Enhancing the effect of 5-aminolevulinic acid based photodynamic therapy in human meningioma cells.
BACKGROUND
The interest in photodynamic therapy (PDT) in cancer treatment has continuously increased since its' advent in the 1960s. In neurosurgery, 5-aminolevulinic acid based photodynamic therapy (5-ALA PDT) is used for malignant glioma in vitro and in vivo. Data about PDT in meningioma, which is the second most frequent primary brain tumor, is sparse. Preliminary work indicated that meningiomas are more resistant to PDT than gliomas. In the present study we evaluated whether the effect of 5-ALA PDT on malignant meningioma cells can be increased by ciprofloxacin and changes in incubation time, factors known to influence the effectiveness of PDT in other tumor entities.


METHODS
An in vitro-PDT model of a malignant human meningioma cell line (KT21-MG) was chosen as screening method. Cultured cells were incubated with varying 5-ALA concentrations for 4h and exposed to PDT (control group). Two experimental groups, one with 5-ALA and ciprofloxacin (group I) and one with 24-h ALA incubation time (group II), were studied, respectively. Cell viability was assessed by WST-1 assay.


RESULTS
Ciprofloxacin and longer ALA incubation time significantly increased the lethal effect of 5-ALA PDT on meningioma cells.


CONCLUSIONS
Efficacy of 5-ALA PDT could be increased by adjunction of ciprofloxacin in conventional clinical dosing and by prolongation of ALA incubation time. As ciprofloxacin is a common antibiotic with good tissue penetration, low toxicity and a favorable risk profile it represents a clinically interesting method for future PDT trials in meningiomas.
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany. Electronic address: cornelius@med.uni-duesseldorf.de.
Jan Frederick
JF
Cornelius
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany.
Philipp Jörg
PJ
Slotty
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany.
Mustafa
M
El Khatib
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany.
Alexander
A
Giannakis
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany.
Brigitte
B
Senger
Neurochirurgische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Moorenstrasse 5, 40229 Düsseldorf, Germany.
Hans Jakob
HJ
Steiger
D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D006801:Humans; D008577:Meningeal Neoplasms / Q000188:drug therapy*; D008579:Meningioma / Q000188:drug therapy*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
D017319:Photosensitizing Agents; D002939:Ciprofloxacin; D000622:Aminolevulinic Acid
5-ALA; Cancer therapy; Cell culture; Meningioma model; Photodynamic therapy