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

Abstract

Background 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. Methods 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. Results 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. Conclusion 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. Electronic supplementary material The online version of this article (10.1186/s12943-019-1046-7) contains supplementary material, which is available to authorized users.

The Circular RNA circZFR Phosphorylates Rb Promoting Cervical Cancer Progression by Regulating the SSBP1/CDK2/cyclin E1 Complex

“…Circ-ACC1 has been demonstrated to directly bind to AMPK β and γ subunits and facilitate AMPK holoenzyme assembly, stability, and activity [48]. CircRHOT1 was found to promote hepatocellular carcinoma (HCC) growth through the recruitment of TIP60 to the promoter of NR2F6 and initiating NR2F6 transcription [49]. A study reported that circZKSCAN1 physically bound an RBP FMRP against CCAR1 complex and inhibited HCC [50].…”

Optimized RNA-targeting CRISPR/Cas13d technology outperforms shRNA in identifying essential circRNAs

“…To evaluate the ability of Cas13d to identify and credential bona-fide essential circRNAs, we next sought to use our optimized Cas13d system to target previously reported essential circRNAs. For instance, circRHOT1 knockout by depleting flanking CSs suppressed HCC's cell proliferation 21 . To determine if Cas13d can validate the essentiality of circRHOT1 in HCC cells, we silenced its expression in two HCC cell lines, Huh7 and PLC/PRF/5 cells ( Fig.…”

CircRHOT1 Mediated Cell Proliferation, Apoptosis and Invasion of Pancreatic Cancer Cells by Sponging miR-125a-3p

“…Further, circRHOT1 promotes proliferation and invasion of pancreatic cancer cells [16]. In HCC, circRHOT1 is significantly upregulated and initiate NR2F6 expression to promote turmor progression, the expression of circRHOT1 was related to patient prognosis [15]. CircRNAs have been regarded as regulators or biological markers in many types of diseases, including pancreatic cancer.…”

“…hsa_circ_0005397 is derived from the RHOT1gene and has been termed circRHOT1.The circRHOT1 expression was related to the pancreatic cancer cell proliferation, invasion and migration [15].…”