8-Methoxypsoralen potentiates the photocytotoxic effect of Photofrin II towards EMT-6 murine tumor cells.
Pretreatment of EMT-6 murine tumor cells for 24 h with 10(-4) M 8-methoxypsoralen (8-MOP) increased the photocytotoxicity of Photofrin II (P2) after cell exposure to low doses (1-1.5 J/cm2) of UVA by two- to three-fold. 8-MOP alone had no cytotoxic action under these experimental conditions and did not significantly change the amount of P2 recovered in cells. 8-MOP enhanced the lipid peroxidation end product formation measured as thiobarbituric acid reactive substances (TBARS) during cell photosensitization by P2. The psoralen alone also slightly increased the TBARS level after UVA exposure. These results suggest that 8-MOP, albeit non-photocytotoxic by itself under our experimental conditions, could enhance the efficiency of P2 by increasing cellular lipid peroxidation following light exposure.
Centro de Quimica Fisica Molecular, Instituto Superior Técnico, Lisboa, Portugal.
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C
Sousa
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Mazière
T S
TS
Melo
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Vincent-Fiquet
J C
JC
Rogez
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Santus
J C
JC
Mazière
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017323:Dihematoporphyrin Ether / Q000494:pharmacology*; D004357:Drug Synergism; D015227:Lipid Peroxidation / Q000187:drug effects; D008730:Methoxsalen / Q000494:pharmacology*; D051379:Mice; D009374:Neoplasms, Experimental / Q000188:drug therapy*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D017392:Thiobarbituric Acid Reactive Substances; D017323:Dihematoporphyrin Ether; D008730:Methoxsalen