Characteristics of palytoxin-induced cytotoxicity in neuroblastoma cells.
Cation fluxes appear to play a key role in palytoxin-induced signal. There are other cellular targets that have not been described as well as the biochemical signaling cascades that transmit palytoxin-stimulated signals remain to be clarified. Since modifications of cations, mainly calcium, are generally associated to cell death or apoptosis, we wanted to further evaluate the effect of palytoxin on cell death. Then, in vitro cytotoxic effects of palytoxin were characterized on human neuroblastoma cells. By using several techniques, we studied markers of cell death and apoptosis, such as cell detachment, mitochondrial membrane potential, caspases, DNA damage, LDH leakage, propidium iodide uptake, F-actin depolymerization and inhibition of cellular proliferation. Results show that palytoxin triggers a series of toxic responses; it inhibits cell proliferation, induces cell rounding, detachment from the substratum and F-actin disruption. Among the apoptotic markers studied we only detected fall in mitochondrial membrane potential. Neither caspases activation nor chromatin condensation or DNA fragmentation were observed in palytoxin-treated cells.
Valverde
I
I
Microbiology and Biotoxins Area, ANFACO-CECOPESCA, Campus Univ de Vigo, Vigo, Spain.
Lago
J
J
Reboreda
A
A
Vieites
J M
JM
Cabado
A G
AG
D000178:Acrylamides / Q000494:pharmacology / Q000633:toxicity*; D000199:Actins / Q000187:drug effects / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002843:Chromatin / Q000187:drug effects / Q000378:metabolism; D003064:Cnidarian Venoms; D053938:DNA Fragmentation / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009447:Neuroblastoma / Q000378:metabolism*; D000095702:Polyether Toxins
D000178:Acrylamides; D000199:Actins; D020169:Caspases; D002843:Chromatin; D003064:Cnidarian Venoms; C010272:palytoxin; D000095702:Polyether Toxins