Functional proteomics of resveratrol-induced colon cancer cell apoptosis: caspase-6-mediated cleavage of lamin A is a major signaling loop

Proteomics. 2006 Apr;6(8):2386-94. doi: 10.1002/pmic.200500366.

Abstract

The study investigated the molecular basis of resveratrol (RSV)-evoked apoptosis in four (Bax+/-, Bax-/-, p53+/+, and p53-/-) HCT116 colon cancer cell lines. RSV induced apoptosis in all the cells in a dose-dependent manner; however, Bax+/- and p53+/+ cells were more susceptible than their knockout counterparts (Bax-/- and p53-/-, respectively). Using Bax+/- cells as a model, proteomic analysis revealed four RSV-responsive events: fragmentation of lamin A/C protein; increase in concentration of a more basic isoelectric variant of the ribosomal protein P0; and decrease in concentration of dUTPase as well as stathmin 1. Lamin A cleavage in response to RSV treatment was confirmed using Western blot analysis. Caspase-6 was activated, which was evidenced by cleavage and accumulation in active form of caspase-6 as well as upregulation of the protease activity. RSV-elicited lamin A cleavage and apoptosis were entirely abrogated by the peptide inhibitors of caspase-6. Likewise, partial knockdown of caspase-6 expression using small interfering RNA resulted in significant inhibition of RSV-elicited lamin A cleavage and apoptosis. Furthermore, the lower apoptosis sensitivity of the knockout cells (Bax-/- and p53-/-) correlated with the relatively reduced processing of caspase-6 and lamin A cleavage. Taken together, these data highlight the critical role of caspase-6 and its cleavage of lamin A in apoptotic signaling triggered by RSV in the colon carcinoma cells, which can be activated in the absence of Bax or p53.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Apoptosis*
  • Caspase 6
  • Caspases / metabolism*
  • Cell Line, Tumor
  • Colonic Neoplasms / drug therapy*
  • Colonic Neoplasms / pathology*
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Lamin Type A / chemistry*
  • Proteomics / methods*
  • Resveratrol
  • Signal Transduction
  • Stilbenes / pharmacology*
  • Transgenes
  • Tumor Suppressor Protein p53 / metabolism
  • bcl-2-Associated X Protein / metabolism

Substances

  • Antineoplastic Agents, Phytogenic
  • Lamin Type A
  • Stilbenes
  • Tumor Suppressor Protein p53
  • bcl-2-Associated X Protein
  • CASP6 protein, human
  • Caspase 6
  • Caspases
  • Resveratrol