Upregulation of iNOS/NO in Cancer Cells That Survive a Photodynamic Challenge: Role of No in Accelerated Cell Migration and Invasion. Int J Mol Sci 2024 May 23;25(11)
Date
06/19/2024Pubmed ID
38891885Pubmed Central ID
PMC11171770DOI
10.3390/ijms25115697Scopus ID
2-s2.0-85195836378 (requires institutional sign-in at Scopus site) 5 CitationsAbstract
Anti-tumor photodynamic therapy (PDT) is a unique modality that employs a photosensitizer (PS), PS-exciting light, and O2 to generate cytotoxic oxidants. For various reasons, not all malignant cells in any given tumor will succumb to a PDT challenge. Previous studies by the authors revealed that nitric oxide (NO) from inducible NO synthase (iNOS/NOS2) plays a key role in tumor cell resistance and also stimulation of migratory/invasive aggressiveness of surviving cells. iNOS was the only NOS isoform implicated in these effects. Significantly, NO from stress-upregulated iNOS was much more important in this regard than NO from preexisting enzymes. Greater NO-dependent resistance, migration, and invasion was observed with at least three different cancer cell lines, and this was attenuated by iNOS activity inhibitors, NO scavengers, or an iNOS transcriptional inhibitor. NO diffusing from PDT-targeted cells also stimulated migration/invasion potency of non-targeted bystander cells. Unless counteracted by appropriate measures, all these effects could seriously compromise clinical PDT efficacy. Here, we will review specific examples of these negative side effects of PDT and how they might be suppressed by adjuvants such as NO scavengers or inhibitors of iNOS activity or expression.
Author List
Girotti AW, Korytowski WAuthor
Albert Girotti PhD, MS Emeritus Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCell Movement
Humans
Neoplasm Invasiveness
Neoplasms
Nitric Oxide
Nitric Oxide Synthase Type II
Photochemotherapy
Photosensitizing Agents
Up-Regulation
