Clinical significance of miRNA-autophagy transcript expression in patients with hepatocellular carcinoma

The Diagnostic Value of MicroRNAs as a Biomarker for Hepatocellular Carcinoma: A Meta-Analysis

BACKGROUND

Recently, the role of microRNAs (miRNAs) in diagnosing cancer has been attracted increasing attention. However, few miRNAs have been applied in clinical practice. The purpose of this study was to evaluate the diagnostic efficacy of miRNAs for hepatocellular carcinoma (HCC) at early stages clinically.

METHODS

A literature search was carried out using PubMed, Web of Science, and EMBASE databases. We explored the diagnostic value of miRNAs in distinguishing HCC from healthy individuals. The quality assessment was performed in Review Manager 5.3 software. The overall sensitivity and specificity and 95% confidence intervals (CIs) were obtained with random-effects models through Stata 14.0 software. And heterogeneity was assessed using Q test and I 2 statistics. Meta-regression and subgroup analyses were conducted based on the sample, nation, quality of studies, and miRNA profiling. The publication bias was evaluated through Deeks' funnel plot.

RESULTS

A total of 34 studies, involving in 2747 HCC patients and 2053 healthy individuals, met the inclusion criteria in the 33 included literature studies. In the summary receiver operating characteristic (sROC) curve, AUC was 0.92 (95% CI, 0.90-0.94), with 0.84 (95% CI, 0.79-0.88) sensitivity and 0.87 (95% CI, 0.83-0.90) specificity. There was no publication bias (P=0.48).

CONCLUSION

miRNAs in vivo can be acted as a potential diagnostic biomarker for HCC, which can facilitate the early diagnosis of HCC in clinical practice.

MiR-490-3p inhibits autophagy via targeting ATG7 in hepatocellular carcinoma

The miR-490-3p was transfected into HepG2 cells to explore the correlation between miR-490-3p and hepatocellular carcinoma cell proliferation, apoptosis, and autophagy and its downstream target gene ATG7. Then we could possibly provide a mechanism for the treatment of hepatocellular carcinoma. MiR-490-3p was screened out by fold change > 4 and P < 0.01 using gene microarray data. The expression level of miR-490-3p was tested by qRT-PCR and the prognosis analysis was achieved by using TCGA data. The cell proliferation was tested via colony formation assay and CCK-8 after the miR-490-3p mimics were transfected into HepG2 cells; the variations of cell cycle and apoptosis was examined by flow cytometry assay; the number of autophagosome was observed by electron microscopy and the changes of autophagy-relative protein LC-II and LC-I as well as their ratio was tested by western blot. MiR-490-3p is low expressed in hepatocellular carcinoma cell lines and tissues. The results of TCGA showed that miR-490-3p high expression indicated better prognosis. After HepG2 cells were transfected with miR-490-3p mimics, cell viability was increased, cell proliferation was enhanced, cell cycle was blocked in G0/G1 phase, cell apoptosis rate was increased, the number of autophagosomes was reduced, autophagy-associated protein LC-II was decreased, and LC-I was increased and their ratio was decreased. After 3-MA was added, cell proliferation was declined, cell apoptosis rate was increased. Besides, the autophagy was inhibited by knocking down the ATG7, which promoted the cell apoptosis. MiR-490-3p could suppress cell proliferation, retard cell cycle and upgrade cell apoptosis by inhibiting autophagy in HCC cells via targeting ATG7. © 2018 IUBMB Life, 70(6):468-478, 2018.