Li Huiping, Liu Fangfang, Qin Wenjing
Department of Respiratory Medicine, First Affiliated Hospital of Henan University, No. 357, Ximen Street, Longting District, Kaifeng, 475000 Henan China.
Cancer Cell Int. 2020 Mar 12;20:78. doi: 10.1186/s12935-020-1162-x. eCollection 2020.
Non-small-cell lung cancer (NSCLC) is one of the common cancers in the world. Circular RNA 0072083 (circ_0072083, circZFR) has been reported to be associated with the progression of NSCLC. In this study, we intended to explore the role and the potential mechanism of circ_0072083 in NSCLC.
Quantitative real time polymerase chain reaction (qRT-PCR) was performed to detect the expression of circ_0072083, its matching linear RNA (zinc finger RNA binding protein (ZFR)) and microRNA-545-3p (miR-545-3p) in NSCLC cells. The ability of colony formation in NSCLC cells was detected by colony formation assay. The apoptosis and cell cycle were measured by flow cytometry. The metastasis was determined by transwell migration and invasion assays. The protein expression of E-cadherin, N-cadherin, Vimentin and Cbl proto-oncogene like 1 (CBLL1) was examined by western blot assay. The interaction between miR-545-3p and circ_0072083 or CBLL1 was predicted by starBase or Targetscan software. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were applied to validate these interactions. Nude mice bearing tumors were used to confirm the role of circ_0072083 and cisplatin (DDP) in vivo.
The level of circ_0072083 was higher in NSCLC tissues and cells relative to that in adjacent non-tumor tissues and normal lung cells. The transfection of si-circ_0072083 inhibited colony formation, cell cycle and metastasis while promoted the apoptosis of NSCLC cells stimulated by DDP. MiR-545-3p was a direct functional target of circ_0072083 in NSCLC cells. CBLL1 could bind to miR-545-3p in NSCLC cells. Circ_0072083 promoted the progression of NSCLC induced by DDP through sponging miR-545-3p and enhancing the enrichment of CBLL1 in vivo and in vitro.
Circ_0072083 depletion contributed to DDP-triggered inhibition of NSCLC tumor through miR-545-3p/CBLL1 axis.
非小细胞肺癌（NSCLC）是全球常见的癌症之一。据报道，环状RNA 0072083（circ_0072083，circZFR）与NSCLC的进展有关。在本研究中，我们旨在探讨circ_0072083在NSCLC中的作用及其潜在机制。
采用定量实时聚合酶链反应（qRT-PCR）检测circ_0072083、其匹配的线性RNA（锌指RNA结合蛋白（ZFR））和微小RNA-545-3p（miR-545-3p）在NSCLC细胞中的表达。通过集落形成试验检测NSCLC细胞的集落形成能力。采用流式细胞术检测细胞凋亡和细胞周期。通过Transwell迁移和侵袭试验测定细胞转移情况。采用蛋白质免疫印迹法检测E-钙黏蛋白、N-钙黏蛋白、波形蛋白和原癌基因Cbl样蛋白1（CBLL1）的蛋白表达。通过starBase或Targetscan软件预测miR-545-3p与circ_0072083或CBLL1之间的相互作用。应用双荧光素酶报告基因检测和RNA免疫沉淀（RIP）试验验证这些相互作用。利用荷瘤裸鼠在体内证实circ_0072083和顺铂（DDP）的作用。
与相邻非肿瘤组织和正常肺细胞相比，circ_0072083在NSCLC组织和细胞中的水平较高。转染si-circ_0072083可抑制NSCLC细胞的集落形成、细胞周期和转移，同时促进DDP刺激的NSCLC细胞凋亡。MiR-545-3p是circ_0072083在NSCLC细胞中的直接功能靶点。CBLL1可在NSCLC细胞中与miR-545-3p结合。Circ_0072083通过在体内外吸附miR-545-3p并增强CBLL1的富集，促进DDP诱导的NSCLC进展。
circ_0072083缺失通过miR-545-3p/CBLL1轴有助于DDP触发对NSCLC肿瘤的抑制作用。
