ABSTRACT

Circular RNAs (circRNAs) have been reported to be related to the development of human cancers. However, the function of circ-FOXM1 in non-small cell lung cancer (NSCLC) was largely unknown. Here, we revealed the role and functional mechanism of circ-FOXM1 in NSCLC progression. The relative expression of circ-FOXM1, microRNA-149-5p (miR-149-5p), and autophagy-related 5 (ATG5) was determined by quantitative real-time polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assay were employed to assess cell viability, apoptosis, and migration, respectively. The relative protein expression was detected by western blot. Furthermore, mouse xenograft was carried out to analyze the effect of circ-FOXM1 on tumor growth in vivo. In addition, the interaction between miR-149-5p and circ-FOXM1 or ATG5 was predicted by Starbase3.0 and confirmed by the dual-luciferase reporter assay and RNA pull-down assay. Circ-FOXM1 and ATG5 levels were upregulated, while the miR-149-5p level was downregulated in NSCLC tissues and cells. Circ-FOXM1 knockdown suppressed NSCLC cell viability, migration, and autophagy, and induced cell apoptosis. Interestingly, circ-FOXM1 targeted miR-149-5p to upregulate the ATG5 level. Moreover, circ-FOXM1 exerted function through repressing miR-149-5p expression, and miR-149-5p exerted function via inhibiting ATG5 expression. Our results suggested that circ-FOXM1 knockdown attenuated the development of NSCLC through modulating the miR-149-5p/ATG5 axis, providing a theoretical basis for the therapy of NSCLC.

摘要

据报道，环状RNA（circRNA）与人类癌症的发展有关。但是，很大程度上未知circ-FOXM1在非小细胞肺癌（NSCLC）中的功能。在这里，我们揭示了circ-FOXM1在NSCLC进展中的作用和功能机制。通过定量实时聚合酶链反应（RT-qPCR）确定circ-FOXM1，microRNA-149-5p（miR-149-5p）和自噬相关5（ATG5）的相对表达。使用Cell Counting Kit-8（CCK-8），流式细胞仪和Transwell分析法分别评估细胞活力，凋亡和迁移。通过蛋白质印迹检测相对蛋白表达。此外，进行了小鼠异种移植以分析circ-FOXM1对体内肿瘤生长的影响。此外，Starbase3.0预测了miR-149-5p与circ-FOXM1或ATG5之间的相互作用，并通过双荧光素酶报告基因测定和RNA下拉测定证实。在NSCLC组织和细胞中，Circ-FOXM1和ATG5水平上调，而miR-149-5p水平下调。Circ-FOXM1抑制可抑制NSCLC细胞的活力，迁移和自噬，并诱导细胞凋亡。有趣的是，circ-FOXM1靶向miR-149-5p以上调ATG5水平。此外，circ-FOXM1通过抑制miR-149-5p的表达发挥功能，而miR-149-5p通过抑制ATG5的表达发挥功能。我们的结果表明，circ-FOXM1敲低通过调节miR-149-5p / ATG5轴而减弱了NSCLC的发展，为NSCLC的治疗提供了理论基础。