Respiratory and Critical Illness Ward 1, Henan Chest Hospital, No. 1, Weiwu Road, Zhengzhou, 450000, Henan, China.
Mol Cell Biochem. 2021 Feb;476(2):689-698. doi: 10.1007/s11010-020-03936-y. Epub 2020 Oct 30.
The current therapeutic strategies for non-small cell lung cancer (NSCLC) are limited and unsatisfactory. MicroRNAs (miRNAs) participate in tumor angiogenesis in NSCLC. The aim of this study was to investigate the role of miR-20a-5p (miR-20a) in human NSCLC metastasis. In the current study, bioinformatics analysis and RT-PCR were performed to examine the expression level of miR-20a in tissues of NSCLC patients and NSCLC cell lines, respectively. Western blot was performed to test the protein levels. Cell proliferation, migration and angiogenesis capacity were tested by 5-ethynyl-29-deoxyuridine (EdU) assay, transwell assay and tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the interaction between miR-20a and paired ribonucleotide reductase regulatory subunit M2 (RRM2). We found that the expression of RRM2 was upregulated, while the expression of miR-20a was downregulated in cancer tissues compared with adjacent tissues in NSCLC patients. We also detected the expression level of RRM2 and miR-20a in NSCLC cell lines, showing A549 cell line exhibited the lowest expression level of miR-20a and highest expression level of RRM2. Overexpressed miR-20a not only dramatically suppressed NSCLC cells proliferation, endothelial cells migration and tube formation in vitro, but also inhibited tumor growth and angiogenesis in vivo. It was demonstrated that miR-20a suppressed NSCLC growth by inhibiting RRM2-mediated PI3K/Akt signaling pathway. These findings indicate that the novel identified miR-20a could function as a tumor suppressor in NSCLC through modulating the RRM2-mediated PI3K/Akt axis, and it could be a valid molecular target for NSCLC treatment.
目前非小细胞肺癌（NSCLC）的治疗策略有限且不尽人意。微小 RNA（miRNA）参与 NSCLC 肿瘤血管生成。本研究旨在探讨 miR-20a-5p（miR-20a）在人 NSCLC 转移中的作用。本研究分别通过生物信息学分析和 RT-PCR 检测 NSCLC 患者组织和 NSCLC 细胞系中 miR-20a 的表达水平，通过 Western blot 检测蛋白水平。通过 5-乙炔基-29-脱氧尿苷（EdU）测定、Transwell 测定和管形成测定分别检测细胞增殖、迁移和血管生成能力。双荧光素酶报告测定（DLR）用于证实 miR-20a 与配对核苷酸还原酶调节亚基 M2（RRM2）之间的相互作用。我们发现与 NSCLC 患者的相邻组织相比，癌症组织中 RRM2 的表达上调，而 miR-20a 的表达下调。我们还检测了 NSCLC 细胞系中 RRM2 和 miR-20a 的表达水平，结果显示 A549 细胞系表现出最低的 miR-20a 表达水平和最高的 RRM2 表达水平。过表达 miR-20a 不仅显著抑制 NSCLC 细胞的体外增殖、内皮细胞的迁移和管形成，而且还抑制体内肿瘤生长和血管生成。结果表明，miR-20a 通过抑制 RRM2 介导的 PI3K/Akt 信号通路抑制 NSCLC 生长。这些发现表明，新鉴定的 miR-20a 可通过调节 RRM2 介导的 PI3K/Akt 轴在 NSCLC 中发挥肿瘤抑制作用，并且可能是 NSCLC 治疗的有效分子靶标。
