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The aim of the present study was to discuss the design of a microfluidic chip consisting of columns, and its use for the enrichment of nasopharyngeal cancer (NPC) cells. A microfluidic chip experiment was simulated using FLUENT software. Within the microfluidic chip, aptamers were bound to the reaction chamber (consisting of columns) using a biotin-avidin system. Cell suspension was introduced into the reaction chamber to capture NPC cells. NPC cells were subsequently eluted, and the capture rate of the cells was calculated. The modified aptamer-bound microfluidic chip was able to capture NPC cells with a capture rate of ~90%. The modified aptamer-bound microfluidic chip has a wide range of potential applications for the diagnosis of NPC. [ABSTRACT FROM AUTHOR]

Tumor recurrence and metastasis of nasopharyngeal cancer (NPC) often result in the failure of treatment due to chemoradioresistance. Cancer stem cells (CSCs) have been observed to drive tumor initiation and tumor chemoradioresistance. Therefore, the poor prognosis of advanced NPC is likely to result from the failure to kill CSCs. Sphere formation may be used as an experimental method to enrich potential CSC subpopulations. At present, there are few reports on NPC tumorspheres. The present study focused on examining the cancer stem-like properties of NPC tumorspheres from NPC cell lines. Western blot analysis revealed that NPC tumorspheres had a higher expression of stem cell markers Nanog homeobox and SRY-box 2, compared with parental cells. It was additionally verified that NPC tumorspheres contained a high aldehyde dehydrogenase (ALDH) enzymatic activity compared with parental cells. ALDH+ cells were amplified by 9- to 10-fold in tumorspheres, compared with parental cells (1.8 vs. 16.9%). The tumorsphere cells exhibited an increased half maximal inhibitory concentration value of >10-fold with cisplatin compared with the control parental cells. Compared with the parental cells, the percentage of side population cells in the tumorsphere cell population increased significantly (10.3 vs. 2.3%; P<0.05). NPC tumorsphere cells demonstrated enhanced resistance to radiation. Further investigation verified that salinomycin inhibited NPC CSCs by selectively targeting its stem cells. Altogether, the data revealed that NPC tumorspheres contain cancer stem-like populations with increased chemoradioresistance. It was suggested that the serum-free culture of NPC cells may provide an appropriate model for researching the sensitivity of CSCs to therapeutic agents. It was additionally revealed that salinomycin is an efficient inhibitor of NPC CSCs, supporting the hypothesis that salinomycin may eliminate CSCs and imply a need for further clinical evaluation. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is prevalent in Africa and East Asia, particularly in the southern areas of China. Previous data has demonstrated that microRNAs (miRNAs/miRs) may be involved in the formation and progression of NPC. The deregulation of miR-342 has been identified in multiple types of cancer. However, to the best of our knowledge, there are no data concerning miR-342 in NPC. The present study aimed to measure miR-342 expression in NPC, and to investigate its roles in NPC initiation and progression, in addition to the underlying molecular mechanisms. miR-342 was significantly downregulated in NPC tissues and cell lines. Low miR-342 expression was associated with distant metastasis and tumor node metastasis stage in patients with NPC. The restoration of the expression of miR-342 suppressed cell proliferation and invasion of NPC in vitro. In addition, ZEB1 was identified as a direct target gene of miR-342 in NPC. Downregulation of ZEB1 mimicked the tumor-suppressive roles of miR-342 in NPC. Taken together, the present study identified that miR-342 directly targeted ZEB1 to inhibit NPC cell growth and invasion, which may provide a novel therapeutic target for the treatments of patients with this malignancy. [ABSTRACT FROM AUTHOR]

Glutathione S-transferases (GSTs) participate in the detoxification and elimination of electrophilic carcinogens by conjugating them to glutathione. Previous studies have reported a potential association between GSTM1 polymorphism and the risk of developing nasopharyngeal cancer (NPC). However, those findings remain controversial. In the present study, a meta-analysis was conducted by pooling the odds ratios (ORs) with the corresponding 95% confidence intervals (CIs) of all the available case-control studies on NPC. A comprehensive search of PubMed, Embase, Web of Science and China National Knowledge Infrastructure databases up to May 13th, 2014 was performed to identify eligible studies. A total of 12 separate publications, involving 1,593 cases of NPC and 2,868 controls, were included in the meta-analysis. The results demonstrated that the null genotype of GSTM1 was significantly associated with increased risk of developing NPC (OR=1.530, 95% CI=1.348-1.737, Pheterogeneity=0.370). Subgroup analysis by ethnicity suggested that Asian carriers of the GSTM1 null genotype were more susceptible to NPC than individuals from other ethnic groups (OR=1.516, 95% CI=1.328-1.731, Pheterogeneity=0.270). Sensitivity analysis confirmed the stability of these observations. In conclusion, the results from the present meta-analysis indicated that the GSTM1 polymorphism may be involved in the development of NPC, particularly in Asians. [ABSTRACT FROM AUTHOR]

Glutathione S-transferases (GSTs) participate in the detoxification and elimination of electrophilic carcinogens by conjugating them to glutathione. Previous studies have reported a potential association between GSTM1 polymorphism and the risk of developing nasopharyngeal cancer (NPC). However, those findings remain controversial. In the present study, a meta-analysis was conducted by pooling the odds ratios (ORs) with the corresponding 95% confidence intervals (CIs) of all the available case-control studies on NPC. A comprehensive search of PubMed, Embase, Web of Science and China National Knowledge Infrastructure databases up to May 13 th , 2014 was performed to identify eligible studies. A total of 12 separate publications, involving 1,593 cases of NPC and 2,868 controls, were included in the meta-analysis. The results demonstrated that the null genotype of GSTM1 was significantly associated with increased risk of developing NPC (OR=1.530, 95% CI=1.348-1.737, P heterogeneity =0.370). Subgroup analysis by ethnicity suggested that Asian carriers of the GSTM1 null genotype were more susceptible to NPC than individuals from other ethnic groups (OR=1.516, 95% CI=1.328-1.731, P heterogeneity =0.270). Sensitivity analysis confirmed the stability of these observations. In conclusion, the results from the present meta-analysis indicated that the GSTM1 polymorphism may be involved in the development of NPC, particularly in Asians.

This study aimed to evaluate the efficacy, toxicity and tolerability of simultaneous modulated accelerated radiation therapy (SMART)-intensity modulated radiotherapy (IMRT) plus cisplatin and 5-fluorouracil (5-FU) chemotherapy for patients with advanced nasopharyngeal cancer (NPC). Forty-five patients with stage II-IV NPC, determined by the American Joint Committee on Cancer system, were treated with prescribed doses of 72 Gy total to the gross tumor volume, 60 Gy to the clinical target volume and metastatic nodal station, and 54 Gy to the clinically-negative neck region. Before radiotherapy, two cycles of cisplatin (30 mg/m(2)/day on days 1-3) plus 5-FU (400 mg/m(2)/day on days 1-5) were delivered every three weeks for two cycles. Patients received two cycles of cisplatin (30 mg/m(2) day on days 1-3) every three weeks during radiotherapy. In addition, two cycles of cisplatin and 5-FU were given after radiation. All patients completed the prescribed radiotherapy and all scheduled cycles of chemotherapy. Thirty of the 45 patients (66.6%) had a complete response at the end of treatment. Grade 3 mucositis occurred in 4/45 patients (8.8%) and grade 3 dermatitis occurred in 5/45 (11.1%) during radiotherapy. Grade 3 neutropenia occurred in 6/45 (13.3%) during concurrent chemotherapy. There was no treatment-related mortality. After a median follow-up time of 51 months, only three patients' treatments had failed. Local and distant failure rates were 1.5 and 3.0%, respectively. SMART-IMRT plus cisplatin and 5-FU chemotherapy showed promising activity with manageable toxicity. It is a feasible regimen and improves locoregional disease control.