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Bacillus thuringiensis parasporal proteins induce cell-cycle arrest and caspase-dependant apoptotic cell death in

Kok-Keong Chan1, Rebecca Shin-Yee Wong, Shar Mariam Mohamed

  • 1Division of Human Biology, School of Medical and Health Sciences, International Medical University, Kuala Lumpur, Malaysia.

Journal of Environmental Pathology, Toxicology and Oncology : Official Organ of the International Society for Environmental Toxicology and Cancer
|May 18, 2012
PubMed

Insights

Bacillus thuringiensis (Bt) 18 parasporal proteins show selective anticancer effects, inducing apoptosis and S-phase cell-cycle arrest in leukemia cells but not normal lymphocytes. Glyceraldehyde 3-phosphate dehydrogenase binding initiates this cell death pathway.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cancer Research

Background:

  • Bacillus thuringiensis (Bt) parasporal proteins are investigated for selective anticancer properties.
  • Understanding the mechanism of action of these proteins against cancer cells is crucial.

Purpose of the Study:

  • To determine the efficacy and cell death mechanisms of Bt 18 parasporal proteins against specific leukemic cell lines.
  • To identify the binding site of these proteins on target cells.

Main Methods:

  • Cell-based assays to assess cell viability and apoptosis.
  • Ultrastructural analysis to observe apoptotic changes.
  • Western blot analysis to identify protein binding targets.

Main Results:

  • Bt 18 parasporal proteins moderately reduced leukemic cell viability, sparing normal human T lymphocytes.
  • Apoptotic activity was confirmed by phosphatidylserine externalization, active caspase-3, and cell cycle analysis, showing S-phase arrest.
  • Glyceraldehyde 3-phosphate dehydrogenase was identified as a binding protein.

Conclusions:

  • Bt 18 parasporal proteins inhibit leukemic cell viability through cell-cycle arrest and apoptosis.
  • Binding to glyceraldehyde 3-phosphate dehydrogenase appears to initiate the apoptotic process in leukemic cells.

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