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Evaluation of Caspase Activation to Assess Innate Immune Cell Death
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TNF-alpha induces apoptosis mediated by AEBSF-sensitive serine protease(s) that may involve upstream caspase-3/CPP32

I C Park1, M J Park, T B Choe

  • 1Laboratory of Cell Biology, Korea Cancer Center Hospital, Nowon-gu, Seoul 139-706, Korea.

International Journal of Oncology
|May 17, 2000
PubMed

Insights

Tumor necrosis factor-alpha (TNF-alpha) triggers apoptosis in gastric cancer cells via caspase-3/CPP32 activation. Serine proteases also play a key role in this TNF-alpha-induced cell death pathway.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Molecular Oncology

Background:

  • Tumor necrosis factor-alpha (TNF-alpha) is a key cytokine involved in inflammation and apoptosis.
  • Gastric adenocarcinoma is a significant cause of cancer mortality worldwide.
  • Understanding the molecular mechanisms of TNF-alpha-induced apoptosis is crucial for developing targeted therapies.

Purpose of the Study:

  • To investigate the roles of caspase-3/CPP32 and serine proteases in TNF-alpha-induced apoptosis in SNU-16 human gastric adenocarcinoma cells.
  • To elucidate the specific molecular events linking TNF-alpha to programmed cell death in this cancer model.

Main Methods:

  • Treatment of SNU-16 cells with TNF-alpha.
  • Analysis of caspase-3/CPP32 activation using specific inhibitors (z-DEVD-fmk).
  • Assessment of protein cleavage (PKCdelta) via immunoblotting.
  • Evaluation of apoptosis markers like DNA fragmentation and chromatin condensation.
  • Inhibition of serine proteases using AEBSF.

Main Results:

  • TNF-alpha induced apoptosis in SNU-16 cells, characterized by caspase-3/CPP32 activation.
  • PKCdelta cleavage occurred in a caspase-3/CPP32-dependent manner following TNF-alpha treatment.
  • Inhibition of caspase-3/CPP32 with z-DEVD-fmk blocked TNF-alpha-induced DNA fragmentation.
  • The serine protease inhibitor AEBSF abrogated all apoptotic features and prevented caspase-3/CPP32 activation, suggesting an upstream role.

Conclusions:

  • Both caspase-3/CPP32 and serine proteases are activated during TNF-alpha-induced apoptosis in SNU-16 gastric cancer cells.
  • Serine protease activation appears to be an upstream event crucial for caspase-3/CPP32 activation in this pathway.
  • These findings highlight a complex protease network involved in TNF-alpha-mediated cell death in gastric adenocarcinoma.

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