Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha 410008, Hunan, China; Otolaryngology Major Disease Research Key Laboratory of Hunan Province, Changsha 410008, Hunan, China.
Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha 410008, Hunan, China; Otolaryngology Major Disease Research Key Laboratory of Hunan Province, Changsha 410008, Hunan, China.
Eur J Cancer. 2013 Jul;49(11):2596-607. doi: 10.1016/j.ejca.2013.03.001. Epub 2013 Apr 10.
Radioresistance severely restricts the clinical treatment of nasopharyngeal carcinoma (NPC). Accumulating evidence demonstrates that aberrant expression of microRNAs (miRNAs) contributes to cancer progression and sensitivity to radiation. Therefore, we aimed to identify miRNAs associated with radioresistance in NPC.
Aberrant miRNA-324-3p expression in NPC CNE-2 cells with radioresistance (CNE-2-Rs), compared to its parental cells, was screened by high-throughput sequencing technology and determined by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) analysis. Bioinformatic analysis was used to predict the downstream target genes of miRNA-324-3p. Then, functional and mechanical analyses of miRNA-324-3p in NPC radioresistance were performed by overexpression and down-regulation of miRNA-324-3p in CNE-2-Rs cells and its parental cells. Finally, the clinical significance of miRNA-324-3p and WNT2B was investigated in NPC tissues.
Our data reveal that the expression of miRNA-324-3p is significantly decreased in CNE-2-Rs cells compared to its parental cells, and WNT2B is predicted to be the downstream target of miRNA-324-3p. Both overexpression and down-regulation of miRNA-324-3p following irradiation result in radiosensitivity alterations and protein changes of WNT2B signalling pathway in CNE-2-Rs cells and its parental cells. Importantly, down-regulation of miRNA-324-3p and up-regulation of WNT2B are significantly correlated with advanced clinical stages of NPC and this inverse expression pattern is also observed in NPC tissues before and after irradiation.
The present study reveals that miRNA-324-3p contributes to the radioresistance of NPC by regulating the WNT2B signalling pathway. Both miRNA-324-3p and WNT2B are potential biomarkers for radioresistance in NPC, which may serve as valuable targets for reversing radioresistance in the management of NPC.
放射抗拒严重限制了鼻咽癌（NPC）的临床治疗。越来越多的证据表明，miRNA（miRNA）的异常表达有助于癌症的进展和对辐射的敏感性。因此，我们旨在确定与 NPC 放射抗拒相关的 miRNAs。
采用高通量测序技术筛选出具有放射抗性的 NPC CNE-2 细胞（CNE-2-Rs）中 miRNA-324-3p 的异常表达，并通过定量逆转录-聚合酶链反应分析（qRT-PCR）进行检测。通过生物信息学分析预测 miRNA-324-3p 的下游靶基因。然后，通过在 CNE-2-Rs 细胞及其亲本细胞中转染 miRNA-324-3p 过表达和下调，研究 miRNA-324-3p 在 NPC 放射抗性中的功能和机械作用。最后，在 NPC 组织中研究了 miRNA-324-3p 和 WNT2B 的临床意义。
我们的数据表明，与亲本细胞相比，CNE-2-Rs 细胞中 miRNA-324-3p 的表达显著降低，WNT2B 被预测为 miRNA-324-3p 的下游靶基因。转染后 miRNA-324-3p 的过表达和下调均导致 CNE-2-Rs 细胞及其亲本细胞中 WNT2B 信号通路的放射敏感性改变和蛋白变化。重要的是，miRNA-324-3p 的下调和 WNT2B 的上调与 NPC 的临床晚期显著相关，并且这种反式表达模式也在 NPC 组织的放疗前后观察到。
本研究表明，miRNA-324-3p 通过调节 WNT2B 信号通路促进 NPC 的放射抗性。miRNA-324-3p 和 WNT2B 均可能是 NPC 放射抗性的潜在生物标志物，可能成为逆转 NPC 放射抗性管理中放射抗性的有价值靶点。
