findings provide valuable clues toward the understanding the of mechanisms of NPC pathogenesis and provide an opportunity to develop new effective clinical therapies in the future.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-186) contains supplementary material, which is available to authorized users.