Nasopharyngeal Carcinoma Cell Lines Research Articles

LncRNA SNHG14 Facilitates Cisplatin Resistance Through Upregulating Notch2 via Binding to U2AF2 in Nasopharyngeal Carcinoma.

Cisplatin (DDP) is one of the commonly used chemotherapeutic drugs for nasopharyngeal carcinoma (NPC) patients, and the resistance of tumor cells to cisplatin is main obstacle for NPC treatment. This study explored effect and possible mechanism of lncRNA small nucleolar RNA host gene 14 (SNHG14) on drug resistance of NPC cells to cisplatin. Levels of SNHG14 and Notch2 in NPC tissues and cells were confirmed using RT-qPCR. Western blot detected Notch2 and ABCB1 expression in NPC cells. IC50 of cisplatin-treated NPC cells was tested utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell proliferation and apoptosis were evaluated utilizing colony formation experiment and flow cytometry, respectively. RNA immunoprecipitation (RIP) assay was utilized to validate the target genes of U2AF2. Notch2 mRNA stability was tested using actinomycin D. SNHG14 level was increased in both cisplatin-resistant NPC tissues and cell lines. SNHG14 silencing in HNE1/DDP cells resulted in inhibition of chemoresistance to cisplatin. Conversely, upregulation of SNHG14 in HNE1 cells enhanced their resistance to cisplatin. SNHG14 exhibited an interaction with U2AF2, leading to stabilization of Notch2 mRNA. Finally, Notch2 was involved in SNHG14-mediated cisplatin resistance in NPC cells. Our findings demonstrate SNHG14 plays a significant role in promoting chemoresistance of NPC cells to cisplatin through U2AF2/Notch2 axis. These results highlight potential therapeutic targets for NPC treatment.

Asparaginase and isoaspartyl peptidase 1 RNA interference suppresses the growth of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is one of the common malignant tumors, and its pathogenesis has not been fully clarified. This study aims to explore the impact of RNA interference on the growth and invasion of NPC cells. Asparaginase and isoaspartyl peptidase 1 (ASRGL1)-short hairpin(sh) RNA expressing lentivirus was used to investigate the effect of ASRGL1 knockdown on NPC cells (C666-1 and SUN-1). The target shASRGL1 gene was determined by mRNA and protein expression in nasopharyngeal carcinoma cells; nasopharyngeal carcinoma cell proliferation viability, migration, invasion, apoptosis, ATP levels, and oxidative stress were examined. The results found that ASRGL1 was found to be highly expressed in NPC tissues and cell lines. shASRGL1 exhibited a high gene expression knockdown efficiency, downregulated the ASRGL1 protein expression in the nasopharyngeal carcinoma cells, suppressed proliferation viability of transfected nasopharyngeal carcinoma cells, inhibited their migration and invasion and ATP levels, promoted nasopharyngeal carcinoma cell apoptosis, ROS, and ferroptosis. shASRGL1 plays a role in protecting against NPC cell growth and invasion.

Curcumin derivative C210 induces Epstein–Barr virus lytic cycle and inhibits virion production by disrupting Hsp90 function

Lytic induction therapy was devised to selectively combat malignancies associated with Epstein–Barr virus (EBV) by triggering viral reactivation from latency. At present, the major challenges of lytic induction therapy are to maximize reactivating efficiencies and meanwhile minimize infectious virion production. C210, a novel curcumin derivative with potent Hsp90 inhibitory activity, was explored for EBV-reactivating and virion-producing effects in EBV-positive nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC) cell lines. And the molecular mechanisms underlying these effects were determined. Follow C210 treatment, EBV lytic RNAs and proteins were upregulated, but infectious virions were not produced. Knockdown of heat shock protein 90 (Hsp90) induced expression of lytic RNAs and proteins, and diminished C210-driven EBV lytic induction. Pretreatment with an X box binding protein 1 (XBP1) inhibitor reduced C210-induced EBV lytic RNA. Furthermore, we demonstrated that C210 inhibited the binding of Hsp90 with its clients, signal transducer and activator of transcription 3 (STAT3) and xeroderma pigmentosum group B-complementing protein (XPB), which subsequently promoted their proteasomal degradation. Degradation of STAT3 by C210 enhanced the EBV-reactivating and anticancer capacity of suberoylanilide hydroxamic acid (SAHA). Depletion of XPB blocked SAHA-induced expression of late viral genes and production of infectious virions. These results elucidate a novel Hsp90 inhibitor targeting EBV lytic phase and extend the research on lytic induction strategy, which may offer reference value in the treatment of EBV-positive malignancies.

Implications of ITCH-mediated ubiquitination of SIX1 on CDC27-cyclinB1 signaling in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) presents a significant medical challenge due to its high incidence rate and poor prognosis, which are attributed primarily to tumor metastasis and drug resistance. Sine oculis homeobox homolog 1 (SIX1) has been identified as a crucial target for cancer treatment. However, its role in NPC remains incompletely understood. This study investigated the mechanisms by which the degradation of the SIX1 protein, which is mediated by ubiquitin, affects the malignant characteristics of NPC throughout the cell cycle. Our findings reveal that reduced expression of the itchy E3 ubiquitin ligase E3 (ITCH) in NPC impedes the degradation of the SIX1 protein, leading to enhance oncogenic properties. Knockdown experiments which SIX1 was inhibited demonstrated a decrease in the proliferation, migration, and invasion of NPC cell lines, whereas overexpression of SIX1 yielded the opposite effects. Further experimental validation revealed that SIX1 promotes NPC progression via the cell division cycle 27 (CDC27)/cyclin B1 axis. These findings provide valuable insights into potential therapeutic targets and prognostic indicators for NPC treatment, emphasizing the ITCH/SIX1/CDC27/cyclin B1 axis as a promising target for novel therapies.

ELAVL1 regulates glycolysis in nasopharyngeal carcinoma cells through the HMGB3/β-catenin axis

BackgroundThe role of ELAVL1 in the progression of various tumors has been demonstrated. Our research aims to investigate how ELAVL1 controls the glycolytic process in nasopharyngeal carcinoma cells through the HMGB3/β-catenin pathway.MethodsThe expression of ELAVL1 was detected in clinical tumor samples and nasopharyngeal carcinoma cell lines. A subcutaneous tumor model was established in nude mice to investigate the role of ELAVL1 in tumor progression. The relationship between HMGB3 and ELAVL1 was validated by RNA pull down and RIP assays. TOPFlash/FOPFlash reporter assay was used to detect β-catenin activity. Assay kits were utilized to measure glucose consumption, lactate production, and G6PD activity in nasopharyngeal carcinoma cells. Western blot was conducted to detect the expression of glycolysis-related proteins. The glycolytic capacity was analyzed through extracellular acidification rate (ECAR).ResultsIn both clinical samples and nasopharyngeal carcinoma cell lines, the expression levels of ELAVL1 mRNA and protein were found to be upregulated. Knockdown of ELAVL1 significantly inhibited the in vivo proliferation of nasopharyngeal carcinoma and suppressed the glycolytic capacity of nasopharyngeal carcinoma cells. ELAVL1 interacts with HMGB3, leading to an increase in the stability of HMGB3 mRNA. Overexpression of HMGB3 elevated the reduced β-catenin activity caused by sh-ELAVL1 and reversed the inhibitory effect of sh-ELAVL1 on cellular glycolytic capacity. Treatment with β-catenin inhibitor (FH535) effectively suppressed the promotion of glycolytic capacity induced by HMGB3 overexpression.ConclusionsELAVL1 promotes glycolysis in nasopharyngeal carcinoma cells by interacting with HMGB3 to stabilize HMGB3 mRNA, thereby activating β-catenin pathway. Therefore, targeting the ELAVL1-HMGB3-β-catenin axis has the potential to be a novel approach for treating nasopharyngeal carcinoma.

Hsa_circ_ROBO1 competes with miR-324-3p and upregulates NME1 to promote tumor metastasis in nasopharyngeal carcinoma

BackgroundThis work aims to explore circ_ROBO1’s function in nasopharyngeal carcinoma (NPC).Methodscirc_ROBO1 expression in NPC tissues and cell lines was measured. The regulation of circ_ROBO1 and/or miR-324-3p on the proliferation, migration, invasion, and apoptosis of NPC cells was investigated by functional experiments. The interplay between circ_ROBO1, miR-324-3p, and NME1 was explored. Tumor growth and metastasis were studied in mice.Resultscirc_ROBO1 was overexpressed in NPC. Knockdown of circ_ROBO1 repressed proliferation, migration, and invasion and induced apoptosis of NPC cells. Loss of circ_ROBO1 reduced tumor growth and metastasis in mice. circ_ROBO1 competed with miR-324-3p to upregulate NME1. Lowering miR-324-3p expression impaired the effect of knockdown of circ_ROBO1on NPC cells.ConclusionOverexpressed circ_ROBO1 promotes NPC development by modifying the miR-324-3p/NME1 axis.

High extracellular matrix stiffness promotes the metastasis of nasopharyngeal carcinoma through STAT3/FGF1 positive feedback regulation activated by JAK2

The stiffness of the extracellular matrix (EM) is known to be associated with tumor metastasis. This study aims to clarify the function and mechanisms of EM stiffness in nasopharyngeal carcinoma (NPC) and to provide a potential therapeutic target for patients with NPC. The NPC cell lines were cultured under varying stiffnesses. Plate cloning, Transwell assays and scratch tests were conducted to compare the phenotypes. Transcriptome sequencing and enrichment analysis were performed to explore the key molecules and the downstream signaling pathways, which were verified via in vitro and in vivo experiments. Our study showed that the NPC cells cultured on a stiff substrate (50 ​kPa) had greater colony formation, invasion and migration abilities than those cultured on a soft substrate. Transcriptome sequencing showed that a stiff environment induced high expression of fibroblast growth factor 1 (FGF1), which suggested a poor prognosis in various malignancies. The phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway played an important role in NPC metastasis activated by the FGF1 autocrine pathway in a stiff environment. The increased FGF1 expression was regulated by the transcription factor STAT3, and a positive feedback regulation between them was observed. The use of the JAK inhibitor Ruxolitinib and JAK2 interference inhibited the activation of STAT3. In conclusion, JAK2 activates STAT3/FGF1 positive feedback regulation and promotes NPC metastasis via the PI3K/Akt signaling pathway in a high-stiffness environment. Hence, FGF1 can be used as a potential therapeutic target for patients with NPC.

Dihydroartemisinin enhances sensitivity of nasopharyngeal carcinoma HNE1/DDP cells to cisplatin-induced apoptosis by promoting ROS production

To investigate the effect of dihydroartemisinin (DHA) for enhancing the inhibitory effect of cisplatin (DDP) on DDP-resistant nasopharyngeal carcinoma cell line HNE1/DDP and explore the mechanism. CCK-8 method was used to assess the survival rate of HNE1/DDP cells treated with DHA (0, 5, 10, 20, 40, 80, and 160 μmol/L) and DDP (0, 4, 8, 16, 32, 64, 128 μmol/L) for 24 or 48 h, and the combination index of DHA and DDP was calculated using Compusyn software. HNE1/DDP cells treated with DHA, DDP, or their combination for 24 h were examined for cell viability, proliferation and colony formation ability using CCK-8, EdU and colony-forming assays. Flow cytometry was used to detect cell apoptosis and intracellular reactive oxygen species (ROS). The expression levels of apoptosis-related proteins cleaved PARP, cleaved caspase-9 and cleaved caspase-3 were detected by Western blotting. The effects of N-acetyl-cysteine (a ROS inhibitor) on proliferation and apoptosis of HNE1/DDP cells with combined treatment with DHA and DDP were analyzed. Different concentrations of DHA and DDP alone both significantly inhibited the viability of HNE1/DDP cells. The combination index of DHA (5 μmol/L) combined with DDP (8, 16, 32, 64, 128 μmol/L) were all below 1. Compared with DHA or DDP alone, their combined treatment more potently decreased the cell viability, colony-forming ability and the number of EdU-positive cells, and significantly increased the apoptotic rate, intracellular ROS level, and the expression levels of cleaved PARP, cleaved caspase-9 and cleaved caspase-3 in HNE1/DDP cells. N-acetyl-cysteine pretreatment obviously attenuated the inhibitory effect on proliferation and apoptosis-inducing effect of DHA combined with DDP in HNE1/DDP cells (P<0.01). DHA enhances the growth-inhibitory and apoptosis-inducing effect of DDP on HNE1/DDP cells possibly by promoting accumulation of intracellular ROS.

Integrating serum metabolomics analysis and network pharmacology to reveal the potential mechanism of Shengmai Jianghuang San in the treatment of nasopharyngeal carcinoma.

Shengmai Jianghuang San (SMJHS) is a traditional Chinese herbal compound reported to inhibit Nasopharyngeal Carcinoma (NPC) progression and enhance radiosensitivity. However, the specific active ingredients and regulatory mechanisms of SMJHS against NPC, particularly under hypoxic conditions, remain unclear. In this study, Sprague-Dawley (SD) rats were gavaged with Shengmai Jianghuang San (SMJHS), and their blood was collected from the abdominal aorta. UHPLC-Q-Exactive orbitrap MS/MS was used to identify the metabolite profiles of SMJHS drug-containing serum. A molecular network of the active compositions in SMJHS targeting NPC was constructed through network pharmacology and molecular docking. The HIF-1α/VEGF pathway was in key positions. The effects of SMJHS on the proliferation, migration, and radiosensitivity of hypoxic NPC cells were assessed by in vitro experiments. NPC cell lines stably overexpressing HIF-1α were established using a lentivirus to investigate the regulation of HIF-1α/VEGF signaling in hypoxic NPC cells by SMJHS. Through a combination of network pharmacological analysis, cellular biofunctional validation, and molecular biochemical experiments, our study found that SMJHS had an anti-proliferative effect on NPC cells cultured under hypoxic conditions, inhibiting their migration and increasing their radiosensitivity. Additionally, SMJHS suppressed the expression of HIF-1α and VEGFA, exhibiting potential as an effective option for improving NPC treatment.

Treatment with autophagic inhibitors enhances oligonol‑induced apoptotic effects in nasopharyngeal carcinoma cells.

Although the combination of chemotherapy and radiotherapy has increased the survival rate of patients with nasopharyngeal carcinoma (NPC), certain patients do not respond well to the treatment and have a poor prognosis. Therefore, novel therapeutic drugs and strategies to improve prognosis of patients with NPC are required. As certain plant extracts can suppress the viability of cancer cells, the present study investigated whether oligonol, a polyphenolic compound primarily found in lychee fruit, exerts anticancer activities in NPC cells. MTT, ELISA and immunoblotting were performed to investigate cell survival, cytokeratin-18 fragment release, and the expression of apoptosis and autophagy markers, respectively. Oligonol decreased the viability of NPC-TW01 and NPC/HK1NPC cell lines. Oligonol increased the protein expression of several apoptosis markers, including cleaved caspase-8 and -3, cleaved PARP and cytokeratin 18 fragment. Moreover, it also increased expression of autophagy markers Beclin 1 and LC3-II, as well as LC3-II/LC3-I ratio in both NPC cell lines. Furthermore, treatment with autophagy inhibitors 3-methyladenine or LY294002 significantly increased oligonol-induced viability inhibition in NPC-TW01 cells. Combined treatment of oligonol + LY294002 reduced LC3-II expression and the LC3II/LC3I ratio while increasing cleaved caspase-8 and -3, cleaved PARP and cytokeratin 18 fragment expression in NPC-TW01 cells. These findings indicated autophagy inhibitors could enhance viability inhibition and apoptotic effects induced by oligonol in NPC cells.

A positive feedback loop between PLD1 and NF-κB signaling promotes tumorigenesis of nasopharyngeal carcinoma

Phospholipase D (PLD) lipid-signaling enzyme superfamily has been widely implicated in various human malignancies, but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma (NPC). Here, we analyze the expressions of 6 PLD family members between 87 NPC and 10 control samples through transcriptome analysis. Our findings reveal a notable upregulation of PLD1 in both NPC tumors and cell lines, correlating with worse disease-free and overall survival in NPC patients. Functional assays further elucidate the oncogenic role of PLD1, demonstrating its pivotal promotion of critical tumorigenic processes such as cell proliferation and migration in vitro, as well as tumor growth in vivo. Notably, our study uncovers a positive feedback loop between PLD1 and the NF-κB signaling pathway to render NPC progression. Specifically, PLD1 enhances NF-κB activity by facilitating the phosphorylation and nuclear translocation of RELA, which in turn binds to the promoter of PLD1, augmenting its expression. Moreover, RELA overexpression markedly rescues the inhibitory effects in PLD1-depleted NPC cells. Importantly, the application of the PLD1 inhibitor, VU0155069, substantially inhibits NPC tumorigenesis in a patient-derived xenograft model. Together, our findings identify PLD1/NF-κB signaling as a positive feedback loop with promising therapeutic and prognostic potential in NPC.

LncRNA DYNLRB2-AS1 promotes gemcitabine resistance of nasopharyngeal carcinoma by inhibiting the ubiquitination degradation of DHX9 protein

Gemcitabine (GEM) based induction chemotherapy is a standard treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, approximately 15 % of patients are still resistant to GEM-containing chemotherapy, which leads to treatment failure. Nevertheless, the underlying mechanisms of GEM resistance remain poorly understood. Herein, based on a microarray analysis, we identified 221 dysregulated lncRNAs, of which, DYNLRB2-AS1 was one of the most upregulated lncRNAs in GEM-resistance NPC cell lines. DYNLRB2-AS1 was shown to function as contain an oncogenic lncRNA that promoted NPC GEM resistance, cell proliferation, but inhibited cell apoptosis. Mechanistically, DYNLRB2-AS1 could directly bind to the DHX9 protein and prevent its interaction with the E3 ubiquitin ligase PRPF19, and thus blocking PRPF19-mediated DHX9 degradation, which ultimately facilitated the repair of DNA damage in the presence of GEM. Clinically, higher DYNLRB2-AS1 expression indicated an unfavourable overall survival of NPC patients who received induction chemotherapy. Overall, this study identified the oncogenic lncRNA DYNLRB2-AS1 as an independent prognostic biomarker for patients with locally advanced NPC and as a potential therapeutic target for overcoming GEM chemoresistance in NPC.

Exosome-Mediated Transfer of ALDH2 in Nasopharyngeal Carcinoma Cells Confers Increased Resistance to Paclitaxel Treatment.

Nasopharyngeal carcinoma (NPC) is an aggressive and highly metastatic malignant tumor. Despite recent therapeutic advances, resistance to Taxol (the generic name of paclitaxel) therapy remains a major challenge in clinical management. Therefore, it is imperative to explore the potential mechanisms of paclitaxel resistance in NPC. This study aimed to investigate the expression of aldehyde dehydrogenase 2 (ALDH2) in NPC cells and its critical role in paclitaxel resistance. Paclitaxel-resistant cell line CNE1/Taxol (CNE1-TR), a drug-resistant cell line, was established by exposing the CNE1 nasopharyngeal carcinoma cell line to progressively increasing concentrations of paclitaxel. Furthermore, we investigated the role of ALDH2 in paclitaxel resistance and the function of exosomes using cell culture, Western blotting, reverse transcription-polymerase chain reaction (RT-PCR), Cell Counting Kit-8 (CCK-8), and nanoparticle tracking analysis. The results showed that in the presence of paclitaxel, the CNE1-TR cells manifested higher survival rate and half-maximal inhibitory concentration (IC50) value compared to the parental cell line, indicating strong resistance to paclitaxel. CNE1-TR cells had significantly upregulated mRNA and protein levels of ALDH2. In addition, exosome analysis showed that CNE1-TR cells were able to deliver ALDH2 via exosomes, increasing paclitaxel resistance in the recipient cells. We observed that the ALDH2 expression levels and paclitaxel resistance in CNE1-TR cells were effectively reduced by blocking the release of exosomes. ALDH2 is not only a key molecular marker indicative of therapeutic efficacy, but also a potential therapeutic target for developing novel anticancer strategies. By blocking the exosomal transport of ALDH2 or directly inhibiting its activity, it may be possible to overcome paclitaxel resistance, thus improving the success rate of clinical treatment.

Prodrug-conjugated tumor-seeking commensals for targeted cancer therapy

Prodrugs have been explored as an alternative to conventional chemotherapy; however, their target specificity remains limited. The tumor microenvironment harbors a range of microorganisms that potentially serve as tumor-targeting vectors for delivering prodrugs. In this study, we harness bacteria-cancer interactions native to the tumor microbiome to achieve high target specificity for prodrug delivery. We identify an oral commensal strain of Lactobacillus plantarum with an intrinsic cancer-binding mechanism and engineer the strain to enable the surface loading of anticancer prodrugs, with nasopharyngeal carcinoma (NPC) as a model cancer. The engineered commensals show specific binding to NPC via OppA-mediated recognition of surface heparan sulfate, and the loaded prodrugs are activated by tumor-associated biosignals to release SN-38, a chemotherapy compound, near NPC. In vitro experiments demonstrate that the prodrug-loaded microbes significantly increase the potency of SN-38 against NPC cell lines, up to 10-fold. In a mouse xenograft model, intravenous injection of the engineered L. plantarum leads to bacterial colonization in NPC tumors and a 67% inhibition in tumor growth, enhancing the efficacy of SN-38 by 54%.

Capsaicin enhances cisplatin-induced anti-metastasis of nasopharyngeal carcinoma by inhibiting EMT and ERK signaling via serpin family B member 2.

Cisplatin (DDP)-based combined chemotherapy or concurrent chemoradiotherapy is the mainstay treatment for advanced-stage nasopharyngeal carcinoma (NPC), but needs improvement due to its severe side effects. Capsaicin (CAP) can enhance the anti-tumor activity of cytotoxic drugs. The aim of this study was to investigate the anti-metastasis activity of CAP in combination with DDP in NPC. Herein, CAP and DDP showed synergistic cytotoxic effects on NPC cells. CAP alone and DDP alone inhibited NPC migration and invasion in vitro and in vivo, and the combination of CAP and DDP had the greatest effect. Moreover, CAP upregulated the mRNA and protein expressions of serpin family B member 2 (SERPINB2). Further results showed that both SERPINB2 mRNA and protein expressions were downregulated in NPC cell lines and tissues and SERPINB2 overexpression inhibited NPC migration and invasion in vitro and in vivo, while silencing SERPINB2 acted oppositely. In addition, SERPINB2 was abnormally expressed in head and neck squamous cell carcinoma and other multiple cancers, and downregulation of SERPINB2 predicted poor prognosis in head and neck squamous cell carcinoma according to the Cancer Genome Atlas database. We further found that SERPINB2 overexpression inhibited epithelial-mesenchymal transition (EMT) and the phosphorylated extracellular signal-regulated kinase (p-ERK), and the inhibitory effect was enhanced by CAP and DDP. Altogether, our results suggest that the combined inhibition of CAP and DDP on NPC metastasis may be related to the inhibition of epithelial-mesenchymal transition and ERK signals mediated by SERPINB2, and CAP may help to improve the efficacy of DDP in the treatment of NPC and develop new therapeutic approaches.

Nasopharyngeal carcinoma with non-squamous phenotype may be a variant of nasopharyngeal squamous cell carcinoma after inhibition of EGFR/PI3K/AKT/mTOR pathway.

Nasopharyngeal carcinoma (NPC) is a cancerous tumor that develops in the nasopharynx epithelium and typically has squamous differentiation. The squamous phenotype is evident in immunohistochemistry, with diffuse nuclear positivity for p63 and p40. Nonetheless, a few NPCs have been identified by clinicopathological diagnosis that do not exhibit the squamous phenotype; these NPCs are currently referred to as non-squamous immunophenotype nasopharyngeal carcinomas (NSNPCs). In a previous work, we have revealed similarities between the histological appearance, etiology, and gene alterations of NSNPC and conventional NPC. According to ultrastructural findings, NSNPC still falls under the category of non-keratinized squamous cell carcinoma that is undifferentiated. NSNPC has an excellent prognosis and a low level of malignancy, according to a retrospective investigation. Based on prior research, we investigated the molecular mechanism of NSNPC not expressing the squamous phenotype and its biological behavior. IHC was used to determine the expression of EGFR, PI3K, AKT, p-AKT, mTOR, p-mTOR, Notch, STAT3 and p-STAT3 in a total of 20 NSNPC tissue samples and 20 classic NPC tissue samples. We obtained human NPC cell lines (CNE-2,5-8F) and used EGFR overexpression plasmid and shRNAs to transfect them. To find out whether mRNA and proteins were expressed in the cells, we used Western blotting and qRT-PCR. Cell biological behavior was discovered using the CCK-8 assay, cell migration assay, and cell invasion assay. EGFR, PI3K, p-AKT and p-mTOR proteins were lowly expressed in NSNPC tissues by immunohistochemistry, compared with classical NPC. In the classical NPC cell lines CNE-2 and 5-8F, overexpression EGFR can up-regulate the expression of p63 through the PI3K/AKT/mTOR pathway, and promote the proliferation, migration, and invasion of nasopharyngeal carcinoma cells. At the same time, knockout of EGFR can down-regulate p63 expression through the PI3K/AKT/mTOR pathway, and inhibit the proliferation, migration, and invasion of nasopharyngeal carcinoma cells. The lack of p63 expression in NSNPC was linked with the inhibition of the EGFR/PI3K/AKT/mTOR pathway, and NSNPC may be a variant of classical NPC.

The circadian clock gene BMAL1 increases radiosensitivity in nasopharyngeal carcinoma cell CNE2

ObjectiveTo investigate the involvement of the circadian clock gene BMAL1 in regulating radiosensitivity in nasopharyngeal carcinoma (NPC). MethodsThe regulatory role of BMAL1 in NPC radiotherapy was investigated using 44 NPC cases and the NPC cell line CNE2, which had been genetically modified to either overexpress or silence BMAL1. Infected CNE2 cells were divided into four groups, including those with BMAL1 overexpression and BMAL1 RNA interference (RNAi), as well as their respective control groups. The group responses to different doses of radiotherapy were examined. ResultsThe 5-year survival rates of the BMAL1 overexpression group demonstrated a significant increase compared to those of the low expression group (p < 0.05). Furthermore, the BMAL1 overexpression group exhibited a higher tumor-growth inhibition rate (p < 0.001) and apoptotic rate (p = 0.004) following radiotherapy; a decreased proportion of S-phase cells (p < 0.001) but an increased proportion of G2/M-phase cells (p = 0.001) after 24 h of 8Gy irradiation; reduced number of cell colonies (p = 0.042), and a lower survival score (p = 0.037). ConclusionsOur findings demonstrate a positive correlation between BMAL1 expression and NPC survival, suggesting that BMAL1 promotes NPC radiosensitivity.

Circular RNA COL1A1 promotes Warburg effect and tumor growth in nasopharyngeal carcinoma

ObjectiveCircular RNAs (circRNAs), pivotal in the pathogenesis and progression of nasopharyngeal carcinoma (NPC), remain a significant point of investigation for potential therapeutic interventions. Our research was driven by the objective to decipher the roles and underlying mechanisms of hsa_circ_0044569 (circCOL1A1) in governing the malignant phenotypes and the Warburg effect in NPC.MethodsWe systematically collected samples from NPC tissues and normal nasopharyngeal epithelial counterparts. The expression levels of circCOL1A1, microRNA-370-5p (miR-370-5p), and prothymosin alpha (PTMA) were quantitatively determined using quantitative polymerase chain reaction (qPCR) and Western blotting. Transfections in NPC cell lines were conducted using small interfering RNAs (siRNAs) or vectors carrying the pcDNA 3.1 construct for overexpression studies. We interrogated the circCOL1A1/miR-370-5p/PTMA axis's role in cellular functions through a series of assays: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide for cell viability, colony formation for growth, Transwell assays for migration and invasion, and Western blotting for protein expression profiling. To elucidate the molecular interactions, we employed luciferase reporter assays and RNA immunoprecipitation techniques.ResultsOur investigations revealed that circCOL1A1 was a stable circRNA, highly expressed in both NPC tissues and derived cell lines. A correlation analysis with clinical pathological features demonstrated a significant association between circCOL1A1 expression, lymph node metastasis, and the tumor node metastasis staging system of NPC. Functionally, silencing circCOL1A1 led to substantial suppression of cell proliferation, migration, invasion, and metabolic alterations characteristic of the Warburg effect in NPC cells. At the molecular level, circCOL1A1 appeared to modulate PTMA expression by acting as a competitive endogenous RNA or 'sponge' for miR-370-5p, which in turn promoted the malignant characteristics of NPC cells.ConclusionTo conclude, our findings delineate that circCOL1A1 exerts its oncogenic influence in NPC through the modulation of the miR-370-5p/PTMA signaling axis.

Near-infrared-triggered Dibenzo[a,c][1,2,5]thiadiazolo[3,4-i]phenazine heterocyclic derivatives for type-I photodynamic and photothermal therapy against human nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) remains endemic in southern China. The general therapeutic consensus is to treat the disease with radiotherapy alone or together with concurrent chemotherapy. But the treatment outcome of NPC remains disappointing with bad prognoses, low overall survival rate and severe side effects. Phototherapy can be a promising approach for treating NPC due to its excellent spatiotemporal selectivity, negligible drug resistance and minimal invasiveness. In this work, two photosensitizers (DTP-Ph and DTP-Et) with similar donor-acceptor structure were designed and constructed for the treatment of NPC. Remarkably, DTP-Ph and DTP-Et show different photo-physicochemical properties as well as mechanisms of phototherapeutic actions, especially DTP-Ph, which exhibits synergistic type-I photodynamic therapy (PDT) and photothermal therapy (PTT) effect under near-infrared (NIR) activation. DTP-Et and DTP-Ph were further encapsulated with F127 to obtain nanoparticles with good water solubility. In intro and in vivo phototherapy evaluations of DTP-Ph NPs display promising phototherapeutic activity with low IC50 value and good tumor growth inhibition (TGI) against human nasopharyngeal carcinoma cell line CNE2 and tumor-bearing xenograft model.

PQR309, a dual PI3K/mTOR inhibitor, synergizes with gemcitabine by impairing the GSK-3β and STAT3/HSP60 signaling pathways to treat nasopharyngeal carcinoma

End-stage nasopharyngeal carcinoma (NPC) has unsatisfactory survival. The limited benefit of chemotherapy and the scarcity of targeted drugs are major challenges in NPC. New approaches to treat late-stage NPC are urgently required. In this study, we explored whether the dual PI3K/mTOR inhibitor, PQR309, exerted a favorable antineoplastic effect and sensitized the response to gemcitabine in NPC. We observed that PI3K expression was positive and elevated in 14 NPC cell lines compared with that in normal nasopharygeal cell lines. Patients with NPC with higher PI3K levels displayed poorer prognosis. We subsequently showed that PQR309 alone effectively decreased the viability, invasiveness, and migratory capability of NPC cells and neoplasm development in mice xenograft models, and dose-dependently induced apoptosis. More importantly, PQR309 remarkably strengthened the anti-NPC function of gemcitabine both in vivo and in vitro. Mechanistically, PQR309 sensitized NPC to gemcitabine by increasing caspase pathway-dependent apoptosis, blocking GSK-3β and STAT3/HSP60 signaling, and ablating epithelial-mesenchyme transition. Thus, targeting PI3K/mTOR using PQR309 might represent a treatment option to promote the response to gemcitabine in NPC, and provides a theoretical foundation for the study of targeted drugs combined with chemotherapy for NPC.