Traditional herbal medicine-derived sulforaphene promotes mitophagic cell death in lymphoma cells through CRM1-mediated p62/SQSTM1 accumulation and AMPK activation

Chem Biol Interact. 2018 Feb 1:281:11-23. doi: 10.1016/j.cbi.2017.12.017. Epub 2017 Dec 13.

Abstract

Sulforaphene (LFS-01) is the major chemical constituent of Raphanus sativus, a medicinal herb used for over a thousand years in traditional Chinese medicine. Here we identified that LFS-01 can selectively eradicate lymphoma cells while sparing normal lymphocytes by triggering concomitant mitophagy and apoptosis. We demonstrated that LFS-01 can retain Nrf2 in the nucleus by covalently modulating CRM1 and consequently upregulate p62/SQSTM1, an essential structural component of the autophagosomes during mitophagic process. We found that LFS-01 treatment also stimulated AMPK and thereby inhibited the mTOR pathway. On the contrary, we revealed that AMPK inhibition can severely impair the LFS-01-mediated mitophagy. Transcriptomic studies confirmed that 15 autophagy-associated genes such as p62/SQSTM1, VCP and BCL2 were differentially expressed after LFS-01 treatment. Furthermore, protein interactome network analysis revealed that the events of apoptosis and the assembly of autophagy vacuole were significant upon LFS-01 exposure. Lastly, we found that LFS-01 exhibited strong efficacy in xenograft mouse model yet with the lack of apparent toxicity to animals. We concluded that LFS-01 triggered mitophagic cell death via CRM1-mediated p62 overexpression and AMPK activation. Our findings provide new insights into the mechanism of action for LFS-01 and highlight its potential applications in treating major human diseases.

Keywords: AMPK; Apoptosis; Autophagy; CRM1; Mitophagy; Natural product; p62.

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Apoptosis / drug effects*
  • Cell Cycle Checkpoints / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Drugs, Chinese Herbal / chemistry*
  • Exportin 1 Protein
  • Humans
  • Isothiocyanates / chemistry
  • Isothiocyanates / pharmacology*
  • Isothiocyanates / therapeutic use
  • Karyopherins / metabolism*
  • Leukocytes, Mononuclear / cytology
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Lymphoma / drug therapy
  • Lymphoma / metabolism
  • Lymphoma / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mitophagy / drug effects*
  • Neoplasms / drug therapy
  • Neoplasms / metabolism
  • Neoplasms / pathology
  • Protein Structure, Tertiary
  • Raphanus / chemistry
  • Raphanus / metabolism
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Sequestosome-1 Protein / metabolism*
  • Signal Transduction / drug effects
  • Up-Regulation / drug effects

Substances

  • Drugs, Chinese Herbal
  • Isothiocyanates
  • Karyopherins
  • Receptors, Cytoplasmic and Nuclear
  • SQSTM1 protein, human
  • Sequestosome-1 Protein
  • AMP-Activated Protein Kinases
  • sulphoraphene