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An In Vitro Approach to Photodynamic Therapy
04:53

An In Vitro Approach to Photodynamic Therapy

Published on: August 17, 2018

Role of p53 and ATM in photodynamic therapy-induced apoptosis

Viola Heinzelmann-Schwarz1, André Fedier, René Hornung

  • 1Department of Obstetrics and Gynecology, Division of Gynecology, University Hospital of Zurich, 8091 Zurich, Switzerland.

Lasers in Surgery and Medicine
|September 2, 2003
PubMed
Abstract

Insights

Photodynamic therapy (PDT) primarily causes cell death through necrosis, independent of p53 and ATM genes. However, these genes play a role in mediating apoptosis during PDT treatment.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Photodynamic therapy (PDT) utilizes laser light-activated photosensitizers to induce cell death.
  • PDT is a therapeutic option for radio- and chemo-resistant tumors.

Purpose of the Study:

  • To investigate if m-THPC-PDT induces cell death via necrosis and/or apoptosis.
  • To determine if p53 and ATM gene status modulate these cell death responses.

Main Methods:

  • Utilized mouse embryonic fibroblasts with varying atm and p53 gene statuses (atm(+/+)p53(+/+), atm(+/+)p53(-/-), atm(-/-)p53(-/-)).
  • Assessed cell death using MTT assay, trypan blue exclusion, TUNEL, and caspase-3 cleavage assays.
  • Determined c-Abl protein levels via immunoblotting.

Main Results:

  • m-THPC-PDT induced rapid, p53- and ATM-independent non-apoptotic cell death (necrosis).
  • Apoptosis was reduced in cells lacking p53 and further reduced with the additional absence of ATM.
  • Apoptosis levels showed an inverse correlation with c-Abl protein levels.

Conclusions:

  • p53 and ATM are not essential for PDT-induced necrosis.
  • p53 and ATM may play a role in facilitating PDT-mediated apoptosis.
  • The findings suggest a complex interplay between gene status and cell death pathways in PDT response.

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