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Background: N6‐methyladenosine (m6A) modification is essential for modulating RNA processing as well as expression, particularly in the context of malignant tumour progression. However, the exploration of m6A modification in nasopharyngeal carcinoma (NPC) remains very limited. Methods: RNA m6A levels were analysed in NPC using m6A dot blot assay. The expression level of methyltransferase‐like 14 (METTL14) within NPC tissues was analysed from public databases as well as RT‐qPCR and immunohistochemistry. The influences on METTL14 expression on NPC proliferation and metastasis were explored via in vitro as well as in vivo functional assays. Targeted genes of METTL14 were screened using the m6A and gene expression profiling microarray data. Actinomycin D treatment and polysome analysis were used to detect the half‐life and translational efficiency of ANKRD22. Flow cytometry, immunofluorescence and immunoprecipitation were used to validate the role of ANKRD22 on lipid metabolism in NPC cells. ChIP‐qPCR analysis of H3K27AC signalling near the promoters of METTL14, GINS3, POLE2, PLEK2 and FERMT1 genes. Results: We revealed METTL14, in NPC, correlating with poor patient prognosis. In vitro and in vivo assays indicated METTL14 actively promoted NPC cells proliferation and metastasis. METTL14 catalysed m6A modification on ANKRD22 messenger ribonucleic acid (mRNA), recognized by the reader IGF2BP2, leading to increased mRNA stability and higher translational efficiency. Moreover, ANKRD22, a metabolism‐related protein on mitochondria, interacted with SLC25A1 to enhance citrate transport, elevating intracellular acetyl‐CoA content. This dual impact of ANKRD22 promoted lipid metabolism reprogramming and cellular lipid synthesis while upregulating the expression of genes associated with the cell cycle (GINS3 and POLE2) and the cytoskeleton (PLEK2 and FERMT1) through heightened epigenetic histone acetylation levels in the nucleus. Intriguingly, our findings highlighted elevated ANKRD22‐mediated histone H3 lysine 27 acetylation (H3K27AC) signals near the METTL14 promoter, which contributes to a positive feedback loop perpetuating malignant progression in NPC. Conclusions: The identified METTL14‐ANKRD22‐SLC25A1 axis emerges as a promising therapeutic target for NPC, and also these molecules may serve as novel diagnostic biomarkers. [ABSTRACT FROM AUTHOR]

Cancer cells prefer glycolysis to support their proliferation. Our previous studies have shown that the long palate, lung, and nasal epithelial cell clone 1 (LPLUNC1) can upregulate prohibitin 1 (PHB1) expression to inhibit the proliferation of nasopharyngeal carcinoma (NPC) cells. Given that PHB1 is an important regulator of cell energy metabolism, we explored whether and how LPLUNC1 regulated glucose glycolysis in NPC cells. LPLUNC1 or PHB1 overexpression decreased glycolysis and increased oxidative phosphorylation (OXPHOS)‐related protein expression in NPC cells, promoting phosphorylated PHB1 nuclear translocation through 14‐3‐3σ. LPLUNC1 overexpression also increased p53 but decreased c‐Myc expression in NPC cells, which were crucial for the decrease in glycolysis and increase in OXPHOS‐related protein expression induced by LPLUNC1 overexpression. Finally, we found that treatment with all‐trans retinoic acid (ATRA) reduced the viability and clonogenicity of NPC cells, decreased glycolysis, and increased OXPHOS‐related protein expression by enhancing LPLUNC1 expression in NPC cells. Therefore, the LPLUNC1‐PHB1‐p53/c‐Myc axis decreased glycolysis in NPC cells, and ATRA upregulated LPLUNC1 expression, ATRA maybe a promising drug for the treatment of NPC. [ABSTRACT FROM AUTHOR]

Long noncoding RNA (lncRNA) have emerged as crucial regulators for a myriad of biological processes, and perturbations in their cellular expression levels have often been associated with cancer pathogenesis. In this study, we identified AATBC (apoptosis‐associated transcript in bladder cancer, LOC284837) as a novel lncRNA. AATBC was found to be highly expressed in nasopharyngeal carcinoma (NPC), and increased AATBC expression was associated with poor survival in patients with NPC. Furthermore, AATBC promoted migration and invasion of NPC cells in vitro, as well as metastasis in vivo. AATBC upregulated the expression of the desmosome‐associated protein pinin (PNN) through miR‐1237‐3p sponging. In turn, PNN interacted with the epithelial–mesenchymal transition (EMT) activator ZEB1 and upregulated ZEB1 expression to promote EMT in NPC cells. Collectively, our results indicate that AATBC promotes NPC progression through the miR‐1237‐3p–PNN–ZEB1 axis. Our findings indicate AATBC as a potential prognostic biomarker or therapeutic target in NPC. [ABSTRACT FROM AUTHOR]

Epstein‐Barr virus (EBV) is a tumorigenic virus that can cause various human malignancies such as nasopharyngeal carcinoma (NPC) and gastric cancer (GC). EBV encodes 44 mature micro (mi)RNAs, mostly exhibiting oncogenic properties and promoting cancer progression. However, we have previously found that one EBV‐encoded miRNA, namely EBV‐miR‐BART6‐3p, acts as a tumor suppressor by inhibiting metastasis and invasion. Here, we report that EBV‐miR‐BART6‐3p inhibits the proliferation of EBV‐associated cancers, NPC, and GC, by targeting and downregulating a long non‐coding RNA (lncRNA), LOC553103. Through proteomics analysis, we determined that stathmin (STMN1) is affected by EBV‐miR‐BART6‐3p and LOC553103. Further, via RNA immunoprecipitation and luciferase reporter assay, we confirmed that LOC553103 directly binds and stabilizes the 3′UTR region of STMN1 mRNA. These results indicate that the EBV‐miR‐BART6‐3p/LOC553103/STMN1 axis regulates the expression of cell cycle‐associated proteins, which then inhibit EBV‐associated tumor cell proliferation. These findings provide potential targets or strategies for novel EBV‐related cancer treatments, as well as contributes new insights into the understanding of EBV infection‐related carcinogenesis. [ABSTRACT FROM AUTHOR]

Inhibin B (INHBB), a heterodimer of a common α‐subunit and a βB‐subunit, is a glycoprotein belonging to the transforming growth factor‐β (TGF‐β) family. In this study, we observed INHBB expression was reduced in nasopharyngeal carcinoma (NPC) tissues compared to non‐tumor nasopharyngeal epithelium tissues, and INHBB was associated with lymph node metastasis, stage of disease, and clinical progress. Positive expression of INHBB in NPC predicted a better prognosis (overall survival, P = 0.038). However, the molecular mechanisms of INHBB have not been addressed in NPC. We induced anoikis‐resistant cells in NPC cell lines under anchorage‐independent conditions, then found epithelial‐mesenchymal transition markers changed, cell apoptosis decreased, cell cycle was modified, and invasion strengthened in anoikis‐resistant NPC cells. These anoikis‐resistant NPC cells showed decreased expression of INHBB compared with adhesion cells. Furthermore, INHBB was found to influence the above‐mentioned changes. In the anoikis‐resistant NPC cells with INHBB overexpression, apoptotic cells increased, S phase cells weakened, vimentin, matrix metallopeptidase‐9, and vascular endothelial growth factor A expression were downregulated, and E‐cadherin expression was upregulated, and vice versa in knockdown of INHBB (INHBB shRNA) anoikis‐resistant NPC cells. Diminished INHBB expression could activate the TGF‐β pathway to phosphorylate Smad2/3 and form complexes in the nucleus, which resulted in the above changes. Thus, our results revealed for the first time that INHBB could suppress anoikis resistance and migration of NPC cells by the TGF‐β signaling pathway, decrease p53 overexpression, and could serve as a potential biomarker for NPC metastasis and prognosis as well as a therapeutic application. Our results showed for the first time that inhibin B could suppress anoikis resistance and migration of nasopharyngeal carcinoma cells by the transforming growth factor‐β signaling pathway, and decrease p53 overexpression. Inhibin B could serve as a potential biomarker for nasopharyngeal carcinoma metastasis and prognosis, as well as a therapeutic application. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is a unique EBV‐associated subtype of head and neck cancer, which has the highest incidence in Southern China and eastern South Asia. The interaction between genetic risk factors and environmental challenge, have been considered to contribute to the development of nasopharyngeal carcinogenesis. Constitutive activation of NF‐κB signaling has been seen in NPC tissues and is associated with unfavorable prognosis. Recently, several whole exome sequencing study consistently revealed that high frequency mutations of NF‐κB pathway negative regulators is common in nasopharyngeal carcinoma, which reinforce the importance of NF‐κB driving oncogenesis. This review focuses on the current state of research in role of NF‐κB in NPC carcinogenesis. We summarized the newly identified loss of function (LOF) mutations on NF‐κB negative regulators leading to it's activation bypass LMP‐1 stimulation. We discussed the critical role of NF‐κB activation in immortalization and transformation of nasopharygeal epithelium. We also depicted how NF‐κB signaling mediated chronic inflammation contribute to persistent EBV infection, immune evasion of EBV infected cells, metabolic reprogramming, and cancer stem cells (CSCs) formation in NPC. Lastly, we discussed the clinical resonance of targeting NF‐κB for NPC precise therapy. [ABSTRACT FROM AUTHOR]

Human SPLUNC1 can suppress nasopharyngeal carcinoma ( NPC) tumor formation; however, the correlation between SPLUNC1expression and NPC patient prognosis has not been reported. In the present study, we used a large-scale sample of 1015 tissue cores to detect SPLUNC1 expression and its association with patient prognosis. SPLUNC1 expression was reduced in NPC samples compared to nontumor nasopharyngeal epithelium tissues. Positive expression of SPLUNC1 in NPC predicted a better prognosis (disease-free survival, P = 0.034; overall survival, P = 0.048). Cox's proportional hazards model revealed that SPLUNC1 could be a significant prognostic factor affecting disease-free survival ( P = 0.027). A c DNA micro-array analyzed by significant analysis of micro-array (SAM) and ingenuity pathway analysis (IPA) revealed that an indirect interaction existed between SPLUNC1 and retinoic acid (RA) in the cancer regulatory network. To further investigate the molecular mechanisms involved, we utilized several bioinformatics tools and identified 12 retinoid X receptors heterodimer binding sites in the promoter region of the SPLUNC1 gene. The transcriptional activity of the SPLUNC1 promoter was up-regulated significantly by all-trans-retinoic acid ( ATRA). SPLUNC1 and retinoic acid receptor expression were induced significantly by ATRA, and removal of ATRA led to a progressive loss of SPLUNC1 and retinoic acid receptor expression. ATRA inhibited proliferation and induced the differentiation of NPC cells. Interestingly, over-expression of SPLUNC1 sensitized NPC cells to ATRA, whereas knockdown of SPLUNC1 in HNE1 cells increased cell viability. Under SPLUNC1 knockdown conditions, differentiation was reversed by ATRA treatment. We concluded that SPLUNC1 could potentially predict prognosis for NPC patients and play an important role in ATRA-induced growth inhibition and differentiation in NPC cells. [ABSTRACT FROM AUTHOR]

Epstein‐Barr virus (EBV) infection leads to cancers with an epithelial origin, such as nasopharyngeal cancer and gastric cancer, as well as multiple blood cell‐based malignant tumors, such as lymphoma. Interestingly, EBV is also the first virus found to carry genes encoding miRNAs. EBV encodes 25 types of pre‐miRNAs which are finally processed into 44 mature miRNAs. Most EBV‐encoded miRNAs were found to be involved in the occurrence and development of EBV‐related tumors. However, the function of EBV‐miR‐BART12 remains unclear. The findings of the current study revealed that EBV‐miR‐BART12 binds to the 3'UTR region of Tubulin Polymerization‐Promoting Protein 1 (TPPP1) mRNA and downregulates TPPP1, thereby promoting the invasion and migration of EBV‐related cancers, such as nasopharyngeal cancer and gastric cancer. The mechanism underlying this process was found to be the inhibition of TPPP1 by EBV‐miRNA‐BART12, which, in turn, inhibits the acetylation of α‐tubulin, and promotes the dynamic assembly of microtubules, remodels the cytoskeleton, and enhances the acetylation of β‐catenin. β‐catenin activates epithelial to mesenchymal transition (EMT). These two processes synergistically promote the invasion and metastasis of tumor cells. To the best of our knowledge, this is the first study to reveal the role of EBV‐miRNA‐BART12 in the development of EBV‐related tumors as well as the mechanism underlying this process, and suggests potential targets and strategies for the treatment of EBV‐related tumors. [ABSTRACT FROM AUTHOR]