Identification of a Functional ceRNA Network to Explore Potential Biomarkers for Hepatocellular Carcinoma

Circ_0003570 Suppresses the progression of hepatocellular carcinoma through miR-182-5p/STARD13 regulatory axis

Background

Emerging evidence have revealed that circRNAs exert important biological effects in the development and progression of various diseases, including cancer. Our study aimed to elaborated the biological effects of hsa-circ_0003570 in hepatocellular carcinoma (HCC) development at the molecular level.

Results

The results of functional experiments showed that knockdown of circ_0003570 induced HCC cell growth, migration and invasion, whereas overexpression of circ_0003570 presented the opposite effects. In vivo experiments, xenograft tumors grown from circ-overexpressed cells had smaller tumor volume and weight than the control group. Further investigations suggested that circ_0003570 may function as a competing endogenous RNA via competitively binding miR-182-5p and thereby regulating the repression of downstream target gene STARD13, which were demonstrated by dual luciferase reporter assay and functional rescued experiments.

Conclusions

Taken together, circ_0003570 suppresses the development of HCC by modulating miR-182-5p/STARD13 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00176-w.

Hsa_circ_0011385 knockdown represses cell proliferation in hepatocellular carcinoma

Circular RNAs (circRNAs), continuous loops of single-stranded RNA, regulate gene expression during the development of various cancers. However, the function of circRNAs in hepatocellular carcinoma (HCC) is rarely discussed. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the mRNA levels of circ_0011385, miR-361-3p, and STC2 in 96 pairs of HCC tissues (tumor tissues and adjacent normal tissues), HCC cell lines, and L02 (human normal liver cell line) cells. The relationships between circ_0011385 expression and clinical features of HCC were evaluated. Functional experiments in vitro or in vivo were used to evaluate the biological function of circ_0011385. Bioinformatics analysis was performed to predict miRNAs and mRNAs sponged by circ_0011385. RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assays were used to elucidate the interactions among circ_0011385, miR-361-3p, and STC2 (stanniocalcin 2). ChIP and dual-luciferase reporter gene assays were used to identify the upstream regulator of circ_0011385. High expression of circ_0011385 was observed in HCC tissues and cell lines and was significantly associated with tumor size, TNM stage, and prognosis. In addition, inhibition of circ_0011385 expression prevented the proliferation of HCC cells in vitro and in vivo. Circ_0011385 sponged miR-361-3p, thereby regulating the mRNA expression of STC2. In addition, the transcription of circ_0011385 was regulated by SP3. Circ_0011385 knockdown suppressed cell proliferation and tumor activity in HCC. Circ_0011385 may therefore serve as a new biomarker in the diagnosis and treatment of HCC.

Current Molecular Biology and Therapeutic Strategy Status and Prospects for circRNAs in HBV-Associated Hepatocellular Carcinoma

Circular RNAs (circRNAs) are newly classified noncoding RNA (ncRNA) members with a covalently closed continuous loop structure that are involved in immune responses against hepatitis B virus (HBV) infections and play important biological roles in the occurrence and pathogenesis of HCC progression. The roles of circRNAs in HBV-associated HCC (HBV-HCC) have gained increasing attention. Substantial evidence has revealed that both tissue and circulating circRNAs may serve as potential biomarkers for diagnostic, prognostic and therapeutic purposes. So far, at least four circRNA/miRNA regulatory axes such as circRNA_101764/miR-181, circRNA_100338/miR-141-3p, circ-ARL3/miR-1305, circ-ATP5H/miR-138-5p, and several circulating circRNAs were reported to be associated with HBV-HCC development. Notably, TGF/SMAD, JAK/STAT, Notch and Wnt/β-catenin signaling pathways may play pivotal roles in this HBV-driven HCC via several circRNAs. Moreover, in non-HBV HCC patients or HCC patients partially infected by HBV, numerous circRNAs have been identified to be important regulators impacting the malignant biological behavior of HCC. Furthermore, the role of circRNAs in HCC drug resistance has become a focus of research with the aim of reversing chemoresistance and immune resistance. Herein, we review the molecular biology of circRNAs in HBV-HCC and their potential in therapeutic strategies.