Tumor necrosis factor-alpha induces apoptosis associated with poly(ADP-ribose) polymerase cleavage in HT-29 colon cancer cells

Anticancer Res. May-Jun 2002;22(3):1635-9.


Background: Tumor necrosis factor-alpha (TNF-alpha) is known for its selective cytotoxic activity on tumour cells. We analysed the response of HT-29 human colon carcinoma cells to this cytokine.

Materials and methods: After TNF-alpha treatment, cell proliferation, cell cycle, reactive oxygen species (ROS) production (flow cytometry), the amount of apoptotic cells (flow cytometry, fluorescence microscopy), cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 activity (Western blotting) were detected.

Results: TNF-alpha induced a decrease of cell growth and viability, an accumulation of cells in the S-phase of the cell cycle, an increase of subdiploid cell population and nuclear chromatin condensation and fragmentation, but not sooner than 96-120 hours. However, earlier events characteristic of apoptosis occurred, such as caspase-3 activation, PARP cleavage to 89 kDa fragment and changes in ROS production.

Conclusion: We demonstrated that, in addition to being an early marker of apoptosis, activation of caspase-3 and degradation of PARP may play a causative role in HT-29 cell death induced by TNF-alpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Caspase 3
  • Caspases / metabolism
  • Cell Death / drug effects
  • Cell Division / drug effects
  • HT29 Cells / drug effects*
  • HT29 Cells / enzymology
  • HT29 Cells / pathology
  • Humans
  • Kinetics
  • Poly(ADP-ribose) Polymerases / metabolism*
  • Reactive Oxygen Species / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology*


  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • Poly(ADP-ribose) Polymerases
  • CASP3 protein, human
  • Caspase 3
  • Caspases