Clusterin contributes to hepatitis C virus-related hepatocellular carcinoma by regulating autophagy

Life Sci. 2020 Sep 1:256:117911. doi: 10.1016/j.lfs.2020.117911. Epub 2020 Jun 3.

Abstract

Aims: To explore the potential regulatory mechanism of differentially expressed mRNAs in Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

Main methods: Patients with HCV-related HCC and age- and gender-matched healthy subjects were enrolled. Differentially expressed mRNAs in the plasma were detected by digital gene expression (DGE) profile analysis. HepG2 and SMMC7721 cells stably transfected with HCV-core protein and the control plasmid were established. And small interfering RNA (siRNA) was used to knockdown the target gene in HCV core-expressing HCC cell lines. mRNA expression was determined by qRT-PCR. Protein expression was measured by Western blot and immunohistochemistry staining.

Key findings: DGE profile data showed aberrant mRNA expression contributed to the progression of HCV-HCC, and clusterin (CLU), which was significantly highly expressed, was chosen as a candidate gene. Further evidence showed CLU was highly expressed in tumor tissues of HCV-HCC patients and HCV core-expressing HCC cell lines, accompanied with enhanced autophagy and upregulation of pro-autophagy genes. And knockdown of CLU in HCC cell lines suppressed cell autophagy, which was indicated by decreased expression of autophagy marker light chain 3B (LC3B) ІІ/І ratio, and downregulated pro-autophagy genes like Beclin1, autophagy-related protein 7 (Atg7) and Lamp2. On the other hand, anti-autophagy genes or regulators, including p62 and phosphorylated mammalian target of rapamycin (p-mTOR), were notably upregulated.

Significance: CLU could promote the progression of HCV-related HCC by regulating autophagy, which might be a potential therapeutic target of HCV-HCC.

Keywords: Autophagy; Clusterin; Hepatitis C virus; Hepatocellular carcinoma.

MeSH terms

  • Aged
  • Apoptosis / drug effects
  • Autophagy / drug effects*
  • Autophagy / genetics
  • Autophagy-Related Protein 7 / metabolism
  • Beclin-1 / metabolism
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Cell Line, Tumor
  • Clusterin / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Knockdown Techniques
  • Genomic Library
  • Hepacivirus / metabolism*
  • Humans
  • Liver / metabolism
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Lysosomal-Associated Membrane Protein 2 / metabolism
  • Male
  • Middle Aged
  • Phosphorylation
  • RNA, Messenger / drug effects
  • RNA, Small Interfering / drug effects
  • RNA-Binding Proteins / metabolism
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Beclin-1
  • Clusterin
  • Lysosomal-Associated Membrane Protein 2
  • RNA, Messenger
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • TOR Serine-Threonine Kinases
  • Autophagy-Related Protein 7