Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, 430030, Wuhan, Hubei, People's Republic of China.
Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Wuhan, Hubei, People's Republic of China.
J Exp Clin Cancer Res. 2022 May 5;41(1):164. doi: 10.1186/s13046-022-02378-2.
Circular RNAs (circRNAs) function as crucial regulators in multiple cancers, including hepatocellular carcinoma (HCC). However, the roles of circRNAs in HCC remains largely unknown.
circTOLLIP was identified in HCC by screening of two public circRNA microarray datasets and detected in HCC cells and tissues through quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). Gain- and loss-of-function assays were performed to confirm the biological effects of circTOLLIP on HCC in vitro and in vivo. Mechanistically, bioinformatics analysis of online databases, MS2-RNA pulldown, biotin-labeled circTOLLIP/miR-516a-5p RNA pulldown, RNA immunoprecipitation (RIP), luciferase reporter assay, fluorescence in situ hybridization assay (FISH) and RNA sequencing were used to confirm the regulation of Eukaryotic initiation factor 4A3 (EIF4A3) on circTOLLIP and the interaction among circTOLLIP, miR-516a-5p and PBX homeobox 3 (PBX3).
circTOLLIP was significantly upregulated in HCC cells and tissues. High circTOLLIP expression was correlated with poor overall survival (OS) and disease-free survival (DFS) in patients. circTOLLIP promoted the proliferation and metastasis of HCC cells in vitro and in vivo. Mechanistically, EIF4A3 promoted the biogenesis of circTOLLIP without affecting its stability. Moreover, circTOLLIP sponged miR-516a-5p to elevate the expression of PBX3, thereby activating the epithelial-to-mesenchymal transition (EMT) pathway and facilitating tumor progression in HCC.
Our findings indicate that EIF4A3-induced circTOLLIP promotes the progression of HCC through the circTOLLIP/miR-516a-5p/PBX3/EMT axis.
环状 RNA（circRNAs）在多种癌症中作为重要的调控因子发挥作用，包括肝细胞癌（HCC）。然而，circRNAs 在 HCC 中的作用在很大程度上仍然未知。
通过筛选两个公共的 circRNA 微阵列数据集，在 HCC 细胞和组织中通过定量实时 PCR（qRT-PCR）和原位杂交（ISH）检测到 circTOLLIP。体外和体内进行增益和缺失功能测定，以确认 circTOLLIP 对 HCC 的生物学影响。通过在线数据库的生物信息学分析、MS2-RNA 下拉、生物素标记的 circTOLLIP/miR-516a-5p RNA 下拉、RNA 免疫沉淀（RIP）、荧光素酶报告基因测定、荧光原位杂交（FISH）和 RNA 测序来证实真核起始因子 4A3（EIF4A3）对 circTOLLIP 的调控以及 circTOLLIP、miR-516a-5p 和 PBX 同源盒 3（PBX3）之间的相互作用。
circTOLLIP 在 HCC 细胞和组织中显著上调。circTOLLIP 高表达与患者的总生存期（OS）和无病生存期（DFS）不良相关。circTOLLIP 促进 HCC 细胞在体外和体内的增殖和转移。机制上，EIF4A3 促进 circTOLLIP 的生物发生而不影响其稳定性。此外，circTOLLIP 海绵吸附 miR-516a-5p 以提高 PBX3 的表达，从而激活上皮间质转化（EMT）途径并促进 HCC 中的肿瘤进展。
我们的研究结果表明，EIF4A3 诱导的 circTOLLIP 通过 circTOLLIP/miR-516a-5p/PBX3/EMT 轴促进 HCC 的进展。
