Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells

  • Authors:
    • Eun Jin Lim
    • Chul-Ho Oak
    • Jeonghoon Heo
    • Young-Ho Kim
  • View Affiliations

  • Published online on: May 24, 2013     https://doi.org/10.3892/or.2013.2494
  • Pages: 856-862
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Abstract

Combined treatment with a photosensitizer and iodide laser [photodynamic therapy (PDT)] has improved the outcome of various cancers. In this study, we investigated the effects of using the photosensitizer methylene blue (MB) in PDT in human lung adenocarcinoma cells. We found that MB enhances PDT-induced apoptosis in association with downregulation of anti-apoptotic proteins, reduced mitochondrial membrane potential (MMP), increased phosphorylation of the mitogen-activated protein kinase (MAPK) and the generation of reactive oxygen species (ROS). In MB-PDT-treated A549 cells, we observed PARP cleavage, procaspase-3 activation, downregulation of the anti-apoptotic proteins Bcl-2 and Mcl-1, and the reduction of mitochondrial membrane potential (MMP). Western blot data showed that phosphorylation of p38 was increased in MB-PDT-treated A549 cells, indicating that several signaling molecules participate in the apoptotic cascade. Our data also showed that apoptotic cell death in MB-PDT-treated cells occurred through a series of steps beginning with the photochemical generation of ROS. Demonstrating the role of ROS, pretreatment of A549 cells with the antioxidant N-acetylcysteine (NAC) followed by MB-PDT resulted in increased cell viability and reduced proteolytic cleavage of PARP.
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August 2013
Volume 30 Issue 2

Print ISSN: 1021-335X
Online ISSN:1791-2431

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Spandidos Publications style
Lim EJ, Oak C, Heo J and Kim Y: Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells. Oncol Rep 30: 856-862, 2013
APA
Lim, E.J., Oak, C., Heo, J., & Kim, Y. (2013). Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells. Oncology Reports, 30, 856-862. https://doi.org/10.3892/or.2013.2494
MLA
Lim, E. J., Oak, C., Heo, J., Kim, Y."Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells". Oncology Reports 30.2 (2013): 856-862.
Chicago
Lim, E. J., Oak, C., Heo, J., Kim, Y."Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells". Oncology Reports 30, no. 2 (2013): 856-862. https://doi.org/10.3892/or.2013.2494