Photodynamic effects of 5-aminolevulinic acid-induced porphyrin on human bladder carcinoma cells in vitro.
The efficiency of 5-aminolevulinic acid (ALA) in photodynamic therapy (PDT) was investigated in vitro using urothelial carcinoma cells of various differentiation. HCV29, RT4 and J82 cells were cultured in 96-well plates, incubated with 25-100 micrograms/ml ALA in serum-containing medium for 4 h, and irradiated at 630, 635 and 640 nm wavelength with light doses of 15-100 J/cm2. The degree of reduced tetrazolium bromide corresponding to cell viability was determined with a colorimetric MTT assay 0, 24 and 48 h after PDT. A remarkable reduction of mitochondrial activity occurred in poorly (J82) and well differentiated (RT4) malignant urothelial cells. Twenty-four hours after photodynamic treatment with 100 micrograms/ml ALA and 50 J/cm2, the metabolic activity of malignant cells was nearly extinguished, while HCV29 cells, derived from normal urothelium, behaved similarly to non-irradiated control cells. The photosensitivity of cells depended on presence or absence of fetal bovine serum (FBS) in the ALA-incubation medium. A wavelength of 635 nm was up to 60% more effective compared with 630 nm, which is more frequently applied in PDT. From the results of our in vitro studies, we can define a "therapeutic window" for malignant cells without damaging benign cells. The time delayed effects and the strong wavelength dependence are important factors for a clinical application.
Riesenberg
R
R
Laserforschungslabor an der Urologischen Klinik, München, Germany.
Fuchs
C
C
Kriegmair
M
M
D000622:Aminolevulinic Acid / Q000494:pharmacology*; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy / Q000473:pathology*; D016895:Culture Media, Serum-Free; D004307:Dose-Response Relationship, Radiation; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007700:Kinetics; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010778:Photochemotherapy; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000473:pathology*
D016895:Culture Media, Serum-Free; D000622:Aminolevulinic Acid