Development Of Nasopharyngeal Carcinoma Research Articles

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.

Epidemiology of nasopharyngeal carcinoma: current insights and future outlook.

Nasopharyngeal carcinoma (NPC) is characterised by its remarkable geographical and ethnic distribution. The interplay between genetic susceptibility, environmental exposures, and Epstein-Barr virus (EBV) infections is indicated in the development of NPC. Exposure to tobacco smoking, dietary factors, and inhalants has been associated with the risk of NPC. Genetic association studies have revealed NPC-associated susceptibility loci, including genes involved in immune responses, xenobiotic metabolism, genome maintenance, and cell cycle regulation. EBV exposure timing and strain variation might play a role in its carcinogenicity, although further investigations are required. Other factors including medical history and oral hygiene have been implicated in NPC. Prevention strategies, including primary prevention and secondary prevention through early detection, are vital in reducing mortality and morbidity of NPC. The current review discusses the global and regional distribution of NPC incidences, the risk factors associated with NPC, and the public health implications of these insights. Future investigations should consider international, large-scale prospective studies to elucidate the mechanisms underlying NPC pathogenesis and develop individualized interventions for NPC.

Epstein-Barr Virus BRLF1 Induces PD-L1 Expression in Nasopharyngeal Carcinoma Cells.

Nasopharyngeal carcinoma (NPC) is a specific human malignancy with unique geographic distribution and genetic backgrounds. Although early treatment with radio-chemotherapy has been proven effective for NPC therapy, its therapeutic efficacy substantially diminishes in the late stages of this malignancy. In the tumor microenvironment of NPC, PD-L1 has been demonstrated as a critical factor in impairing T cell activation. As an etiological role for NPC development, it is found that Epstein-Barr virus (EBV) latent proteins upregulated PD-L1 expression. However, whether EBV lytic protein affects PD-L1 expression remains unclear. In this study, through monitoring the mRNA expression pattern of lytic genes and PD-L1 in EBV-positive NPC cell line NA, EBV immediately-early gene BRLF1(Rta) was found to have the potential for PD-L1 activation. Furthermore, we identified that Rta expression enhanced PD-L1 expression in mRNA and protein levels through quantitative real-time polymerase chain reaction and western blotting analysis. The luciferase reporter assay revealed that Rta expression enhanced PD-L1 promoter activity. We also demonstrated that Rta-induced PD-L1 expressions could impair interleukin 2 secretion of T cells, and this mechanism may be through ERK activation. These results displayed the importance of EBV Rta in PD-L1 expression in NPC and may give an alternative target for NPC therapy.

Precision Medicine for Nasopharyngeal Cancer-A Review of Current Prognostic Strategies.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV) driven malignancy arising from the nasopharyngeal epithelium. Current treatment strategies depend on the clinical stage of the disease, including the extent of the primary tumour, the extent of nodal disease, and the presence of distant metastasis. With the close association of EBV infection with NPC development, EBV biomarkers have shown promise in predicting treatment outcomes. Among the omic technologies, RNA and miRNA signatures have been widely studied, showing promising results in the research setting to predict treatment response. The transformation of radiology images into measurable features has facilitated the use of radiomics to generate predictive models for better prognostication and treatment selection. Nonetheless, much of this work remains in the research realm, and challenges remain in clinical implementation.

Impact of toll-like receptor 4 variations on nasopharyngeal carcinoma risk and survival in tunisian population.

The Toll-like receptor 4 (TLR4), an important member of the host's innate immune response, is coded by a polymorphic gene. This polymorphism could be a predisposing factor for NasoPharyngeal Carcinoma (NPC). To determine the association between TLR4 gene polymorphisms and the susceptibility to NPC in a cohort of Tunisian affected patients. Genomic DNAs from 245 unrelated patients affected by undifferentiated carcinoma type (UCNT) and 264 unrelated healthy controls were genotyped for the five single nucleotides polymorphisms (SNPs) of TLR4 locus (4434 A>G (rs1927914),7263 G>C (rs10759932), 6134 A>G(rs4986790), 8851C>T (rs 4986791), 5272 T>C(rs11536889), +8469 T>C (rs11536891)) by Taqman® 5'-nuclease assay. Among all polymorphisms studied, only the rs4986790 G and rs4986791 T alleles were significantly more prevalent in patients' group than controls (45% vs. 38%; p=0.03; pc=0.06) and increased the risk of the NPC (OR=1.3, 95% CI=1.01-1.69). Also, we found that the frequency of the rs4986790 AA and rs4986791 TT genotypes was significantly higher in controls than in patients (25.7% vs 37%; p=0.006, pc=0.02) and conferred a protector factor in NPC (OR= 0.59, 95% CI= 0.39-0.87). Further, based on the Kaplan-Meier survival curve we observed also the positive effect ofrs1927914 AA genotype on a prognostic of NPC (p=0.006; pc=0.01). Our study demonstrated that impaired production of TLR4 seems to be a risk factor of NPC development but functional studies are needed to confirm these findings. As to rs1927914 AA appears to be a good biomarker for better survival in a patient with NPC.

An Evaluation of Treatment Outcomes and Associated Factors in Nasopharyngeal Cancer Patients at a Tertiary Cancer Center in the United Arab Emirates.

Background and objective Nasopharyngeal carcinoma (NPC) presents a complex epidemiological pattern influenced by demographic characteristics, risk factors such as Epstein-Barr virus (EBV) infection, and smoking. Understanding the clinical profile and optimizing treatment strategies for NPC requires comprehensive analyses of these factors. In light of this, this study aimed to analyze the epidemiological patterns, histological characteristics, and treatment outcomes of NPCpatients diagnosed and treated at a single center from 2016 to 2023. Materials and methods This retrospective study was conducted at Tawam Hospital in the United Arab Emirates (UAE), focusing on patients diagnosed with NPC.It involved the analysis of patient age distribution to identify epidemiological patterns, histological examination to classify NPC types according to WHO guidelines, and evaluation of treatment outcomes based on induction chemotherapy regimens and concurrent chemoradiotherapy protocols. The effectiveness of various chemotherapy combinations, particularly cisplatin and 5-fluorouracil (Cis+5FU), was assessed alongside the integration of advanced radiotherapy techniques like intensity-modulated radiotherapy (IMRT). Results In this study of 41 NPC patients, the age distribution varied widely, ranging from 10 to 74 years, with a mean age of >40 years. There was a significantmale predominance (82.93%). Most patients were non-smokers (68.29%) and did not consume alcohol (92.68%), and there was a high prevalence of EBV positivity (100%). At diagnosis, 80.49% had no metastases. The primary treatment was chemotherapy induction, with a 73.17% uptake and a 92.68% completion rate, leading to a 65.85% complete response (CR) rate. No significant association was found between smoking status and treatment response (p=0.7657). Pathologically, non-keratinizing undifferentiated squamous carcinoma was the most common variant (75.61%). The Cis+5FUregimen was the most frequently employed method (56.67%), associated with a 76.47% CR rate. Concurrent chemotherapy was administered to 87.80% of patients, with the weekly Cis regimen being the most used one (56.09%), resulting in a significant CR rate. Combining radiation therapy with concurrent and induction chemotherapy yielded high CR rates (RT+cCT: 66.66%, RT+cCT+iCT: 80%). Survival analysis revealed the highest 36-month survival rate (46.43%) in the RT+cCT+iCT group, suggesting a potential benefit from incorporating induction chemotherapy into the treatment regimen. Conclusions This study illustrates the impact of demographic variables, EBV infection, and smoking on the development and treatment outcomes of NPC. It points to the success of customized chemotherapy and advanced radiotherapy strategies. Yet, it is limited by its retrospective nature and single-center focus, and hence we recommend multicentric studies to broaden the applicability of the results and improve NPC treatment approaches for varied patient groups.

Baicalein targets STMN1 to inhibit the progression of nasopharyngeal carcinoma via regulating the Wnt/β-catenin pathway.

Nasopharyngeal carcinoma is a common malignancy in the head and neck. Baicalein has been reported to exert the anticancer effects on various cancers. In this study, our aim was to explore the function of baicalein in the development of nasopharyngeal carcinoma and further investigate the potential underlying mechanisms. Cell Counting Kit (CCK)-8 assay, EdU assay, sphere formation assay, flow cytometry, and transwell invasion assay were conducted to determine cell proliferation, stemness, apoptosis, and invasion, respectively. Western blot was performed to examine the protein levels of PCNA, MMP9, STMN1, β-catenin, and Wnt3A. The mRNA level of STMN1 was assessed using real-time quantitative polymerase chain reaction (RT-qPCR). Xenograft tumor model was carried out to evaluate the effects of baicalein on tumor growth in vivo. Immunohistochemistry (IHC) assay was used to detect the levels of PCNA, MMP9, and STMN1 in tumor tissues from mice. Baicalein significantly induced cell apoptosis and impeded cell proliferation, invasion, and stemness of nasopharyngeal carcinoma cells. STMN1 was highly expressed in nasopharyngeal carcinoma, and baicalein could directly downregulate STMN1 expression. STMN1 knockdown hampered the progression of nasopharyngeal carcinoma cells. Moreover, the effects of baicalein on cell proliferation, stemness, invasion, and apoptosis in nasopharyngeal carcinoma cells were harbored by STMN1 overexpression. Baicalein regulated STMN1 to inhibit the activation of the Wnt/β-catenin pathway. SKL2001, an agonist of the Wnt/β-catenin pathway, could reverse the effects of STMN1 knockdown on the progression of nasopharyngeal carcinoma. In addition, baicalein markedly impeded tumor growth in vivo. Baicalein regulated the STMN1/Wnt/β-catenin pathway to restrain the development of nasopharyngeal carcinoma.

N6-Methyladenosine reader HNRNPC-mediated downregulation of circITCH prevents miR-224-3p sequestering and contributes to tumorigenesis in nasopharyngeal carcinoma.

N6-Methyladenosine (m6A) RNA methylation modulators are implicated in nasopharyngeal carcinoma (NPC). Circular RNAs (circRNAs) stimulate/inhibit the development of NPC by sponging microRNAs (miRNAs). Herein, m6A modifications affecting the circRNA/miRNA axis in NPC were explored. Twenty prognostic m6A RNA methylation regulators were identified from 504 head/neck squamous cell carcinoma and 44 normal samples from The Cancer Genome Atlas (TCGA). Differentially expressed miRNAs were screened from the TCGA and Gene Expression Omnibus (GEO) databases. RNA-binding protein (RBP)-circRNA and circRNA-miRNA interactive pairs were verified using RBPmap and RNAhybrid, respectively. The RBP/circRNA/miRNA network was constructed using Cytoscape. Furthermore, CircITCH (hsa_circ_00059948), HNRNPC, and miR-224-3p expressions were detected by western blotting and quantitative polymerase chain reaction. The role of circITCH in NPC was examined using apoptosis, scratch wound healing, transwell invasion, and cell counting kit-8 assays. Finally, CircITCH-miR-224-3p and circITCH-HNRNPC interactions were assessed by dual-luciferase reporter and RNA-immunoprecipitation (RIP) assays, respectively. Bioinformatics analysis revealed that high pathological grade, late-stage tumors, and low survival were associated with increased HNRNPC expression. MiR-224-3p was upregulated in NPC and sequestered by circITCH. Construction of the RBP/circRNA/miRNA network highlighted the HNRNPC/circITCH/miR-224-3p axis. In vitro experiments demonstrated decreased circITCH expression and increased HNRNPC and miR-224-3p expressions in NPC. In NPC cells overexpressing circITCH, HNRNPC and miR-224-3p expressions were significantly decreased. Dual-luciferase assays demonstrated a targeting relationship between circITCH and miR-224-3p, and RIP assays demonstrated interaction of HNRNPC targets with circITCH. CircITCH overexpression inhibited NPC progression by sequestering miR-224-3p, and HNRNPC reduced circITCH expression through direct interaction.

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

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

EBV abortive lytic cycle promotes nasopharyngeal carcinoma progression through recruiting monocytes and regulating their directed differentiation.

Epstein-Barr virus (EBV) is associated with several types of human cancer including nasopharyngeal carcinoma (NPC). The activation of EBV to the lytic cycle has been observed in advanced NPC and is believed to contribute to late-stage NPC development. However, how EBV lytic cycle promotes NPC progression remains elusive. Analysis of clinical NPC samples indicated that EBV reactivation and immunosuppression were found in advanced NPC samples, as well as abnormal angiogenesis and invasiveness. To investigate the role of the EBV lytic cycle in tumor development, we established a system that consists of two NPC cell lines, respectively, in EBV abortive lytic cycle and latency. In a comparative analysis using this system, we found that the NPC cell line in EBV abortive lytic cycle exhibited the superior chemotactic capacity to recruit monocytes and polarized their differentiation toward tumor-associated macrophage (TAM)-like phenotype and away from DCs, compared to EBV-negative or EBV-latency NPC cells. EBV-encoded transcription activator ZTA is responsible for regulating monocyte chemotaxis and TAM phenotype by up-regulating the expression of GM-CSF, IL-8, and GRO-α. As a result, TAM induced by EBV abortive lytic cycle promotes NPC angiogenesis, invasion, and migration. Overall, this study elucidated the role of the EBV lytic life cycle in the late development of NPC and revealed a mechanism underlying the ZTA-mediated establishment of the tumor microenvironment (TME) that promotes NPC late-stage progression.

PSMC2 knockdown exerts an anti-tumor role in nasopharyngeal carcinoma through regulating AKT signaling pathway

ABSTRACT Nasopharyngeal carcinoma is a major public health problem in several countries, particularly in Southeast Asia and North Africa. However, the mechanism underlying the malignant biological behaviors of nasopharyngeal carcinoma is not fully clear. Our study intended to investigate the functional importance and molecular mechanism of proteasome 26 S subunit ATPase 2 (PSMC2) in the progression of nasopharyngeal carcinoma. We examined the expression of PSMC2 in both nasopharyngeal carcinoma tissues and normal healthy tissues using immunohistochemistry (IHC). Additionally, we conducted a series of cell experiments to verify the functional roles of PSMC2 and to explore the underlying pathway involved. The results revealed that PSMC2 was significantly upregulated in nasopharyngeal carcinoma tissues compared to normal tissues. Moreover, high PSMC2 was shown to closely correlate with the pathological stage and tumor infiltrate in nasopharyngeal carcinoma patients. Functionally, we observed a suppression of nasopharyngeal carcinoma progression upon knocking down PSMC2. This was evidenced by inhibited cell proliferation and migration in vitro, as well as impaired cell growth in vivo, along with increased apoptosis. Mechanistically, the inhibitory effects of PSMC2 silence on nasopharyngeal carcinoma could be reversed by the addition of AKT activator. Overall, our study sheds light on a novel mechanism underlying the development and progression of nasopharyngeal carcinoma, with PSMC2 exerting a positive regulatory role through the modulation of the AKT signaling pathway. A deeper understanding of PSMC2 may contribute to the development of improved treatment strategies for nasopharyngeal carcinoma.

CircBRD7 attenuates tumor growth and metastasis in nasopharyngeal carcinoma via epigenetic activation of its host gene.

BRD7 was identified as a tumor suppressor in nasopharyngeal carcinoma (NPC). Circular RNAs (CircRNAs) are involved in the occurrence and development of NPC as oncogenes or tumor suppressors. However, the function and mechanism of the circular RNA forms derived from BRD7 in NPC are not well understood. In this study, we first identified that circBRD7 was a novel circRNA derived from BRD7 that inhibited cell proliferation, migration, invasion of NPC cells, as well as the xenograft tumor growth and metastasis invivo. Mechanistically, circBRD7 promoted the transcriptional activation and expression of BRD7 by enhancing the enrichment of histone 3 lysine 27 acetylation (H3K27ac) in the promoter region of its host gene BRD7, and BRD7 promoted the formation of circBRD7. Therefore, circBRD7 formed a positive feedback loop with BRD7 to inhibit NPC development and progression. Moreover, restoration of BRD7 expression rescued the inhibitory effect of circBRD7 on the malignant progression of NPC. In addition, circBRD7 demonstrated low expression in NPC tissues, which was positively correlated with BRD7 expression and negatively correlated with the clinical stage of NPC patients. Taken together, circBRD7 attenuates the tumor growth and metastasis of NPC by forming a positive feedback loop with its host gene BRD7, and targeting the circBRD7/BRD7 axis is a promising strategy for the clinical diagnosis and treatment of NPC.

The interaction and mediation effects between the host genetic factors and Epstein-Barr virus VCA-IgA in the risk of nasopharyngeal carcinoma.

Previous studies have demonstrated strong associations between host genetic factors and Epstein-Barr virus (EBV) VCA-IgA with the risk of nasopharyngeal carcinoma (NPC). However, the specific interplay between host genetics and EBV VCA-IgA on NPC risk is not well understood. In this two-stage case-control study (N = 4804), we utilized interaction and mediation analysis to investigate the interplay between host genetics (genome-wide association study-derived polygenic risk score [PRS]) and EBV VCA-IgA antibody level in the NPC risk. We employed a four-way decomposition analysis to assess the extent to which the genetic effect on NPC risk is mediated by or interacts with EBV VCA-IgA. We consistently found a significant interaction between the PRS and EBV VCA-IgA on NPC risk (discovery population: synergy index [SI] = 2.39, 95% confidence interval [CI] = 1.85-3.10; replication population: SI = 3.10, 95% CI = 2.17-4.44; all pinteraction < 0.001). Moreover, the genetic variants included in the PRS demonstrated similar interactions with EBV VCA-IgA antibody. We also observed an obvious dose-response relationship between the PRS and EBV VCA-IgA antibody on NPC risk (all ptrend < 0.001). Furthermore, our decomposition analysis revealed that a substantial proportion (approximately 90%) of the genetic effects on NPC risk could be attributed to host genetic-EBV interaction, while the risk effects mediated by EBV VCA-IgA antibody were weak and statistically insignificant. Our study provides compelling evidence for an interaction between host genetics and EBV VCA-IgA antibody in the development of NPC. These findings emphasize the importance of implementing measures to control EBV infection as a crucial strategy for effectively preventing NPC, particularly in individuals at high genetic risk.

Effects of abnormal expression of CD73 on malignant phenotype of nasopharyngeal carcinoma.

Cluster of differentiation (CD) 73, encoded by the NT5E gene, plays important enzymatic and non-enzymatic roles in cells. There is growing evidence show that CD73 is a key regulator in the development of tumor. Nasopharyngeal carcinoma (NPC) is one of the most common cancers in east and southeast Asia. It is urgent to know more about the mechanism of NPC development and find diagnostic markers for the patients. In this research, we carried out western blot, immunohistochemistry and qRT-PCR to investigate the expression level of CD73 and found that NPC tissues had higher level of CD73 than normal tissues. We also detected the relationship between its expression level with the clinicopathological features and prognosis of NPC patients. The results showed that CD73 expression was related to the clinical stages, lymph node metastasis and survival state of NPC patients. More importantly, patients with higher expression of CD73 had poorer prognosis. Then, CD73 was knocked down in NPC cells (CNE2 and CNE1), and its effects on cell proliferation and migration were investigated by CCK8, colony formation, Transwell and wound-healing assays. We found that knocking down the expression of CD73 in NPC cells could inhibit cells malignant phenotype. Collectively, CD73 plays important roles in NPC malignant behavior and might act as a novel target for the diagnosis and treatment of NPC.

Identification of galactosamine-(N-acetyl)-6-sulfatase (GALNS) as a novel therapeutic target in progression of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a commonly diagnosed malignancy in southern China and southeast Asia. Previous studies have identified galactosamine-(N-acetyl)-6-sulfatase (GALNS) as a potential biomarker for multiple cancers. However, it is unknown whether GALNS plays a role in NPC development, and the underlying mechanisms remain unclear. In this study, we found that GALNS is overexpressed in NPC cell lines and tissues compared to the normal nasopharyngeal counterparts. Knocking down GALNS expression in the NPC cells significantly decreased their proliferation in vitro, and inhibited xenograft growth in a mouse model. Mechanistically, the anti-proliferative effect of GALNS silencing was the result of autophagy induction via the inhibition of PI3K–AKT–mTOR signaling pathway. Taken together, GALNS drives the progression of NPC via PI3K–AKT–mTOR signaling-mediated autophagy, and is therefore a promising therapeutic target.

NUCB-2/Nesfatin-1 promotes the proliferation of nasopharyngeal carcinoma cells.

The association of NUCB-2/Nesfatin-1 with nasopharyngeal carcinoma (NPC) remains unclear. We clarified the role of NUCB-2/Nesfatin-1 in the development, progression and diagnosis of NPC. In nasopharyngeal carcinoma cell lines (5-8F, 6-10B, CNE1, CNE2 and NP69), western blotting, MTT, EdU and other techniques were performed to investigate the role of NUCB-2 in nasopharyngeal carcinoma. 70 tissue samples (39 NPC and 31 rhinitis) and 140 serum samples (including NPC, rhinitis, other head and neck tumors and healthy control) were included to explore the expression of NUCB-2 and its metabolite Nesfatin-1 in tissues or serum of patients with nasopharyngeal carcinoma. NUCB-2 level in NPC tissue was higher than that in rhinitis tissue (P < 0.05). Suppression of NUCB-2 in the NPC cell line CNE2 inhibited proliferation and clone formation of the cells; on the contrary, improvement of NUCB-2 in the NPC cell line CNE1 promoted cell propagation and clone development. An elevated serum level of NUCB-2 in NPC patients was detected, compared to that in patients with other head and neck tumors, rhinitis or healthy donors. Determination of nesfatin-1 combined with EA-IgA, VCA-IgA and Rta-IgG in serum samples for NPC diagnosis reached a sensitivity of 93.6% and a specificity of 94.5%, while the positive and negative predictive value of this diagnostic model was 89.8% and 96.6%, and the accuracy yielded 94.2%. This study revealed that NUCB-2 could enhance proliferation of NPC cells and NUCB-2/nesfatin-1 has the potential to be a serological marker to aid early diagnosis of nasopharyngeal carcinoma.

The Burden of Epstein-Barr Virus (EBV) and Its Determinants among Adult HIV-Positive Individuals in Ethiopia.

Epstein-Barr virus (EBV) is a well-known risk factor for the development of nasopharyngeal carcinoma, Hodgkin's lymphoma (HL), and Non-Hodgkin's lymphoma (NHL). People with HIV infection (PWH) are at increased risk for EBV-associated malignancies such as HL and NHL. Nevertheless, there are limited data on the burden of EBV among this population group in Ethiopia. Hence, this study aimed to determine the burden of EBV infection among adult HIV-positive individuals in Ethiopia and assess the determinants of EBV DNA positivity. We conducted a cross-sectional study at the Tikur Anbessa Specialised Hospital from March 2020 to March 2021. Two hundred and sixty individuals were enrolled in this study, including 179 HIV-positive and 81 HIV-negative individuals. A structured questionnaire was used to capture demographic and individual attributes. In addition, the clinical data of patients were also retrieved from clinical records. EBV viral capsid antigen (VCA) IgG antibody was measured by multiplex flow immunoassay, and EBV DNA levels were tested by quantitative real-time polymerase chain reaction (q-PCR) assays targeting the EBNA-1 open reading frame (ORF). Descriptive statistics were conducted to assess each study variable. A multivariable logistic regression model was applied to evaluate the determinants of EBV infection. Statistical significance was determined at a p-value < 0.05. Two hundred and fifty-three (97.7%) study participants were seropositive for the EBV VCA IgG antibody. Disaggregated by HIV status, 99.4% of HIV-positive and 93.8% of HIV-negative participants were EBV seropositive. In this study, 49.7% of HIV-positive and 24.7% of HIV-negative individuals were EBV DNA positive. PWH had a higher risk of EBV DNA positivity at 3.05 times (AOR: 3.05, 95% CI: 1.40-6.67). Moreover, among PWH, those with an HIV viral load greater than 1000 RNA copies/mL (AOR = 5.81, 95% CI = 1.40, 24.13) had a higher likelihood of EBV DNA positivity. The prevalence of EBV among PWH was significantly higher than among HIV-negative individuals. Higher HIV viral loads in PWH were associated with an increased risk of EBV DNA positivity. Since the increases in the viral load of EBV DNA among PWH could be related to the risk of developing EBV-associated cancers, it is necessary for more research on the role of EBV in EBV-associated cancer in this population group to be carried out.

SRSF3/AMOTL1 splicing axis promotes the tumorigenesis of nasopharyngeal carcinoma through regulating the nucleus translocation of YAP1

Dysregulation of serine/arginine splicing factors (SRSFs) and abnormal alternative splicing (AS) have been widely implicated in various cancers but scarcely investigated in nasopharyngeal carcinoma (NPC). Here we examine the expression of 12 classical SRSFs between 87 NPC and 10 control samples, revealing a significant upregulation of SRSF3 and its association with worse prognosis in NPC. Functional assays demonstrate that SRSF3 exerts an oncogenic function in NPC progression. Transcriptome analysis reveals 1,934 SRSF3-regulated AS events in genes related to cell cycle and mRNA metabolism. Among these events, we verify the generation of a long isoform of AMOTL1 (AMOTL1-L) through a direct bond of the SRSF3 RRM domain with the exon 12 of AMOTL1 to promote exon inclusion. Functional studies also reveal that AMOTL1-L promotes the proliferation and migration of NPC cells, while AMOTL1-S does not. Furthermore, overexpression of AMOTL1-L, but not -S, significantly rescues the inhibitory effects of SRSF3 knockdown. Additionally, compared with AMOTL1-S, AMOTL1-L has a localization preference in the intracellular than the cell membrane, leading to a more robust interaction with YAP1 to promote nucleus translocation. Our findings identify SRSF3/AMOTL1 as a novel alternative splicing axis with pivotal roles in NPC development, which could serve as promising prognostic biomarkers and therapeutic targets for NPC.

Epstein–Barr virus microRNA miR-BART2-5p accelerates nasopharyngeal carcinoma metastasis by suppressing RNase Ⅲ endonuclease DICER1

The development and progression of nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) infection. NPC is usually asymptomatic until it spreads to other sites, and more than 70% of cases are classified as locally advanced disease at diagnosis. EBV-positive nasopharyngeal cancer tissues express only limited viral latent proteins, but express high levels of the EBV-encoded BamHI-A rightward transcript (BART) miRNA molecules. Here, we report that EBV-miRNA-BART2-5p (BART2-5p) promotes NPC cell invasion and metastasis invivo and invitro but has no effect on NPC cell proliferation and apoptosis. In addition, BART2-5p altered the mRNA and miRNA expression profiles of NPC cells. The development of human tumors has been reported to be associated with altered miRNAs expression, and overall miRNAs expression is reduced in many types of tumors. We found that BART2-5p downregulated the expression of several miRNAs that could exert oncogenic functions. Mechanistically, BART2-5p directly targets the RNase III endonuclease DICER1, inhibiting its function of cleaving double-stranded stem-loop RNA into short double-stranded RNA, which in turn causes altered expression of a series of key epithelial-mesenchymal transition molecules, and reverting DICER1 expression can rescue this phenotype. Furthermore, analysis from clinical samples showed a negative correlation between BART2-5p and DICER1 expression. According to our study, high expression of BART2-5p in tissues and plasma of patients with NPC is associated with poor prognosis. Our results suggest that, BART2-5p can accelerate NPC metastasis through modulating miRNA profiles which are mediated by DICER1, implying a novel role of EBV miRNAs in the pathogenesis of NPC.

High-throughput identification of regulatory elements and functional assays to uncover susceptibility genes for nasopharyngeal carcinoma

Large-scale genetic association studies have identified multiple susceptibility loci for nasopharyngeal carcinoma (NPC), but the underlying biological mechanisms remain to be explored. To gain insights into the genetic etiology of NPC, we conducted a follow-up study encompassing 6,907 cases and 10,472 controls and identified two additional NPC susceptibility loci, 9q22.33 (rs1867277; OR= 0.74, 95% CI= 0.68-0.81, p= 3.08×10-11) and 17q12 (rs226241; OR= 1.42, 95% CI= 1.26-1.60, p= 1.62×10-8). The two additional loci, together with two previously reported genome-wide significant loci, 5p15.33 and 9p21.3, were investigated by high-throughput sequencing for chromatin accessibility, histone modification, and promoter capture Hi-C (PCHi-C) profiling. Using luciferase reporter assays and CRISPR interference (CRISPRi) to validate the functional profiling, we identified PHF2 at locus 9q22.33 as a susceptibility gene. PHF2 encodes a histone demethylase and acts as a tumor suppressor. The risk alleles of the functional SNPs reduced the expression of the target gene PHF2 by inhibiting the enhancer activity of its long-range (4.3 Mb) cis-regulatory element, which promoted proliferation of NPC cells. In addition, we identified CDKN2B-AS1 as a susceptibility gene at locus 9p21.3, and the NPC risk allele of the functional SNP rs2069418 promoted the expression of CDKN2B-AS1 by increasing its enhancer activity. The overexpression of CDKN2B-AS1 facilitated proliferation of NPC cells. In summary, we identified functional SNPs and NPC susceptibility genes, which provides additional explanations for the genetic association signals and helps to uncover the underlying genetic etiology of NPC development.