Epithelial-Mesenchymal Transition (EMT) Induced by TGF-β in Hepatocellular Carcinoma Cells Reprograms Lipid Metabolism

Int J Mol Sci. 2021 May 24;22(11):5543. doi: 10.3390/ijms22115543.

Abstract

(1) Background: The transforming growth factor (TGF)-β plays a dual role in liver carcinogenesis. At early stages, it inhibits cell growth and induces apoptosis. However, TGF-β expression is high in advanced stages of hepatocellular carcinoma (HCC) and cells become resistant to TGF-β induced suppressor effects, responding to this cytokine undergoing epithelial-mesenchymal transition (EMT), which contributes to cell migration and invasion. Metabolic reprogramming has been established as a key hallmark of cancer. However, to consider metabolism as a therapeutic target in HCC, it is necessary to obtain a better understanding of how reprogramming occurs, which are the factors that regulate it, and how to identify the situation in a patient. Accordingly, in this work we aimed to analyze whether a process of full EMT induced by TGF-β in HCC cells induces metabolic reprogramming. (2) Methods: In vitro analysis in HCC cell lines, metabolomics and transcriptomics. (3) Results: Our findings indicate a differential metabolic switch in response to TGF-β when the HCC cells undergo a full EMT, which would favor lipolysis, increased transport and utilization of free fatty acids (FFA), decreased aerobic glycolysis and an increase in mitochondrial oxidative metabolism. (4) Conclusions: EMT induced by TGF-β in HCC cells reprograms lipid metabolism to facilitate the utilization of FFA and the entry of acetyl-CoA into the TCA cycle, to sustain the elevated requirements of energy linked to this process.

Keywords: EMT; HCC; TGF-beta; beta oxidation; lipid metabolism; liver; oxidative metabolism.

MeSH terms

  • Carcinoma, Hepatocellular / metabolism*
  • Cell Movement / drug effects
  • Epithelial-Mesenchymal Transition / drug effects*
  • Epithelial-Mesenchymal Transition / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / genetics
  • Gene Silencing
  • Hep G2 Cells
  • Humans
  • Lipid Metabolism / drug effects*
  • Liver Neoplasms / metabolism*
  • Metabolome / drug effects*
  • Metabolome / genetics
  • Metabolomics
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Oxidative Phosphorylation / drug effects
  • Receptors, Transforming Growth Factor beta / genetics
  • Receptors, Transforming Growth Factor beta / metabolism
  • Transcriptome / drug effects*
  • Transcriptome / genetics
  • Transforming Growth Factor beta / pharmacology*

Substances

  • Receptors, Transforming Growth Factor beta
  • Transforming Growth Factor beta