Objective To screen out the potential prediction genes for nasopharyngeal carcinoma(NPC)from the gene microarray data of NPC samples and then verify the genes by cell experiments.Methods The NPC dataset was downloaded from Gene Expression Omnibus,and limma package was employed to screen out the differentially expressed genes.Weighted correlation network analysis package was used for weighted gene co-expression network analysis,and Venn diagram was drawn to find the common genes.The gene ontology annotation and Kyoto encyclopedia of genes and genomes pathway enrichment were then performed for the common genes.The biomarkers for NPC were further explored by protein-protein interaction network,LASSO regression,and non-parametric tests.Real-time quantitative PCR and Western blotting were employed to determine the mRNA and protein levels of key predictors of NPC,so as to verify the screening results.Results There were 622 up-regulated genes and 351 down-regulated genes in the GSE12452 dataset.A total of 116 common genes were obtained by limma analysis and weighted gene co-expression network analysis.The common genes were mainly involved in the biological processes of cell proliferation and regulation and regulation of intercellular adhesion.They were mainly enriched in Rap1,Ras,and tumor necrosis factor signaling pathways.Six key genes were screened out,encoding angiopoietin-2(ANGPT2),dual oxidase 2(DUOX2),coagulation factor Ⅲ(F3),interleukin-15(IL-15),lipocalin-2,and retinoic acid receptor-related orphan receptor B(RORB).Real-time quantitative PCR and Western blotting showed that the NPC cells had up-regulated mRNA and protein levels of ANGPT2 and IL-15 and down-regulated mRNA and protein levels of DUOX2,F3,and RORB,which was consistent with the results predicted by bioinformatics.Conclusion ANGPT2,DUOX2,F3,IL-15 and RORB are potential predictive molecular markers and therapeutic targets for NPC,which may be involved in Rap1,Ras,tumor necrosis factor and other signaling pathways.
Humans ; Nasopharyngeal Carcinoma/genetics* ; Interleukin-15 ; Dual Oxidases ; Computational Biology ; Nasopharyngeal Neoplasms/genetics*

OBJECTIVE: To investigate the mechanism by which Chinese medicine Shengmai Yin (SMY) reverses epithelial-mesenchymal transition (EMT) through lipocalin-2 (LCN2) in nasopharyngeal carcinoma (NPC) cells CNE-2R. METHODS: Morphological changes in EMT in CNE-2R cells were observed under a microscope, and the expressions of EMT markers were detected using quantitative real-time PCR (RT-qPCR) and Western blot assays. Through the Gene Expression Omnibus dataset and text mining, LCN2 was found to be highly related to radiation resistance and EMT in NPC. The expressions of LCN2 and EMT markers following SMY treatment (50 and 100 µ g/mL) were detected by RT-qPCR and Western blot assays in vitro. Cell proliferation, migration, and invasion abilities were measured using colony formation, wound healing, and transwell invasion assays, respectively. The inhibitory effect of SMY in vivo was determined by observing a zebrafish xenograft model with a fluorescent label. RESULTS: The CNE-2R cells showed EMT transition and high expression of LCN2, and the use of SMY (5, 10 and 20 µ g/mL) reduced the expression of LCN2 and reversed the EMT in the CNE-2R cells. Compared to that of the CNE-2R group, the proliferation, migration, and invasion abilities of SMY high-concentration group were weakened (P<0.05). Moreover, SMY mediated tumor growth and metastasis in a dose-dependent manner in a zebrafish xenograft model, which was consistent with the in vitro results. CONCLUSIONS SMY can reverse the EMT process of CNE-2R cells, which may be related to its inhibition of LCN2 expression. Therefore, LCN2 may be a potential diagnostic marker and therapeutic target in patients with NPC.
Animals ; Humans ; Nasopharyngeal Carcinoma/genetics* ; Epithelial-Mesenchymal Transition ; Zebrafish ; Cell Proliferation ; Cell Line, Tumor ; Nasopharyngeal Neoplasms/radiotherapy* ; Cell Movement ; Gene Expression Regulation, Neoplastic

Humans ; Carcinogenesis/genetics* ; Gene Expression Regulation, Neoplastic ; Genes, cdc ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; RNA Helicases/metabolism*

OBJECTIVES: Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignant tumor with unique geographical and ethnic distribution characteristics. NPC is mostly found in south China and Southeast Asia, and its treatment mainly depends on radiotherapy and chemotherapy. However, NPC is usually found in the late stage, and local recurrence and distant metastasis are common, leading to poor prognosis. The receptor tyrosine kinase AXL is up-regulated in various tumors and it is involved in tumor proliferation, migration, invasion, and other processes, which are associated with poor prognosis of tumors. This study aims to detect the expression of AXL in NPC cell lines and tissues, and to investigate its biological function of AXL and the underlying molecular mechanisms in regulation of NPC. METHODS: The expression levels of AXL in normal nasopharyngeal epithelial tissues and NPC tissues were analyzed by GSE68799, GSE12452, and GSE53819 data sets based on Gene Expression Omnibus (GEO) database. The Cancer Genome Atlas (TCGA) database was used to analyze the relationship between AXL and prognosis of head and neck squamous cell carcinoma (HNSC). The indicators of prognosis included overall survival (OS), disease-free interval (DFI), disease-specific survival (DSS), and progression-free interval (PFI). Western blotting assay was used to detect the AXL protein expression levels in normal nasopharyngeal epithelial cell line and NPC cell lines. Immunohistochemical method was used to detect AXL expression levels in normal nasopharyngeal epithelial tissues and NPC tissues. Cell lines with stable AXL knockdown were established by infecting 5-8F and Fadu cells with lentivirus interference vector, and cell lines with stable AXL overexpression were established by infecting C666-1 and HK-1 cells with lentivirus expression vector. Real-time PCR and Western blotting were used to detect the efficiency of knockdown and overexpression in stable cell lines. The effects of AXL knockdown or overexpression on proliferation, migration, and invasion of NPC cells were detected by CCK-8, plate colony formation, and Transwell assays, and the effect of AXL knockdown on tumor growth in nude mice was detected by subcutaneous tumor formation assay. The sequence of AXL upstream 2.0 kb promoter region was obtained by UCSC online database. The PROMO online database was used to predict AXL transcription factors with 0% fault tolerance, and the JASPAR online database was used to predict the binding sites of ETS1 to AXL. Real-time PCR and Western blotting were used to detect the effect of ETS1 on AXL protein and mRNA expression. The AXL upstream 2.0 kb promoter region was divided into 8 fragments, each of which was 250 bp in length. Primers were designed for 8 fragments. The binding of ETS1 to AXL promoter region was detected by chromatin immuno-precipitation (ChIP) assay to determine the direct regulatory relationship between ETS1 and AXL. Rescue assay was used to determine whether ETS1 affected the proliferation, migration, and invasion of NPC cells through AXL. RESULTS: Bioinformatics analysis showed that AXL was highly expressed in NPC tissues (P<0.05), and AXL expression was positively correlated with OS, DFI, DSS, and PFI in HNSC patients. Western blotting and immunohistochemical results showed that AXL was highly expressed in NPC cell lines and tissues compared with the normal nasopharyngeal epithelial cell line and tissues. Real-time PCR and Western blotting results showed that knockdown and overexpression efficiency in the stable cell lines met the requirements of subsequent experiments. The results of CCK-8, plate colony formation, Transwell assays and subcutaneous tumor formation in nude mice showed that down-regulation of AXL significantly inhibited the proliferation, migration, invasion of NPC cells and tumor growth (all P<0.05), and the up-regulation of AXL significantly promoted the proliferation, migration, and invasion of NPC cells (all P<0.05).As predicted by PROMO and JASPAR online databases, ETS1 was a transcription factor of AXL and had multiple binding sites in the AXL promoter region. Real-time PCR and Western blotting results showed that knockdown or overexpression of ETS1 down-regulated or up-regulated AXL protein and mRNA expression levels. ChIP assay result showed that ETS1 bound to AXL promoter region and directly regulate AXL expression. Rescue assay showed that AXL rescued the effects of ETS1 on proliferation, migration and invasion of NPC cells (P<0.05). CONCLUSIONS AXL is highly expressed in NPC cell lines and tissues, which can promote the malignant progression of NPC, and its expression is regulated by transcription factor ETS1.
Animals ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Mice ; Mice, Nude ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/metabolism* ; RNA, Messenger/genetics* ; Sincalide/metabolism* ; Transcription Factors/genetics*

OBJECTIVES: Genetic mutation is one of the important causes for tumor genesis and development, but genetic mutation in nasopharyngeal carcinoma (NPC) has rarely been reported. This study explored the role of phosphatidylinositol 3 kinase-protein kinase B (PI3K-Akt), mammalian target of rapamycin (mTOR), and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway in the efficacy and prognosis in patients with NPC. METHODS: A total of 31 patients with advanced NPC, who came from the Affiliated Cancer Hospital of Xiangya School of Medicine of Central South University/Hunan Provincial Cancer Hospital, were enrolled. All of the exons of 288 genes, introns of 38 genes and promoters or fusion breakpoint regions from the nasopharyngeal biopsy tissues before treatment were detected by the gene sequencing platform Illumina NextSeq CN500. The coding regions of 728 genes were carried out a high-depth sequencing of target region capture, and the 4 variant types of tumor genes (including point mutations, insertion deletions of small fragments, copy number variations, and currently known fusion genes) were detected. All of 31 patients received platinum-based induction chemotherapy combined with concurrent chemoradiotherapy and were followed up for a long time. RESULTS: The 3-year regional failure-free survival (RFFS) and disease-free survival (DFS) in patients with PI3K-Akt pathway mutation were significantly lower than those in unmutated patients (χ²=6.647, P<0.05). The 3-year RFFS and DFS in patients with mTOR pathway mutations were significantly lower than those in unmutated patients, and there was significant difference (χ²=5.570, P<0.05). The rate of complete response (CR) in patients with unmutated AMPK pathway was significantly higher than that in patients with mutation at 3 months after treatment (P<0.05), and the 3-year RFFS and DFS in patients with AMPK pathway mutation were significantly lower than those in unmutated patients (χ²=4.553, P<0.05). PI3K-Akt/mTOR/AMPK signaling pathway mutations and pre-treatment EB virus DNA copy numbers were independent prognostic factors for 3-year RFFS and DFS in patients with NPC (both P<0.05). CONCLUSIONS The NPC patients with PI3K-Akt/mTOR/AMPK signaling pathway mutation have poor prognosis, and the detection of PI3K-Akt, mTOR, AMPK driver genes and signaling pathways by next-generation sequencing is expected to provide new idea for basic research and targeted therapy of NPC.
AMP-Activated Protein Kinases/metabolism* ; DNA Copy Number Variations ; Humans ; Mutation ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Prognosis ; Proto-Oncogene Proteins c-akt/metabolism* ; Signal Transduction ; Sirolimus ; TOR Serine-Threonine Kinases/metabolism*

Objective: To study the effect of circ-WHSC1 on the growth, metastasis and radiosensitivity of nasopharyngeal carcinoma cells and its molecular mechanism. Methods: Cancerous tissues and adjacent tissues were collected from 23 patients with nasopharyngeal carcinoma, and real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression levels of circ-WHSC1, miR-338-3p, and ELAVL1 mRNA. Western blot was used to detect the expression of ELAVL1 protein. Nasopharyngeal carcinoma cells 5-8F and SUNE1 were divided into si-NC group, si-circ-WHSC1 group, pCD5-ciR group, circ-WHSC1 group, anti-miR-NC group, anti-miR-338-3p group, miR-NC group, miR-338-3p group, si-circ-WHSC1+ anti-miR-NC group, si-circ-WHSC1+ anti-miR-338-3p group, miR-338-3p+ pcDNA group, miR-338-3p+ ELAVL1 group. Tetramethylazolium salt colorimetric method (MTT) was used to detect cell viability. Clone formation test was used to detect cell clone formation and cell radiosensitivity. Flow cytometry was used to detect cell apoptosis. Transwell was used to detect cell migration and invasion. Dual luciferase assay was used to detect the targeting relationship between circ-WHSC1 and miR-338-3p, miR-338-3p and ELAVL1. The SUNE1 cells stably transfected with sh-circ-WHSC1 were injected into nude mice and irradiated with radiation, and then the tumor volume and weight of mice were detected. Results: The expressions of circ-WHSC1 (1.57±0.94 vs 3.78±1.18, 1.00±0.10 vs 1.64±0.14/2.00±0.21/2.81±0.26/3.36±0.34) and ELAVL1 (1.28±0.74 vs 3.36±0.77, 1.00±0.08 vs 2.51±0.19/3.27±0.27) in nasopharyngeal carcinoma tissues and cells were increased, and the expression of miR-338-3p (3.13±0.96 vs 1.37±0.98, 1.00±0.08 vs 0.48±0.08/0.38±0.07) was decreased (P<0.05). After knockdown of circ-WHSC1, the activity of nasopharyngeal carcinoma cells was decreased [(100.00±8.00)% vs (51.33±8.62)%, (100.00±10.10)% vs (41.02±7.31)%], the number of clone-forming cells was decreased (101.00±8.54 vs 50.33±8.02, 114.00±14.10 vs 42.33±10.01), the rate of apoptosis was increased [(5.37±1.20)% vs (18.3±1.01)%, (6.5±1.18)% vs (22.43±1.40)%], and the numbers of migration (136.00±13.00 vs 72.33±9.50, 154.00±14.10 vs 62.67±11.50) and invasion (113.67±11.59 vs 60.67±9.07, 124.33±15.57 vs 50.33±9.01) were decreased; after different doses of radiation, the cell survival score was decreased (0.23±0.04 vs 0.06±0.01, 0.32±0.07 vs 0.05±0.02) (P<0.05). Circ-WHSC1 targeted and negatively regulated miR-338-3p. Inhibition of miR-338-3p affected the effect of knockdown of circ-WHSC1 on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. MiR-338-3p targeted and negatively regulated ELAVL1; ELAVL1 overexpression affected the effects of miR-338-3p on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. After the cells stably transfected with sh-circ-WHSC1 were injected into nude mice, the tumor volume [(884.67±95.63)mm(3) vs (487.33±76.51)mm(3)] and weight [(899.01±88.54)mg vs (558.67±75.04) mg] of the nude mice were reduced; after further irradiation, the tumor volume [(395.00±73.50)mm(3) vs 243.13±42.51)mm(3)] and weight[ (452.33±67.30)mg vs (211.09±57.51)mg] of the nude mice were reduced (P<0.05). Circ-WHSC1 regulated the expression of ELAVL1 by targeting miR-382. Conclusion: Knockdown of circ-WHSC1 can inhibit the growth and metastasis of nasopharyngeal carcinoma cells by targeting miR-338-3p/ELAVL1 axis, and enhances the radiosensitivity of nasopharyngeal carcinoma cells.
Mice ; Animals ; Nasopharyngeal Carcinoma/radiotherapy* ; Mice, Nude ; MicroRNAs/genetics* ; Antagomirs ; Cell Line, Tumor ; Radiation Tolerance/genetics* ; Nasopharyngeal Neoplasms/pathology* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic

Objective: To explore the effect of dormant polyploid giant cancer cells (PGCC) on nasopharyngeal carcinoma (NPC) recurrence and to clarify the role of inhibition of autophagy in inhibiting NPC-PGCC formation and preventing NPC recurrence. Methods: NPC cells-derived PGCC (NPC-PGCC) were induced by paclitaxel (PTX), and the morphology, polyploid characteristics and cell activity of PGCC were identified by light microscopy, immunofluorescence and Live/Dead cell double staining assays. RNA-seq was used to analyze the differentially expressed genes between NPC-PGCC and diploid nasopharyngeal carcinoma cells CNE2. Functional enrichment and pathway annotation analysis of differentially expressed genes were performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG). The level of autophagy in NPC-PGCC cells was assessed by Western Blot and transmission electron microscopy analysis. The role of autophagy in the formation of NPC-PGCC and the effect of NPC-PGCC on the recurrence of nasopharyngeal carcinoma were studied using a highly clinically relevant mouse nasopharyngeal carcinoma recurrence model. Statistical analysis was performed using GraphPad Prism 6 and P-values<0.05 were considered statistically significant. Results: NPC-PGCC induced by paclitaxel had the characteristics of burst-like division after dormancy. GO enrichment and KEGG pathway analyses identified the significant biological processes and pathways mainly concentrated in autophagy and related pathways involving the differentially expressed genes between NPC-PGCC and diploid nasopharyngeal carcinoma cells CNE2. The autophagy level was significantly enhanced in NPC-PGCC cells. In a highly clinically relevant mouse nasopharyngeal carcinoma recurrence model, the number of PGCC in the primary tumor of the nude mice treated with cisplatin were higher than those of the other groups. In nude mice pretreated with autophagy inhibitor and then co-treatment with autophagy inhibitor and cisplatin, the number of PGCC in primary tumors was less and the recurrence rate was significantly lower than in other groups. Conclusions: The mechanism of dormant polyploid giant cancer cells formation is related to autophagy. Inhibition of autophagy can inhibit the formation of PGCC and thus prevent the recurrence of nasopharyngeal carcinoma.
Animals ; Autophagy ; Carcinoma/genetics* ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Cisplatin/pharmacology* ; Gene Expression Regulation, Neoplastic ; Mice ; Mice, Nude ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/pathology* ; Paclitaxel/pharmacology* ; Polyploidy

Apoptosis ; Cell Cycle ; Cell Division ; Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Gene Silencing ; Humans ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; Replication Protein A/genetics*

Objective: To explore the impacts of miR-18a overexpression or depression on the radiosensitivities of nasopharyngeal carcinoma cell line CNE1 and CNE2 and underlying mechanisms. Methods: CNE1 and CNE2 were transfected with miR-18a mimics, inhibitor and the corresponding control vectors. qRT-PCR and western blot were used to determine the ataxia telangiectasia mutated (ATM) expressions in CNE1 and CNE2. CNE1 and CNE2 with stably expressing miR-18a and miR-18a siRNA were constructed. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the impacts of the miR-18a overexpression or depression combined with irradiation on the cell growth. Flow cytometry was used to detect the cell apoptosis and cell cycle. Colony formation assay was used to evaluate the raodiosensitivities of cells. Acridine orange (AO) staining and western blot were used respectively to test the autophagy and the expressions of related proteins. Independent samples t test was used to compare the mean value between groups by using SPSS 16.0. Results: ATM mRNA was decreased significantly in CNE1 and CNE2 cells transfected with 100 or 200 nmol/L miR-18a mimics for 48 hours (CNE1: RQ=0.174±0.139 and 0.003±0.001, t=9.939 and 19 470.783;CNE2: RQ=0.024±0.008 and 0.019±0.012, t=270.230 and 137.746, respectively, all P<0.001). ATM proteins were also decreased after transfected with 100 or 200 nmol/L miR-18a mimics for 72 hours. While in the cells transfected with 100 and 200 nmol/L miR-18a inhibitor for 48 hours, the expressions of ATM mRNA were upregulated significantly (CNE1: RQ=9.419±2.495 and 2.500±1.063, t=-4.427 and -41.241; CNE2: RQ=7.210±0.171 and 115.875±15.805, t=-62.789 and -12.589, all P<0.05), and the expressions of ATM proteins increased after transfected for 72 hours. The growth of cells with miR-18a overexpression plus 4 Gy irradiation were obviously inhibited compared to that of cells with the 4Gy irradiation alone; while the growth of miR-18a-inhibited cells increased compared to that of cells with 4 Gy irradiation alone (all P<0.05). CNE1 transfected with 100 nmol/L miR-18a mimics plus 4 Gy irradiation showed the higher apoptosis rate than the cells with 4 Gy irradiation alone ((22.9±2.1)% vs. (16.3±1.0)%, t=-4.870, P<0.01). Compared to the cells with 4 Gy irradiation alone, miR-18a-overexpressed cells plus 4 Gy irradiation decreased their percentages in G1 phases ((20.2±3.0)% vs. (29.8±4.4)%, t=3.119) and G2/M phases ((21.5±0.9)% vs. (33.4±3.1)%, t=6.410, P<0.05 for both), and increased their percentages in S phases ((56.7±4.9)% vs. (36.8±6.4)%, t=-4.246, P<0.05), and these cells possessed less colony number after exposure to different doses of irradiation, more autophagy-lysosome number, and more expressions of LC3 proteins (all P<0.05). There were no significant differences in the expressions of p62 expressions between different groups of cells. Conclusion: Overexpression of miR-18a can enhance the radiosensitivities of NPC cells by targeting ATM to abrogate G1/S, G2/M arrest and to induce autophagy and apoptosis.
Apoptosis ; Autophagy ; Cell Line, Tumor ; Cell Proliferation ; G2 Phase Cell Cycle Checkpoints ; Humans ; MicroRNAs/genetics* ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; Radiation Tolerance

OBJECTIVE: To investigate the effects of Yes-associated protein 1 (YAP1) knockdown on the proliferation, migration and invasion in human nasopharyngeal carcinoma (NPC) cells. METHODS: We detected the expression of YAP1 mRNA and protein in different NPC cell lines and an immortalized nasopharyngeal epithelial cell line using RT-PCR and Western blotting. Two YAP1-targeting small interfering RNAs (siRNA) were transfected into NPC cell lines S26 and S18, and the knockdown efficiency was confirmed by RT-PCR and Western blotting. The effect of YAP1 knockdown on the proliferation of the NPC cells was determined by cell counting and colony formation assay; wound healing assay and Transwell assay were used to analyze the changes in the cell migration and invasion abilities in each group. Western blotting was used to analyze the changes in the expressions of c-myc, E-cadherin, N-cadherin and vimentin in the NPC cells after YAP1 knockdown. RESULTS: YAP1 was highly expressed in the NPC cell lines. Compared with the negative control group, the NPC cell lines with YAP1 knockdown showed significantly lowered YAP1 expressions at both the mRNA and protein levels ( < 0.05). YAP1 knockdown significantly suppressed the growth, cloning formation, migration and invasion of the NPC cells as compared with control cells ( < 0.01). YAP1 knockdown obviously decreased the expression levels of c-myc, N-cadherin and vimentin and increased E-cadherin expression in the NPC cells. CONCLUSIONS YAP1 knockdown siRNA suppresses the proliferation, migration and invasion of NPC cells , suggesting that YAP1 may serve as a therapeutic target for NPC.
Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Nasopharyngeal Carcinoma ; genetics ; Neoplasm Invasiveness ; Phosphoproteins ; genetics ; metabolism