MOTS-c relieves hepatocellular carcinoma resistance to TRAIL-induced apoptosis under hypoxic conditions by activating MEF2A

Exp Cell Res. 2025 Jan 1;444(1):114354. doi: 10.1016/j.yexcr.2024.114354. Epub 2024 Nov 22.

Abstract

Background: Mitochondrial ORF of the 12S rRNA type-c (MOTS-c) as an AMPK agonist can regulate the expression of adaptive nuclear genes to promote cell homeostasis. However, the investigation of MOTS-c in hepatocellular carcinoma (HCC) is insufficient. This study aims to reveal the role of MOTS-c on HCC cell apoptosis.

Methods: Huh7 and HCCLM3 cells were incubated with MOTS-c under a hypoxic condition. MOTS-c levels were quantified by enzyme-linked immunosorbent assay in the peripheral blood of HCC patients and healthy controls. Cell viability was detected by 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis was investigated by flow cytometry and Tunel assay. Protein expression was detected by western blotting or immunohistochemistry assay. Dual-luciferase reporter assay and chromatin immunoprecipitation assay were performed to identify the association among myocyte enhancer factor 2A (MEF2A), death receptor 4 (DR4) and DR5. A tumor-bearing nude mouse model was conducted to assess the effect of MOTS-c on HCC tumor formation in vivo.

Results: MOTS-c levels in the peripheral blood of HCC patients were significantly lower compared to healthy individuals. MOTS-c promoted HCC cell apoptosis under hypoxia conditions. Hypoxia stimulation decreased the protein expression of MEF2A, DR4, DR5, fas-associating via death domain (FADD) and caspase-8, while these effects were attenuated after MOTS-c treatment. MOTS-c induced TRAIL-induced apoptosis of HCC cells by activating MEF2A through the phosphorylation of AMPK under hypoxia treatment. In addition, MEF2A transcriptionally up-regulated DR4 and DR5. MOTS-c activated MEF2A to regulate DR4 and DR5 expression, further mediating TRAIL-induced apoptosis. Further, MOTS-c treatment relieved hypoxia-induced tumor growth in vivo.

Conclusion: MOTS-c relieved hypoxia-induced HCC cell resistance to TRAIL-caused apoptosis by activating MEF2A.

Keywords: AMPK; HCC; MEF2A; MOTS-C; TRAIL-Induced apoptosis; hypoxia.

MeSH terms

  • Animals
  • Apoptosis* / drug effects
  • Carcinoma, Hepatocellular* / drug therapy
  • Carcinoma, Hepatocellular* / genetics
  • Carcinoma, Hepatocellular* / metabolism
  • Carcinoma, Hepatocellular* / pathology
  • Cell Hypoxia / drug effects
  • Cell Line, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Liver Neoplasms* / drug therapy
  • Liver Neoplasms* / genetics
  • Liver Neoplasms* / metabolism
  • Liver Neoplasms* / pathology
  • MEF2 Transcription Factors* / genetics
  • MEF2 Transcription Factors* / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude*
  • Middle Aged
  • Receptors, TNF-Related Apoptosis-Inducing Ligand / genetics
  • Receptors, TNF-Related Apoptosis-Inducing Ligand / metabolism
  • TNF-Related Apoptosis-Inducing Ligand* / metabolism
  • TNF-Related Apoptosis-Inducing Ligand* / pharmacology
  • Xenograft Model Antitumor Assays

Substances

  • TNF-Related Apoptosis-Inducing Ligand
  • MEF2 Transcription Factors
  • MEF2A protein, human
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • TNFSF10 protein, human