Circ_0003998 enhances doxorubicin resistance in hepatocellular carcinoma by regulating miR-218-5p/EIF5A2 pathway

Diagn Pathol. 2020 Dec 11;15(1):141. doi: 10.1186/s13000-020-01056-1.


Background: The involvement of circular RNAs (circRNAs) in chemoresistance of tumors has been identified. Herein, this study aims to investigate the role and the underlying mechanism of circ_0003998 in doxorubicin (DOX) resistance in hepatocellular carcinoma (HCC).

Methods: The expression of circ_0003998 and microRNA (miR)-218-5p and eukaryotic translation initiation factor 5A-2 (EIF5A2) mRNA was detected using quantitative real-time polymerase chain reaction. Cell viability, migration and invasion were analyzed using cell counting kit-8, colony formation and transwell assay, respectively. The levels of matrix metallopeptidase 9 (MMP-9), E-cadherin, Vimentin, N-cadherin and EIF5A2 protein were detected using western blot. The interaction between miR-218-5p and circ_0003998 or EIF5A2 was confirmed by dual-luciferase reporter assay. In vivo experiments were performed using murine xenograft models.

Results: Circ_0003998 was elevated in HCC tissues, DOX-resistant tissues and cells, and circ_0003998 knockdown promoted DOX-sensitivity in HCC by inhibiting resistant cell viability, migration, invasion and EMT in vitro and enhanced DOX cytotoxicity in vivo. Bioinformatics analysis revealed circ_0003998 inhibited miR-218-5p expression, which was clarified to be a target of circ_0003998, and circ_0003998 knockdown sensitized HCC cell to DOX by sponging miR-218-5p. EIF5A2 was a target of miR-218-5p, and miR-218-5p mitigated DOX resistance in HCC cells through modulating EIF5A2 expression. Additionally, circ_0003998 served as a competing endogenous RNA for miR-218-5p to regulate EIF5A2 expression.

Conclusion: Circ_0003998 knockdown sensitized HCC cell to DOX by regulating miR-218-5p/EIF5A2 axis, indicating new markers of poor response to DOX and potential therapeutic strategies for the chemotherapy of HCC.

Keywords: Doxorubicin resistance; EIF5A2; HCC; circ_0003998; miR-218-5p.

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / pathology*
  • Cell-Free Nucleic Acids / genetics*
  • Doxorubicin
  • Drug Resistance, Neoplasm / genetics*
  • Gene Expression Regulation, Neoplastic / genetics
  • Heterografts
  • Humans
  • Liver Neoplasms / genetics
  • Liver Neoplasms / pathology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • MicroRNAs / genetics*
  • Peptide Initiation Factors / genetics*
  • RNA-Binding Proteins / genetics*


  • Antibiotics, Antineoplastic
  • Cell-Free Nucleic Acids
  • MIRN218 microRNA, human
  • MicroRNAs
  • Peptide Initiation Factors
  • RNA-Binding Proteins
  • eukaryotic translation initiation factor 5A
  • Doxorubicin