Cited by 49Photodynamic Therapy Research StudiesGlioma Diagnosis and TreatmentNanoplatforms for cancer theranostics

Antagonistic Effects of Endogenous Nitric Oxide in a Glioblastoma Photodynamic Therapy Model

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Fahey, Jonathan M., Emmer, Joseph V., Korytowski, Witold, Hogg, Neil, Girotti, Albert W.·2016·Photochemistry and Photobiology

Abstract

Gliomas are aggressive brain tumors that are resistant to conventional chemotherapy and radiotherapy. Much of this resistance is attributed to endogenous nitric oxide (NO). Recent studies revealed that 5‐aminolevulinic acid (ALA)‐based photodynamic therapy (PDT) has advantages over conventional treatments for glioblastoma. In this study, we used an in vitro model to assess whether NO from glioblastoma cells can interfere with ALA‐PDT. Human U87 and U251 cells expressed significant basal levels of neuronal NO synthase (nNOS) and its inducible counterpart (iNOS). After an ALA/light challenge, iNOS level increased three‐ to fourfold over 24 h, whereas nNOS remained unchanged. Elevated iNOS resulted in a large increase in intracellular NO. Extent of ALA/light‐induced apoptosis increased substantially when an iNOS inhibitor or NO scavenger was present, implying that iNOS/NO was acting cytoprotectively. Moreover, cells surviving a photochallenge exhibited a striking increase in proliferation, migration and invasion rates, iNOS/NO again playing a dominant role. Also observed was a large iNOS/NO‐dependent increase in matrix metalloproteinase‐9 activity, decrease in tissue inhibitor of metalloproteinase‐1 expression and increase in survivin and S100A4 expression, each effect being consistent with accelerated migration/invasion as a prelude to metastasis. Our findings suggest introduction of iNOS inhibitors as pharmacologic adjuvants for glioblastoma PDT.

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  • Increased NO production after low doses of ALA-PDT with less than ~25% cell killing not only prevented tumor cell death but also made surviving tumor cells more proliferative and migratory.

    “Such increased NO production, which occurred after low doses of ALA-PDT with less than ~25% cell killing, not only prevented tumor cell death but also made surviving tumor cells more proliferative and migratory [144,145,146].”

    From 5-Aminolevulinic Acid as a Theranostic Agent for Tumor Fluorescence Imaging and Photodynamic Therapy (2023) · cites this paper as [145]

    The Results report that iNOS/NO protected U87 and U251 glioblastoma cells against ALA/light-induced killing, and that surviving U87 cells showed NO-dependent increases in proliferation and migration. The experiments used a low light fluence of 1 J/cm², but the passages in our copy do not establish the claim’s specific threshold of less than ~25% cell killing. (LLM, conf=0.84)

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Research works printed but not linked: 1

  1. [56]Bechet D Mordon SR Guillemin F Barberi-Heyob MA 2014 Photodynamic therapy of malignant brain tumours: a complementary approach to conventional therapies Cancer Treatment Rev 40 229 241 22858248

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Authors
Fahey, J. M., Emmer, J. V., Korytowski, W., Hogg, N., & Girotti, A. W.
Affiliations
  • Medical College of Wisconsin (US)
  • Jagiellonian University (PL)
Corresponding author
Girotti, Albert W.
Venue
Photochemistry and Photobiology
Publisher
Wiley
Published
2016-10-17
Volume
92
Issue
6
Pages
842-853
ISSN
  • 0031-8655 (ISSN-L)
  • 1751-1097
OpenAlex
W2510529496
Cited by
49
References
72
Citations by year
2026: 2 · 2025: 6 · 2024: 5 · 2023: 8 · 2022: 3 · 2021: 5 · 2020: 5 · 2019: 6 · 2018: 5 · 2017: 1 · 2016: 3
FWCI
4.47
Type
journal article
Language
en
Open access
Locations
  • Photochemistry and Photobiology (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Jagiellonian University Repository (Jagiellonian University) (submittedVersion, cc-by-nc-nd)
Funders
  • U.S. Public Health Service (CA70823)
  • National Cancer Institute
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Photodynamic Therapy Research Studies
  • Health Sciences › Medicine › Genetics › Glioma Diagnosis and Treatment
  • Physical Sciences › Engineering › Biomedical Engineering › Nanoplatforms for cancer theranostics
Keywords
glioblastoma, photodynamic therapy, 5-aminolevulinic acid, nitric oxide, inducible nitric oxide synthase, neuronal nitric oxide synthase, apoptosis, cell migration and invasion, MMP-9, TIMP-1, survivin, S100A4, iNOS inhibitors, NO scavenger, metastasis
MeSH terms
Adjuvants, Pharmaceutic, Aminolevulinic Acid, Animals, Cell Survival, Glioblastoma, Humans, Nitric Oxide, Photochemotherapy, Apoptosis, Cell Line, Tumor, Nitric Oxide Synthase Type II

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