Long noncoding RNA cytoskeleton regulator RNA promotes cell invasion and metastasis by titrating miR-613 to regulate ANXA2 in nasopharyngeal carcinoma

Background Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors. Long noncoding RNAs play critical roles in tumorigenesis. Methods Real-time quantitative PCR arrays were used to evaluate the expression levels of cytoskeleton regulator RNA (CYTOR) in NPC tissues and cells. Cell counting kit-8 and colony formation analyses were used to test the NPC cell viability, while wound healing and transwell assays were employed to detect cell invasion and migration ability. Luciferase reporter assay and Western blot analyses were employed to explore the relationships among CYTOR, miR-613, and ANXA2. Results We found that CYTOR expression was elevated both in NPC tissues and cells. Functional assays revealed that CYTOR promoted the invasion and migration of NPC cells. The established spontaneous lymph node metastasis model also confirmed that CYTOR promoted NPC cell metastasis in vivo. Mechanically, we found that the subcellular localization of CYTOR mostly occurred in the cell cytoplasm. Luciferase reporter and RIP assays confirmed that CYTOR functioned as the molecular sponge of miR-613. Subsequent experiments confirmed that ANXA2 was directly targeted by miR-613. Gain- and loss-of-function studies further confirmed that CYTOR induced the upregulation of ANXA2 by competitively binding to miR-613, thus leading to NPC metastasis. Conclusion Our results highlight the importance of CYTOR in NPC development and provide new insights into potential therapeutic targets for NPC.

背景 鼻咽癌（NPC）是最常见的头颈部恶性肿瘤之一。长链非编码RNA在肿瘤发生中起关键作用。 方法 采用实时定量PCR芯片评估细胞骨架调节因子RNA（CYTOR）在鼻咽癌组织和细胞中的表达水平。采用细胞计数试剂盒 - 8和集落形成分析检测鼻咽癌细胞活力，同时采用划痕愈合和Transwell实验检测细胞侵袭和迁移能力。采用荧光素酶报告基因实验和蛋白质印迹分析探索CYTOR、miR - 613和膜联蛋白A2（ANXA2）之间的关系。 结果 我们发现CYTOR在鼻咽癌组织和细胞中的表达均升高。功能实验表明CYTOR促进鼻咽癌细胞的侵袭和迁移。建立的自发性淋巴结转移模型也证实CYTOR在体内促进鼻咽癌细胞转移。从机制上讲，我们发现CYTOR主要定位于细胞质。荧光素酶报告基因实验和RNA结合蛋白免疫沉淀（RIP）实验证实CYTOR作为miR - 613的分子海绵发挥作用。后续实验证实ANXA2是miR - 613的直接靶标。功能获得和缺失研究进一步证实CYTOR通过与miR - 613竞争性结合诱导ANXA2上调，从而导致鼻咽癌转移。 结论 我们的研究结果强调了CYTOR在鼻咽癌发展中的重要性，并为鼻咽癌的潜在治疗靶点提供了新的见解。