Liu Rongfeng, Zhang Lingling, Xu Zhihong, Cui Yanzhi
Department of Medical Oncology, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
Zhongguo Fei Ai Za Zhi. 2020 Apr 20;23(4):223-232. doi: 10.3779/j.issn.1009-3419.2020.104.03. Epub 2020 Mar 30.
MicroRNAs (miRNAs) are non-coding small molecule RNAs that are widely found in eukaryotic organisms, although some miRNAs have been found in tumors, the expression and effects of miR-665 on small cell lung cancer (SCLC) are unclear. The aim of this study was to analyze the effects of miR-665 on proliferation, cycle, invasion and migration of SCLC cells, and to explore the role of miR-665 in SCLC and its working mechanism.
The expression of miR-665 in SCLC tissues and adjacent normal tissues was detected by qRT-PCR. TargetScan predicted potential target genes for miR-665 and validated with dual luciferase reporter assays, qRT-PCR and Western blot. CCK8 assay, flow cytometry, Transwell and wound healing assay to detect the effects of miR-665 and LLGL1 on proliferation, invasion, migration and S-phase fraction of SCLC cell line NCI-H446, NCI-H1688. A nude mouse xenograft model of SCLC was constructed and the effect of miR-665 on tumor growth in mice was observed.
The expression of miR-665 in SCLC tissues was significantly higher than that in non-tumor normal tissues. MiR-665 could target 3'-UTR of LLGL1 and inhibit its expression. Compared with non-tumor normal tissues, the expression of LLGL1 was significantly lower in SCLC tissues. Inhibition of miR-665 expression could inhibit proliferation, S-phase fraction, invasion and migration ability of SCLC NCL-H446 cells, and interference LLGL1 expression could reverse this inhibition effect. Up-regulation of miR-665 expression could promoted proliferation, S-phase fraction, invasion and migration ability of SCLC NCI-H1688 cells, but this promotion effect was also reversed by overexpression of LLGL1. In a nude mouse xenograft model of SCLC, inhibition of miR-665 expression could up-regulate LLGL1 protein expression and inhibit tumor growth, while up-regulation of miR-665 expression could produce opposite results.
The expression of miR-665 is closely related to SCLC. miR-665 can promote the biological behavior of SCLC cells by inhibiting the expression of target gene LLGL1, and miR-665 play a role in tumor-promoting genes in SCLC.
微小RNA（miRNA）是广泛存在于真核生物中的非编码小分子RNA，虽然在肿瘤中已发现一些miRNA，但miR-665在小细胞肺癌（SCLC）中的表达及作用尚不清楚。本研究旨在分析miR-665对SCLC细胞增殖、周期、侵袭和迁移的影响，探讨miR-665在SCLC中的作用及其作用机制。
采用qRT-PCR检测miR-665在SCLC组织及癌旁正常组织中的表达。TargetScan预测miR-665的潜在靶基因，并通过双荧光素酶报告基因检测、qRT-PCR和蛋白质免疫印迹法进行验证。采用CCK8法、流式细胞术、Transwell实验和伤口愈合实验检测miR-665和LLGL1对SCLC细胞系NCI-H446、NCI-H1688增殖、侵袭、迁移和S期分数的影响。构建SCLC裸鼠异种移植模型，观察miR-665对小鼠肿瘤生长的影响。
miR-665在SCLC组织中的表达明显高于非肿瘤正常组织。MiR-665可靶向LLGL1的3'-UTR并抑制其表达。与非肿瘤正常组织相比，LLGL1在SCLC组织中的表达明显降低。抑制miR-665表达可抑制SCLC NCL-H446细胞的增殖、S期分数、侵袭和迁移能力，干扰LLGL1表达可逆转这种抑制作用。上调miR-665表达可促进SCLC NCI-H1688细胞的增殖、S期分数、侵袭和迁移能力，但这种促进作用也可被LLGL1过表达逆转。在SCLC裸鼠异种移植模型中，抑制miR-665表达可上调LLGL1蛋白表达并抑制肿瘤生长，而上调miR-665表达则产生相反的结果。
miR-665的表达与SCLC密切相关。miR-665可通过抑制靶基因LLGL1的表达促进SCLC细胞的生物学行为，miR-665在SCLC中发挥促癌基因的作用。
