Migration Of Nasopharyngeal Carcinoma Cells Research Articles

MiR-2110 induced by chemically synthesized cinobufagin functions as a tumor-metastatic suppressor via targeting FGFR1 to reduce PTEN ubiquitination degradation in nasopharyngeal carcinoma.

Tumor cell metastasis is the key cause of death in patients with nasopharyngeal carcinoma (NPC). MiR-2110 was cloned and identified in Epstein-Barr virus (EBV)-positive NPC, but its role is unclear in NPC. In this study, we investigated the effect of miR-2110 on NPC metastasis and its related molecular basis. In addition, we also explored whether miR-2110 can be regulated by cinobufotalin (CB) and participate in the inhibition of CB on NPC metastasis. Bioinformatics, RT-PCR, and in situ hybridization were used to observe the expression of miR-2110 in NPC tissues and cells. Scratch, Boyden, and tail vein metastasis model of nude mouse were used to detect the effect of miR-2110 on NPC metastasis. Western blot, Co-IP, luciferase activity, colocalization of micro confocal and ubiquitination assays were used to identify the molecular mechanism of miR-2110 affecting NPC metastasis. Finally, miR-2110 induced by CB participates in CB-stimulated inhibition of NPC metastasis was explored. The data showed that increased miR-2110 significantly suppresses NPC cell migration, invasion, and metastasis. Suppressing miR-2110 markedly restored NPC cell migration and invasion. Mechanistically, miR-2110 directly targeted FGFR1 and reduced its protein expression. Decreased FGFR1 attenuated its recruitment of NEDD4, which downregulated NEDD4-induced phosphatase and tensin homolog (PTEN) ubiquitination and degradation and further increased PTEN protein stability, thereby inactivating PI3K/AKT-stimulated epithelial-mesenchymal transition signaling and ultimately suppressing NPC metastasis. Interestingly, CB, a potential new inhibitory drug for NPC metastasis, significantly induced miR-2110 expression by suppressing PI3K/AKT/c-Jun-mediated transcription inhibition. Suppression of miR-2110 significantly restored cell migration and invasion in CB-treated NPC cells. Finally, a clinical sample assay indicated that reduced miR-2110 was negatively correlated with NPC lymph node metastasis and positively related to NPC patient survival prognosis. In summary, miR-2110 is a metastatic suppressor involving in CB-induced suppression of NPC metastasis.

Comparative Proteomics Identified EXOSC1 as a Target Protein of Anticancer Peptide LVTX-8 in Nasopharyngeal Carcinoma Cells.

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy that usually occurs among the nose and throat. Due to mild initial symptoms, most patients are diagnosed in the late stage, and the recurrence rate of tumors is high, resulting in many deaths every year. Traditional radiotherapy and chemotherapy are prone to causing drug resistance and significant side effects. Therefore, searching for new bioactive drugs including anticancer peptides is necessary and urgent. LVTX-8 is a peptide toxin synthesized from the cDNA library of the spider Lycosa vittata, which is consisting of 25 amino acids. In this study, a series of in vitro cell experiments such as cell toxicity, colony formation, and cell migration assays were performed to exam the anticancer activity of LVTX-8 in NPC cells (5-8F and CNE-2). The results suggested that LVTX-8 significantly inhibited cell proliferation and migration of NPC cells. To find the potential molecular targets for the anticancer capability of LVTX-8, high-throughput proteomic and bioinformatics analysis were conducted on NPC cells. The results identified EXOSC1 as a potential target protein with significantly differential expression levels under LVTX-8+/LVTX-8- conditions. The results in this research indicate that spider peptide toxin LVTX-8 exhibits significant anticancer activity in NPC, and EXOSC1 may serve as a target protein for its anticancer activity. These findings provide a reference for the development of new therapeutic drugs for NPC and offer new ideas for the discovery of biomarkers related to NPC diagnosis. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (https://proteomecentral.proteomexchange.org) via the iProX partner repository with the data set identifier PXD050542.

MiR-122-5p regulates erastin-induced ferroptosis via CS in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a tumor that occurs in the nasopharynx. Although advances in detection and treatment have improved the prognosis of NPC the treatment of advanced NPC remains challenging. Here, we explored the effect of microRNA (miR)-122-5p on erastin-induced ferroptosis in NPC cells and the role of ferroptosis in the development of NPC. The effect of miR-122-5p silencing and overexpression and the effect of citrate synthase on erastin-induced lipid peroxidation in NPC cells was analyzed by measuring the amounts of malondialdehyde, Fe2+, glutathione, and reactive oxygen species and the morphological alterations of mitochondria. The malignant biological behavior of NPC cells was examined by cell counting kit-8, EDU, colony formation, Transwell, and wound healing assays. The effects of miR-122-5p on cell proliferation and migration associated with ferroptosis were examined in vivo in a mouse model of NPC generated by subcutaneous injection of NPC cells. We found that erastin induced ferroptosis in NPC cells. miR-122-5p overexpression inhibited CS, thereby promoting erastin-induced ferroptosis in NPC cells and decreasing NPC cell proliferation, migration, and invasion.

Activation of the MEK/ERK Pathway Mediates the Inhibitory Effects of Silvestrol on Nasopharyngeal Carcinoma Cells via RAP1A, HK2, and GADD45A.

Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with Epstein-Barr virus (EBV) infection. Chemoradiotherapy is the mainstream treatment for locally advanced NPC, and chemotherapeutic drugs are an indispensable part of NPC treatment. However, the toxic side-effects of chemotherapy drugs limit their therapeutic value, and new chemotherapy drugs are urgently needed for NPC. Silvestrol, an emerging natural plant anticancer molecule, has shown promising antitumor activity in breast cancer, melanoma, liver cancer, and other tumor types by promoting apoptosis in cancer cells to a greater extent than in normal cells. However, the effects of silvestrol on NPC and its possible molecular mechanisms have yet to be fully explored. Cell counting kit-8 (CCK-8), cell scratch, flow cytometry, 5-ethynyl-2'-deoxyuridine (EdU), and Western blot (WB) assays were used to evaluate the effects of silvestrol on the cell viability, cell cycle, apoptosis, and migration of NPC cells. RNA sequencing (RNA-Seq) was used to study the effect of extracellular signal-regulated kinase (ERK) inhibitors on the cell transcriptome, and immunohistochemistry (IHC) to assess protein expression levels in patient specimens. Silvestrol inhibited cell migration and DNA replication of NPC cells, while promoting the expression of cleaved caspase-3, apoptosis, and cell cycle arrest. Furthermore, silvestrol altered the level of ERK phosphorylation. The ERK-targeted inhibitor LY3214996 attenuated silvestrol-mediated inhibition of NPC cell proliferation but not migration. Analysis of RNA-Seq data and WB were used to identify and validate the downstream regulatory targets of silvestrol. Expression of GADD45A, RAP1A, and hexokinase-II (HK2) proteins was inhibited by silvestrol and LY3214996. Finally, IHC revealed that GADD45A, RAP1A, and HK2 protein expression was more abundant in cancer tissues than in non-tumor tissues. Silvestrol inhibits the proliferation of NPC cells by targeting ERK phosphorylation. However, the inhibition of NPC cell migration by silvestrol was independent of the Raf-MEK-ERK pathway. RAP1A, HK2, and GADD45A may be potential targets for the action of silvestrol.

E2F1-EP300 co-activator complex potentiates immune escape in nasopharyngeal carcinoma through the mediation of MELK.

Nasopharyngeal carcinoma (NPC) is characterized by a highly suppressive microenvironment that protects tumor cells against immune attack and facilitates tumor progression. MELK is upregulated in various tumors, whereas its function in the immune escape remains largely unknown. In this study, we investigated the role of MELK during immune escape in NPC. Differentially expressed genes were filtered using GEO datasets and PPI network analysis. NPC cell colony formation and motility were examined, and the impact of CD8⁺ T cells on NPC cells was evaluated. A xenograft model was constructed to detect the growth of tumor cells and the T-cell phenotype of tumor infiltration. ChIP-qPCR and dual-luciferase assays were used to verify the transcriptional regulation of MELK by EP300/E2F1. MELK was overexpressed in NPC, and sh-MELK suppressed the clonogenic ability, migration, and invasion of NPC cells and promoted the killing effects of CD8⁺ T cells. These in vitro findings were reproduced in vivo. EP300 synergized E2F1 to regulate the transcription of MELK in NPC cells. Loss of EP300 or E2F1 reverted the malignant phenotype of NPC cells and promoted the immune effect of CD8⁺ T cells. MELK further suppressed the immune effect of CD8⁺ T cells in the presence of sh-E2F1. EP300 coordinated with E2F1 to promote the transcription of MELK which promoted the growth of NPC cells and repressed the killing effect of CD8⁺ T cells. Blockage of MELK may be a potential way to suppress the immune escape of NPC cells.

Lactoferrin mediates epithelial-mesenchymal transformation by regulating the PI3K/AKT/mTOR pathway to inhibit nasopharyngeal carcinoma metastasis.

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck. Epithelial-mesenchymal transition (EMT) is a major player in regulating NPC transfer. There is increasing evidence that lactotransferrin (LTF) is an important regulator of EMT conversion. However, the potential role and mechanisms of LTF in regulating NPC cell EMT remain unclear. In this study, quantitative real-time PCR (qRT‒PCR) and Western blotting were applied to measure the expression of LTF in NPC cells. Subsequently, the influences of LTF on the proliferation, migration and invasion of NPC cells were verified by functional acquisition experiments. Finally, Western blotting was used to analyze the effects of EMT-related proteins and phosphoinositol 3-kinase (PI3K)/Akt/mammalian rapamycin target (mTOR) signaling pathways. The data of this study indicate that LTF was underexpressed in human NPC cells, and upregulation of LTF could restrain NPC cell proliferation, invasion, migration and EMT transformation. Moreover, the effects of LTF on NPC cell metastasis and EMT are partly determined by the PI3K/AKT/mTOR pathway. This study suggests that LTF is a potential biomarker of NPC and that LTF-mediated EMT progression plays a tumor-suppressive role in the progression of NPC metastasis.

Abstract 1109: LINC01770 stabilizes TEAD1 expression to mediates nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis

Abstract Background: Long noncoding RNAs (lncRNAs) regulate various essential biological processes, including cell proliferation, differentiation, apoptosis, migration, and invasion. However, in nasopharyngeal carcinoma (NPC), the clinical significance and mechanisms of lncRNAs in malignant progression are unknown. Methods: LINC01770 expression was determined using quantitative real-time reverse transcription PCR, and its prognostic value was evaluated using Kaplan-Meier survival analysis. RNA sequencing and bioinformatic analysis were used to determine the potential function of LINC01770, and its biological effects were investigated using in vitro and in vivo experiments. Mass spectrometry-coupled RNA pull-down assays and western blotting identified LINC01770 interacting proteins, followed by confirmation using RNA immunoprecipitation (RIP) assays. Ferroptosis and lipid peroxidation were detected using flow cytometry. Results: LINC01770 was overexpressed in NPC tissues according to microarray screening. Patients with NPC showing high LINC01770 expression experienced shorter survival and worse prognosis. In vitro and in vivo experiments suggested that knockdown of LINC01770 expression significantly inhibited the proliferation, migration, and invasion of NPC cells. Sequencing and functional complementation experiments showed that LINC01770 regulates the proliferation and metastasis of NPC through TEA domain transcription factor 1 (TEAD1). Meanwhile, RIP and PCR experiments suggested that LINC01770 and TEAD1 were common targets of microRNAs miR-615-5p and miR-1293. Overexpression of LINC01770 promoted ferroptosis in vitro and in vivo through the TEAD1/Acyl-CoA synthetase long chain family member 4 (ACSL4)/transferrin receptor (TFRC) pathway. Conclusions: LINC01770 is a prognostic biomarker for NPC and participates in the regulation of TEAD1 signaling pathway through competitive binding to miRNA-615-5p and miRNA-1293, resulting in NPC metastasis and progression. Radiation resistant cells are in a delicate balance between lipid peroxidation and increased vulnerability to ferroptosis, suggesting that ferroptosis could be used to kill NPC cells and reverse their radiotherapy resistance during the malignant progression of NPC caused by high expression of LINC01770. Thus, inducing ferroptosis could be used to treat recurrent and refractory NPC. Citation Format: Qingqing Xu, Ciming Sun, Suixian Zhang, Xuan Li, Lei Chen, Ming Chen. LINC01770 stabilizes TEAD1 expression to mediates nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1109.

Evolutionary analysis of LMP-1 genetic diversity in EBV-associated nasopharyngeal carcinoma: Bioinformatic insights into oncogenic potential

EBV latent membrane protein 1 (LMP-1) is an important oncogene involved in the induction and maintenance of EBV infection and the activation of several cell survival and proliferative pathways. The genetic diversity of LMP-1 has an important role in immunogenicity and tumorigenicity allowing escape from host cell immunity and more metastatic potential of LMP-1 variants. This study explored the evolutionary of LMP-1 in EBV-infected patients at an advanced stage of nasopharyngeal carcinoma (NPC). Detection of genetic variability in LMP-1 genes was carried out using Sanger sequencing. Bioinformatic analysis was conducted for translation and nucleotide alignment. Phylogenetic analysis was used to construct a Bayesian tree for a deeper understanding of the genetic relationships, evolutionary connections, and variations between sequences. Genetic characterization of LMP-1 in NPC patients revealed the detection of polymorphism in LMP-1 Sequences. Motifs were identified within three critical LMP-1 domains, such as PQQAT within CTAR1 and YYD within CTAR2. The presence of the JACK3 region at specific sites within CTAR3, as well as repeat regions at positions (122−132) and (133–143) within CTAR3, was also annotated. Additionally, several mutations were detected including 30 and 69 bp deletions, 33 bp repeats, and 15 bp insertion. Although LMP-1 strains appear to be genetically diverse, they are closely related to 3 reference strains: prototype B95.8, Med- 30 bp deletion, and Med + 30 bp deletion. In our study, one of the strains harboring the 30 bp deletion had both bone and bone marrow metastasis which could be attributed to the fact that LMP-1 is involved in tumor metastasis, evasion and migration of NPC cells. This study provided valuable insights into genetic variability in LMP-1 sequences of EBV in NPC patients. Further functional studies would provide a more comprehensive understanding of the molecular characteristics, epidemiology, and clinical implications of LMP-1 polymorphisms in EBV-related malignancies.

M 6 A reader IGF2BP1 reduces the sensitivity of nasopharyngeal carcinoma cells to Taxol by upregulation of AKT2.

Taxol is widely used in the treatment of nasopharyngeal carcinoma (NPC); nevertheless, the acquired resistance of NPC to Taxol remains one of the major obstacles in clinical treatment. In this study, we aimed to investigate the role and mechanism of insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in Taxol resistance of NPC. Taxol-resistant NPC cell lines were established by exposing to gradually increased concentration of Taxol. Relative mRNA and protein levels were tested using qRT-PCR and western blot, respectively. NPC cell viability and apoptosis were assessed by cell counting kit-8 and flow cytometry analysis, respectively. Cell migration and invasion capacities were measured using transwell assay. Interaction between IGF2BP1 and AKT2 was examined by RNA immunoprecipitation assay. The N6-methyladenosine level of AKT2 was tested using methylated RNA immunoprecipitation-qPCR. IGF2BP1 expression was enhanced in Taxol-resistant NPC cell lines. Knockdown of IGF2BP1 strikingly enhanced the sensitivity of NPC cells to Taxol and repressed the migration and invasion of NPC cells. Mechanistically, IGF2BP1 elevated the expression of AKT2 by increasing its mRNA stability. Furthermore, overexpression of AKT2 reversed the inhibitory roles of IGF2BP1 silence on Taxol resistance and metastasis. Our results indicated that IGF2BP1 knockdown enhanced the sensitivity of NPC cells to Taxol by decreasing the expression of AKT2, implying that IGF2BP1 might be promising candidate target for NPC treatment.

BPIFB1, Serving as a Downstream Effector of EBV-miR-BART4, Blocks Immune Escape of Nasopharyngeal Carcinoma via Inhibiting PD-L1 Expression.

Nasopharyngeal carcinoma (NPC) is one of the most common tumors of head and neck in the Southeast Asia. PD-L1-dependent immune escape plays a critical role involved in NPC development. BPIFB1 has previously reported to take tumor-suppressive actions on NPC cell proliferation and migration. Nonetheless, the function of BPIFB1 in immune escape remains largely elusive. Expression pattern on mRNA and protein levels of target genes in NPC patients' samples and cell lines were examined by qRT-PCR, western blot, and immunohistochemistry staining, respectively. The assessment of CD8+ T-cell apoptosis and expression was determined by flow cytometry. Molecular interactions were verified using chromatin immunoprecipitation (ChIP) and luciferase reporter assay. BPIFB1 was downregulated in NPC tumor tissues, exhibiting a negative correlation of PD-L1. Overexpression of BPIFB1 significantly inhibited the expression of PD-L1, suppressing the apoptosis and enhancing the expression of CD8+ T cells. Mechanistically, BPIFB1 was found to repress the expression of STAT1, which was identified to be an upstream activator of PD-L1. Furthermore, the EBV-encoded miR-BART4 overexpressed in NPC cells could directly target and inhibit BPIFB1. This study provided a comprehensive understanding of the molecular mechanism for the upstream and downstream pathway of BPIFB1 related with immune escape, indicating a novel approach for the treatment of NPC.

The role and molecular mechanism of NOP16 in the pathogenesis of nasopharyngeal carcinoma.

We aimed to explore the effects of NOP16 on the pathogenesis of nasopharyngeal carcinoma (NPC) and the related mechanism. In this study, the expression level of NOP16 in NPC tissues and adjacent tissues was measured by qRT-polymerase chain reaction(PCR) and immunohistochemistry (IHC)tests. In the in vitro study, the expression levels of NOP16 and RhoA/phosphatidylinositol 3-kinase(PI3K)/Akt/c-Myc and IKK/IKB/NF-κB signalling pathway-related proteins in NPC cells were measured by qRT-PCR and Western blot (WB). CCK8 assays and colony formation assays were used to detect cell proliferation. Transwell assays were used to detect the migration and invasion ability of NPC cells. Flow cytometry and WB were used to measure the level of apoptosis. For the in vivo study, NPC xenograft models were established in nude mice, and tumour weight and volume were recorded. The expression levels of NOP16 and RhoA/PI3K/Akt/c-Myc signalling pathway-related proteins and mRNAs were measured by immunofluorescence, qRT-PCR and WB experiments. In clinical samples, the results of qRT-PCR and IHC experiments showed that the expression level of NOP16 was significantly increased in NPC tissues. In the in vitro study, the results of qRT-PCR and WB experiments showed that NOP16 was significantly increased in NPC cells. The CCK8 assay, colony formation assay, transwell assay and flow cytometry results showed that knocking out NOP16 inhibited the proliferation, migration and invasion of NPC cells and increased apoptosis. WB results showed that knocking out NOP16 inhibited the RhoA/PI3K/Akt/c-Myc and IKK/IKB/NF-κB signalling pathways. These effects were reversed by 740Y-P (PI3K activator). In the in vivo study, knockdown of NOP16 reduced tumour volume and weight and inhibited the RhoA/PI3K/Akt/c-Myc signalling pathway. In conclusion, knockdown of NOP16 inhibited the proliferation, migration and invasion of NPC cells and induced apoptosis by inhibiting the RhoA/PI3K/Akt/c-Myc and IKK/IKB/NF-κB pathways, leading to the malignant phenotype of NPC.

MiR-25 enhances the proliferation, invasion and migration of nasopharyngeal carcinoma cells through targeted regulation of RAGE expression

Purpose: To determine the effect of microRNA-25 (miR-25) on the proliferation, invasion, and migration of nasopharyngeal carcinoma cells, and the involvement of targeted regulation of late glycation end product receptor (RAGE) in the process.Methods: Three groups of cells comprising; routinely cultured nasopharyngeal normal epithelial cell line NP69 without any treatment (blank control group), untreated human nasopharyngeal carcinoma cell line 5-8F, also cultured routinely (nasopharyngeal carcinoma group) and 5-8F human nasopharyngeal carcinoma cells infected with lentiviral vectors for miR-25 gene knockdown and cultured after stable transduction (miR-25 knockdown group). Cell proliferation was assessed using CCK-8 assay, while Western blot assay and quantitative polymerase chain reaction (qPCR) were used to measure protein and mRNA expression levels of relevant genes. Transwell assay was utilized to evaluate cell migration and invasion.Results: The miR-25 expression level was significantly increased in nasopharyngeal carcinoma group (p < 0.05). Cell proliferation, migration, and invasion rates in miR-25 knockdown group were lower than those in nasopharyngeal carcinoma group (p < 0.05). Apoptosis rate of cells and levels of apoptotic proteins were significantly elevated, whereas bcl-2 level was significantly reduced in miR-25 knockdown group when compared to nasopharyngeal carcinoma group (p < 0.05). Protein expression levels of RAGE and S100P was significantly increased in nasopharyngeal carcinoma group, but significantly down-regulated in miR-25 knockdown group (p < 0.05). Conclusion: Expression of miR-25 increases in nasopharyngeal carcinoma cells. Suppression of miR25 results in decreased viability of nasopharyngeal carcinoma cells and inhibits cell proliferation, migration, and invasion, while enhancing apoptosis. The mechanism underlying these effects was associated with modulation of protein expressions of RAGE and S100P. Targeted regulation of late glycation end-product receptors hold promising potential as prospective biomarker for therapeutic interventions targeting specific cancers.

Stiffness promotes cell migration, invasion, and invadopodia in nasopharyngeal carcinoma by regulating the WT-CTTN level.

Matrix stiffness potently promotes the malignant phenotype in various biological contexts. Therefore, identification of gene expression to participate in mechanical force signals transduced into downstream biochemical signaling will contribute substantially to the advances in nasopharyngeal carcinoma (NPC) treatment. In the present study, we detected that cortactin (CTTN) played an indispensable role in matrix stiffness-induced cell migration, invasion, and invadopodia formation. Advances in cancer research have highlighted that dysregulated alternative splicing contributes to cancer progression as an oncogenic driver. However, whether WT-CTTN or splice variants (SV1-CTTN or SV2-CTTN) regulate matrix stiffness-induced malignant phenotype is largely unknown. We proved that alteration of WT-CTTN expression modulated matrix stiffness-induced cell migration, invasion, and invadopodia formation. Considering that splicing factors might drive cancer progression through positive feedback loops, we analyzed and showed how the splicing factor PTBP2 and TIA1 modulated the production of WT-CTTN. Moreover, we determined that high stiffness activated PTBP2 expression. Taken together, our findings showed that the PTBP2-WT-CTTN level increases upon stiffening and then promotes cell migration, invasion, and invadopodia formation in NPC.

Esketamine induces apoptosis of nasopharyngeal carcinoma cells through the PERK/CHOP pathway

Nasopharyngeal carcinoma, a malignant tumor prevalent in southeast Asia and north Africa, still lacks effective treatment. Esketamine, an N-methyl-D-aspartatic acid (NMDA) receptor (NMDAR) antagonist, is widely used in clinical anesthesia. Emerging evidence suggests that esketamine plays an important role in inhibiting tumor cell activity. However, the underlying mechanisms of esketamine on nasopharyngeal carcinoma remain unknown. In this study, we found that esketamine inhibited the proliferation and migration of nasopharyngeal carcinoma cells. Mechanically, transcriptome sequencing and subsequent verification experiments revealed that esketamine promoted the apoptosis of nasopharyngeal carcinoma cells through endoplasmic reticulum stress PERK/ATF4/CHOP signaling pathway mediated by NMDAR. Additionally, when combined with esketamine, the inhibitory effect of cisplatin on the proliferation of nasopharyngeal carcinoma cells was significantly enhanced. These findings provide new insights into future anti-nasopharyngeal carcinoma clinical strategies via targeting the NMDAR/PERK/CHOP axis alone or in combination with cisplatin.

CCDC86 promotes the aggressive behavior of nasopharyngeal carcinoma by positively regulating EGFR and activating the PI3K/Akt signaling.

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck. A number of studies have confirmed that coiled-coil domain-containing protein 86 (CCDC86) plays an important role in the pathogenesis of lymphoma but the role of CCDC86 in NPC has not yet been reported. Here, in vivo and in vitro experiments were conducted to explore whether CCDC86 plays a role in the pathogenesis of NPC and to identify the specific mechanism. We found that CCDC86 was highly expressed in NPC tissues and cells, and the expression level of CCDC86 was correlated with the prognosis of patients with advanced NPC. CCDC86 promoted the proliferation, invasion, and migration of NPC cells in vivo and in vitro by promoting the EMT process and upregulating the expression of MMPs. Then, we confirmed that EGFR is a downstream target gene of CCDC86 and that CCDC86 can promote the proliferation, invasion, and migration of NPC cells by upregulating the expression of EGFR and activating downstream PI3K/Akt. Furthermore, we confirmed that CCDC86 did not directly bind to EGFR but positively regulated EGFR by binding to NPM1. CCDC86 is expected to be used as a novel biomarker and therapeutic target for predicting the prognosis of NPC.

Network pharmacology, molecular docking and experimental study of CEP in nasopharyngeal carcinoma

Ethnopharmacological relevanceThe Stephania cephalantha Hayata is an important traditional medicinal plant widely used in traditional medicine to treat cancer. Cepharanthine (CEP) was extracted from the roots of Stephania cephalantha Hayata. It has been found to exhibit anticancer activity in different types of cancer cells. Nevertheless, the activity of CEP against nasopharyngeal carcinoma (NPC) and its underlying mechanism warrant further investigation. Aims of the studyNPC is an invasive and highly metastatic malignancy that affects the head and neck region. This research aimed to investigate the pharmacological properties and underlying mechanism of CEP against NPC, aiming to offer novel perspectives on treating NPC using CEP. Materials and methodsIn vitro, the pharmacological activity of CEP against NPC was evaluated using the CCK-8 assay. To predict and elucidate the anticancer mechanism of CEP against NPC, we employed network pharmacology, conducted molecular docking analysis, and performed Western blot experiments. In vivo validation was performed through a nude mice xenograft model of human NPC, Western blot and immunohistochemical (IHC) assays to confirm pharmacological activity and the mechanism. ResultsIn a dose-dependent manner, the proliferation and clonogenic capacity of NPC cells were significantly inhibited by CEP. Additionally, NPC cell migration was suppressed by CEP. The results obtained from network pharmacology experiments revealed that anti-NPC effect of CEP was associated with 8 core targets, including EGFR, AKT1, PIK3CA, and mTOR. By performing molecular docking, the binding capacity of CEP to the candidate core proteins (EGFR, AKT1, PIK3CA, and mTOR) was predicted, resulting in docking energies of −10.0 kcal/mol for EGFR, −12.4 kcal/mol for PIK3CA, −10.8 kcal/mol for AKT1, and -8.6 kcal/mol for mTOR. The Western blot analysis showed that CEP effectively suppressed the expression of EGFR and the phosphorylation levels of downstream signaling proteins, including PI3K, AKT, mTOR, and ERK. After CEP intervention, a noteworthy decrease in tumor size, without inducing any toxicity, was observed in NPC xenograft nude mice undergoing in vivo treatment. Additionally, IHC analysis demonstrated a significant reduction in the expression levels of EGFR and Ki-67 following CEP treatment. ConclusionCEP exhibits significant pharmacological effects on NPC, and its mechanistic action involves restraining the activation of the EGFR/PI3K/AKT pathway. CEP represents a promising pharmaceutical agent for addressing and mitigating NPC.

USP7 inhibits the progression of nasopharyngeal carcinoma via promoting SPLUNC1-mediated M1 macrophage polarization through TRIM24

Reprogramming of macrophages toward an M1 phenotype is a novel strategy to induce anticancer immunity. However, the regulatory mechanisms of M1 macrophage polarization and its functional roles in nasopharyngeal carcinoma (NPC) progression need to be further explored. Here we found that SPLUNC1 was highly expressed and responsible for M1 macrophage polarization. JAK/STATs pathway activation was involved in SPLUNC1-mediated M1 macrophage polarization. Importantly, regulation of SPLUNC1 in macrophages affected CM-mediated influence on NPC cell proliferation and migration. Mechanistically, USP7 deubiquitinated and stabilized TRIM24, which promoted SPLUNC1 expression via recruitment of STAT3 in M1 macrophages. Depletion of TRIM24 inhibited M1 macrophage polarization, which facilitated NPC cell growth and migration. However, over-expression of USP7 exhibited the opposite results and counteracted the tumorigenic effect of TRIM24 silencing. Finally, the growth and metastasis of NPC cells in vivo were repressed by USP7-induced M1 macrophage polarization via modulating TRIM24/SPLUNC1 axis. USP7 delayed NPC progression via promoting macrophage polarization toward M1 through regulating TRIM24/SPLUNC1 pathway, providing evidence for the development of effective antitumor immunotherapies for NPC.

Expressions of NLRP3, Caspase-1, and GSDMD in nasopharyngeal carcinoma tissue and association with recurrence and metastasis

Objective: To investigate the expressions of Nod-like receptor protein 3 (NLRP3), cysteine-aspartic acid protease 1 (Caspase-1), and Gasdermin D (GSDMD) in nasopharyngeal carcinoma (NPC), and their relationships with the recurrence and metastasis of NPC. Methods: A retrospective study was conducted on 421 patients diagnosed with NPC between December 2014 and January 2020. The expressions of NLRP3, Caspase-1, and GSDMD in pathological specimens were examined with immunohistochemistry and multiplex immunofluorescence staining. Univariate and multivariate Cox regression analyses were applied to identify the factors influencing NPC recurrence and metastasis. In vitro experiments with NPC cell line HNE-2 were used to explore the functional mechanisms of NLRP3, Caspase-1, and GSDMD. Results: Multivariate Cox analysis revealed that tumor staging of Ⅲ-Ⅳ(HRrecurrence=2.74, 95%CIrecurrence: 1.61-4.65; HRmetastasis=1.90, 95%CImetastasis: 1.04-3.49) and pre-treatment plasma EBV-DNA levels≥1 500 copies/ml (HRrecurrence=1.91, 95%CIrecurrence: 1.13-3.23; HRmetastasis=2.07, 95%CImetastasis: 1.23-3.50)were independent risk factors for NPC recurrence and metastasis, while positive expression of NLRP3(HRrecurrence=0.17, 95%CIrecurrence: 0.08-0.35; HRmetastasis=0.30, 95%CImetastasis: 0.15-0.59), Caspase-1(HRrecurrence=0.32, 95%CIrecurrence: 0.18-0.59; HRmetastasis=0.43, 95%CImetastasis: 0.25-0.76), and GSDMD(HRrecurrence=0.48, 95%CIrecurrence: 0.25-0.91; HRmetastasis=0.96, 95%CImetastasis: 0.53-1.74) served as independent protective factors. Age (HR=1.02, 95%CI: 1.01-1.04) and intensity-modulated radiotherapy (HR=0.51, 95%CI: 0.30-0.88) were independent factors for NPC recurrence, whereas chemotherapy (HR=0.50, 95%CI: 0.29-0.88) acted as an independent protective factor for NPC metastasis (all P<0.05). NPC patients with positive expressions of the three proteins had higher locoregional recurrence-free survival, distant metastasis-free survival, and overall survival compared to those with negative expressions (all P<0.05). In vitro experiments revealed that the overexpression of NLRP3 activated the NLRP3/Caspase-1/GSDMD signaling pathway, as evidenced by Western Blot analysis. Enzyme-linked immunosorbent assay and scanning electron microscopy demonstrated that overexpression of NLRP3 promoted pyroptosis in HNE-2 cells. Cellular functional assays further confirmed that overexpression of NLRP3 significantly inhibited the proliferation, invasion, and migration of HNE-2 cells. Conclusion: Positive expressions of NLRP3, Caspase-1, and GSDMD serves as independent protective factors for recurrence and metastasis of NPC, potentially by promoting cell pyroptosis and thus inhibiting NPC cell proliferation, invasion, and migration.

Overexpressed Gαi1 exerts pro-tumorigenic activity in nasopharyngeal carcinoma

The current study tested the expression and potential functions of Gαi1 in nasopharyngeal carcinoma (NPC). The Cancer Genome Atlas (TCGA) database results demonstrate that Gαi1 transcripts’ number in NPC tissues is significantly higher than that in the normal nasal epithelial tissues. Its overexpression correlates with poor survival in certain NPC patients. Moreover, Gαi1 is significantly upregulated in NPC tissues of local primary patients and in different primary human NPC cells. Whereas its expression is relatively low in cancer-surrounding normal tissues and in primary nasal epithelial cells. Genetic silencing (via shRNA strategy) or knockout (via CRISPR-sgRNA method) of Gαi1 substantially suppressed viability, proliferation, cell cycle progression, and migration in primary NPC cells, causing significant caspase-apoptosis activation. Contrarily, ectopic Gαi1 expression exerted pro-tumorigenic activity and strengthened cell proliferation and migration in primary NPC cells. Gαi1 is important for Akt-mTOR activation in NPC cells. Akt-S6K phosphorylation was downregulated after Gαi1 shRNA or KO in primary NPC cells, but strengthened following Gαi1 overexpression. In Gαi1-silenced primary NPC cells, a S473D constitutively-active mutant Akt1 (caAkt1) restored Akt-S6K phosphorylation and ameliorated Gαi1 shRNA-induced proliferation inhibition, migration reduction and apoptosis. Bioinformatics analyses proposed zinc finger protein 384 (ZNF384) as a potential transcription factor of Gαi1. In primary NPC cells, ZNF384 shRNA or knockout (via CRISPR-sgRNA method) decreased Gαi1 mRNA and protein expression, whereas ZNF384 overexpression upregulated it. Importantly, there was an increased binding between ZNF384 protein and the Gαi1 promoter in human NPC tissues and different NPC cells. In vivo studies showed that intratumoral injection of Gαi1-shRNA-expressing adeno-associated virus (AAV) impeded subcutaneous NPC xenograft growth in nude mice. Gαi1 downregulation, Akt-mTOR inactivation, and apoptosis induction were detected in Gαi1-silenced NPC xenograft tissues. Gαi1 KO also effectively inhibited the growth of NPC xenografts in nude mice. Together, overexpressed Gαi1 exerts pro-tumorigenic activity in NPC possibly by promoting Akt-mTOR activation.

Circular RNA EFR3A promotes nasopharyngeal carcinoma progression through modulating the miR-654-3p/EFR3A axis.

Nasopharyngeal carcinoma (NPC) originates from the nasopharyngeal epithelium. hsa_circ_0135761 (circEFR3A), a newly identified circRNA, presented elevation in NPC via high-throughput sequencing. This study aimed to clarify the molecular mechanism of circEFR3A in the carcinogenesis of NPC. Based on RT-qPCR, subcellular fractionation, RNase R digestion and actinomycin D assays, we evaluated circEFR3A expression characteristics in NPC cells. We found that the circEFR3A was located in the cytoplasm of NPC cells, presented upregulation and stably expressed in NPC cells. Loss-of-function assays clarified the effects of circEFR3A on NPC cell malignant behaviors. The results demonstrated that circEFR3A knockdown facilitated NPC cell apoptosis but repressed NPC cell proliferation and migration. Furthermore, the regulatory mechanism of circEFR3A in NPC was explored. Bioinformatics and mechanism experiments revealed that cicrEFR3A positively modulated EFR3A by competitively binding with miR-654-3p in NPC cells. Additionally, rescue assays showed that the suppressive effects of cicrEFR3A knockdown on NPC cell proliferation, migration and apoptosis were countervailed by EFR3A upregulation. Xenograft tumor-bearing mouse models were established to investigate the role of cicrEFR3A in NPC tumorigenesis in vivo, and the results indicated that circEFR3A silencing suppressed tumor growth in mice. In conclusion, circEFR3A is highly expressed and functions as an oncogene in NPC progression. circEFR3A facilitates NPC cell proliferation and migration by binding to miR-654-3p to upregulate EFR3A, providing a potential new direction for seeking therapeutic plans for NPC.