Epigenetic upregulation and functional role of the mitochondrial aspartate/glutamate carrier isoform 1 in hepatocellular carcinoma

Biochim Biophys Acta Mol Basis Dis. 2019 Jan;1865(1):38-47. doi: 10.1016/j.bbadis.2018.10.018. Epub 2018 Oct 12.

Abstract

Metabolic reprogramming is a common hallmark of cancer cells. Although some biochemical features have been clarified, there is still much to learn about cancer cell metabolism and its regulation. Aspartate-glutamate carrier isoform 1 (AGC1), encoded by SLC25A12 gene, catalyzes an exchange between intramitochondrial aspartate and cytosolic glutamate plus a proton across the mitochondrial membrane, so supplying aspartate to the cytosol. SLC25A12, expressed in brain, heart, and skeletal muscle, is silenced in normal liver. Here, we demonstrate that SLC25A12 gene is reactivated in hepatocellular carcinoma (HCC) HepG2 cell line through histone acetylation and CREB recruitment. Furthermore, SLC25A12 knockdown by small interfering RNA, impairs HepG2 cell proliferation by inducing cell cycle arrest. AGC1 sustains HCC cell growth by supplying cytosolic aspartate for nucleotide biosynthesis. In addition, SLC25A12-silenced HCC cells show a strong reduction of cell migration. Overall, we have provided evidence for molecular mechanisms controlling SLC25A12 gene expression in liver and pointing to an important role for AGC1 in HCC.

Keywords: Aspartate-glutamate carrier isoform 1 (AGC1); Cancer metabolism; Epigenetics; Gene expression; Hepatocellular carcinoma (HCC); SLC25A12.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems, Acidic / metabolism*
  • Antiporters / metabolism*
  • Aspartic Acid / metabolism*
  • Brain / metabolism
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Cell Cycle
  • Cell Line, Tumor
  • Cell Proliferation
  • Epigenesis, Genetic*
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Gene Silencing
  • Glutamic Acid / metabolism*
  • Heart
  • Hep G2 Cells
  • Humans
  • Liver Neoplasms / metabolism*
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / metabolism
  • Muscle, Skeletal / metabolism
  • Protein Isoforms / metabolism*
  • Up-Regulation*

Substances

  • Amino Acid Transport Systems, Acidic
  • Antiporters
  • Mitochondrial Membrane Transport Proteins
  • Protein Isoforms
  • SLC25A12 protein, human
  • aspartate-glutamate carrier
  • Aspartic Acid
  • Glutamic Acid