Cytotoxic effects of gemcitabine-loaded liposomes in human anaplastic thyroid carcinoma cells.
BACKGROUND
Identification of effective systemic antineoplastic drugs against anaplastic thyroid carcinomas has particularly important implications. In fact, the efficacy of the chemotherapeutic agents presently used in these tumours, is strongly limited by their low therapeutic index.


METHODS
In this study gemcitabine was entrapped within a pegylated liposomal delivery system to improve the drug antitumoral activity, thus exploiting the possibility to reduce doses to be administered in cancer therapy. The cytotoxic effects of free or liposome-entrapped gemcitabine was evaluated against a human thyroid tumour cell line. ARO cells, derived from a thyroid anaplastic carcinoma, were exposed to different concentrations of the drug. Liposomes formulations were made up of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol/1,2-distearoyl-sn-glycero-3-phosphoethanolamine-MPEG (8:3:1 molar ratio). Cell viability was assessed by both trypan bleu dye exclusion assay and fluorimetric analysis of cell DNA content.


RESULTS
A cytotoxic effect of free gemcitabine was present only after 72 h incubation (ARO cell mortality increased of approximately 4 fold over control at 1 microM, 7 fold at 100 microM). When gemcitabine was encapsulated in liposomes, a significant effect was observed by using lower concentrations of the drug (increased cell mortality of 2.4 fold vs. control at 0.3 microM) and earlier exposure time (24 h).


CONCLUSIONS
These findings show that, in vitro against human thyroid cancer cells, the gemcitabine incorporation within liposomes enhances the drug cytotoxic effect with respect to free gemcitabine, thus suggesting a more effective drug uptake inside the cells. This may allow the use of new formulations with lower dosages (side effect free) for the treatment of anaplastic human thyroid tumours.
Celano
Marilena
M
Department of Pharmacobiological Sciences, University of Catanzaro "Magna Graecia", 88100 Catanzaro, Italy. celano.donato@tiscali.it
Calvagno
Maria Grazia
MG
Bulotta
Stefania
S
Paolino
Donatella
D
Arturi
Franco
F
Rotiroti
Domenicoantonio
D
Filetti
Sebastiano
S
Fresta
Massimo
M
Russo
Diego
D
D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002470:Cell Survival / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D003841:Deoxycytidine / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004337:Drug Carriers; D006801:Humans; D008081:Liposomes; D013964:Thyroid Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D014407:Tumor Cells, Cultured; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D004337:Drug Carriers; D008081:Liposomes; D003841:Deoxycytidine; D000093542:Gemcitabine