Long intergenic non-protein coding RNA 02570 promotes nasopharyngeal carcinoma progression by adsorbing microRNA miR-4649-3p thereby upregulating both sterol regulatory element binding protein 1, and fatty acid synthase

Our previous studies have elucidated a possible connection between long intergenic non-protein coding RNA 2570 (LINC02570) and nasopharyngeal carcinoma (NPC). However, the precise mechanism by which LINC02570 promotes NPC remains unknown. We used quantitative polymerase chain reaction (qPCR) to detect LINC02570 expression in nasopharyngeal cell lines, NPC tissues, and chronic rhinitis tissues. Subcellular LINC02570 localization was confirmed by fluorescence in situ hybridization (FISH). The effects of LINC02570 stable knockdown and overexpression on viabillity, proliferation, migration, and invasion were analyzed using 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl-2-H-Tetrazolium bromide (MTT), a colorimetric focus-formation assay, a wound healing assay, and transwell assays. RNA crosstalk analysis in silico predicted microRNA-4649-3p (miR-4649-3p) binding to LINC02570 or sterol regulatory element binding transcription factor 1 (SREBF1). A dual luciferase reporter assay was used to confirm potential interactions. Sterol regulatory element binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression were detected by western blotting. The results suggest that LINC02570 is upregulated in late clinical stage NPC patients, and promotes NPC progression by adsorbing miR-4649-3p to up-regulate SREBP1 and FASN. This study elucidates a potential chemotherapeutic target involved in lipid metabolism in NPC.

本团队前期研究已阐明长链基因间非编码RNA2570（LINC02570）与鼻咽癌（NPC）之间存在潜在关联，但LINC02570促进鼻咽癌发生发展的确切分子机制仍未明确。本研究采用实时定量聚合酶链反应（qPCR）检测鼻咽细胞系、鼻咽癌组织及慢性鼻炎组织中LINC02570的表达水平；通过荧光原位杂交（FISH）验证LINC02570的亚细胞定位。分别采用3-(4,5-二甲基-2-噻唑)-2,5-二苯基-2-H-四氮唑溴盐（MTT）比色法、集落形成实验、划痕愈合实验及Transwell实验，分析LINC02570稳定敲低与过表达对细胞活力、增殖、迁移及侵袭能力的影响。通过生物信息学RNA互作分析，预测得到可与LINC02570或固醇调节元件结合转录因子1（SREBF1）结合的微小RNA-4649-3p（miR-4649-3p）；采用双荧光素酶报告基因实验验证二者的潜在相互作用。通过蛋白质印迹法检测固醇调节元件结合蛋白1（SREBP1）与脂肪酸合酶（FASN）的表达水平。研究结果显示，LINC02570在临床晚期鼻咽癌患者中呈高表达，并通过吸附miR-4649-3p以上调SREBP1及FASN的表达，进而促进鼻咽癌的进展。本研究阐明了一个参与鼻咽癌脂质代谢的潜在化疗靶点。