RESUMO
In the present study the role of poly(ADP)ribosylation on rubitecan induced caspase dependent cell death was evaluated. We show that Top1 poisoning by rubitecan induces caspase mediated apoptosis which was reduced by PARP inhibitor olaparib in zebrafish embryo. Collectively our data introduces zebrafish as a valuable model for PARP related biomedical research.
Assuntos
Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores da Topoisomerase I/farmacologia , Peixe-Zebra/embriologia , Animais , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Sinergismo Farmacológico , Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/análise , Poli(ADP-Ribose) Polimerase-1/químicaRESUMO
Topoisomerase poisons are known to stabilize covalent enzyme-DNA intermediates forming covalent cleavage complexes, which are highly cytotoxic especially for dividing cells and thus, make topoisomerases targets for cancer therapy. Topoisomerases have been extensively studied in mammalian model systems, whereas in other vertebrate models including zebrafish, they still remain less characterized. Here we show similarities in the genotoxic effects of zebrafish and mammalian systems towards topoisomerase I (Top1) poisons and PARP inhibitor - olaparib. On the other hand we observed that topoisomerase II (Top2) poisons (doxorubicin and etoposide) did not affect 1 day post fertilization embryo viability, however in cells isolated from Top2 drug treated embryos the formation of DNA cleavage complexes was observed by comet assay. We explain this by cellular drug uptake limitation in live zebrafish embryos versus unimpeded drug influx in cells isolated from Top2 poisons pre-treated embryos. We also demonstrate that EDTA facilitates the extraction of Top2 from zebrafish nuclei and recovers both, basal and Top2 poison induced DNA damage.