Jiang Wei, Zhang Chengpeng, Kang Yunteng, Li Guangbin, Feng Yu, Ma Haitao
Department of Thoracic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
Ann Transl Med. 2021 Jan;9(2):138. doi: 10.21037/atm-20-8019.
In recent years, there have been increasing reports that dysregulated circular RNAs (circRNAs) play a key role in the carcinogenesis of lung adenocarcinoma (LUAC). However, the role of circRNAs in early-stage LUAC is poorly understood.
The Gene Expression Omnibus (GEO) database and qRT-PCR were used to verify the abnormal expression of circRNAs, miRNAs and genes in early-stage LUAC tissues. shRNA and miRNA inhibitor are designed and synthesized to knock down circ_104640 and microRNA (miR)-145-5p expression. CCK-8 assay, colony formation assay and flow cytometry were used to study the effect of circ_104640 on cell proliferation and apoptosis. Bioinformatics analysis, dual luciferase reporter assays and argonaute 2 (Ago2) RNA immunoprecipitation (RIP) assays were chosen to find out the potential target of circ_104640.
Based on the GEO database and tissue sample from our institution, we identified that the circRNA circ_104640, the miR-145-5p, and CCL20 (C-C motif chemokine ligand 20) were abnormally expressed in the tissues of early-stage LUAC. In vitro experiments showed that circ_104640 could exist stably in the cytoplasm, and a short pin RNA that targeted circ_104640 (sh-circ) inhibited cell growth and promoted apoptosis of LUAC cells. Dual luciferase reporter assays and Ago2 (RIP) assays confirmed the Ago2-dependent interaction of circ_104640 and miR-145-5p. In terms of mechanisms, we found that circ_104640 increased the expression of CCL20 by sponging miR-145-5p.
Our research demonstrated that circ_104640 could accelerate the proliferation of LUAC cells, while inhibiting LUAC cell apoptosis. circ_104640 may be a potential novel biomarker and therapeutic target for early-stage LUAC.
近年来，越来越多的报道表明，失调的环状RNA（circRNA）在肺腺癌（LUAC）的致癌过程中起关键作用。然而，circRNA在早期LUAC中的作用尚不清楚。
利用基因表达综合数据库（GEO）和qRT-PCR验证早期LUAC组织中circRNA、miRNA和基因的异常表达。设计并合成短发夹RNA（shRNA）和miRNA抑制剂以敲低circ_104640和微小RNA（miR）-145-5p的表达。采用CCK-8法、集落形成试验和流式细胞术研究circ_104640对细胞增殖和凋亡的影响。选择生物信息学分析、双荧光素酶报告基因试验和AGO2 RNA免疫沉淀试验（RIP）来找出circ_104640的潜在靶点。
基于GEO数据库和我们机构的组织样本，我们发现circRNA circ_104640、miR-145-5p和CCL20（C-C基序趋化因子配体20）在早期LUAC组织中异常表达。体外实验表明，circ_104640可以稳定存在于细胞质中，靶向circ_104640的短发夹RNA（sh-circ）抑制LUAC细胞的生长并促进其凋亡。双荧光素酶报告基因试验和AGO2（RIP）试验证实了circ_104640与miR-145-5p之间存在AGO2依赖性相互作用。在机制方面，我们发现circ_104640通过海绵吸附miR-145-5p增加CCL20的表达。
我们的研究表明，circ_104640可以加速LUAC细胞的增殖，同时抑制LUAC细胞凋亡。circ_104640可能是早期LUAC的潜在新型生物标志物和治疗靶点。
