MicroRNA-183 and microRNA-141 are potential risk factors for poor prognosis in patients with nasopharyngeal carcinoma

Extracellular vesicles derived from paclitaxel-sensitive nasopharyngeal carcinoma cells deliver miR-183-5p and impart paclitaxel sensitivity through a mechanism involving P-gp

Paclitaxel treatment has been applied for late-stage nasopharyngeal carcinoma (NPC), but therapy failure usually occurs due to paclitaxel resistance. Besides, microRNAs (miRs) delivered by extracellular vesicles (EVs) have been demonstrated as promising biomarkers affecting cancer development. Our work clarified the role of bioinformatically predicted miR-183-5p, which could be delivered by EVs, in the paclitaxel resistance of NPC. Downstream targets of miR-183-5p were predicted in publicly available databases, followed by GO enrichment analysis. A confirmatory dual-luciferase reporter assay determined the targeting relationship between miR-183-5p and P-glycoprotein (P-gp). The shuttling of extracellular miR-183-5p was identified by immunofluorescence. EVs transferred miR-183-5p from paclitaxel-sensitive NPC cells to paclitaxel-resistant NPC cells. Furthermore, overexpression of miR-183-5p and under-expression of P-gp occurred in clinical samples and cells of NPC. High expression of miR-183-5p corresponded to better survival of paclitaxel-treated patients. The effects of manipulated expression of miR-183-5p on NPC cell activities, tumor growth, and paclitaxel resistance were investigated in vitro and in vivo. Its effect was achieved through negatively regulating drug transporters P-gp. Ectopically expressed miR-183-5p enhanced the cancer-suppressive effects of paclitaxel by targeting P-gp, corresponding to diminished cell viability and tumor growth. Taken together, this work goes to elucidate the mechanical actions of miR-183-5p delivered by EVs and its significant contribution towards paclitaxel sensitivity to NPC. 1. This study provides mechanistic insight into the role of miR-183-5p-containing EVs in NPC. 2. The intercellular transportation of miR-183-5p is mediated by EVs in NPC. 3. Overexpressing miR-183-5p facilitates the anti-tumor effects of paclitaxel in NPC. 4. miR-183-5p suppresses paclitaxel resistance of NPC cells by inhibiting P-gp.

A novel three-microRNA signature for predicting survival in patients with nasopharyngeal carcinoma

BACKGROUND/PURPOSE

Nasopharyngeal carcinoma (NPC) is a malignant neoplasm of the head and neck. This study aims to use integrated bioinformatics technologies to develop a predictive miRNA-signature correlated with the prognosis of NPC.

MATERIALS AND METHODS

Initially, the differentially expressed miRNAs (DEMs) in NPC were identified, and then DEMs related to the prognosis of NPC were further screened. Subsequently, the relatively important DEMs identified by random forest algorithm were used to construct a predictive signature by multivariate COX regression analysis. Moreover, PCA, Kaplan-Meier analysis, time-dependent ROC analysis, and univariate and multivariate COX regression analysis were performed to evaluate the ability of the signature in risk identification and prognosis prediction in NPC.

RESULTS

Hsa-miR-29c, hsa-miR-30e and hsa-miR-93 were selected from DEMs to construct a signature, and their abnormal expression was significantly associated with poor prognosis of NPC. The average AUC values of 1- to 5-year OS, DFS and DMFS predicted by the signature were all above 0.7, and showed better clinical independence than other indexes. In addition, 295 differentially expressed mRNAs could be used as potential target genes of the 3 DEMs. Among them, 56 differentially expressed mRNAs were related to PFS. GO and KEGG enrichment analysis indicated that the poor prognosis of NPC was related to the abnormality of chromosomes, cytokines, and chemokines.

CONCLUSION

We constructed a three-miRNA signature with good independent performance in predicting the prognosis for NPC. This study may lay the foundation for exploring new therapeutic targets and improving survival outcomes in NPC patients.

EGFR-rich extracellular vesicles derived from highly metastatic nasopharyngeal carcinoma cells accelerate tumour metastasis through PI3K/AKT pathway-suppressed ROS

Nasopharyngeal carcinoma (NPC) is the most common cancer with high metastatic potential that occurs in the epithelial cells of the nasopharynx. Distant metastases are the primary cause for treatment failure and mortality of NPC patients. However, the underlying mechanism responsible for the initiation of tumour cell dissemination and tumour metastasis in NPC is not well understood. Here, we demonstrated that epidermal growth factor receptor (EGFR) was highly expressed in tumour tissues of NPC patients with distant metastases and was associated with a decrease in reactive oxygen species (ROS). We also revealed that extracellular vesicles (EVs) transfer occurred from highly to poorly metastatic NPC cells, mediating cell-cell communication and enhancing the metastatic potential of poorly metastatic NPC cells. Further experiments indicated that EVs derived from highly metastatic NPC cells induced the up-regulation of EGFR and down-regulation of ROS in low metastatic NPC cells. Mechanistically, EGFR-rich EVs-mediated EGFR overexpression down-regulated intracellular ROS levels through the PI3K/AKT pathway, thus promoting the metastatic potential of poorly metastatic NPC cells. Strikingly, treatment with EVs secreted from highly metastatic NPC cells was significantly associated with rapid NPC progression and shorter survival in xenografted mice. These findings not only improve our understanding of EVs-mediated NPC metastatic mechanism but also have important implications for the detection and treatment of NPC patients accompanied by aberrant EGFR-rich EVs transmission.