Necroptosis modulated by autophagy is a predominant form of melanoma cell death induced by sanguilutine

Biol Chem. 2012 Jul;393(7):647-58. doi: 10.1515/hsz-2011-0279.

Abstract

We show that the plant quaternary benzo[c]phenanthridine alkaloid sanguilutine (SL) is a strong inducer of caspase-independent non-apoptotic death in human melanoma cells. Necrostatin-1, a specific inhibitor of necroptosis, completely reversed the cytotoxic effect of SL, suggesting that necroptosis was a predominant type of cell death induced by SL in these cells. In addition, we showed that SL can trigger an autophagic response, as confirmed by GFP-LC3 puncta formation and LC3-II accumulation. Interestingly, we observed a significant decrease in the viability of melanoma cells treated with combination of autophagy inhibitors (3-methyladenine, bafilomycin-A1 and LY294002) and SL. Our results further indicated that autophagy may serve as a pro-survival mechanism, delaying the induction of necroptosis in melanoma cells. The ability of SL to induce caspase-independent non-apoptotic cell death (necroptosis) suggests its possible therapeutic potential in the treatment of apoptosis-resistant melanoma tumours. Furthermore, SL might serve as a useful tool for studying the mechanisms of necroptosis and autophagy induction and the interplay between these two processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Antineoplastic Agents / antagonists & inhibitors
  • Antineoplastic Agents / pharmacology*
  • Autophagy / drug effects*
  • Benzophenanthridines / antagonists & inhibitors
  • Benzophenanthridines / pharmacology*
  • Caspases / metabolism
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Imidazoles / pharmacology
  • Indoles / pharmacology
  • Melanoma / pathology*
  • Microtubule-Associated Proteins / metabolism
  • Necrosis / chemically induced
  • Proto-Oncogene Proteins c-bcl-2 / metabolism

Substances

  • Antineoplastic Agents
  • Benzophenanthridines
  • Imidazoles
  • Indoles
  • MAP1LC3A protein, human
  • Microtubule-Associated Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • necrostatin-1
  • sanguilutine
  • 3-methyladenine
  • Caspases
  • Adenine