Nasopharyngeal Carcinoma Cell Proliferation Research Articles

Long Noncoding RNA CRNDE Functions as an Oncogene to Facilitate Aggressive Behaviors of Nasopharyngeal Carcinoma Cells by Modulating miR-3163/TWIST1 Axis.

Long noncoding RNA (lncRNA) CRNDE has been broadly implicated in many malignancies. The aim of this study was to explore the function and potential mechanisms of CRNDE in nasopharyngeal carcinoma (NPC). Here, we discovered that CRNDE level was increased in NPC tissues and cell lines. Additionally, elevated CRNDE positively correlated with large tumor size, advanced TNM stage, distant metastasis, EBV infection and worse prognosis. Furthermore, depletion of CRNDE significantly impaired the capacity of proliferation, migration and invasion in NPC cells. Mechanically, CRNDE could serve as a molecular sponge of miR-3163 to regulate the expression of TWIST1. Importantly, the inhibitory effects of CRNDE knockdown on cell proliferation and metastasis were blocked by silence of miR-3163 or restoration of TWIST1 expression. Overall, our data highlighted that CRNDE could promote NPC progression via altering miR-3163/TWIST1 axis, suggesting CRNDE as a potential prognostic biomarker and therapeutic target for NPC treatment.

LINC00641 contributes to nasopharyngeal carcinoma cell malignancy through FOXD1 upregulation at the post-transcriptional level.

Nasopharyngeal carcinoma (NPC) is a common tumor in the head and neck and is prevalent in China, especially in the southern regions. Molecular mechanisms have attracted much attention in NPC research. FOXD1 has been reported to be a tumor promoter in various cancers. The present study was designed to explore the function of FOXD1 in NPC cells. Functional analyses, including the trypan blue staining assay, EdU and JC-1 assay, and flow cytometry analysis, revealed that FOXD1 facilitated NPC cell proliferation and inhibited NPC cell apoptosis. Next, by means of "starBase" database and mechanism analyses, such as RIP assay, RNA pull-down assay and luciferase reporter assay, miR-378a-3p was found to target FOXD1 and negatively regulate FOXD1 expression in NPC cells. Moreover, miR-378a-3p plays a suppressive role in NPC cells. LINC00641 was identified as a sponge of miR-378a-3p and positively modulated FOXD1 expression in NPC cells. Finally, a series of rescue assays indicated that LINC00641 accelerated NPC cell proliferation and hindered NPC cell apoptosis through FOXD1 upregulation. In conclusion, the present study demonstrated an innovative ceRNA mechanism of LINC00641/miR-378a-3p/FOXD1 in NPC cells, which might provide new insights into NPC treatment.

Circular RNA ITCH attenuates the progression of nasopharyngeal carcinoma by inducing PTEN upregulation via miR-214.

Circular RNA itchy E3 ubiquitin protein ligase (circ-ITCH) has previously been reported to play a key role in carcinogenesis. Nevertheless, the role of circ-ITCH in nasopharyngeal carcinoma (NPC) remains to be explored. Gene expression analysis was performed using a quantitative real-time polymerase chain reaction, western blotting and immunohistochemistry. The role of circ-ITCH in NPC was explored using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, colony formation, transwell invasion, scratch healing and xenograft tumor assays. Furthermore, luciferase reporter assay was carried out to assess the interactions among circ-ITCH, microRNA-214 (miR-214) and phosphatase and tensin homolog (PTEN). The levels of circ-ITCH and PTEN were decreased, whereas the level of miR-214 was increased in NPC tissues collected from 28 subjects compared to normal nasopharynx tissues collected from 15 subjects. Moreover, a negative correlation between circ-ITCH and miR-214 expression and a positive correlation between circ-ITCH and PTEN expression were observed in NPC tissues. Downregulation of circ-ITCH expression was also observed in NPC cell lines. In addition, upregulation of circ-ITCH markedly inhibited NPC cell proliferation, migration and invasion. Furthermore, circ-ITCH was confirmed to exert its function by sponging miR-214. PTEN was found to be a direct target gene of miR-214 and its expression was negatively correlated with miR-214 expression in NPC tissues. Moreover, our results showed that the circ-ITCH/miR-214 axis regulated NPC proliferation, migration and invasion through regulating the expression of PTEN. Upregulation of circ-ITCH or PTEN blocked miR-214-mediated promotion of NPC tumorigenesis in vitro. Additionally, upregulation of circ-ITCH also suppressed NPC tumorigenesis in vivo. The present study demonstrated that circ-ITCH suppressed NPC tumorigenesis by upregulating PTEN expression through interacting with miR-214, thus proposing a novel mechanism for NPC inhibition.

Hedyotis diffusae Herba-Andrographis Herba inhibits the cellular proliferation of nasopharyngeal carcinoma and triggers DNA damage through activation of p53 and p21.

Dysregulation of the cell cycle and the resulting aberrant cellular proliferation has been highlighted as a hallmark of cancer. Certain traditional Chinese medicines can inhibit cancer growth by inducing cell cycle arrest. In this study we explore the effect of Hedyotis diffusae Herba-Andrographis Herba on the cell cycle of nasopharyngeal carcinoma (NPC). Hedyotis diffusae Herba-Andrographis Herba-containing serum was prepared and then added to the cell culture medium. BrdU, comet, and FUCCI assays, western blot analysis and flow cytometry analysis revealed that Hedyotis diffusae Herba-Andrographis Herba treatment significantly alters cell proliferation, DNA damage, and cell cycle distribution. Xenograft mouse model experiments were performed, confirming these in vitro findings in vivo. Treatment with Hedyotis diffusae Herba-Andrographis Herba inhibited cell proliferation, promoted DNA damage, and arrested NPC cells progression from G1 to S phase. Further examination of the underlying molecular mechanisms revealed that treatment with Hedyotis diffusae Herba-Andrographis Herba increased the expression of p53 and p21, while reducing that of CCND1, Phospho-Rb, E2F1, γH2AX, and Ki-67 both in vivo and in vitro. Conversely, the inhibition of p53 and p21 could abolish the promoting effect of Hedyotis diffusae Herba-Andrographis Herba on the NPC cell cycle arrest at the G1 phase, contributing to the proliferation of NPC cells. Hedyotis diffusae Herba-Andrographis Herba suppressed the tumor growth in vivo. Overall, these findings suggest that Hedyotis Diffusae Herba-Andrographis prevent the progression of NPC by inducing NPC cell cycle arrest at the G1 phase through a p53/p21-dependent mechanism, providing a novel potential therapeutic treatment against NPC.

Retraction: The inhibition of tumor protein p53 by microrna-151a-3p induced cell proliferation, migration and invasion in nasopharyngeal carcinoma.

This article is being retracted from Bioscience Reports at the request of the Editor-in-Chief and the Editorial Board following receipt of a notification from a reader, alerting the Editorial Board to the inhibitor panel in Figure 3C, which contains a significant number of data points overlapping with that from figures in other publications by different authors.The authors have been contacted in regards to the Retraction, and have not responded to the Journal's queries and the concerns raised. Given the extent of the issues raised, the Editorial Board stand by the decision to retract the article.

Retraction: The inhibition of tumor protein p53 by microrna-151a-3p induced cell proliferation, migration and invasion in nasopharyngeal carcinoma

Retraction: The inhibition of tumor protein p53 by microrna-151a-3p induced cell proliferation, migration and invasion in nasopharyngeal carcinoma

Circ_0000215 Exerts Oncogenic Function in Nasopharyngeal Carcinoma by Targeting miR-512-5p.

Background: Increasing circular RNAs (circRNAs) are reported to participate in cancer progression. Nonetheless, the role of circRNAs in nasopharyngeal carcinoma (NPC) has not been fully clarified. This work is aimed to probe the role of circ_0000215 in NPC.Methods: Circ_0000215 expression in NPC tissues and cell lines was examined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay, 5-bromo-2′-deoxyuridine (BrdU) assay, scratch healing assay and Transwell experiment were executed to investigate the regulatory function of circ_0000215 on the proliferation, migration and invasion of NPC cells. RNA immunoprecipitation (RIP), pull-down and dual-luciferase reporter experiments were utilized to determine the binding relationship between circ_0000215 and miR-512-5p, and between miR-512-5p and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) 3′UTR. The effects of circ_0000215 on NPC growth and metastasis in vivo were examined with nude mice model. Western blot was applied to detect the regulatory effects of circ_0000215 and miR-512-5p on PIK3R1 expression.Results: Circ_0000215 was overexpressed in NPC tissues and cell lines. The functional experiments confirmed that knockdown of circ_0000215 impeded the growth and metastasis of NPC cells in vitro and in vivo. Additionally, circ_0000215 could also work as a molecular sponge to repress miR-512-5p expression. PIK3R1 was validated as a target gene of miR-512-5p, and circ_0000215 could increase the expression level of PIK3R1 in NPC cells via suppressing miR-512-5p.Conclusion: Circ_0000215 is overexpressed in NPC and exerts oncogenic effects in NPC through regulating miR-512-5p/PIK3R1 axis.

We Hypothesize That BMAL1 Has a Positive Regulatory Effect on the Radiosensitivity of Nasopharyngeal Carcinoma

<h3>Purpose/Objective(s)</h3> BMAL1 is a core biological clock gene, which is expressed rhythmically in a variety of tumor cells, and is related to cancer cell proliferation and chemotherapy sensitivity. Radiotherapy is the main treatment for nasopharyngeal carcinoma (NPC). However, the role of baml1 in radiotherapy for nasopharyngeal carcinoma is unclear. <h3>Materials/Methods</h3> We used 5 types of nasopharyngeal carcinoma cells (CNE1, CNE2, HONE1, C666-1, 5-8F) and normal nasopharyngeal epithelial cells NP69 as the research objects, and detected the transcription level changes of BMAL1 mRNA within 24 hours by RT-PCR. Furthermore, after overexpression and knockdown of BMAL1 in nasopharyngeal carcinoma CNE1 cells and transplanted tumors in nude mice, the effects of BMAL1 on the proliferation of CNE1 cells and subcutaneous transplanted tumors and the changes after radiotherapy were observed. Finally, RT-PCR and Western Blot were used to detect BMAL1, P53, P21 gene and protein expression in tumor tissues. <h3>Results</h3> The results suggest that the expression level of the circadian clock gene BMAL1 in NPC cell lines and NP69 cells fluctuates with time. Overexpression of BMAL1 can inhibit the proliferation of NPC cells, while knockdown promotes the proliferation of NPC cells. In the xenograft model, we observed that up-regulation of BMAL1 inhibited tumor growth and enhanced the sensitivity of NPC cells to radiotherapy, accompanied by increased expression of P53 and P21. Down-regulating BMAL1 promotes tumor growth, reduces the sensitivity of radiotherapy, and decreases the expression of P53 and P21. <h3>Conclusion</h3> BMAL1 showed rhythmic expression in NPC cells and NP69. BMAL1 plays a tumor suppressor effect in NPC, and can increase the sensitivity of NPC to radiotherapy, which may be related to the up-regulation of P53 and P21 protein expression. It is speculated that BMAL1 may become a new prognostic biomarker and new therapeutic target for NPC.

WIPI-1 inhibits metastasis and tumour growth via the WIPI-1-TRIM21 axis and MYC regulation in nasopharyngeal carcinoma

The metastatic rate of nasopharyngeal carcinoma (NPC) is the highest among head and neck tumours. Additionally, distant metastasis is the main cause of therapy failure and mortality in NPC. Thus, novel biomarkers are needed for designing new therapeutic strategies to improve the prognosis of this disease. In this study, qRT-PCR and western blotting revealed that the expression of the WD repeat domain phosphoinositide interacting 1 (WIPI-1) was markedly decreased in NPC cells and tissues. Furthermore, low WIPI-1 expression closely correlated with poor prognosis in NPC patients. In vitro functional experiments revealed that overexpression or knockdown of WIPI-1 repressed or facilitated the migration, colony formation, and proliferation of NPC cells. Consistent with the in vitro studies, WIPI-1 significantly inhibited tumour growth, invasion and metastasis in popliteal lymph node metastasis, lung metastasis, and xenograft mouse models in vivo. Mechanistically, WIPI-1 directly interacted with tripartite motif containing 21 (TRIM21) and enhanced starvation-induced autophagy by interacting with TRIM21 in NPC cells. Moreover, MYC gene expression was markedly increased in the WIPI-1 knockdown group, as demonstrated by RNA-seq analysis and qRT-PCR validation. Altogether, WIPI-1 acts as a tumour suppressor gene in NPC that inhibits tumour growth and metastasis. Targeting WIPI-1 may be a novel treatment approach for NPC.

MiR-663b promotes tumor cell proliferation, migration and invasion in nasopharyngeal carcinoma through targeting TUSC2.

[This retracts the article DOI: 10.3892/etm.2017.4608.].

Silencing of NACC1 inhibits the proliferation, migration and invasion of nasopharyngeal carcinoma cells via regulating the AKT/mTOR signaling pathway.

Nucleus accumbens-associated protein 1 (NACC1) has been reported to serve as an oncogenic role in several types of cancer; however, its role in nasopharyngeal carcinoma (NPC) remains to be determined. The present study aimed to investigate the role of NACC1 in NPC and elucidate the underlying mechanisms. Therefore, NACC1 expression in the normal nasopharyngeal epithelial cell line, NP69, and various NPC cell lines was determined by reverse transcription-quantitative PCR and western blot analyses. NACC1 expression was silenced in the NPC SUNE-1 cell line by transfection with a short hairpin RNA. Cell viability, proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) were then evaluated using MTT, colony formation, wound healing, Transwell and western blot assays, respectively. SC79 was employed to activate AKT expression in NACC1-silenced SUNE-1 cells, and the aforementioned cellular processes were observed. The results revealed that NACC1 expression was upregulated in NPC cell lines. NACC1-knocdown inhibited SUNE-1 cell proliferation, migration, invasion and EMT. Moreover, the levels of phosphorylated AKT and mTOR were decreased upon NACC1 silencing. Mechanistically, the presence of SC79 significantly blocked all the effects of NACC1-knockdown on SUNE-1 cells. The findings of the present study demonstrated that NACC1-knockdown effectively suppressed NPC cell proliferation, migration and invasion by inhibiting the activation of the AKT/mTOR signaling pathway. NACC1 may thus serve as a potential target for the diagnosis and therapy of NPC.

Influences of S100A8 and S100A9 on Proliferation of Nasopharyngeal Carcinoma Cells through PI3K/Akt Signaling Pathway.

Objective To investigate the effects of S100A8 and S100A9 on proliferation in nasopharyngeal carcinoma cells and the regulatory effects of PI3K/Akt signaling pathway. Methods Nasopharyngeal carcinoma cells (CNE1) were cultured and randomly divided into three groups: control group, S100A8/S100A9 overexpression group, and siRNA S100A8/S100A9 group. CCK-8 method was used to detect the effect of S100A8 and S100A9 on the viability of nasopharyngeal carcinoma cells. The effects of S100A8 and S100A9 on the colony forming ability of nasopharyngeal carcinoma cells were detected by colony forming assay. The effects of S100A8 and S100A9 on the proliferation of nasopharyngeal carcinoma cells were detected by EdU staining. The mRNA levels of PI3K and Akt were detected by RT-PCR. The expression levels of PI3K and Akt in NPC cells were detected by Western blot. Wortmannin, an inhibitor of PI3K/Akt pathway, was used to inhibit the activation of PI3K/Akt pathway. Results Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were increased in the overexpression group. Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were decreased in the siRNA group. After inhibiting the activation of PI3K/Akt pathway, the viability of NPC cells in the overexpression group decreased significantly at 48 h and 72 h, while that in the siRNA group increased significantly. Conclusion SiRNA S100A8 and S100A9 could inhibit the proliferation of nasopharyngeal carcinoma cells, and the underlying mechanism may be related to the inhibition of PI3K/Akt signaling pathway.

Key genes affecting the progression of nasopharyngeal carcinoma identified by RNA-sequencing and bioinformatic analysis.

Background: The present work was conducted to screen the potential biomarkers affecting nasopharyngeal carcinoma (NPC) progression through RNA-sequencing (RNA-seq), bioinformatic analysis and functional experiments.Materials and Methods: Six normal samples and five NPC clinical samples were collected for RNA-seq analysis. The expression levels in both groups were determined through student’s t-test. We identified genes of P < 0.01 as the differentially expressed genes (DEGs). In addition, gene set enrichment analysis (GSEA) was conducted. Afterwards, STRING V10 database was employed to extract protein interactions among the DEGs. Later, we established a protein-protein interaction (PPI) network, and used the Cytoscape software for network visualization. qRT-PCR was conducted to verify hub genes from clinical samples. Then, the function of CXCL10 in cell proliferation, apoptosis, invasion and migration was evaluated.Results: A total of 2024 DEGs were identified, among which, 1449 were down-regulated and 575 were up-regulated. The PPI was constructed, and the hub genes including Insulin Like Growth Factor 1 (IGF1), C-X-C Motif Chemokine Ligand 10 (CXCL10), Interleukin 13 (IL13), Intercellular Adhesion Molecule 1 (ICAM1), G Protein Subunit Gamma Transducin 1 (GNGT1), Matrix Metallopeptidase 1 (MMP1), Neurexin 1 (NRXN1) and Matrix Metallopeptidase 3 (MMP3) were obtained. The expression levels of CXCL10, IGF1, MMP3, MMP1, ICAM1, and IL-13 were significantly up-regulated in tumor tissues. High expression levels of CXCL10, MMP3 and ICAM1 predicted poor prognosis of NPC patients. CXCL10 silencing suppressed NPC cell proliferation and migration.Conclusions: CXCL10 may serve as a potential key gene affecting NPC genesis and progression.

Gemcitabine synergizes with cisplatin to inhibit nasopharyngeal carcinoma cell proliferation and tumor growth.

In a recently published phase III clinical trial, gemcitabine (GEM) plus cisplatin (DDP) induction chemotherapy significantly improved recurrence-free survival and overall survival and became the standard of care among patients with locoregionally advanced NPC. However, the molecular mechanisms of GEM synergized with DPP in NPC cells remain elucidated. These findings prompt us to explore the effect of the combination between GEM and DDP in NPC cell lines through proliferative phenotype, immunofluorescence, flow cytometry, and western blotting assays. In vitro studies reveal that GEM or DPP treated alone induces cell cycle arrest, promotes cell apoptosis, forces DNA damage response, and GEM synergism with DDP significantly increases the above effects in NPC cells. In vivo studies indicate that GEM or DPP treated alone significantly inhibits the tumor growth and prolongs the survival time of mice injected with SUNE1 cells compared to the control group. Moreover, the mice treated with GEM combined with DDP have smaller tumors and survive longer than those in GEM or DPP treated alone group. In addition, P-gp may be the key molecule that regulates the synergistic effect of gemcitabine and cisplatin. GEM synergizes with DPP to inhibit NPC cell proliferation and tumor growth by inducing cell cycle arrest, cell apoptosis, and DNA damage response, which reveals the mechanisms of combined GEM and DDP induction chemotherapy in improving locoregionally advanced NPC.

Exosomal transfer of miR-106a-5p contributes to cisplatin resistance and tumorigenesis in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC), a subclass of cancers of the neck and head, is a predominant cause of cancer‐associated death worldwide. Hence, there is a critical need for research into NPC‐related treatment strategies. Cisplatin is a promising therapy option for NPCs and other cancers that is frequently utilized. Some patients acquire resistance to cisplatin therapy, which complicates the successful use of cisplatin treatment in NPCs. Although exosomal transfer of oncogenic miRNAs has been shown to improve recipient cell proliferation, metastasis and chemoresistance, the molecular mechanism behind this effect on NPC has yet to be fully understood. Exosomal microRNAs (miRNAs) from cisplatin‐resistant cells were identified as significant mediators of chemoresistance in NPC cells in this investigation. Initially, we found that exosomal miR‐106a‐5p levels in the serum of chemoresistant and last‐cycle patients were greater than in that of non‐resistant and first‐cycle patients. Also, exosomal miR‐106a‐5p enhanced the proliferative ability of NPC cells. Mechanistically, exosomal miR‐106a‐5p targets ARNT2, which further activates AKT phosphorylation, and thus promotes NPC cell proliferation, decreases apoptosis and in turn regulates tumorigenesis. We found similar results using in vivo NPC models, where exosomal miR‐106a‐5p through regulation of ARNT2 (aryl hydrocarbon receptor nuclear translocator 2) promoted tumorigenesis. Taken together, these findings indicate that exosomal miR‐106a‐5p could be a promising diagnostic biomarker and drug target for patients with NPC.

The oncogenic role of HIF-1\u03b1/miR-182-5p/ZFP36L1 signaling pathway in nasopharyngeal carcinoma

BackgroundAccumulating evidence indicates that dysregulation of miR-182-5p can serve as diagnostic and prognostic biomarkers for some cancers, whereas the role of miR-182-5p has not been explored in nasopharyngeal carcinoma (NPC). Our study aims to elucidate the biological function of miR-182-5p in NPC and the potential molecular mechanism involved.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine miR-182-5p expression in NPC primary tissues and cell lines. Immunohistochemistry (IHC) for ZFP36L1 was conducted in NPC samples. Western blot was used to evaluate protein expression in cell lines. A series of functional assays were carried out to evaluate the roles of miR-182-5p and ZFP36L1 in tumor development and progression of NPC. Bioinformatics tools and luciferase reporter assays were utilized to identify the potential mechanisms of action. Moreover, rescue experiments were applied to explore whether ZFP36L1 mediated the effects of miR-182-5p in NPC.ResultsUp-regulation of miR-182-5p was significantly associated with tumor development and poor prognosis in patients with NPC. Functional study demonstrated that miR-182-5p overexpression enhanced, whereas suppression of miR-182-5p impeded NPC cell proliferation, migration, tumorigenesis and metastasis. Mechanistically, miR-182-5p interacted with ZFP36L1 at two sites in its 3′ un-translated region (UTR) and repressed ZFP36L1 expression in NPC. Consistently, an inverse correlation was observed between the expression levels of miR-182-5p and ZFP36L1 using clinical NPC tissues, and down-regulation of ZFP36L1 in NPC predicts poor survival. Furthermore, overexpression of miR-182-5p in NPC was partly attributable to the transcriptional activation effect induced by hypoxia-inducible factor 1α (HIF-1α).ConclusionsOur data suggests that miR-182-5p facilitates cell proliferation and migration in NPC through its ability to down-regulate ZFP36L1 expression, and that the HIF-1α/miR-182-5p/ZFP36L1 axis may serve as a novel therapeutic target in the management of NPC.

Nasopharyngeal Carcinoma: The Role of the EGFR in Epstein-Barr Virus Infection.

Epstein–Barr virus (EBV), a type 4 γ herpes virus, is recognized as a causative agent in nasopharyngeal carcinoma (NPC). Incidence of EBV-positive NPC have grown in recent decades along with worse outcomes compared with their EBV-negative counterparts. Latent membrane protein 1 (LMP1), encoded by EBV, induces NPC progression. The epidermal growth factor receptor (EGFR), a member of the ErbB family of receptor tyrosine kinases (RTK), is a driver of tumorigenesis, including for NPC. Little data exist on the relationship between EGFR and EBV-induced NPC. In our initial review, we found that LMP1 promoted the expression of EGFR in NPC in two main ways: the NF-κB pathway and STAT3 activation. On the other hand, EGFR also enhances EBV infection in NPC cells. Moreover, activation of EGFR signalling affects NPC cell proliferation, cell cycle progression, angiogenesis, invasion, and metastasis. Since EGFR promotes tumorigenesis and progression by downstream signalling pathways, causing poor outcomes in NPC patients, EGFR-targeted drugs could be considered a newly developed anti-tumor drug. Here, we summarize the major studies on EBV, EGFR, and LMP1-regulatory EGFR expression and nucleus location in NPC and discuss the clinical efficacy of EGFR-targeted agents in locally advanced NPC (LA NPC) and recurrent or metastatic NPC (R/M NPC) patients.

Effect of miR-25 on Proliferation of Nasopharyngeal Carcinoma Cells through Wnt/β-Catenin Signaling Pathway.

Objective To investigate the biological role and potential mechanism of miR-25 in nasopharyngeal carcinoma. Methods The expression of miR-25 in nasopharyngeal carcinoma cell lines was detected by qRT-PCR. The effect of inhibition of miR-25 expression on the proliferative activity of nasopharyngeal carcinoma cell line HONE-1 was examined by CCK-8 method. Flow cytometry was used to detect the effect of miR-25 expression inhibition on the apoptosis rate of nasopharyngeal carcinoma cell line HONE-1. The miRNA target gene prediction site TargetScan predicts the target protein action site of miR-124 and verifies whether miR-25 interacts with the target by luciferase activity assay, qPCR, and Western experiments. The miR-25 inhibitor and target egg gene expression plasmids were cotransfected into HONE-1 cells for rescue experiments to investigate whether miR-25 inhibits proliferation of nasopharyngeal carcinoma cells by target genes. At the same time, qRT-PCR was used to detect the mRNA expression levels of Wnt/β-catenin pathway key proteins TCF4, c-Myc, and Cyclin D1 in different transfected cells. Results miR-25 expression was upregulated in nasopharyngeal carcinoma cell lines. Functional studies showed that inhibition of miR-25 expression significantly inhibited the proliferation of nasopharyngeal carcinoma cell line HONE-1 (p < 0.05). Inhibition of miR-25 expression by flow cytometry significantly promoted apoptosis (p < 0.05). Detection of dual luciferase activity indicated that DKK3 is a direct target site for miR-25. Western blots showed that inhibition of miR-25 significantly upregulated DKK3 mRNA and protein levels. Supplementation with DKK3 significantly attenuated the inhibitory effect of miR-25 on the proliferation of nasopharyngeal carcinoma cell line HONE-1 (p < 0.05). qRT-PCR found that mRNA levels of TCF4, c-Myc, and Cyclin D1 were significantly upregulated in miR-25-transfected cells compared to control transfection. QRT PCR showed that the mRNA and protein levels of Tcf4, c-myc, and Cyclin D1 were significantly upregulated in miR-25 overexpression-transfected cells. Conclusion Inhibition of miR-25 expression promotes DKK3 gene expression, and inactivation of Wnt/β-catenin signaling pathway inhibits proliferation and promotes apoptosis of nasopharyngeal carcinoma cells.

Downregulation of SHCBP1 Inhibits Proliferation, Migration, and Invasion in Human Nasopharyngeal Carcinoma Cells.

Background SHC SH2 domain-binding protein 1 (SHCBP1), one of the members of Src homolog and collagen homolog (Shc) family, has been reported to be overexpressed in several malignant cancers and involved in tumor progression. However, the expression of SHCBP1 in nasopharyngeal carcinoma (NPC) remains unclear, and its clinical significance remains to be further elucidated. Methods The expression of SHCBP1 mRNA in 35 pair samples of NPC and adjacent normal tissues of NPC was detected by RT-qPCR. The expression level of SHCBP1 protein and mRNA in the selected cells was detected by western blot and RT-qPCR, respectively. The effects of SHCBP1 on NPC in vitro were observed by MTT method, colony formation assay, apoptosis assay, cell cycle assay, wound healing assay, transwell migration assay, and transwell invasion assay. Results SHCBP1 was highly expressed in clinical tissues and NPC cell lines, and SHCBP1 knockdown significantly inhibited NPC cell proliferation. Overexpression of SHCBP1 promoted NPC cell proliferation, migration, and invasion in NPC cell lines. Silencing SHCBP1 expression can delay cell cycle and inhibit cell apoptosis. Conclusion Our results suggest that SHCBP1 may promote proliferation and metastasis of NPC cells, which represents that SHCBP1 may act as a new indicator for predicting the prognosis of NPC and a new target for clinical treatment.

Epstein-Barr virus microRNA BART10-3p promotes dedifferentiation and proliferation of nasopharyngeal carcinoma by targeting ALK7.

Non-keratinizing nasopharyngeal carcinoma, the major subtype of nasopharyngeal carcinoma, is characterized by low differentiation and a close relation to Epstein-Barr virus infection, which indicates a link between Epstein-Barr virus oncogenesis and loss of differentiation, and raises our interest in investigating the involvement of Epstein-Barr virus in nasopharyngeal carcinoma dedifferentiation. Our previous study showed abundant expression of an Epstein-Barr virus-encoded microRNA, BART10-3p, in nasopharyngeal carcinoma tissues, but the association between BART10-3p and nasopharyngeal carcinoma differentiation remains unknown. Here, we examined the expression and prognostic value of BART10-3p, and undertook bioinformatics analysis and functional assays to investigate the influence of BART10-3p on nasopharyngeal carcinoma differentiation and proliferation and the underpinning mechanism. Microarray analysis identified BART10-3p as the most significantly upregulated Epstein-Barr virus-encoded microRNA in nasopharyngeal carcinoma tissues and the upregulation was confirmed in two public datasets. The expression of BART10-3p was an independent unfavorable prognosticator in nasopharyngeal carcinoma and its integration with the clinical stage showed improved prognosis predictive performance. Bioinformatics analysis suggested a potential role of BART10-3p in tumor differentiation and progression. Functional assays demonstrated that BART10-3p could promote nasopharyngeal carcinoma cell dedifferentiation, epithelial-mesenchymal transition, and proliferation in vitro, and tumorigenicity in vivo. Mechanistically, BART10-3p directly targeted the 3'UTR of ALK7 and suppressed its expression. Reconstitution of ALK7 rescued BART10-3p-induced malignant phenotypes. Overall, our study demonstrates that BART10-3p promotes dedifferentiation and proliferation of nasopharyngeal carcinoma by targeting ALK7, suggesting a promising therapeutic opportunity to reverse the malignant phenotypes of nasopharyngeal carcinoma.