Evaluation of firefly luciferase bioluminescence mediated photodynamic toxicity in cancer cells.
OBJECTIVE
This work investigated whether fLuc-catalyzed oxidation of D-luciferin generates sufficient light to induce photodynamic toxicity in cancer cells.


METHODS
Light emission was assessed via cooled CCD (charge-coupled device) camera. Parental and fLuc expressing cancer cells were exposed to subtoxic concentrations of photosensitizers (Rose Bengal or hypericin) and D-luciferin, sunlight, or lamplight. Toxicity was assessed by MTT assay.


RESULTS
fLuc expressing cells emitted up to 500-fold higher levels of photons than parental cell lines. Although exposure to photosensitizer and sunlight reduced survival of various cell lines, survival of fLuc expressing cells incubated with photosensitizer and D-luciferin, or photosensitizer and lamplight, did not differ significantly from parental or untreated cells.


CONCLUSIONS
Contesting recent reports, fLuc bioluminescence does not generate sufficient photons to induce Rose Bengal or hypericin photodynamic toxicity in a range of malignant and nonmalignant cell lines, and is not suitable as a generalizable approach to antineoplastic therapy.
Schipper
Meike L
ML
Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University, E 150 Clark Center, 318 Campus Drive, Palo Alto, CA 94305-5427, USA.
Patel
Manishkumar R
MR
Gambhir
Sanjiv S
SS
D000818:Animals; D000873:Anthracenes; D000970:Antineoplastic Agents / Q000627:therapeutic use; D006224:Cricetinae; D006801:Humans; D008027:Light; D049409:Luciferases, Firefly / Q000627:therapeutic use*; D051379:Mice; D009369:Neoplasms / Q000628:therapy*; D010569:Perylene / Q000031:analogs & derivatives / Q000627:therapeutic use; D010778:Photochemotherapy / Q000379:methods*; D017785:Photons / Q000627:therapeutic use; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D051381:Rats; D012395:Rose Bengal / Q000627:therapeutic use; D013472:Sunlight; D014162:Transfection; D014407:Tumor Cells, Cultured
D000873:Anthracenes; D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D012395:Rose Bengal; D010569:Perylene; C004965:hypericin; D049409:Luciferases, Firefly