Hypericin photo-induced apoptosis involves the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and activation of caspase-8.
Hypericin (HYP) is a photosensitizing pigment from Hypericum perforatum that displays cytotoxic effects in neoplastic cell lines. Therefore, HYP is presently under consideration as a new anticancer drug in photodynamic therapy. Here, we investigated the mechanism of action of HYP photo-induced apoptosis of Jurkat cells compared to the cytostatic drug paclitaxel (PXL). Both photoactivated HYP and PXL similarly increased the activity of caspase-8 and caspase-3, and drug-induced apoptosis of Jurkat cells was completely blocked by inhibitors of caspase-8 (Z-IETD-FMK) and caspase-3 (Z-DEVD-FMK). The involvement of death receptors was analyzed using neutralizing monoclonal antibodies against Fas (SM1/23), FasL (NOK-2) and TNF-R1 (MAB225), and a polyclonal rabbit anti-human TNF-related apoptosis-inducing ligand (TRAIL) antiserum. TRAIL antibody blocked TRAIL-induced and HYP photo-induced, but not PXL-induced apoptosis of Jurkat cells. In contrast, PXL-induced, but not HYP-induced apoptosis was blocked by the SM1/23 and NOK-2 antibodies. Anti-TNF-R1 antibody had no effect. These findings suggest that HYP photo-induced apoptosis of Jurkat cells is mediated in part by the TRAIL/TRAIL-receptor system and subsequent activation of upstream caspases.
Department of Dermatology, University of Freiburg, Hauptstrasse 7, D-79104, Freiburg, Germany. schempp@haut.ukl.uni-freiburg.de
C M
CM
Schempp
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B
Simon-Haarhaus
C C
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Termeer
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JC
Simon
D000873:Anthracenes; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D019169:Jurkat Cells; D008027:Light; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology; D010569:Perylene / Q000031:analogs & derivatives* / Q000494:pharmacology*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D019014:fas Receptor / Q000378:metabolism
D000873:Anthracenes; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D009842:Oligopeptides; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C403753:benzyloxycarbonyl-isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone; D019014:fas Receptor; D010569:Perylene; C004965:hypericin; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D017239:Paclitaxel