Fan Chen, Zhu Xiaoli, Zhou Qi, Wang Weidong
Department of Intervention, Wuxi People's Hospital, Nanjing Medical University, Wuxi 214023, China.
Department of Intervention, The First Affiliated Hospital of Soochow University, Suzhou 215006, China.
J Oncol. 2022 Jul 21;2022:2674163. doi: 10.1155/2022/2674163. eCollection 2022.
Noncoding RNAs exert critical biological effects in hepatocellular carcinoma (HCC). The role of circFMN2, a newly discovered functional RNA in prostate cancer and colorectal cancer, was investigated for the first time in sorafenib-resistance HCC cells.
The level of circFMN2 was assessed via quantitative real-time PCR (qRT-PCR). Cell proliferation was detected via CCK-8 and colony formation assay. Cell apoptosis was measured via the TUNEL assay and flow cytometry analysis. A Western blot assay was conducted to detect the CCHC-type zinc finger nucleic acid binding protein (CNBP) level and ubiquitination. RNA pull-down assay and RNA immunoprecipitation were carried out to explore the interaction between circFMN2 and CNBP.
CircFMN2 was highly expressed in multidrug-resistant (MDR) cells. CircFMN2 overexpression exerted pro-proliferation effects in sorafenib-treated HCC cells, while depletion of circFMN2 displayed negative effect on sorafenib-treated MDR cells. Moreover, CNBP was verified as the binding protein of circFMN2. CNBP was upregulated in MDR cells, which was achieved by inhibition of ubiquitination by circFMN2. Besides, CNBP overexpression was found to boost sorafenib resistance in HCC cells.
CircFMN2 is aberrantly expressed in sorafenib-resistant HCC cells and contributes to sorafenib resistance in HCC cells via upregulation of CNBP by restraining ubiquitination.
非编码RNA在肝细胞癌（HCC）中发挥关键生物学作用。首次在索拉非尼耐药的HCC细胞中研究了环状FMN2（circFMN2）这一在前列腺癌和结直肠癌中新发现的功能性RNA的作用。
通过定量实时PCR（qRT-PCR）评估circFMN2的水平。通过CCK-8和集落形成试验检测细胞增殖。通过TUNEL试验和流式细胞术分析测量细胞凋亡。进行蛋白质免疫印迹试验以检测CCHC型锌指核酸结合蛋白（CNBP）水平和泛素化。进行RNA下拉试验和RNA免疫沉淀以探索circFMN2与CNBP之间的相互作用。
circFMN2在多药耐药（MDR）细胞中高表达。circFMN2过表达在索拉非尼处理的HCC细胞中发挥促增殖作用，而circFMN2的缺失对索拉非尼处理的MDR细胞显示出负面影响。此外，CNBP被证实为circFMN2的结合蛋白。CNBP在MDR细胞中上调，这是通过circFMN2抑制泛素化实现的。此外，发现CNBP过表达可增强HCC细胞对索拉非尼的耐药性。
circFMN2在索拉非尼耐药的HCC细胞中异常表达，并通过抑制泛素化上调CNBP来促进HCC细胞对索拉非尼的耐药性。
