Involvement of the circular RNA/microRNA/glucose-6-phosphate dehydrogenase axis in the pathological mechanism of hepatocellular carcinoma

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.

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

BACKGROUND

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is the fourth leading cause of cancer-related deaths worldwide. Previous evidence shows that the expression of circulating RNA ZFR (circZFR) is upregulated in HCC tissues. However, the molecular mechanism of circZFR in HCC is unclear.

METHODS

Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was employed to detect the expression of circZFR, microRNA-624-3p (miR-624-3p) and WEE1 in HCC tissues and cells. RNase R assay and actinomycin D treatment assay were used to analyze the characteristics of circZFR. For functional analysis, the capacities of colony formation, cell proliferation, cell apoptosis, migration and invasion were assessed by colony formation assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry assay and transwell assay. Western blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition (EMT)-related proteins. The interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Xenograft models were established to determine the role of circZFR in vivo.

RESULTS

circZFR and WEE1 were upregulated, while miR-624-3p expression was reduced in HCC tissues and cells. circZFR could sponge miR-624-3p, and WEE1 was a downstream gene of miR-624-3p. Knockdown of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR-624-3p inhibitor restored this change. Overexpression of WEE1 abolished the inhibitory effect of miR-624-3p mimic on HCC cells. Mechanistically, circZFR acted as a competitive endogenous RNA (ceRNA) to regulate WEE1 expression by targeting miR-624-3p. Furthermore, in vivo studies have illustrated that circZFR knockdown inhibited tumor growth.

CONCLUSIONS

circZFR knockdown reduced HCC cell proliferation, migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis, suggesting that the circZFR/miR-624-3p/WEE1 axis might be a potential target for HCC treatment.

LncRNA n339260 functions in hepatocellular carcinoma progression via regulation of miRNA30e-5p/TP53INP1 expression

BACKGROUND

Currently, the molecular mechanism of the interaction between lncRNAs and microRNAs (miRNAs) and the target of miRNAs in tumor vasculogenic mimicry (VM) formation have not been clarified. Our aim is to study the interaction between lncRNA n339260 and miRNA30e-5p in the formation of VM.

METHODS

Animal xenografts were established, 104 hepatocellular carcinoma (HCC) patients' frozen tissues were obtained and HCC cells in vitro were used to observe the role of n339260 in HCC progression.

RESULTS

In vivo experiment showed lncRNA n339260 promoted tumor growth and VM formation. LncRNA n339260 and miRNA30e-5p were found to be associated with VM formation, metastasis and survival time in HCC patients. In vitro experiment showed that LncRNA n339260 could inhibit miRNA30e-5p expression and TP53INP1 was found to be the downstream targets of miRNA30e-5p. Snail, MMP2, MMP9, VE-cadherin, vimentin and N-cadherin overexpression and the downregulation of TP53INP1 and E-cadherin were observed in HCCLM3 and HepG2 cells overexpressing lncRNA n339260 or in cells with decreased expression of miRNA30e-5p.

CONCLUSION

LncRNA n339260 promotes the development of VM, and lncRNA n339260 may enhance Snail expression by decreasing the expression of miRNA30e-5p, thereby reducing TP53INP1 expression. Therefore, a potential lncRNA n339260- miRNA30e-5p- TP53INP1 regulatory axis was associated with HCC progression.

Construction of a competing endogenous RNA network to analyse glucose-6-phosphate dehydrogenase dysregulation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumour with high rates of morbidity and mortality worldwide. Therefore, it is of great significance to find new molecular markers for HCC diagnosis and treatment. G6PD is known to be dysregulated in a variety of tumours. In addition, the ceRNA network plays a crucial role in the occurrence and development of HCC. However, the mechanism by which the ceRNA network regulates G6PD in HCC remains unclear. We used TCGA-LIHC data to analyse the possibility of using G6PD as an independent prognostic marker. Univariate Cox proportional hazards regression, multivariate Cox proportional hazards regression, and receiver operating characteristic curve analysis were used to analyse the influence of G6PD overexpression on the prognosis of HCC patients. We also analysed the biological function of G6PD, its effect on the immune microenvironment, and drug sensitivity. Finally, we constructed a ceRNA network of lncRNAs/miR-122-5p/G6PD to explore the regulatory mechanism of G6PD. G6PD was highly expressed in HCC, was related to pathological stage and poor prognosis, and could be used as an independent prognostic indicator of HCC. The expression of G6PD was closely related to the immune microenvironment of HCC. In addition, the expression of G6PD in HCC could be regulated by the ceRNA network. Therefore, G6PD can be used as an immunotherapy target to improve the survival and prognosis of HCC patients, and the ceRNA regulatory network of G6PD has potential diagnostic and therapeutic value for HCC.