Liu Weipeng, Jiang Hong, Li Yuanqiang
Department of Gastrointestinal Surgery, The First College of Clinical Medical Science, China Three Gorges University, Phase 3, Jiangshan Duojiao, Wujiagang District, Yichang City, Hubei, 443000, China.
Open Life Sci. 2022 May 18;17(1):563-576. doi: 10.1515/biol-2022-0036. eCollection 2022.
Circular-RNA friend leukemia virus integration 1 (circ-FLI1; hsa_circ_0000370) is a noninvasive biomarker for the diagnosis of colon carcinoma (CC). Herein, we intended to investigate its functions and competing endogenous RNA (ceRNA) mechanisms in CC cells. In terms of expression status, circ-FLI1 was abnormally upregulated in CC patients' tumors and cells, paralleled with DKC1 upregulation and miR-197-3p downregulation. Most strikingly, there was a direct target relationship between miR-197-3p and circ-FLI1 or DKC1 based on the starbase database, dual-luciferase reporter assay, and RNA immunoprecipitation. Functionally, the colony formation assay, MTS method, fluorescence-activated cell sorting method, cell cycle and apoptosis assays, and transwell assays were performed, and the results revealed that interfering circ-FLI1 and re-expressing miR-197-3p could restrict colony formation, cell viability, cell cycle progression, and migration/invasion of CC cells with apoptosis rate elevation; besides, they promoted oxaliplatin (L-OHP)-induced cell viability inhibition. Furthermore, there were counteractive effects between circ-FLI1 silencing and miR-197-3p depletion, miR-197-3p overexpression and DKC1 restoration on regulating CC cell functions and L-OHP resistance. With a xenograft tumor model, the anti-growth role of circ-FLI1 silencing was also found with or without L-OHP treatment. Collectively, we demonstrated that circ-FLI1 might confer L-OHP resistance and malignant progression of CC presumably through the circ-FLI1/miR-197-3p/DKC1 ceRNA axis.
环状RNA Friend白血病病毒整合1（circ-FLI1；hsa_circ_0000370）是一种用于结肠癌（CC）诊断的非侵入性生物标志物。在此，我们旨在研究其在CC细胞中的功能及竞争性内源RNA（ceRNA）机制。就表达状态而言，circ-FLI1在CC患者的肿瘤和细胞中异常上调，同时伴有DKC1上调和miR-197-3p下调。最显著的是，基于starbase数据库、双荧光素酶报告基因检测和RNA免疫沉淀，miR-197-3p与circ-FLI1或DKC1之间存在直接靶向关系。在功能上，进行了集落形成试验、MTS法、荧光激活细胞分选法、细胞周期和凋亡试验以及Transwell试验，结果显示干扰circ-FLI1和重新表达miR-197-3p可抑制CC细胞的集落形成、细胞活力、细胞周期进程以及迁移/侵袭，并提高凋亡率；此外，它们还促进了奥沙利铂（L-OHP）诱导的细胞活力抑制。此外，circ-FLI1沉默与miR-197-3p缺失、miR-197-3p过表达与DKC1恢复之间在调节CC细胞功能和L-OHP耐药性方面存在拮抗作用。在异种移植肿瘤模型中，无论有无L-OHP处理，均发现circ-FLI1沉默具有抗生长作用。总体而言，我们证明circ-FLI1可能通过circ-FLI1/miR-197-3p/DKC1 ceRNA轴赋予CC细胞L-OHP耐药性和恶性进展。
