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Cell Death Associated with Abnormal Mitosis Observed by Confocal Imaging in Live Cancer Cells
15:53

Cell Death Associated with Abnormal Mitosis Observed by Confocal Imaging in Live Cancer Cells

Published on: August 21, 2013

Brevinin-2R(1) semi-selectively kills cancer cells by a distinct mechanism, which involves the

Saeid Ghavami1, Ahmad Asoodeh, Thomas Klonisch

  • 1Department of Biochemistry and Medical Genetics, Manitoba Institute of Cell Biology, Cancer Care Manitoba, Winnipeg, Manitoba, Canada.

Journal of Cellular and Molecular Medicine
|May 23, 2008
PubMed

Insights

Brevinin-2R, a frog-derived defensin, selectively kills cancer cells by disrupting lysosomal and mitochondrial pathways. This novel compound triggers cell death through mechanisms involving autophagy, offering a potential new avenue for cancer therapy.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Pharmacology

Background:

  • Brevinin-2R is a novel non-hemolytic defensin isolated from Rana ridibunda skin.
  • Defensins are known for their antimicrobial properties and potential anticancer activities.

Purpose of the Study:

  • To investigate the cytotoxic effects of Brevinin-2R on various cancer cell lines and primary cells.
  • To elucidate the molecular mechanisms underlying Brevinin-2R-induced cell death.

Main Methods:

  • Cytotoxicity assays on cancer cell lines (Jurkat, BJAB, HT29/219, SW742, L929, MCF-7, A549) and primary cells (PBMC, T cells, fibroblasts).
  • Analysis of cell death markers including mitochondrial membrane potential (ΔPsim), ATP levels, reactive oxygen species (ROS), caspase activation, and apoptosis-inducing factor (AIF) release.
  • Investigation of Brevinin-2R interaction with cellular compartments like endosomes and lysosomes, and the role of autophagy.

Main Results:

  • Brevinin-2R demonstrated preferential cytotoxicity towards malignant cells compared to primary cells.
  • Resistance to Brevinin-2R was observed in cells overexpressing Bcl2 or a dominant-negative mutant of BNIP3.
  • Early indicators of cell death included decreased mitochondrial membrane potential, reduced ATP levels, and increased ROS production, without caspase activation.
  • Brevinin-2R interacts with endosomes, and its effects are mediated by lysosomal membrane permeabilization and cathepsin activity.
  • Autophagosomes were detected, suggesting a role for autophagy-like cell death.

Conclusions:

  • Brevinin-2R selectively targets cancer cells, indicating its potential as an anticancer agent.
  • The cell death mechanism involves the lysosomal-mitochondrial pathway and is associated with autophagy.
  • Brevinin-2R represents a promising lead compound for developing novel cancer therapeutics.

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