A prognostic four-gene signature and a therapeutic strategy for hepatocellular carcinoma: Construction and analysis of a circRNA-mediated competing endogenous RNA network.

BACKGROUND: Hepatocellular carcinoma (HCC) has a poor long-term prognosis. The competition of circular RNAs (circRNAs) with endogenous RNA is a novel tool for predicting HCC prognosis. Based on the alterations of circRNA regulatory networks, the analysis of gene modules related to HCC is feasible. METHODS: Multiple expression datasets and RNA element targeting prediction tools were used to construct a circRNA-microRNA-mRNA network in HCC. Gene function, pathway, and protein interaction analyses were performed for the differentially expressed genes (DEGs) in this regulatory network. In the protein-protein interaction network, hub genes were identified and subjected to regression analysis, producing an optimized four-gene signature for prognostic risk stratification in HCC patients. Anti-HCC drugs were excavated by assessing the DEGs between the low- and high-risk groups. A circRNA-microRNA-hub gene subnetwork was constructed, in which three hallmark genes, KIF4A, CCNA2, and PBK, were subjected to functional enrichment analysis. RESULTS: A four-gene signature (KIF4A, CCNA2, PBK, and ZWINT) that effectively estimated the overall survival and aided in prognostic risk assessment in the The Cancer Genome Atlas (TCGA) cohort and International Cancer Genome Consortium (ICGC) cohort was developed. CDK inhibitors, PI3K inhibitors, HDAC inhibitors, and EGFR inhibitors were predicted as four potential mechanisms of drug action (MOA) in high-risk HCC patients. Subsequent analysis has revealed that PBK, CCNA2, and KIF4A play a crucial role in regulating the tumor microenvironment by promoting immune cell invasion, regulating microsatellite instability (MSI), and exerting an impact on HCC progression. CONCLUSIONS: The present study highlights the role of the circRNA-related regulatory network, identifies a four-gene prognostic signature and biomarkers, and further identifies novel therapy for HCC.

Downregulation of microRNA-586 Inhibits Proliferation, Invasion and Metastasis and Promotes Apoptosis in Human Osteosarcoma U2-OS Cell Line.

In this study, we aim to examine the association of microRNA-586 (miR-586) with osteosarcoma (OS) cell proliferation, apoptosis, invasion, and metastasis. U2-OS cell lines were divided into 4 groups: an miR-586 group, anti-miR-586 group, control group (empty plasmid) and blank group (no plasmid). qRT-PCR was used to detect miR-586 expression, cell counting kit-8 and EdU assays to detect cell proliferation, flow cytometry to detect cell cycle distribution, Annexin V/PI double staining to detect cell apoptosis, and the Transwell assay to detect cell invasion and metastasis. miR-586 expression was significantly higher in the miR-586 group but significantly lower in the anti-miR-586 group compared with the control and blank groups. Cell proliferation at 2-5 days after cell transfection and the EdU-positive cell number increased obviously in the miR-586 group but decreased clearly in the anti-miR-586 group. In the miR-586 group, cells at G0/G1 stage and apoptosis cells significantly decreased, while cells at G2/M and S stages and invasive and metastatic cells significantly increased compared to the control and blank groups; however, opposite trends were found in the anti-miR-586 group. Downregulation of miR-586 expression in OS may inhibit cell proliferation, invasion and metastasis, and promote cell apoptosis.