Dysregulated microRNAs (miRNAs) are involved in carcinoma progression, metastasis, and poor prognosis. We demonstrated that in nasopharyngeal carcinoma (NPC), transactivated MIR106A-5p promotes a malignant phenotype by functioning as a macroautophagy/autophagy suppressor by targeting BTG3 (BTG anti-proliferation factor 3) and activating autophagy-regulating MAPK signaling. MIR106A-5p expression was markedly increased in NPC cases based on quantitative real-time PCR, miRNA microarray, and TCGA database analysis findings. Moreover, MIR106A-5p was correlated with advanced stage, recurrence, and poor clinical outcomes in NPC patients. In addition to three-dimensional cell culture assays, zebrafish and BALB/c mouse tumor models revealed that overexpressed MIR106A-5p targeted BTG3 and accelerated the NPC malignant phenotype by inhibiting autophagy. BTG3 promoted autophagy, and its expression was correlated with poor prognosis in NPC. Attenuation of autophagy, mediated by the MIR106A-5p-BTG3 axis, occurred because of MAPK pathway activation. MIR106A-5p overexpression in NPC was due to increased transactivation by EGR1 and SOX9. Our findings may lead to novel insights into the pathogenesis of NPC. Abbreviations: ACTB: actin beta; ATG: autophagy-related; ATG5: autophagy related 5; BLI: bioluminescence; BTG3: BTG anti-proliferation factor 3; CASP3: caspase 3; ChIP: chromatin immunoprecipitation; CQ: chloroquine; Ct: threshold cycle; DAPI: 4ʹ,6-diamidino-2-phenylindole; DiL: 1,1ʹ-dioctadecyl-3,3,3ʹ,3ʹ-tetramethylindocarbocyanine perchlorate; EBSS: Earle’s balanced salt solution; EGR1: early growth response 1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GEO: Gene Expression Omnibus; GFP: green fluorescent protein; IF: immunofluorescence; IHC: immunohistochemistry; ISH: in situ hybridization; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MIR106A-5p: microRNA 106a-5p; miRNAs: microRNAs; MKI67: marker of proliferation ki-67; mRNA: messenger RNA; MTOR: mechanistic target of rapamycin kinase; NPC: nasopharyngeal carcinoma; qRT-PCR: quantitative real-time PCR; siRNA: small interfering RNA; SOX9: SRY-box transcription factor 9; SQSTM1: sequestosome 1; TCGA: The Cancer Genome Atlas; WB: western blot.

Distant metastasis accompanied by angiogenesis is the main cause of nasopharyngeal carcinoma (NPC)-related death. Nuclear exosomes (nEXOs) are potential tumour biomarkers. High mobility group box 3 (HMGB3), a nuclear protein, is known to be overexpressed in cancers. However, its role in NPC has not been elucidated. Here, we explore for the first time the function of nEXO HMGB3 in tumour angiogenesis involved in NPC metastasis using a series of in vitro experiments with NPC cell lines and clinical specimens and in vivo experiments with tumour xenograft zebrafish angiogenesis model. We found a high expression of HMGB3 in NPC, accompanied by the formation of micronuclei, to be associated with metastasis. Furthermore, the NPC-secreted HMGB3 expression was associated with tumour angiogenesis. Moreover, HMGB3-containing nEXOs, derived from the micronuclei of NPC cells, were ingested by the human umbilical vein endothelial cells (HUVECs), and accelerated angiogenesis in vitro and in vivo. Importantly, western blotting and flow cytometry analysis showed that circulating nEXO HMGB3 positively correlated with NPC metastasis. In summary, nEXO HMGB3 can be a significant biomarker of NPC metastasis and provide a novel basis for anti-angiogenesis therapy in clinical metastasis.

Background: Immunosuppression significantly contributes to treatment failure in nasopharyngeal carcinoma (NPC). Messenger RNA (mRNA) modifications such as methylation and acetylation play crucial roles in immunosuppression. However, N4-acetylcytidine (ac4C), the only acetylation modification event has rarely been studied in NPC. Methods: First, clinical tissue samples and nude mouse models were used to explore the expression of N-acetyltransferase 10 (NAT10) in NPC and its influence on it. Second, The Cancer Genome Atlas immune database and transgenic mouse peripheral blood immune cell panel were used to verify the immune cells mainly affected by NAT10. Then, NAT10 ac4C acetylation modification and expression of significantly upregulated transcription factors were explored by acetylated RNA immunoprecipitation sequence binding to RNA sequencing. Then, the downstream regulatory genes of CCAAT enhancer binding protein γ (CEBPG), dead box helicase 5 (DDX5) and helicase-like transcription factors (HLTF) were analyzed by luciferase report and chromatin Immunoprecipitation. Finally, the effect of inhibition of NAT10 on anti-programmed cell death protein 1 (PD-1) treatment sensitivity was verified by animal models. Results: In this study, we aimed to explore the role of NAT10, the enzyme responsible for ac4C modification, in NPC progression and patient prognosis. Elevated NAT10 promoted NPC progression and correlated with poor prognosis in patients with NPC. NAT10-mediated ac4C modification of CEBPG, DDX5, and HLTF mRNA improved their stability and translation efficiency, with the NAT10/ac4C/DDX5 axis upregulating high mobility group box 1 (HMGB1) and inhibiting CD4+ and CD8+ T cells. Inhibition of NAT10 increased the sensitivity to PD-1 therapy. Additionally, HLTF was found to transcriptionally regulate NAT10, indicating the formation of an HLTF-NAT10 positive feedback loop. Conclusions: Our study elucidates the mechanism by which the NAT10/DDX5/HMGB1 axis promotes the immunosuppression of NPC by promoting T-cell dysfunction. In addition, NAT10 knockdown can enhance anti-PD-1 treatment sensitivity as a combination therapy for NPC.

Sorafenib, an anticancer drug, has been shown to induce ferroptosis in cancer cells. However, resistance to sorafenib greatly limits its therapeutic efficacy, and the exact mechanism of resistance is not fully understood. This study investigated the role of N‐Acetyltransferase 10 (NAT10) in influencing the anticancer activity of sorafenib in nasopharyngeal carcinoma (NPC) and its molecular mechanism. NAT10 expression was significantly upregulated in NPC. Mechanistically, NAT10 promotes proteins of solute carrier family 7 member 11 (SLC7A11) expression through ac4C acetylation, inhibiting sorafenib‐induced ferroptosis in NPC cells. The combined application of sorafenib and the NAT10 inhibitor remodelin significantly inhibits SLC7A11 expression and promotes ferroptosis in NPC cells. In vivo knockout of NAT10 inhibited the growth of sorafenib‐resistant NPC. Our findings suggest that NAT10 inhibition might be a promising therapeutic approach to enhance the anticancer activity of sorafenib.

Distant metastasis is currently the main factor affecting the prognosis of nasopharyngeal carcinoma (NPC), and understanding the mechanisms of metastasis and identifying reliable therapeutic targets are critical for improving prognosis and achieving clinical translation. Macrophages, as important immune cells in the tumor microenvironment (TME), have been shown to regulate metastasis. And extracellular vesicles (EVs) secreted by stromal cells and tumor cells play the important role in intercellular communication in the tumor microenvironment. However, the role of NPC-EVs on macrophages and their function in regulating macrophages to affect metastasis has not been fully clarified. In this study, we report that NPC-EVs can be uptake by macrophages and alter macrophage polarization, for the first time, we identified the genes implicated in these regulatory functions: SCARB1, HAAO, and CYP1B1. Moreover, we found that SCARB1 was positively associated with metastasis and poor prognosis of NPC. Interestingly, we found that SCARB1-rich EVs promoted M1 macrophages ferroptosis to decrease M1 macrophages infiltration by upregulating the HAAO level while decreasing phagocytosis of M2 macrophages by upregulating the CYP1B1 level. Finally, we identified the SCARB1-binding gene KLF9, which is involved in the transcription of HAAO and CYP1B1. Our findings showed that SCARB1-EVs promoted metastasis by co-regulating M1 and M2 macrophage function. The related mechanism will provide a new therapeutic strategy to help patients with NPC improve their prognosis.

Resident adipocytes under a hypoxic tumor microenvironment exert an increasingly important role in cell growth, proliferation, and invasion in cancers. However, the communication between adipocytes and cancer cells during nasopharyngeal carcinoma (NPC) progression is poorly understood. Here, we demonstrate that hypoxic adipocyte‐derived exosomes are key information carriers that transfer low expression of miR‐433‐3p into NPC cells. In addition, luciferase reporter assays detected that hypoxia inducible factor‐1α (HIF‐1α) induced miR‐433‐3p transcription through five binding sites at its promoter region. Concordantly, the low expression of miR‐433‐3p promoted proliferation, migration, and lipid accumulation in NPC cells via targeting stearoyl‐CoA desaturase 1 (SCD1) are suggested by functional studies. Consistent with these findings, in tumor‐bearing mice, NPC cells with low HIF‐1α expression, high miR‐433‐3p expression, and low SCD1 expression were equally endowed with remarkably reduced potential of tumorigenesis. Collectively, our study highlights the critical role of the HIF‐1α‐miR‐433‐3p‐SCD1 axis in NPC progression, which can serve as a mechanism‐based potential therapeutic approach.