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The timing of radiotherapy (RT) delivery has been reported to affect both cancer survival and treatment toxicity. However, the association among the timing of RT delivery, survival, and toxicity in locally advanced nasopharyngeal carcinoma (LA-NPC) has not been investigated. We retrospectively reviewed patients diagnosed with LA-NPC who received definitive RT at multiple institutions. The median RT delivery daytime was categorized as morning (DAY) and night (NIGHT). Seasonal variations were classified into the darker half of the year (WINTER) and brighter half (SUMMER) according to the sunshine duration. Cohorts were balanced according to baseline characteristics using propensity score matching (PSM). Survival and toxicity outcomes were evaluated using Cox regression models. A total of 355 patients were included, with 194/161 in DAY/NIGHT and 187/168 in WINTER/SUMMER groups. RT delivered during the daytime prolonged the 5-year overall survival (OS) (90.6% vs. 80.0%, p  = 0.009). However, the significance of the trend was lost after PSM ( p  = 0.068). After PSM analysis, the DAY cohort derived a greater benefit in 5-year progression-free survival (PFS) (85.6% vs. 73.4%, p  = 0.021) and distant metastasis-free survival (DMFS) (89.2% vs. 80.8%, p  = 0.051) in comparison with the NIGHT subgroup. Moreover, multivariate analysis showed that daytime RT was an independent prognostic factor for OS, PFS, and DMFS. Furthermore, daytime RT delivery was associated with an increase in the incidence of leukopenia and radiation dermatitis. RT delivery in SUMMER influenced only the OS significantly (before PSM: p  = 0.051; after PSM: p  = 0.034). There was no association between toxicity and the timing of RT delivery by season. In LA-NPC, the daytime of radical RT served as an independent prognostic factor. Furthermore, RT administered in the morning resulted in more severe toxic side effects than that at night, which needs to be confirmed in a future study.

Cancer stem cells (CSCs) are a source of tumour recurrence in patients with nasopharyngeal carcinoma (NPC); however, the function of microRNA-124 (miR-124) in NPC CSCs has not been clearly defined. In this study, we investigated the role of miR-124 in NPC CSCs. qRT-PCR was performed to measure miR-124 expression in NPC tissues and cell lines and the effects of miR-124 on stem-like properties and radiosensitivity of NPC cells measured. Luciferase reporter assays and rescue experiments were used to investigate the interaction of miR-124 with the 3'UTR of junctional adhesion molecule A (JAMA). Finally, we examined the effects of miR-124 in an animal model and clinical samples. Down-regulation of miR-124 was detected in cancer tissues and was inversely associated with tumour stage and lymph node metastasis. Overexpression of miR-124 inhibited stemness properties and enhanced radiosensitivity of NPC cells in vitro and in vivo via targeting JAMA. Up-regulation of miR-124 was correlated with superior overall survival of patients with NPC. Our study demonstrates that miR-124 can inhibit stem-like properties and enhance radiosensitivity by directly targeting JAMA in NPC. These findings provide novel insights into the molecular mechanisms underlying therapy failure in NPC., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Recurrence or metastasis resulting from radioresistance are the main challenges for the treatment of nasopharyngeal carcinoma (NPC). A great deal of evidence supports the role of abnormal expression of miRNAs in radioresistance and malignancy. In some cancers, miR-483-5p is associated with inferior disease-specific survival. Therefore, we investigated the role of miR-483-5p in NPC radiosensitivity and the mechanism by which the miR-483-5p affects the radiosensitivity of NPC cells. In this study, we show that the overexpression of miR-483-5p decreases the radiosensitivity of NPC cells in vitro and in vivo. Mechanistically, miR-483-5p exerts these functions by decreasing radiation-induced apoptosis and DNA damage, and by increasing NPC cell colony formation, via targeting death-associated protein kinase 1 (DAPK1). Finally, our results confirm that the upregulation of miR-483-5p is correlated with advanced clinical stage and inferior overall survival of patients with NPC. These findings provide novel insights into our understanding of the molecular mechanisms underlying therapy failure in NPC. Modulation of miR-483-5p and DAPK1 levels may provide a new approach for increasing the radiosensitivity of these tumors.

Objective To establish an optimal limiting dose for dose limiting rings placed in the anterior and posterior regions of the neck for reducing head and neck lymphedema under intensity-modulated radiation therapy(IMRT) for early nasopharyngeal carcinoma(NPC) from a dosimetric perspective. Method Fifteen newly diagnosed early-stage nasopharyngeal carcinoma patients who underwent CT localization for radiotherapy at the Cancer Hospital of Guangzhou Medical University from January to September 2022 were included in the study. Each case was designed with five sets of radiotherapy plans. Plan A consisted of conventional unlimited-field plans, while Plans B-E consisted of limited-field plans with dose constraints set at 20, 18, 16, and 14 Gy, respectively, with the remaining parameters consistent with Plan A. The impact on target coverage and organ-at-risk constraints was evaluated through variance analysis and pairwise multiple comparisons using a randomized block design to determine the optimal dose limits. Results The gradient of 16Gy was determined as the optimal dose limiting cutoff point for achieving the balance between target coverage and organ limiting dose. Compared with the conventional plan, The plans with the placement of a cervical anterior and posterior dose limiting ring (16Gy) did not change the target dose coverage (P > 0.05), but only yielded a slight change in the homogeneity index (P < 0.05). It did not cause any changes of the dosage in the inner ear, mandible, and brainstem (all P > 0.05), but lead to statistically significant reductions in the oral cavity, throat, and thyroid (all P < 0.05). It caused a slight increase of the dose in the parotid gland and spinal cord (both P < 0.05), but the increased dose was anyhow within the tolerance range. Conclusion The dosimetric investigation determines an optimal dose limit cutoff point for the cervical anterior and posterior dose limiting rings. It is expected to provide a design method for IMRT plans to reduce head and neck lymphedema after radiotherapy for early NPC. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. Hyperthermia is widely used in combination with chemotherapy and radiotherapy to enhance therapeutic efficacy in NPC treatment, but the underlying anti-tumor mechanisms of hyperthermia remain unclear. Complement C3 has been reported to participate in the activation of immune system in the tumor microenvironment, leading to tumor growth inhibition. In this study, we aimed to explore the effect and mechanisms of hyperthermia and investigate the functional role of complement C3 in NPC hyperthermia therapy (HT). The serum levels of complement C3 before and after hyperthermia therapy in patients with NPC were analyzed. NPC cell lines SUNE1 and HONE1 were used for in vitro experiment to evaluate the function of complement C3 and HT on cell proliferation and apoptosis. SUNE1 xenograft mouse model was established and tumor-bearing mice were treated in water bath at a constant temperature of 43°C. Tumor samples were collected at different time points to verify the expression of complement C3 by immunohistochemical staining and western blot. The differential expressed genes after hyperthermia were analyzed by using RNA sequencing. We found that complement could enhance hyperthermia effect on suppressing proliferation and promoting apoptosis of tumor cells in NPC. Hyperthermia decreased the mRNA expression of complement C3 in tumor cells, but promoted the aggregation and activation circulating C3 in NPC tumor tissue. By using in vitro hyperthermia-treated NPC cell lines and SUNE1 xenograft tumor-bearing mice, we found that the expression of heat shock protein 5 (HSPA5) was significantly upregulated. Knockdown of HSPA5 abrogated the anti-tumor effect of hyperthermia. Moreover, we demonstrated that hyperthermia downregulated CD55 expression via HSPA5/NFκB (P65) signaling and activated complement cascade. Our findings suggest that therapeutic hyperthermia regulates complement C3 activation and suppresses tumor development via HSPA5/NFκB/CD55 pathway in NPC. Complement was involved in the anti-tumor effect of hyperthermia in vitro. Hyperthermia markedly increased the expression of heat shock protein 5 (HSPA5) and decreased the expression of CD55 which regulated the activation of complement C3 and complement cascade. Activation of HSPA5/NFκB (P65) signaling pathway resulted in a decrease in CD55 expression. [ABSTRACT FROM AUTHOR]

Radiotherapy and adjuvant cisplatin (DDP) chemotherapy are standard administrations applied to treat nasopharyngeal carcinoma (NPC). However, the molecular changes and functions of DDP in NPC chemo-resistance remain poorly understood. In the present study, transcriptomic sequencing between 5-8F and 5-8F/DDP cells was performed to identify differential expression and alternative splicing (AS) characteristics in DDP-resistant NPC cells. Transcriptomic profiling identified 1,757 upregulated genes and 1,473 downregulated differentially expressed genes (DEGs). Bioinformatic analysis revealed that these DEGs were associated with or participated in important biological regulatory functions in NPC. Validation of 20 significant DEGs using quantitative real-time reverse transcription PCR showed that the expression patterns of 17 mRNAs were in accordance with the sequencing data. Intron retention was identified as the major AS event in chemoresistant cells. Furthermore, the expression level of matrix metalloproteinase 1 (MMP1), which was one of the most upregulated mRNAs in the chemoresistant cell lines, was significantly associated with the migration, invasion, and proliferation of NPC cells in vitro. Our study revealed that dysregulated genes and AS-mediated DDP chemoresistance might play important roles in NPC development and progression. Targeting aberrantly expressed genes might clarify the pathogenesis of NPC and contribute to developing new therapeutic strategies for NPC. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) have been documented as having an important role in the development of cancer. Broccoli is very popular in large groups of the population and has anticancer properties. Junctional adhesion molecule A (JAMA) is preferentially concentrated at tight junctions and influences cell morphology and migration. Epithelial–mesenchymal transition (EMT) is a developmental program associated with cancer progression and metastasis. In this study we aimed to investigate the role of miRNAs from broccoli in human nasopharyngeal cancer (NPC). We demonstrated that a total of 84 conserved miRNAs and 184 putative novel miRNAs were found in broccoli by sequencing technology. Among these, miR156a was expressed the most. In addition, synthetic miR156a mimic inhibited the EMT of NPC cells in vitro. Furthermore, it was confirmed that JAMA was the target of miR156a mimic as validated by 3’ UTR luciferase reporter assays and western blotting. Knockdown of JAMA was consistent with the effects of miR156a mimic on the EMT of NPC, and the up-regulation of JAMA could partially restore EMT repressed by miR156a mimic. In conclusion, these results indicate that the miR156a mimic inhibits the EMT of NPC cells by targeting the 3’ UTR of JAMA. These miRNA profiles of broccoli provide a fundamental basis for further research. Moreover, the discovery of miR156a may have clinical implications for the treatment of patients with NPC. [ABSTRACT FROM AUTHOR]