Inhibited Nasopharyngeal Carcinoma Cell Proliferation Research Articles

Lactate dehydrogenase A promotes nasopharyngeal carcinoma progression through the TAK1/NF-κB Axis.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that originates in the nasopharyngeal mucosa and is common in China and Southeast Asian countries. Cancer cells reprogram glycolytic metabolism to promote their growth, survival and metastasis. Glycolysis plays an important role in NPC development, but the underlying mechanisms remain incompletely elucidated. Lactate dehydrogenase A (LDHA) is a crucial glycolytic enzyme, catalyzing the last step of glycolysis. This study aims to investigate the exact role of LDHA, which catalyzes the conversion of pyruvate into lactate, in NPC development. The western blot and immunohistochemical (IHC) results indicated that LDHA was significantly upregulated in NPC cells and clinical samples. LDHA knockdown by shRNA significantly inhibited NPC cell proliferation and invasion. Further knockdown of LDHA dramatically weakened the tumorigenicity of NPC cells in vivo. Mechanistic studies showed that LDHA activated TGF-β-activated kinase 1 (TAK1) and subsequent nuclear factor κB (NF-κB) signaling to promote NPC cell proliferation and invasion. Exogenous lactate supplementation restored NPC cell proliferation and invasion inhibited by LDHA knockdown, and this restorative effect was reversed by NF-κB inhibitor (BAY 11-7082) or TAK1 inhibitor (5Z-7-oxozeaenol) treatment. Moreover, clinical sample analyses showed that LDHA expression was positively correlated with TAK1 Thr187 phosphorylation and poor prognosis. Our results suggest that LDHA and its major metabolite lactate drive NPC progression by regulating TAK1 and its downstream NF-κB signaling, which could become a therapeutic target in NPC.

Hsa_circ_0028007 regulates the progression of nasopharyngeal carcinoma through the miR-1179/SQLE axis.

Nasopharyngeal carcinoma (NPC) is one of the most ordinary malignant tumors. Current research has suggested that circular RNAs play an important role in tumor genesis and progression. The purpose of this study is to explore the function and underlying mechanisms of circ_0028007 in NPC. The levels of circ_0028007, miR-1179, and Squalene epoxidase (SQLE) were detected by quantitative real-time polymerase chain reaction. Cell proliferation was detected by colony formation assay and thymidine analog 5-ethynyl-2'-deoxyuridine assay. Cell apoptosis was detected by flow cytometry. Relevant kits detected caspase-3, glucose, and lactate levels. Western blot assay was used to detect the related protein content. Dual-luciferase reporter assay and RNA pull-down assay were used to examine the target relationship between miR-1179 and circ_0028007 or SQLE. circ_0028007 and SQLE were highly expressed in NPC, while miR-1179 was lowly expressed. circ_0028007 silencing inhibited NPC cell proliferation and promoted apoptosis. However, the effect of circ_0028007 down-regulation on NPC cells was partially restored by co-transfection with miR-1179 inhibitor. Overexpression of SQLE partially restored the cell proliferation inhibited by circ_0028007 knockdown. circ_0028007 could regulate NPC progression via the miR-1179/SQLE axis. Therefore, circ_0028007 might be a new therapeutic target for NPC.

Hypoxia-induced degradation of PICK1 by RBCK1 promotes the proliferation of nasopharyngeal carcinoma cells

AimsHypoxia is an important feature of nasopharyngeal carcinoma (NPC). “Protein interacting with PRKCA 1” (PICK1) is commonly downregulated in human malignancies and is functionally related to poor prognosis. However, there is a limited understanding of the upstream mechanisms regulating PICK1 currently. Main methodsPICK1 and HIF-1α expression levels were analyzed by Immunohistochemistry (IHC), western blotting, and quantitative real-time PCR assay. Protein stability and ubiquitin assays were used to investigate PICK1 protein degradation. Immunofluorescence and co-immunoprecipitation assays were used to demonstrate the interaction between RBCK1 and PICK1. Gene knockdown by siRNA transfection was used to investigate the role of HIF-1α and RBCK1 in hypoxia-induced PICK1 degradation. Cell Counting Kit-8 (CCK-8), 5-Ethynyl-2′-deoxyuridine (EdU) assays and subcutaneous xenograft nude models were used to explore the roles of RBCK1 and PICK1 in NPC cell proliferation. Key findingsPICK1 expression in NPC tissue was negatively relative to that of HIF-1α. HIF-1α downregulated PICK1 expression by facilitating its ubiquitination by the E3 ligases RANBP2-type and C3HC4-type zinc finger containing 1 (RBCK1), thereby enhancing proteasome-mediated PICK1 degradation. RBCK1 knockdown inhibited NPC cell proliferation, which was ameliorated by double knockdown of RBCK1/PICK1. SignificanceThese data provide evidence for an NPC cell adaptation mechanism to hypoxia, where HIF-1α regulates RBCK1, which targets PICK1 for degradation to promote cell proliferation.

Circ_0000285 regulates nasopharyngeal carcinoma progression through miR-1278/FNDC3B axis.

Nasopharyngeal carcinoma (NPC) is cancer with high mortality and poor prognosis. Circular RNAs (circRNAs) have been identified in a wide variety of cancers. But the functional mechanism of circ_000285 in NPC remains unclear. To decipher the biological function and molecular mechanism of circ_000285 in NPC. Quantitative PCR (RT-qPCR) was applied for detecting the expression of circ_0000285, miR-1278, and FNDC3B. Western blot was used to measure the protein levels of Fibronectin type III domain containing 3B (FNDC3B), Bcl2 associated X (Bax), and B cell leukemia/lymphoma 2 (Bcl2). Cell proliferation, migration, and invasion were analyzed by colony formation, 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays. Cell apoptosis was detected by flow cytometry assays. ELISA assay was used to analyze Caspase-3 activity. Bioinformatics was used to predict, and the target relationship between miR-1278 and circ_0000285 or FNDC3B was verified by luciferase reporter assay. Tumor xenograft models were established to examine how circ_0000285 functions during the mediation of NPC tumor growth in vivo. Increased circ_0000285 and FNDC3B expressions, and a decreased miR-1278 expression were observed in NPC tissues and cell lines. Knockdown of circ_0000285 inhibited NPC cell proliferation, migration, invasion, and while promoting NPC cell apoptosis in vitro. Circ_0000285 knockdown-mediated anti-tumor effects in NPC cells could be largely reversed by silencing of miR-1278 or overexpression of FNDC3B. Circ_0000285 could up-regulate FNDC3B expression by sponging miR-1278 in NPC cells. Knockdown of circ_0000285 could inhibit tumor growth in vivo. Circ_0000285 upregulates FNDC3B expression by adsorbing miR-1278 to promote NPC development.

LINC00173 facilitates tumor progression by stimulating RAB1B-mediated PA2G4 and SDF4 secretion in nasopharyngeal carcinoma.

An increasing number of studies have found that long non-coding RNA (lncRNA) play important roles in driving the progression of nasopharyngeal carcinoma (NPC). Our microarray screening revealed that expression of the lncRNA long intergenic non-protein coding RNA 173 (LINC00173) was upregulated in NPC. However, its role and mechanism in NPC have not yet been elucidated. In this study, we demonstrate that high LINC00173 expression indicated a poor prognosis in NPC patients. Knockdown of LINC00173 significantly inhibited NPC cell proliferation, migration and invasion invitro. Mechanistically, LINC00173 interacted and colocalized with Ras-related protein Rab-1B (RAB1B) in the cytoplasm, but the modulation of LINC00173 expression did not affect the expression of RAB1B at either the mRNA or protein levels. Instead, relying on the stimulation of RAB1B, LINC00173 could facilitate the extracellular secretion of proliferation-associated 2G4 (PA2G4) and stromal cell-derived factor 4 (SDF4; also known as 45-kDa calcium-binding protein) proteins, and knockdown of these proteins could reverse the NPC aggressive phenotype induced by LINC00173 overexpression. Moreover, invivo LINC00173-knockdown models exhibited a marked slowdown in tumor growth and a significant reduction in lymph node and lung metastases. In summary, LINC00173 serves as a crucial driver for NPC progression, and the LINC00173-RAB1B-PA2G4/SDF4 axis might provide a potential therapeutic target for NPC patients.

Quercetin acts as a novel anti-cancer drug to suppress cancer aggressiveness and cisplatin-resistance in nasopharyngeal carcinoma (NPC) through regulating the yes-associated protein/Hippo signaling pathway

BackgroundQuercetin has been proven to be effective for cancer treatment, including nasopharyngeal carcinoma (NPC). Also, Quercetin sensitizes cancer cells to current chemical drugs to improve their therapeutic efficacy. However, up until now, the molecular mechanisms that quercetin exerted its therapeutic effects on NPC have not been fully delineated. MethodsCell proliferation abilities were examined by CCK-8 assay and colony formation assay. Real-Time qPCR and Western Blot analysis were used to detect gene expressions at RNA and protein levels. Cell mobility was determined by wound scratch assay and transwell assay. Cell death was detected using flow cytometry (FCM). Tumorigenesis of the NPC cells was determined by in vivo tumor-bearing mice models. Hematoxylin and eosin (H&E) and TUNEL staining were used to detect the tumor metastasis to lung tissues and dead cells, respectively. ResultsHere, we validated that quercetin exerted its anti-tumor effects and increased cisplatin-sensitivity in NPC in vitro and in vivo. Specifically, quercetin inhibited NPC cell proliferation, viability, mobility, epithelial-mesenchymal transition (EMT), and tumorigenesis, and induced cell death, resulting in the inhibition of NPC progression. In addition, the NPC cells were subjected to a continuously increasing doses of cisplatin to generate cisplatin-resistant NPC (NPC/CDDP) cells. Interestingly, quercetin significantly enhanced the cytotoxic effects of high-dose cisplatin on NPC/CDDP cells. Furthermore, the potential underlying mechanisms were uncovered, and the results evidenced that quercetin inhibited Yes-associated protein (YAP) expression and its translocation to the nucleus, leading to the recovery of the Hippo pathway, inhibition of cancer progression, and increase in cisplatin-resistance. Mechanistically, upregulation of YAP by its gene manipulating vectors abrogated the inhibiting effects of quercetin on NPC malignant phenotypes, which also made NCP/CDDP cells irresponsive to high-dose cisplatin-quercetin co-treatments. ConclusionCollectively, our data evidenced that quercetin inhibited YAP to recover the Hippo pathway, which further inhibited NPC pathogenesis and increased susceptibility of NCP/CDDP cells to cisplatin treatment.

Knockdown of RFC4 inhibits the cell proliferation of nasopharyngeal carcinoma in vitro and in vivo.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that mainly occurs in East and Southeast Asia. Although patients benefit from the main NPC treatments (e.g., radiotherapy and concurrent chemotherapy), persistent and recurrent diseases still occur in some NPC patients. Therefore, investigating the pathogenesis of NPC is of great clinical significance. In the present study, replication factor c subunit 4 (RFC4) is a key potential target involved in NPC progression via bioinformatics analysis. Furthermore, the expression and mechanism of RFC4 in NPC were investigated in vitro and in vivo. Our results revealed that RFC4 was more elevated in NPC tumor tissues than in normal tissues. RFC4 knockdown induced G2/M cell cycle arrest and inhibited NPC cell proliferation in vitro and in vivo. Interestingly, HOXA10 was confirmed as a downstream target of RFC4, and the overexpression of HOXA10 attenuated the silencing of RFC4-induced cell proliferation, colony formation inhibition, and cell cycle arrest. For the first time, this study reveals that RFC4 is required for NPC cell proliferation and may play a pivotal role in NPC tumorigenesis.

Dracaena cinnabari Methanolic Extract impairing Migration and inhibiting Growth of Nasopharyngeal Carcinoma Cells through Induction of Intrinsic Apoptotic Pathway In Vitro

The resin of Dracaena cinnabari Balf. f. has demonstrated antiviral, antibacterial, antioxidative, analgesic and anti-inflammatory properties, which presents some proof for its effectiveness in traditional use. Despite the broad health benefits of Dracaena cinnabari, few research has been conducted on its anti-tumour effect. We have previously shown that Dracaena cinnabari Balf. f methanolic extract (DCBME) induces apoptotic cell death in human tongue squamous cell carcinoma cell line and significantly reduces its migration capacity. The anti-tumour potential and mechanism of action of DCBME in Nasopharyngeal Carcinoma (NPC) have not yet been elucidated. In our recent paper, we showed the disruption of mitochondrial membrane potential and the induction of the intrinsic apoptotic pathway through caspase 3/7 activation. In the present study, we aim to investigate the effect of DCBME on proliferation, morphological changes, cell death, cell cycle arrest and cell migration of NPC cells. NPC cells (C666-1 and HK-1) were treated with DCBME and the mechanism underlying its anti-tumour effect was explored by examining cell proliferation, induction of apoptosis and cell migration using MTT assay, phase-contrast and fluorescence microscopy, propidium iodide staining, DNA fragmentation and wound healing assays. DCBME significantly inhibited NPC cell proliferation in a time and dose-dependent manner. It induced marked apoptotic morphological changes, apoptotic DNA laddering and S and/or G2/M-phase cell cycle arrest. DCBME also inhibited the migration of NPC cells. Together with our previously reported anti-tumour effect of DCBME, the findings suggest that DCBME deserves further investigation as a promising anti-tumour agent for human Nasopharyngeal Carcinoma cells therapy.

Integrative Pan-Cancer Analysis of KIF15 Reveals Its Diagnosis and Prognosis Value in Nasopharyngeal Carcinoma.

BackgroundKIF15 plays a vital role in many biological processes and has been reported to influence the occurrence and development of certain human cancers. However, there are few systematic evaluations on the role of KIF15 in human cancers, and the role of KIF15 in the diagnosis and prognosis of nasopharyngeal carcinoma (NPC) also remains unexplored. Therefore, this study aimed to conduct a pan-cancer analysis of KIF15 and evaluate its diagnostic and prognostic potential in NPC.MethodsThe expression pattern, prognostic value, molecular function, tumor mutation burden, microsatellite instability, and immune cell infiltration of KIF15 were examined based on public databases. Next, the diagnostic value of KIF15 in NPC was analyzed using the Gene Expression Omnibus (GEO) database and immunohistochemistry (IHC). Kaplan–Meier curves, Cox regression analyses, and nomograms were used to evaluate the effects of KIF15 expression on NPC prognosis. Finally, the effect of KIF15 on NPC was explored by in vitro experiments.ResultsThe expression of KIF15 was significantly upregulated in 20 out of 33 cancer types compared to adjacent normal tissue. Kyoto Encyclopedia of Genes and Genomes enrichment (KEGG) analysis showed that KIF15 could participate in several cancer-related pathways. The increased expression level of KIF15 was correlated with worse clinical outcomes in many types of human cancers. Additionally, KIF15 expression was related to cancer infiltration of immune cells, tumor mutation burden, and microsatellite instability. In the analysis of NPC, KIF15 was significantly upregulated based on the GEO database and immunohistochemistry. A high expression of KIF15 was negatively associated with the prognosis of patients with NPC. A nomogram model integrating clinical characteristics and KIF15 expression was established, and it showed good predictive ability with an area under the curve value of 0.73. KIF15 knockdown significantly inhibited NPC cell proliferation and migration.ConclusionsOur findings revealed the important and functional role of KIF15 as an oncogene in pan-cancer. Moreover, high expression of KIF15 was found in NPC tissues, and was correlated with poor prognosis in NPC. KIF15 may serve as a potential therapeutic target in NPC treatment.

CircTMTC1 contributes to nasopharyngeal carcinoma progression through targeting miR-495-MET-eIF4G1 translational regulation axis

Nasopharyngeal carcinoma (NPC) is the most common primary malignancy arising from the epithelial cells of nasopharynx. CircTMTC1 is upregulated in NPC patients, but its role and molecular mechanism in NPC are unknown. Normal nasopharyngeal epithelium and tumor tissues were collected. The expression of circTMTC1, miR-495, MET/eIF4G1 pathway-related molecules were examined. Colony formation and transwell assays were used to assess cell proliferation, migration, and invasion. Cell apoptosis was analyzed by annexin V and propidium iodide (PI) staining. Gene interaction was examined by RNA immunoprecipitation (RIP) and luciferase activity assays. Subcutaneous and intravenous xenograft mouse models were established to analyze NPC growth and metastasis in vivo. CircTMTC1 was highly expressed and miR-495 was downregulated in NPC, which were associated with poor prognosis of NPC. Both circTMTC1 knockdown and miR-495 overexpression inhibited NPC cell proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) and promoted cell apoptosis. CircTMTC1 directly targeted miR-495 to promote the expression of its downstream target gene MET. miR-495 knockdown enhanced the expression of c-Myc, Cyclin D1, and survivin and accelerated NPC cell proliferation, migration, invasion, and EMT through targeting MET and activating the MET-eIF4G1 axis. CircTMTC1 silence inhibited NPC growth and lung metastasis by targeting the miR-495-MET-eIF4G1 translational regulation axis in vivo. CircTMTC1 accelerates NPC progression through targeting miR-495 and consequently activating the MET-eIF4G1 translational regulation axis, suggesting potential therapeutic targets for NPC treatment.

Long non-coding RNA LUADT1 promotes nasopharyngeal carcinoma cell proliferation and invasion by downregulating miR-1207-5p

ABSTRACT Nasopharyngeal carcinoma (NPC) is a typical type of malignant tumor. This research paper aims to study the function and mechanism of long non-coding RNA lung adenocarcinoma-related transcript 1 (lncRNA-LUADT1) in the progression of NPC. In this study, the expressions of lncRNA-LUADT1, miR-1207-5p, and TEAD1 in NPC tissues and cell lines were detected by RT-qPCR. Initially, the expression of lncRNA-LUADT1 and TEAD1 were significantly up-regulated in NPC tissues and cells, while miR-1207-5p was significantly down-regulated. Next, miR-1207-5p was confirmed to bind to lncRNA-LUADT1 or TEAD1 by bioinformatics and luciferase reporter assay. In addition, after interfering with lncRNA-LUADT1 expression, experiments of CCK8, EDU staining, and Transwell invasion were used to detect proliferation, invasion, and migration of NPC cells. The results showed that interfering with lncRNA-LUADT1 expression could inhibit the proliferation, invasion, and migration of NPC cells. Western blot showed that lncRNA-LUADT1 knockdown significantly decreased the expression of Hippo/YAP pathway protein (YAP1 and TAZ). However, interfering with the expression of miR-1207-5p reversed these results. In addition, the nude mouse tumor formation experiment suggested that low-expressed lncRNA-LUADT1 reduced the volume and weight of tumor tissues. In summary, lncRNA-LUADT1 down-regulation could inhibit NPC cell proliferation and invasion, which may be achieved through regulating miR-1207-5p expression and affecting TEAD1 expression, thus inhibiting the activation of Hippo/YAP signaling pathway.

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.

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.

Tenascin-C promotes epithelial-to-mesenchymal transition and the mTOR signaling pathway in nasopharyngeal carcinoma.

Tenascin-C (TNC) is a large extracellular matrix glycoprotein that promotes cell adhesion and tissue remodeling, and is involved in the transduction of cellular signaling pathways. The present study aimed to investigate the role of TNC and determine its effect in nasopharyngeal carcinoma (NPC). TNC gene transcription and expression were analyzed using the NPC dataset and immunohistochemistry analysis of NPC tissues. Weighted gene co-expression network and gene enrichment analyses were performed to determine the potential molecular mechanisms underlying the effects of TNC in NPC. TNC expression was suppressed in NPC cells, and the effects were determined both in vitro and in vivo. The results demonstrated that TNC gene transcription and expression were high in NPC tissues compared with normal tissues. Notably, TNC knockdown inhibited NPC cell proliferation, migration and invasion. In addition, TNC knockdown inhibited tumor growth in mice. In vitro, TNC knockdown inhibited epithelial-to-mesenchymal transition (EMT) and decreased activity of the PI3K/AKT/mTOR signaling pathway in NPC cells. Taken together, these results suggest that TNC promotes cell proliferation, EMT and activity of the PI3K/AKT/mTOR signaling pathway in NPC cells, and thus functions as an oncogene.

CircRNA circTRAF3 promotes nasopharyngeal carcinoma metastasis through targeting miR-203a-3p/AKT3 axis

Distant metastasis is still the main cause of death in patients with nasopharyngeal carcinoma (NPC), and its mechanism is not fully understood. In this study, we studied the biological function and molecular mechanism of circular RNA circTRAF3 in NPC metastasis. We found that the increase in circTRAF3 is associated with the metastasis and survival of NPC patients. Knockdown of circTRAF3 could inhibit NPC cell proliferation and cell invasion, and induce apoptosis in vitro and in vivo. Further mechanism studies demonstrated that circTRAF3 eliminated the inhibitory effect of miR-203a-3p on AKT3 by adsorbing miR-203a-3p, and finally played the role of oncogene in NPC. Our findings reveal a new type of circRNA, circTRAF3, which acts as an oncogene in NPC and targets miR-203a-3p/AKT3 pathway. The circTRAF3/miR-203a-3p/AKT3 pathway may be a potential therapeutic target for metastatic NPC.

Inhibition of cell proliferation and radioresistance by miR-383-5p through targeting RNA binding protein motif (RBM3) in nasopharyngeal carcinoma.

BackgroundRNA binding protein motif (RBM3) is associated with radioresistance in nasopharyngeal carcinoma (NPC), and miR-383-5p was predicted to target the 3'-untranslated region (3'UTR) of RBM3 messenger RNA (mRNA). Our study aimed to investigate the role and the mechanisms of miR-383-5p targeting RBM3 in NPC cell proliferation and radioresistance (RR).MethodsThe expression of miR-383-5p was detected by Real-time quantitative PCR (qRT-PCR) between RS (Radiosensitivity) and RR (Radioresistance) NPC patient- tissue specimens and cell lines. Cell Counting Kit-8 (CCK-8) and Clonogenic survival assay were applied to analyze the effect of miR-383-5p on NPC cell proliferation and radioresistance. Possible downstream target of miR-383-5p in NPC cells, RBM3was evaluated by luciferase assay and qRT-PCR. miR-383-5p inhibited NPC cell proliferation and radioresistance through RBM3 by rescue experiments. The effect of miR-383-5p on radiation-induced apoptosis was explored through Flow cytometric analysis and Western blotting. Western blotting was analyzed the molecular of RBM3-mediated Jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK) signaling pathwaysResultsThe expression of miR-383-5p was decreased in radioresistant NPC tissues and cells. miR-383-5p inhibited cell proliferation and radioresistance in CNE1/IR cells. We also observed that therapeutic administration of a miR-383-5p agomir dramatically sensitized NPC xenografts to radiation in a mouse model. Conversely, in the same xenograft model, administration of a miR-383-5p antagomir dramatically increased NPC resistance to radiation. miR-383-5p targeted the 3'UTR of RBM3. miR-383-5p inhibited NPC cell proliferation and radioresistance through RBM3. Finally, we found that miR-383-5p increased radiation-induced apoptosis, activated JNK signaling, and inhibited ERK signaling.ConclusionsOur study revealed that miR-383-5p targeted the 3'UTR of RBM3 and contributed to the efficacy of NPC radiation therapy by altering the RBM3-mediated JNK and ERK signaling pathways.

Overexpressed circRANBP17 acts as an oncogene to facilitate nasopharyngeal carcinoma via the miR-635/RUNX2 axis.

Circular RNAs (circRNAs) are implicated in the initiation and progress of several diseases, including cancer. However, the precise role of circRNAs in human nasopharyngeal carcinoma (NPC) remains unclear. In this research, we found a new circRNA hsa_circ_0001554 (circRANBP17), which was derived from the RAN binding protein 17 (RANBP17). Our qRT-PCR data found that circRANBP17 expression was up-regulated in NPC tissue and cells. Functional silencing studies revealed that circRANBP17 inhibited NPC cell proliferation and invasion in vitro, and circRANBP17 down-regulation also reduced tumor growth in nude mice. MiR-635 was demonstrated as a direct target of circRANBP17; circRANBP17 up-regulated RUNX2 expression levels by sponging miR-635, thereby promoting NPC proliferation and invasion. Thus, our data provide the evidence for the first time that circRANBP17 is a new onco-circRNA via miR-635/RUNX2 axis regulation, and may function as a novel therapeutic target for NPC treatment.

Effects of Dicer1 targeted by EBV-miR-BART6-5p on biological properties and radiosensitivity of nasopharyngeal carcinoma.

To discuss the effects of Epstein-Barr virus (EBV)-encoded BamHI A rightward transcript (BART) microRNA (miR-BART6-5p) by targeting Dicer1 on biological properties and radiosensitivity of nasopharyngeal carcinoma (NPC). NPC patients (n = 96) treated with radiotherapy were collected from Jan 2010 to Jan 2011. Real-time quantitative PCR (qRT-PCR) and western blot were carried out to measure the expression of miR-BART6-5p and Dicer1. Dual luciferase reporter gene assay verified that miR-BART6-5p targeted Dicer1. CCK8, wound-healing, Transwell and Annexin-FITC/PI were employed to evaluate the effects of Dicer1 mediated by miR-BART6-5p on biological characteristics of NPC cells. The radiosensitivity of miR-BART6-5p targeting Dicer1 was assessed in vitro and in vivo. Increased miR-BART6-5p and decreased Dicer1 were discovered in NPC patients, displaying a close association with T-stage, clinical stage, as well as Pre-DNA of NPC. While elevated Dicer1 and miR-BART6-5p down-regulation in NPC patients were found after effective radiotherapy. Both miR-BART6-5p and Dicer1 were prognostic factors of NPC. Down-regulation of miR-BART6-5p could enhance Dicer1 expression and inhibit NPC cell proliferation, invasion and migration with promoted apoptosis. Clone formation assay also showed miR-BART6-5p down-regulation reduced planting efficiency (PE), which further decreased with the increased dose of irradiation. Injection with miR-BART6-5p inhibitors in nude mice after 6-Gy irradiation contributed to the overexpression of Dicer1 and the inhibition of tumor growth. EBV-miR-BART6-5p may target Dicer1 to facilitate proliferation and metastasis of NPC cells and suppress apoptosis, thus being a new target for NPC therapy.

CYLD Promotes Apoptosis of Nasopharyngeal Carcinoma Cells by Regulating NDRG1.

PurposeNasopharyngeal carcinoma (NPC) is among the most common malignancies derived from the epithelium of the nasopharynx. To date, the regulatory networks involved in NPC have not been fully identified. Previous studies revealed multiple loss-of-function mutations in NPC and specifically in cylindromatosis lysine 63 deubiquitinase (CYLD); however, the exact role of CYLD in NPC progression and its potential mechanism remains unclear.MethodsWe performed immunohistochemical (IHC) staining and real-time quantitative polymerase chain reaction (qPCR) to measure CYLD expression in NPC tissues, and Western blot was conducted to determine CYLD levels in NPC cell lines. Cell proliferation was detected by CCK8 assay and colony formation analysis, and apoptosis was determined by Annexin V/propidium iodide staining. Potential targets of CYLD were verified by co-immunoprecipitation and mass spectrometry. Xenograft assay was conducted to confirm the role of CYLD in vivo.ResultsWe found that CYLD levels were significantly decreased in both NPC tissues and cell lines, and that CYLD overexpression inhibited NPC cell proliferation and promoted apoptosis. Additionally, we revealed that CYLD bound and upregulated N-Myc downstream regulated 1 (NDRG1), and that silencing NDRG1 abolished the tumor-suppressor effect of CYLD on NPC cells. Furthermore, CYLD suppressed tumor growth in xenograft mice models.ConclusionThese results suggest CYLD as a tumor suppressor, potential biomarker for diagnosing NPC, and therapeutic target.

FNDC3B 3'-UTR shortening escapes from microRNA-mediated gene repression and promotes nasopharyngeal carcinoma progression.

Alternative polyadenylation (APA), which induces shortening of the 3′‐UTR, is emerging as an important feature in cancer development and progression. Nevertheless, the effects and mechanisms of APA‐induced 3′‐UTR shortening in nasopharyngeal carcinoma (NPC) remain largely unclear. Fibronectin type III domain containing 3B (FNDC3B) tended to use proximal polyadenylation site and produce shorter 3′‐UTR according to our previous sequencing study. Herein, we found that FNDC3B with shorter 3′‐UTR could escape from miRNA‐mediated gene repression, and caused its increased expression in NPC. Knocking down of FNDC3B inhibited NPC cell proliferation, migration, invasion, and metastasis in vitro and in vivo. Overexpression of FNDC3B, especially those with shorter 3′‐UTR, promoted NPC progression. Furthermore, the mechanism study revealed that FNDC3B could bind to and stabilize myosin heavy chain 9 (MYH9) to activate the Wnt/β‐catenin signaling pathway. In addition, MYH9 could reverse the inhibitory effects of FNDC3B knockdown in NPC. Altogether, our results suggested that the 3′‐UTR shortening of FNDC3B mRNA mediated its overexpression in NPC and promoted NPC progression by targeting MYH9. This newly identified FNDC3B‐MYH9‐Wnt/β‐catenin axis could represent potential targets for individualized treatment in NPC.