microRNA-29a suppresses cell proliferation by targeting SPARC in hepatocellular carcinoma

Int J Mol Med. 2012 Dec;30(6):1321-6. doi: 10.3892/ijmm.2012.1140. Epub 2012 Sep 25.

Abstract

In the present study, we constructed a lentivirus vector encoding the miR-29a precursor and established two stably infected cell lines, PLC-29a and 97L-29a. The overexpression of miR-29a was confirmed by TaqMan RT-PCR and significantly suppressed the growth of the hepatocellular carcinoma cell lines MHCC-97L and PLC. Dual-luciferase reporter assays indicated that the SPARC mRNA 3'UTR was directly targeted by miR-29a since the mutated 3'UTR was not affected. Silencing SPARC expression by RNAi knockdown resulted in a similar effect as miR-29a overexpression on hepatocellular carcinoma (HCC) cell growth regulation. Anti-miR-29a oligonucleotides (AMOs) upregulated the levels of SPARC in the HCC cells. The phosphorylation of AKT/mTOR downstream of SPARC was inhibited in miR-29a-overexpressing HCC cells. We further examined and compared the expression levels of miR-29a in HCC tissues and the corresponding nearby non-cancerous liver tissues of 110 patients with HCC by qRT-PCR, and significantly lower expression of miR-29a was observed in the tissues affected by HCC. Our findings demonstrate that the expression of miR-29a is important in the regulation of the SPARC-AKT pathway and HCC growth.

MeSH terms

  • Adult
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Proliferation
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Gene Knockdown Techniques
  • Humans
  • Liver / metabolism
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • MicroRNAs / physiology*
  • Middle Aged
  • Osteonectin
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA Interference
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism
  • Up-Regulation

Substances

  • MIRN29a microRNA, human
  • MicroRNAs
  • Osteonectin
  • SPARC protein, human
  • Tumor Suppressor Proteins
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases