Circular RNA circRHOT1 promotes hepatocellular carcinoma progression by initiation of NR2F6 expression

• Published in: Molecular cancer Vol. 18; no. 1; p. 119
• Main Authors: Wang, Liyan, Long, Haiyan, Zheng, Qinghua, Bo, Xiaotong, Xiao, Xuhua, Li, Bin
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 19.07.2019; BioMed Central; BMC
• Subjects: Animals; Apoptosis; Apoptosis - genetics; Bioindicators; Bioinformatics; Biological markers; Biomarkers; Biomarkers, Tumor; Biotin; Cancer; Cancer metastasis; Carcinoma; Carcinoma, Hepatocellular - blood; Carcinoma, Hepatocellular - genetics; Carcinoma, Hepatocellular - pathology; Cell adhesion & migration; Cell culture; Cell cycle; Cell growth; Cell migration; Cell Movement - genetics; Cell proliferation; Cell Proliferation - genetics; Chemotherapy; circRHOT1; Circular RNA; CRISPR; Development and progression; Disease Models, Animal; Disease Progression; Flow cytometry; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Genes; Genetic aspects; Genetic research; Hepatocellular carcinoma; Humans; Hybridization; Liver cancer; Liver Neoplasms - blood; Liver Neoplasms - genetics; Liver Neoplasms - pathology; Medical prognosis; Metastases; Metastasis; Mice; Mitochondrial Proteins - genetics; Northern blotting; Novels; NR2F6; Patient outcomes; Prognosis; Repressor Proteins - genetics; rho GTP-Binding Proteins - genetics; Ribonucleic acid; RNA; RNA Interference; RNA, Circular - blood; RNA, Circular - genetics; TIP60; Transcription; Tumorigenesis; Tumors; Xenograft Model Antitumor Assays; Xenografts; United States > US; Hepatocellular carcinoma; circRHOT1; TIP60; NR2F6
• ISSN: 1476-4598; 1476-4598
• DOI: 10.1186/s12943-019-1046-7

Increasing evidence has revealed a close relationship between non-coding RNAs and cancer progression. Circular RNAs (circRNAs), a recently identified new member of non-coding RNAs, are demonstrated to participate in diverse biological processes, such as development, homeostatic maintenance and pathological responses. The functions of circRNAs in cancer have drawn wide attention recently. Until now, the expression patterns and roles of circRNAs in hepatocellular carcinoma (HCC) have remained largely unknown. Bioinformatics method was used to screen differentially expressed novel circRNAs in HCC. Northern blotting, qRT-PCR, in situ hybridization (ISH) and RNA-FISH were utilized to analyzed the expression of circRHOT1 in HCC tisues.CCK8, colony formation, EdU assays were used to analyze proliferation of HCC cells. Transwell assay was utilized to analyze HCC cell migration and invasion. FACS was used for apoptosis analysis. Xenograft experiments were used to analyze tumor growth in vivo. Mass spectrum, RNA pulldown, RIP and EMSA was utilized to test the interaction between circRHOT1 and TIP60. RNA-sequencing method was used to analyze the downstream target gene of circRHOT1. We identified circRHOT1 (hsa_circRNA_102034) as a conserved and dramatically upregulated circRNA in HCC tissues. HCC patients displaying high circRHOT1 level possessed poor prognosis. Through in vitro and in vivo experiments, we demonstrated circRHOT1 significantly promoted HCC growth and metastasis. Regarding the mechanism, we conducted a RNA pulldown with a biotin-labeled circRHOT1-specific probe and found that circRHOT1 recruited TIP60 to the NR2F6 promoter and initiated NR2F6 transcription. Moreover, NR2F6 knockout inhibited growth, migration and invasion, whereas rescuing NR2F6 in circRHOT1-knockout HCC cells rescued the proliferation and metastasis abilities of HCC cells. Taken together, circRHOT1 inhibits HCC development and progression via recruiting TIP60 to initiate NR2F6 expression, indicating that circRHOT1 and NR2F6 may be potential biomarkers for HCC prognosis.