Protoporphyrin IX induces apoptosis in HeLa cells prior to photodynamic treatment

Pharmacol Rep. 2007 Jul-Aug;59(4):474-9.

Abstract

Photodynamic therapy (PDT) combining treatment with a light-excited compound and laser light induction, via cellular ROS generation, kills cancer cells by damaging organelles and impairing metabolic pathways. As the exact mechanisms underlying cancer cell death due to PDT treatment remain controversial, the influence of photosensitizer itself, protoporphyrin IX (PpIX) on cancer cells was investigated. The concentration-dependent viability of HeLa cells was estimated after PpIX-treatment. Microscopic analyses revealed that treated cells exhibited apoptosis-like morphology: blebbing, chromatin condensation, nuclear fragmentation, asymmetry of cellular membrane. These results shed a new light on cancer cell death due to PDT because they showed that PpIX can induce apoptosis without light excitation.

MeSH terms

  • Apoptosis / drug effects*
  • Apoptosis / genetics
  • Apoptosis / radiation effects
  • Cell Membrane Permeability / drug effects
  • Cell Membrane Permeability / radiation effects
  • Cell Nucleus / drug effects
  • Cell Nucleus / radiation effects
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Cell Survival / radiation effects
  • Chromatin / drug effects
  • Chromatin / radiation effects
  • Comet Assay / methods
  • DNA Fragmentation / drug effects
  • DNA Fragmentation / radiation effects
  • Dose-Response Relationship, Drug
  • HeLa Cells
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Microscopy, Fluorescence
  • Photochemotherapy
  • Photosensitizing Agents / pharmacology
  • Protoporphyrins / pharmacology*
  • Time Factors

Substances

  • Chromatin
  • Photosensitizing Agents
  • Protoporphyrins
  • Hydrogen Peroxide
  • protoporphyrin IX