Zhang H, Jiang J, He X, Zhou Q
Department of Ultrasound, The second affiliated hospital of Xi'an Jiaotong University, NO. 157 West Fifth Road, Xi'an, 710004, Shaanxi, China.
J Endocrinol Invest. 2023 Apr;46(4):713-725. doi: 10.1007/s40618-022-01921-4. Epub 2022 Oct 13.
Circular RNAs (circRNAs) have essential roles in the malignant progression of papillary thyroid carcinoma (PTC). Circ_0002111 was reported to facilitate cell proliferation and invasion abilities in PTC. This study was performed to explore the regulatory mechanism of circ_0002111 in PTC progression.
Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used for the level detection of circ_0002111, microRNA-134-5p (miR-134-5p) and Follistatin Like 1 (FSTL1). Cell proliferation was assessed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay, EdU assay and colony formation assay. Cell migration ability was determined by transwell assay. Glycolysis was analyzed by extracellular acidification rate (ECAR), oxygen consumption rate (OCR), glucose consumption and lactate production. The protein quantification was performed through western blot. Xenograft tumor assay was used for the functional analysis of circ_0002111 in vivo. The target interaction was confirmed by dual-luciferase reporter assay and RNA pull-down assay.
The significant upregulation of circ_0002111 was detected in PTC samples and cells. PTC cell proliferation, migration and glycolytic metabolism were suppressed after circ_0002111 downregulation. PTC tumorigenesis in vivo was also inhibited by circ_0002111 knockdown. In addition, circ_0002111 could target miR-134-5p and si-circ_0002111#1-induced inhibition of PTC progression was relieved by miR-134-5p expression downregulation. Furthermore, FSTL1 was a target gene for miR-134-5p and miR-134-5p served as a tumor repressor in PTC by targeting FSTL1. Moreover, circ_0002111 could increase the FSTL1 level via sponging miR-134-5p.
All results indicated that circ_0002111 promoted the malignant behaviors of PTC cells partly by regulating the miR-134-5p/FSTL1 molecular network.
环状RNA（circRNAs）在甲状腺乳头状癌（PTC）的恶性进展中起重要作用。据报道，circ_0002111可促进PTC细胞的增殖和侵袭能力。本研究旨在探讨circ_0002111在PTC进展中的调控机制。
采用逆转录定量聚合酶链反应（RT-qPCR）检测circ_0002111、微小RNA-134-5p（miR-134-5p）和卵泡抑素样蛋白1（FSTL1）的水平。通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法、EdU法和集落形成试验评估细胞增殖。通过Transwell试验测定细胞迁移能力。通过细胞外酸化率（ECAR）、耗氧率（OCR）、葡萄糖消耗和乳酸生成分析糖酵解。通过蛋白质免疫印迹进行蛋白质定量。采用异种移植瘤试验在体内分析circ_0002111的功能。通过双荧光素酶报告基因试验和RNA下拉试验确认靶标相互作用。
在PTC样本和细胞中检测到circ_0002111显著上调。circ_0002111下调后，PTC细胞增殖、迁移和糖酵解代谢受到抑制。circ_0002111敲低也抑制了体内PTC肿瘤的发生。此外，circ_0002111可靶向miR-134-5p，下调miR-134-5p表达可缓解si-circ_0002111#1诱导的PTC进展抑制。此外，FSTL1是miR-134-5p的靶基因，miR-134-5p通过靶向FSTL1在PTC中发挥肿瘤抑制作用。此外，circ_0002111可通过海绵吸附miR-134-5p增加FSTL1水平。
所有结果表明，circ_0002111部分通过调节miR-134-5p/FSTL1分子网络促进PTC细胞的恶性行为。
