Violacein induces death of resistant leukaemia cells via kinome reprogramming, endoplasmic reticulum stress and Golgi apparatus collapse

PLoS One. 2012;7(10):e45362. doi: 10.1371/journal.pone.0045362. Epub 2012 Oct 11.

Abstract

It is now generally recognised that different modes of programmed cell death (PCD) are intimately linked to the cancerous process. However, the mechanism of PCD involved in cancer chemoprevention is much less clear and may be different between types of chemopreventive agents and tumour cell types involved. Therefore, from a pharmacological view, it is crucial during the earlier steps of drug development to define the cellular specificity of the candidate as well as its capacity to bypass dysfunctional tumoral signalling pathways providing insensitivity to death stimuli. Studying the cytotoxic effects of violacein, an antibiotic dihydro-indolone synthesised by an Amazon river Chromobacterium, we observed that death induced in CD34(+)/c-Kit(+)/P-glycoprotein(+)/MRP1(+) TF1 leukaemia progenitor cells is not mediated by apoptosis and/or autophagy, since biomarkers of both types of cell death were not significantly affected by this compound. To clarify the working mechanism of violacein, we performed kinome profiling using peptide arrays to yield comprehensive descriptions of cellular kinase activities. Pro-death activity of violacein is actually carried out by inhibition of calpain and DAPK1 and activation of PKA, AKT and PDK, followed by structural changes caused by endoplasmic reticulum stress and Golgi apparatus collapse, leading to cellular demise. Our results demonstrate that violacein induces kinome reprogramming, overcoming death signaling dysfunctions of intrinsically resistant human leukaemia cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Calpain / antagonists & inhibitors
  • Cell Death / drug effects*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Death-Associated Protein Kinases
  • Endoplasmic Reticulum Stress
  • Golgi Apparatus / drug effects*
  • Humans
  • Indoles / therapeutic use*
  • Leukemia / drug therapy*
  • Proto-Oncogene Proteins c-akt / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • Indoles
  • DAPK1 protein, human
  • Death-Associated Protein Kinases
  • Proto-Oncogene Proteins c-akt
  • Cyclic AMP-Dependent Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Calpain
  • violacein

Grants and funding

This work was supported by grants from TopInstitute pharma (The Netherlands), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). CVF was supported by a research fellowship from CNPq. GMF was supported by the Dutch Cancer Society (grant EMCR 2010-4737). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.