RESUMO
Radiotherapy plays an important role in the treatment of nasopharyngeal carcinoma (NPC), however, 20% of patients with NPC exhibit unusual radioresistance. Patients with radioresistance are at risk of recurrence, so it is imperative to explore the mechanism of resistance to radiotherapy. In the past, studies on the mechanism of radioresistance have been restricted to DNA damage and related cell cycle remodeling or apoptosis. So far, no studies have explored the relationship between radioresistance and metastasis. Through the analysis of clinical samples, we observed that the metastasis rate of recurrent NPC was much higher than that of primary patients. In vitro and in vivo experiments showed that NPC cells with acquired radioresistance exhibited a stronger ability for invasion and metastasis. Mechanistically, we found that the Epstein-Barr virus (EBV)-encoded miRNA BART8-3p was increased in patients with NPC, and its expression was positively correlated with adverse prognostic factors, such as radioresistance. Besides this, miR-BART8-3p promoted the epithelial-mesenchymal transition, invasion, and metastasis of radioresistant NPC cells by targeting and inhibiting their PAG1 host gene. These findings suggested a novel role for EBV-miR-BART8-3p in promoting NPC radioresistance-associated metastasis and highlighted its potential value as a prognostic indicator or therapeutic target.
Assuntos
Herpesvirus Humano 4/fisiologia , MicroRNAs/genética , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/virologia , Tolerância a Radiação , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Sequência de Bases , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal , Células HEK293 , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Nus , MicroRNAs/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , Ligação Proteica , Resultado do Tratamento , Vimentina/metabolismoRESUMO
BACKGROUND: In the process of international communication in Chinese Wushu (ICCW), the government controls the orientation, scale, pace. However, the ICCW currently lacks a standardised government capacity structural system, and a detailed study of framework construction may be required to ensure the smooth development of the ICCW. OBJECTIVES: This study aims to clarify these elements and construct a framework for a governmental capacity system for ICCW. METHODS: For this purpose, an expert interview outline was designed, and in-depth interviews were conducted with 61 experts. Using grounded theory in the qualitative research method, NVivo 12 software was used to conduct a three-level coding analysis of the interview text for data processing and analysis. RESULTS: We extracted 58 opening codes and 11 tree nodes and categorised them into three core categories: supply side government capacity, environment-side government capacity, and demand-side government capacity, accounting for 62.36 %, 24.76 %, and 12.86 % of the total, respectively, which jointly constructed the framework structure system of the governmental capacity system for the ICCW. CONCLUSIONS: This study found that these three-dimensional government capacities have synergistic effects and that multiple measures work together. The government should ensure the supply side's direct promotion effect; the environmental side's indirect influencing effect; and the demand side's internal driving effect to promote ICCW. Meanwhile, a closed-loop systematic study of communication processes should be conducted in combination with communication organisations and individuals.
RESUMO
Aberrant cancer metabolism contributes to cell proliferation and tumor progression. However, the contribution of enhanced glycolysis, observed during cancer metabolism, to the pathogenesis and progression of nasopharyngeal carcinoma (NPC) remains unclear. CYLD, an NF-κB inhibitor, is frequently deficient in NPC. Here, we investigated the role of CYLD in the metabolic reprogramming of NPC and found that restoration of CYLD expression suppressed glycolysis in NPC cells. Mechanistic dissection showed that CYLD stabilized p53 and facilitated its nuclear translocation, thereby enhancing p53 activity by removing K63-linked and K48-linked ubiquitin chains of p53, which can bind to the PFKFB3 promoter and inhibit its transcription. Additionally, CYLD interacted with FZR1 to promote APC/C-FZR1 E3 ligase activity, which further ubiquitinated and degraded PFKFB3 via the 26S proteasomal system. Furthermore, clinical tissue array analysis indicated that low expression of CYLD was correlated with high expression of PFKFB3 and poor prognosis among patients with NPC. In conclusion, CYLD suppressed PFKFB3 expression via two factors, namely, p53 and FZR1, to inhibit glycolysis and delay tumor growth and progression in NPC. CYLD is a biomarker indicating poor prognosis of patients with NPC.
Assuntos
Neoplasias Nasofaríngeas , Proteína Supressora de Tumor p53 , Linhagem Celular Tumoral , Enzima Desubiquitinante CYLD/genética , Enzima Desubiquitinante CYLD/metabolismo , Humanos , Proteínas I-kappa B/metabolismo , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/patologia , Fosfofrutoquinase-2/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina/metabolismo , UbiquitinaçãoRESUMO
Radiotherapy is essential to the treatment of nasopharyngeal carcinoma (NPC) and acquired or innate resistance to this therapeutic modality is a major clinical problem. However, the underlying molecular mechanisms in the radiation resistance in NPC are not fully understood. Here, we reanalyzed the microarray data from public databases and identified the protein tyrosine phosphatase receptor type D (PTPRD) as a candidate gene. We found that PTPRD was downregulated in clinical NPC tissues and NPC cell lines with its promoter hypermethylated. Functional assays revealed that PTPRD overexpression sensitized NPC to radiation in vitro and in vivo. Importantly, miR-454-3p directly targets PTPRD to inhibit its expression and biological effect. Interestingly, mechanistic analyses indicate that PTPRD directly dephosphorylates STAT3 to enhance Autophagy-Related 5 (ATG5) transcription, resulting in triggering radiation-induced autophagy. The immunohistochemical staining of 107 NPC revealed that low PTPRD and high p-STAT3 levels predicted poor clinical outcome. Overall, we showed that PTPRD promotes radiosensitivity by triggering radiation-induced autophagy via the dephosphorylation of STAT3, thus providing a potentially useful predictive biomarker for NPC radiosensitivity and drug target for NPC radiosensitization.
Assuntos
Carcinoma Nasofaríngeo , Fator de Transcrição STAT3 , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAsRESUMO
PURPOSE: Nasopharyngeal carcinoma (NPC) is among the most common malignancies derived from the epithelium of the nasopharynx. To date, the regulatory networks involved in NPC have not been fully identified. Previous studies revealed multiple loss-of-function mutations in NPC and specifically in cylindromatosis lysine 63 deubiquitinase (CYLD); however, the exact role of CYLD in NPC progression and its potential mechanism remains unclear. METHODS: We performed immunohistochemical (IHC) staining and real-time quantitative polymerase chain reaction (qPCR) to measure CYLD expression in NPC tissues, and Western blot was conducted to determine CYLD levels in NPC cell lines. Cell proliferation was detected by CCK8 assay and colony formation analysis, and apoptosis was determined by Annexin V/propidium iodide staining. Potential targets of CYLD were verified by co-immunoprecipitation and mass spectrometry. Xenograft assay was conducted to confirm the role of CYLD in vivo. RESULTS: We found that CYLD levels were significantly decreased in both NPC tissues and cell lines, and that CYLD overexpression inhibited NPC cell proliferation and promoted apoptosis. Additionally, we revealed that CYLD bound and upregulated N-Myc downstream regulated 1 (NDRG1), and that silencing NDRG1 abolished the tumor-suppressor effect of CYLD on NPC cells. Furthermore, CYLD suppressed tumor growth in xenograft mice models. CONCLUSION: These results suggest CYLD as a tumor suppressor, potential biomarker for diagnosing NPC, and therapeutic target.