NPC Cell Research Articles

METTL14 contributes to the progression of nasopharyngeal carcinoma through regulating the stability of AOC1 mRNA

BackgroundNasopharyngeal carcinoma (NPC) is a malignant epithelial tumor of the nasopharyngeal mucosa with a high incidence rate all over the world. Methyltransferase-like 14 (METTL14) is a major RNA N6-adenosine methyltransferase implicated in tumor progression by regulating RNA function. This study is designed to explore the biological function and mechanism of METTL14 in NPC.MethodsMETTL14 and Amine oxidase copper containing 1 (AOC1) expression were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The protein levels of METTL14, AOC1, Cyclin D1, B-cell lymphoma-2 (Bcl-2), and N-cadherin were measured using western blot. Cell proliferation, cycle progression, apoptosis, migration, and invasion were assessed using 5-ethynyl-2’-deoxyuridine (EdU), Colony formation, flow cytometry, wound scratch, and transwell assays. The interaction between METTL14 and AOC1 was verified using RNA immunoprecipitation (RIP), methylated RNA immunoprecipitation (MeRIP), and dual-luciferase reporter assays. The biological role of METTL14 on NPC tumor growth was examined by the xenograft tumor model in vivo.ResultsMETTL14 and AOC1 were highly expressed in NPC tissues and cells. Moreover, METTL14 knockdown might block NPC cell proliferation, migration, invasion, and induce cell apoptosis in vitro. In mechanism, METTL14 might enhance the stability of AOC1 mRNA via m6A methylation. METTL14 silencing might repress NPC tumor growth in vivo.ConclusionMETTL14 might boosted the development of NPC cells partly by regulating the stability of AOC1 mRNA, which provided a promising therapeutic target for NPC treatment.

Nasopharyngeal carcinoma cell screening based on nuclear targeting Surface-Enhanced Raman Scattering (SERS) detection

BackgroundNasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma arising from the nasopharyngeal mucosal lining. Diagnosis of NPC at early stage can improve the outcome of patients and facilitate reduction in cancer mortality. The most significant change between cancer cells and normal cells is the variation of cell nucleus. Therefore, accurately detecting the biochemical changes in nucleus between cancer cells and normal cells has great potential to explore diagnostic molecular markers for NPC. Highly sensitive surface-enhanced Raman scattering (SERS) could reflect the biochemical changes in the process of cell cancerization at the molecular level. However, rapid nuclear targeting SERS detection remains a challenge. ResultsA novel and accurate nuclear-targeting SERS detection method based on electroporation was proposed. With the assistance of electric pulses, nuclear-targeting nanoprobes were rapidly introduced into different NPC cells (including CNE1, CNE2, C666 cell lines) and normal nasopharyngeal epithelial cells (NP69 cell line), respectively. Under the action of nuclear localization signaling peptides (NLS), the nanoprobes entering cells were located to the nucleus, providing high-quality nuclear SERS signals. Hematoxylin and eosin (H&E) staining and in situ cell SERS imaging confirmed the excellent nuclear targeting performance of the nanoprobes developed in this study. The comparison of SERS signals indicated that there were subtle differences in the biochemical components between NPC cells and normal nasopharyngeal cells. Furthermore, SERS spectra combined with principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to diagnose and distinguish NPC cell samples, and high sensitivity, specificity, and accuracy were obtained in the screening of NPC cells from normal nasopharyngeal epithelial cells. SignificanceTo the best of our knowledge, this is the first study that employing nuclear-targeting SERS testing to screen nasopharyngeal carcinoma cells. Based on the electroporation technology, nanoprobes can be rapidly introduced into living cells for intracellular biochemical detection. Nuclear-targeting SERS detection can analyze the biochemical changes in the nucleus of cancer cells at the molecular level, which has great potential for early cancer screening and cytotoxicity analysis of anticancer drugs.

IGF-1R mediates crosstalk between nasopharyngeal carcinoma cells and osteoclasts and promotes tumor bone metastasis

BackgroundNasopharyngeal carcinoma (NPC) poses a significant health burden in specific regions of Asia, and some of NPC patients have bone metastases at the time of initial diagnosis. Bone metastasis can cause pathologic fractures and pain, reducing patients' quality of life, and is associated with worse survival. This study aims to unravel the complex role of insulin-like growth factor 1 receptor (IGF-1R) in NPC bone metastasis, offering insights into potential therapeutic targets.MethodsWe assessed IGF-1R expression in NPC cells and explored its correlation with bone metastasis. Experiments investigated the impact of osteoclast-secreted IGF-1 on the IGF-1R/AKT/S6 pathway in promoting NPC cell proliferation within the bone marrow. Additionally, the reciprocal influence of tumor-secreted Granulocyte–macrophage colony-stimulating factor (GM-CSF) on osteoclast differentiation and bone resorption was examined. The effects of IGF-1 neutralizing antibody, IGF-1R specific inhibitor (NVP-AEW541) and mTORC inhibitor (rapamycin) on nasopharyngeal carcinoma bone metastasis were also explored in animal experiments.ResultsElevated IGF-1R expression in NPC cells correlated with an increased tendency for bone metastasis. IGF-1, secreted by osteoclasts, activated the IGF-1R/AKT/S6 pathway, promoting NPC cell proliferation in the bone marrow. Tumor-secreted GM-CSF further stimulated osteoclast differentiation, exacerbating bone resorption. The IGF-1 neutralizing antibody, NVP-AEW541 and rapamycin were respectively effective in slowing down the rate of bone metastasis and reducing bone destruction.ConclusionThe intricate interplay among IGF-1R, IGF-1, and GM-CSF highlights potential therapeutic targets for precise control of NPC bone metastasis, providing valuable insights for developing targeted interventions.

MiR-186 regulates epithelial–mesenchymal transformation to promote nasopharyngeal carcinoma metastasis by targeting ZEB1

ObjectivesNasopharyngeal carcinoma (NPC) is an aggressive epithelial cancer. The expression of miR-186 is decreased in a variety of malignancies and can promote the invasion and metastasis of cancer cells. This study aimed to explore the role and possible mechanism of miR-186 in the metastasis and epithelial–mesenchymal transformation (EMT) of NPC. MethodsThe expression of miR-186 in NPC tissues and cells was detected by RT-PCR. Then, miR-186 mimic was used to transfect NPC cell lines C666-1 and CNE-2, and cell activity, invasion and migration were detected by CCK8, transwell and scratch assay, respectively. The expression of EMT-related proteins was analyzed by western blotting analysis. The binding relationship between miR-186 and target gene Zinc Finger E-Box Binding Homeobox 1 (ZEB1) was confirmed by double luciferase assay. ResultsThe expression of miR-186 in NPC was significantly decreased, and transfection of miR-186 mimic could significantly inhibit the cell activity, invasion, and migration, and regulate the protein expressions of E-cadherin, N-cadherin and vimentin in C666-1 and CNE-2 cells. Further experiments confirmed that miR-186 could directly target ZEB1 and negatively regulate its expression. In addition, ZEB1 has been confirmed to be highly expressed in NPC, and inhibition of ZEB1 could inhibit the activity, invasion, metastasis and EMT of NPC cells. And co-transfection of miR-186 mimic and si-ZEB1 could further inhibit the proliferation and metastasis of NPC. ConclusionmiR-186 may inhibit the proliferation, metastasis and EMT of NPC by targeting ZEB1, and the miR-186/ZEB1 axis plays an important role in NPC.

Global Proteomics for Identifying the Alteration Pathway of Niemann–Pick Disease Type C Using Hepatic Cell Models

Niemann–Pick disease type C (NPC) is an autosomal recessive disorder with progressive neurodegeneration. Although the causative genes were previously identified, NPC has unclear pathophysiological aspects, and patients with NPC present various symptoms and onset ages. However, various novel biomarkers and metabolic alterations have been investigated; at present, few comprehensive proteomic alterations have been reported in relation to NPC. In this study, we aimed to elucidate proteomic alterations in NPC and perform a global proteomics analysis for NPC model cells. First, we developed two NPC cell models by knocking out NPC1 using CRISPR/Cas9 (KO1 and KO2). Second, we performed a label-free (LF) global proteomics analysis. Using the LF approach, more than 300 proteins, defined as differentially expressed proteins (DEPs), changed in the KO1 and/or KO2 cells, while the two models shared 35 DEPs. As a bioinformatics analysis, the construction of a protein–protein interaction (PPI) network and an enrichment analysis showed that common characteristic pathways such as ferroptosis and mitophagy were identified in the two model cells. There are few reports of the involvement of NPC in ferroptosis, and this study presents ferroptosis as an altered pathway in NPC. On the other hand, many other pathways and DEPs were previously suggested to be associated with NPC, supporting the link between the proteome analyzed here and NPC. Therapeutic research based on these results is expected in the future.

Enhancing Nasopharyngeal Carcinoma Cell Separation with Selective Fibronectin Coating and Topographical Modification on Polydimethylsiloxane Scaffold Platforms.

The extracellular matrix (ECM) serves as a complex scaffold with diverse physical dimensions and surface properties influencing NPC cell migration. Polydimethylsiloxane (PDMS), a widely used biocompatible material, is hydrophobic and undesirable for cell seeding. Thus, the establishment of a biomimetic model with varied topographies and surface properties is essential for effective NPC43 cell separation from NP460 cells. This study explored how ECM surface properties influence NP460 and NPC43 cell behaviors via plasma treatments and chemical modifications to alter the platform surface. In addition to the conventional oxygen/nitrogen (O2/N2) plasma treatment, O2 and argon plasma treatments were utilized to modify the platform surface, which increased the hydrophilicity of the PDMS platforms, resulting in enhanced cell adhesion. (3-aminopropyl)triethoxysilane and fibronectin (FN) were used to coat the PDMS platforms uniformly and selectively. The chemical coatings significantly affected cell motility and spreading, as cells exhibited faster migration, elongated cell shapes, and larger spreading areas on FN-coated surfaces. Furthermore, narrower top layer trenches with 5 µm width and a lower concentration of 10 µg/mL FN were coated selectively on the platforms to limit NP460 cell movements and enhance NPC43 cell separation efficiency. A significantly high separation efficiency of 99.4% was achieved on the two-layer scaffold platform with 20/5 µm wide ridge/trench (R/T) as the top layer and 40/10 µm wide R/T as the bottom layer, coupling with 10 µg/mL FN selectively coated on the sidewalls of the top and bottom layers. This work demonstrated an innovative application of selective FN coating to direct cell behavior, offering a new perspective to probe into the subtleties of NPC cell separation efficiency. Moreover, this cost-effective and compact microsystem sets a new benchmark for separating cancer cells.

ACSL4 promotes ferroptosis and M1 macrophage polarization to regulate the tumorigenesis of nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a head and neck malignant tumor with a high incidence and recurrence rate. The crosstalk between ferroptosis and tumor-associated macrophages (TAMs) is thought to have major implications in interfering with cancers. We intended to explore the effect of acyl-CoA synthetase long-chain family member 4 (ACSL4) on the pathogenesis of NPC via ferroptosis and TAMs. MethodsDifferential genes in NPC patients were analyzed using publicly available databases, and the ferroptosis-related gene ACSL4 was identified. Expression of ACSL4 in NPC cell lines and xenografted mice was examined. Colony formation, cell proliferation, migration, and invasion were assessed. The abundance of epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, and Vimentin) was confirmed. Lipid peroxidation levels and related markers were measured. Clophosome was administered to determine the role of TAMs in NPC mice. ResultsLow levels of ACSL4 were observed in NPC patients and CNE-2 and 5-8F cells. Erastin (a ferroptosis inducer) and ACSL4 increased lipid peroxidation, decreased cell viability, colony formation, cell proliferation, migration and invasion, and inhibited EMT. Moreover, Erastin and ACSL4 promoted M2 to M1 macrophage polarization. The effects of erastin and ACSL4 were additive. Ferrostatin-1, an inhibitor of ferroptosis, exerted the opposite effect and reversed the beneficial effects of ACSL4 overexpression. In xenograft mice, ACSL4 and clophosome hindered the growth of NPC, and extra clophosome slightly enhanced the antitumor effect of ACSL4. ConclusionOur findings indicated that ACSL4 inhibited the pathogenesis of NPC, at least through crosstalk between ferroptosis and macrophages, providing potential direction for NPC therapy.

A 3-gene signature comprising CDH4, STAT4 and EBV-encoded LMP1 for early diagnosis and predicting disease progression of nasopharyngeal carcinoma

PurposeNasopharyngeal carcinoma is highly metastatic but difficult to detect in its early stages. It is critical to develop a simple and highly efficient molecular diagnostic method for early detection of NPC in clinical biopsies.MethodsThe transcriptomic data of primary NPC cell strains were used as a discovery tool. Linear regression approach was used to define signatures distinctive between early and late stage of NPC. Expressions of candidates were validated with an independent set of biopsies (n = 39). Leave-one-out cross-validation technique was employed to estimate the prediction accuracy on stage classification. The clinical relevance of marker genes was verified using NPC bulk RNA sequencing data and IHC analysis.ResultsThree genes comprising CDH4, STAT4, and CYLD were found to have a significant differentiating power to separate NPC from normal nasopharyngeal samples and predicting disease malignancy. IHC analyses showed stronger CDH4, STAT4, and CYLD immunoreactivity in adjacent basal epithelium compared with that in tumor cells (p < 0.001). EBV-encoded LMP1 was exclusively expressed in NPC tumors. Using an independent set of biopsies, we showed that a model combining CDH4, STAT4, and LMP1 had a 92.86% of diagnostic accuracy, whereas a combination of STAT4 and LMP1 had a 70.59% accuracy for predicting advanced disease. Mechanistic studies suggested that promoter methylation, loss of DNA allele, and LMP1 contributed to the suppressive expression of CDH4, CYLD, and STAT4, respectively.ConclusionA model combining CDH4 and STAT4 and LMP1 was proposed to be a feasible model for diagnosing NPC and predicting late stage of NPC.

Mitochondrial non-coding RNA in nasopharyngeal carcinoma: Clinical diagnosis and functional analysis.

Background: Nasopharyngeal carcinoma is a common head and neck cancer with high incidence in Southeast Asia. Despite advances in treatment, the diagnosis of NPC remains a challenge due to its non-specific symptoms and high rate of false negatives. In this study, we aimed to identify novel non-coding RNAs (ncRNAs) as diagnostic biomarkers for NPC. Mitochondrial non-coding RNAs (mtio-ncRNAs) have been shown to play important roles in regulating various cellular processes. However, their specific functions and underlying mechanisms are largely unknown. Methods: We investigated the expression and biological function of mtio-ncRNAs in the human NPC cell line C666-1. By using high-throughput sequencing, we identified several significantly expressed mtio-ncRNAs in C666-1 cells and analyzed their target genes and enriched pathways using tsRFUN. Results: Our results showed that these significantly expressed mtio-ncRNAs mainly enriched in Cancer Gene Neighborhoods and targeted genes GCM1 and ACTG1. To validate the bioinformatics predictions, we synthesized two mtio-ncRNAs, t00846456 and t00048674, and transfected them into C666-1 cells. Our results showed that the expression of GCM1 was significantly increased by transfection of t00846456, while the expression of ACTG1 was significantly increased by transfection of t0048674. Additionally, the migration ability of the transfected cells was also enhanced. Discussion: Our findings provide novel insights into the biological functions of mtio-ncRNAs and their potential applications in cancer diagnosis and treatment.

Notoginsenoside R1 induces oxidative stress and modulates LPS induced immune microenvironment of nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a malignant tumor with high incidence. Notoginsenoside R1 (NGR1) is the main active compound of total Panax notoginseng saponin, and has multiple anti-tumor effects. This study aimed to investigate the effect and mechanism of NGR1 in NPC. MaterialsNPC cells were treated with different doses of NGR1. The NGR1 function in NPC was evaluated using Cell Counting Kit-8, Transwell, Western blot, flow cytometry, immunofluorescence assay, and quantitative real-time PCR. Meanwhile, the NGR1 mechanism in NPC was assessed by rescue experiments. Furthermore, the NGR1 function in vivo was determined by constructing an NPC xenotransplantation model, TUNEL, and immunohistochemistry assays. ResultsNGR1 repressed NPC cell growth and invasion but facilitated NPC cell apoptosis and oxidative stress. Also, NGR1 alleviated inflammation in NPC cells. Mechanistically, NGR1 restrained NPC cell growth and induced oxidative stress in NPC cells, while these effects were abolished after lipopolysaccharide (an activator of the TRAF6/NF-κB pathway) treatment, implying that NGR1 reduced NPC cell growth and induced oxidative stress in NPC cells by the inactivation of TRAF6/NF-κB axis. Moreover, in vivo studies further proved the palliative effect of NGR1 on NPC. ConclusionNGR1 inhibited NPC cell growth and induced oxidative stress in NPC cells by inactivating TRAF6/NF-κB axis.

Sanguinarine suppresses cell proliferation, migration and invasion in nasopharyngeal carcinoma inhibiting mTOR signaling.

To confirm the anti-NPC effect of sanguinarine (SA) through a series of wet experiments. NPC cell viability was determined by proliferation experiment. Cell clone formation experiment, cell scratch test, transwell migration and invasion experiment and flow cytometry-based cell apoptosis assay were further performed. In addition, Western blotting was performed to investigate the cell signaling pathway. All the relevant experimental data were statistically processed using SPSS 16.0 software. The results showed that sanguinarine represented a time and dose dependent inhibition effects on NPC cell proliferation including the low differentiated CNE2 cells and high metastatic 5-8F cells, along with the cell cloning ability reduction. In addition, sanguinarine has a certain inhibitory effect on the invasion and migration of NPC cells. Mechanistically, sanguinarine displayed the anti-NPC effects mainly involved into the suppression of mTOR signaling and cell apoptosis, which is closely associated with the tumor growth and metastatic malignancy. Collectively, we discover that sanguinarine is a new high-efficiency anti-NPC monomer of Chinese medicine, with a value for the follow-up pre-clinical research.

STAT3 regulates SRGN and promotes metastasis of nasopharyngeal carcinoma through the FoxO1-miR-148a-5p-CREB1 axis

AbstractNasopharyngeal carcinoma (NPC), which is marked by a distinct distribution, is a common subtype of epithelial carcinoma arising from the nasopharyngeal mucosal lining. SRGN acts as an important and poor prognostic factor of NPC through multiple different mechanisms. However, the biological role and mechanism of SRGN in NPC remain unknown. Expression levels of miR-148a-5p, CREB1, FoxO1, and SRGN in NPC tissues and cell lines were tested by qRT-PCR or/and Western blot. The impacts of miR-148a-5p, CREB1, FoxO1, and SRGN on NPC cell viability, proliferation, migration, and invasion were estimated in vitro by CCK-8, colony formation, wound healing and Transwell experiments, and in vivo by a xenograft tumor model. JASPAR analysis was used to predict the binding activity of Foxo1 (CREB1) with the miR-148a-5p (SRGN) promoter, and the interaction was validated by EMSA and ChIP assays. The miR-148a-5p-CREB1 interaction was validated by a dual-luciferase reporter and RIP assays. CREB1 and SRGN were increased while miR-148a-5p was decreased in NPC. Silencing of SRGN and CREB1, as well as miR-148a-5p overexpression, repressed NPC tumor progression in vitro and in vivo. CREB1 promoted SRGN expression in NPC by targeting the promoter area of SRGN. Silencing of FoxO1 facilitated NPC tumor progression, while silencing of STAT3 repressed NPC tumor progression. FoxO1 bound to and regulated miR-148a-5p in NPC, and miR-148a-5p targeted CREB1. Additionally, FoxO1 knockdown abolished the downregulation of CREB1 and SRGN induced by STAT3 silencing. Our results suggest that STAT3 regulates SRGN and promotes the growth and metastasis of NPC through the FoxO1-miR-148a-5p-CREB1 axis.

Molecular mechanism of FBXW7-mediated ubiquitination modification in nasopharyngeal carcinoma cell proliferation in vitro and in vivo

ObjectivesNasopharyngeal carcinoma (NPC) is a type of keratinizing squamous cell malignancy. Ubiquitination, a common protein posttranslational modification, participates in cancer development. This study sought to investigate the mechanism of F-box and WD repeat domain containing 7 (FBXW7) in NPC cell proliferation in vivo and in vitro. MethodsFBXW7, Homeobox A10 (HOXA10), and bone morphogenetic protein-2 (BMP2) expression levels in NPC tissues and cells were detected by RT-qPCR and Western blotting. Cell proliferation was assessed by cell counting kit-8 and colony formation assays. The binding of FBXW7 to HOXA10 and HOXA10 ubiquitination level were detected via co-immunoprecipitation and ubiquitination assay. Cells were treated with MG132 (the proteasome inhibitor), followed by the determination of HOXA10 ubiquitination and protein levels. The binding of HOXA10 to BMP2 was testified via dual-luciferase and chromatin immunoprecipitation assays. Collaborative experiments were performed to confirm the role of HOXA10 or BMP2 in FBXW7-mediated NPC cell proliferation. Xenograft tumor assay was performed to confirm the role of FBXW7/HOXA10/BMP2 in vivo. ResultsFBXW7 was under-expressed, while HOXA10 and BMP2 were up-expressed in NPC tissues and cells. FBXW7 overexpression restricted NPC cell proliferation. Mechanically, FBXW7 bound to HOXA10 to promote ubiquitination-based degradation of HOXA10 and further reduced the binding of HOXA10 to the BMP2 promoter and inhibited BMP2 transcription. Overexpression of HOXA10 or BMP2 attenuated the role of FBXW7 overexpression in inhibiting NPC cell proliferation. FBXW7 overexpression reduced Ki67 positive rate and repressed tumor growth. ConclusionFBXW7 overexpression promoted HOXA10 ubiquitination-based degradation and further inhibited BMP2 transcription, consequently restricting NPC cell proliferation in vitro and in vivo.

LncRNA FAM225A activates the cGAS-STING signaling pathway by combining FUS to promote CENP-N expression and regulates the progression of nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a common malignant tumor and long non-coding RNAs (lncRNAs) are widely involved in NPC development. Nevertheless, the role of lncRNA FAM225A in NPC remain unclear. Here, we evaluated the effect of FAM225A on NPC cell proliferation, migration and epithelial-mesenchymal transition (EMT). MethodsLevels of FAM225A and CENP-N in NPC tissues and cells were measured using RT-qPCR. Western blot assessed CENP-N, Snail, E-cadherin, N-cadherin, Vimentin, cGAS and p-STING levels. FAM225A expression was knocked down by sh-FAM225A or overexpressed by pcDNA-FAM225A. RIP and RNA pull-down verified the binding between FAM225A, CENP-N and FUS. Cell proliferation, migration and invasion were evaluated by CCK8, colony formation and transwell assays. ResultsFAM225A and CENP-N expression levels were evaluated in NPC tissues and cell lines. FAM225A knockdown inhibited NPC cell proliferation, migration and EMT. FAM225A stabilized CENP-N mRNA by recruiting FUS. FAM225A activated cGAS-STING by regulating the expression of CENP-N to promote NPC cell proliferation, migration and EMT. ConclusionFAM225A regulates NPC progression via FUS/CENP-N mediated cGAS-STING signaling pathway, which provides new therapeutic targets for developing new NPC treatments.

Aberrant miR-874-3p/leptin/EGFR/c-Myc signaling contributes to nasopharyngeal carcinoma pathogenesis

BackgroundLeptin is important in physiological and pathological functions in various cancers, however, the significance and mechanisms of leptin in nasopharyngeal carcinoma remain ambiguous.MethodsLeptin expression was analyzed by QPCR, immunohistochemistry, Western blotting, and TCGA database. The impact of gain- or loss-of-function of leptin were determined by MTT, colony formation, wound healing, and Transwell assays in NPC cells, and by a xenograft tumor model. Leptin-modulated glucose consumption and lactate production were assessed by ELISA. Furthermore, leptin-regulated signaling pathways were examined by QPCR and Western blotting assays. The immunoprecipitation assay was conducted to determine interaction between leptin and EGFR. In addition, miR-874-3p-regulated leptin expression was evaluated using bioinformatics, QPCR, luciferase assay, AGO2-RIP assay, and Western blotting.ResultsIn this study, we found that leptin was highly expressed in the sera and tumor tissues of patients with NPC, and elevated leptin expression was associated with advanced clinical features and poor prognosis. Functional assays demonstrated that leptin remarkably promoted NPC cell growth, motility, and glycolysis in vitro and in vivo. Mechanistically, leptin associated with EGFR, resulting in enhanced cell growth through the regulation of cell-cycle related markers, glycolysis-related genes, and EGFR/AKT/c-Myc signaling. Moreover, leptin potentiated the invasive capacity of NPC cells by promoting EMT. We further explored that miR-874-3p influenced leptin-mediated NPC progression. Overexpression of miR-874-3p prevented cell growth, motility, glucose consumption, and lactate production in NPC cells, whereas miR-874-3p inhibition had the opposite effects. AGO-RIP assays confirmed that Argonaute 2 (AGO2), a protein associated with miR-874-3p, regulated leptin expression in NPC cells. The rescue assays indicated that inhibition of leptin suppressed the effects of miR-874-3p inhibitor. In clinical specimens, miR-874-3p was negatively correlated with leptin.ConclusionsLeptin may serve as a novel prognostic factor and potential therapeutic target for patients with NPC. In addition, a newly discovered regulatory axis of leptin/EGFR/AKT/c-Myc can provide a novel therapeutic strategy for NPC.

Long non-coding RNA opa-interacting protein 5 antisense transcript 1 (LncRNA OIP5-AS1) promoted cisplatin resistance in nasopharyngeal carcinoma via the miR-378a-3p/nicotinamide N-methyltransferase axis

LncRNAs involve in chemoresistance of human cancers. However, the role and molecular mechanisms of lncRNA OIP5-AS1 in the chemoresistance of NPC are still unexplored. In our study, upregulated OIP5-AS1 was found in cisplatin (CDDP)-resistant NPC tumors and cell lines. Functional assays revealed OIP5-AS1 knockdown suppressed malignant behaviors, but stimulated apoptosis of CDDP-resistant NPC cells. Furthermore, we demonstrated OIP5-AS1 positively regulated NNMT by directly targeting miR-378a-3p. In addition, its inhibition partially abolished the inhibitory effects of OIP5-AS1 silencing on malignancy of CDDPresistant NPC cells, whereas NNMT knockdown reverse these effects. In sum, our results indicated OIP5-AS1 contributed to the CDDP resistance of NPC by sponging miR-378a-3p to increase NNMT expression.

Pentagalloylglucose suppresses the growth and migration of human nasopharyngeal cancer cells via the GSK3β/β-catenin pathway in vitro and in vivo

BackgroundNasopharyngeal carcinoma (NPC) is a type of malignant squamous cell tumour originating from the nasopharynx epithelium. Pentagalloylglucose (PGG) is a natural polyphenolic compound that exerts anticancer effects in many types of tumours. However, the role and underlying mechanism of PGG in NPC cells have not been fully defined. PurposeThis study aimed to investigate the anticancer activity of PGG as well as the potential mechanism in NPC cells. MethodsThe effects of PGG on the proliferation, apoptosis and cell cycle distribution of CNE1 and CNE2 cells were assessed by MTT and flow cytometry assays. Cell migration was evaluated using wound healing and transwell assays. The expression of microtubule-associated protein 1 light chain 3 beta (LC3B) was observed by immunofluorescence staining. Western blotting was used to explore the levels of related proteins and signalling pathway components. Furthermore, the effects of PGG on NPC cell growth were analysed in a xenograft mouse model in vivo using cisplatin as a positive control. ResultsPGG dose-dependently inhibited the proliferation of CNE1 and CNE2 cells. PGG regulated the cell cycle by altering p53, cyclin D1, CDK2, and cyclin E1 protein levels. PGG induced apoptosis and autophagy in NPC cells and elevated the Bax/Bcl-2 ratio and the protein levels of LC3B. Moreover, PGG decreased NPC cell migration by increasing E-cadherin and decreasing N-cadherin, vimentin and CD44 protein levels. Mechanistically, PGG treatment downregulated p-mTOR and β-catenin expression but upregulated p-p38 MAPK and p-GSK3β expression. In addition, PGG significantly inhibited NPC cell tumour growth and lung metastasis in vivo. ConclusionPGG may suppress cell proliferation, induce apoptosis and autophagy, and decrease the metastatic capacity of NPC cells through the p38 MAPK/mTOR and Wnt/β-catenin pathways. The present study provides evidence for PGG as a potential therapy for NPC.

CircFOXM1 acts as a ceRNA to upregulate SMAD2 and promote the progression of nasopharyngeal carcinoma.

BackgroundIn recent years, the development of high‐throughput sequencing technology has promoted the rapid development of circRNA‐related research. Studies have found that circRNA plays a key role in a variety of tumors, but few people study the role of circRNA in nasopharyngeal carcinoma. Under comprehensive treatments, the 5‐year survival rate can reach about 70%, but some patients still have distant metastases or recurrences after treatment. Therefore, it is very important to study the molecular mechanisms of the proliferation and invasion of nasopharyngeal carcinoma.MethodsQRT‐PCR was applied to detect the relative expression level of circFOXM1 in NPC and nasopharyngeal epithelial cell lines. We knocked down circFOXM1 and studied the influence of circFOXM1 on NPC cells. Nuclear and cytoplasmic RNA isolation experiments, fluorescence in situ hybridization (FISH), bioinformatics analysis, the dual‐luciferase reporter experiment, Western Blot, and other experiments were conducted to verify the relationships among circFOXM1, miR‐136‐5p, and SMAD2. We collected clinical NPC samples to prove the effect of circFOXM1 on the prognosis and treatment of NPC.ResultsIn this study, we found that circFOXM1 is highly expressed in nasopharyngeal carcinoma tissue cells compared with adjacent normal tissues and is related to the staging of nasopharyngeal carcinoma. High expression of circFOXM1 indicates a poor prognosis for nasopharyngeal carcinoma. Knockdown of CircFOXM1 inhibited the proliferation and invasion of nasopharyngeal carcinoma cells.ConclusionCircFOXM1 promotes the malignant proliferation of nasopharyngeal carcinoma cells by regulating the miR‐136‐5p‐SMAD2 axis.

LncRNA IGBP1-AS1 targets miR-150-5p to increase ZEB1 expression in nasopharyngeal carcinoma.

BackgroundNasopharyngeal carcinoma (NPC), which is a form of cancer arising from the epithelium of the nasopharynx, remains highly prevalent, particularly in Southeast Asia and Southern China. Dysregulated long non-coding RNAs (lncRNAs) are involved in several malignancies, including the growth and aggression of tumors. LncRNA IGBP1-AS1 plays an important role in the advancement of breast cancer, but its role in NPC has not yet been explored.MethodsLncRNA IGBP1-AS1 levels in human NPC samples compared with their matched adjacent normal tissues by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The proliferation alteration of NPC cells was tested in vitro. Luciferase reporter assay and RNA immunoprecipitation (RIP) were carried out to reveal the interaction between lncRNA IGBP1-AS1, miR-150-5p, and zinc finger e-box binding homeobox 1 (ZEB1).ResultsIn the study, we found that IGBP1-AS1 was found to be significantly upregulated in the NPC samples and cell lines. The knockdown of IGBP1-AS1 impeded in-vitro proliferation of the NPC cells. Bioinformatics and reporter assays revealed an association between IGBP1-AS1 and miR-150-5p. The expression of ZEB1 was increased by the microRNA (miRNA) sequestering in human NPC.ConclusionsThe progression of NPC tumors is facilitated by lncRNA IGBP1-AS1 via miR-150-5p and regulates ZEB1 expression.

Investigation of the inhibitory effects of simvastatin in RPMI 2650: An in-vitro study

Objective: The present study was carried out to investigate the antiproliferative effects of simvastatin involving Human Squamous Nasal Cell Carcinoma (RPMI 2650 cell line), which is one of the most common head and neck cancers with the highest incidence and mortality rates in Asian countries. The anti-cancer effects of simvastatin in NPC have not yet been investigated in depth, hence it will be illustrated in the present study. Materials and methods: The cells were treated with various concentrations of Simvastatin in a dose dependent (0, 0.1, 0. 4, 3.0 mg/ml) and time dependent (24, 48 and 72 hours) manner. The cancer cell viability was then assessed by using MTT assay at absorbance of 590 nm. Results: Simvastatin induced reduction in cell viability number and induced apoptosis in RPMI 2650 cell line. Simvastatin for 72 h significantly reduced cell growth as compared to 48 and 24 h pre-incubation with simvastatin treatment. After 72 h incubation with 0.1 mg/ml, 0.4 mg/ml and 3.0 mg/ml simvastatin, the cell viability decreased from 100% in treated control cells to 23%, 21% and 14% respectively. Conclusions: This finding demonstrate the potential of simvastatin and probably may have therapeutic benefit for NPC cell growth.