title: Nuclear factor kappa B binding activity in mouse L1210 cells following photofrin II-mediated photosensitization.
abstract: Clinical photodynamic therapy (PDT) uses the photosensitizer photofrin II to produce singlet molecular oxygen and other reactive oxygen intermediates for localized tumor tissue cytotoxicity. In this report, we show that PDT enhances the DNA binding activity of nuclear factor kappa B (NF kappa B), a transactivator of cytokine gene expression. Photosensitization following a 16 h incubation of photofrin II induced NF kappa B binding activity in mouse leukemia L1210 cells 10-fold above that observed in exponentially growing cultures. Serum starvation, as well as drug-alone and light-alone controls, elevated basal NF kappa B binding activity two- to three-fold. Upstream stimulatory factor binding activity was not modulated by any of the cell treatments and was used to standardize gel mobility shift data. This study identifies porphyrin-mediated PDT as an inducer of NF kappa B binding activity, extending recent findings that NF kappa B activation is a general response to oxidative stress.
authors.affiliation: Department of Molecular Pharmacology & Toxicology, University of Southern California.
authors.forename: S W
authors.initials: SW
authors.lastname: Ryter
authors.forename: C J
authors.initials: CJ
authors.lastname: Gomer
mesh_terms: D000818:Animals; D001483:Base Sequence; D004273:DNA, Neoplasm / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D017323:Dihematoporphyrin Ether / Q000494:pharmacology*; D007939:Leukemia L1210 / Q000378:metabolism*; D008027:Light; D051379:Mice; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D011485:Protein Binding; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D051720:Upstream Stimulatory Factors
chemical_list: D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D014157:Transcription Factors; D051720:Upstream Stimulatory Factors; D017323:Dihematoporphyrin Ether