Oligonucleotides targeted against a junction oncogene are made efficient by nanotechnologies.
OBJECTIVE
Antisense oligonucleotides (AON) against junction EWS-Fli-1 oncogene (which is responsible for the Ewing Sarcoma) are particularly interesting for targeting chromosomal translocations that are only found in tumor cells. However, these AON have proved in the past to be ineffective in vivo because of their susceptibility to degradation and their poor intracellular penetration. The aim of this study was to improve the delivery of these molecules through the use of nanotechnologies.


METHODS
Two different AONs, and their controls, both targeted against the junction area of the fusion gene EWS-Fli-1 were used. Nanocapsules were employed to deliver a phosphorothioate AON and its control. The nanospheres were used to deliver a chimeric phosphorothioate, phosphodiester AON, with 5 additional bases in 5' which allow this AON to be structured with a loop. These formulations were injected intratumorally to nude mice bearing the experimental EWS-Fli-1 tumor. The tumour volume was estimated during the experiments by two perpendicular measurements length (a) and width (b) of the tumour and was calculated as ab(2)/2. Northern blot analysis was also performed after removing the tumors 24 h after the treatment with a single dose of AON either free or associated with nanotechnologies.


RESULTS
This study shows for the first time that AON against EWS-Fli-1 oncogene may inhibit with high specificity the growth of an EWS-Fli-1 dependent tumor grafted to nude mice provided they are delivered by nanocapsules or nanospheres. In this experience, the antisense effect was confirmed by the specific down regulation of EWS-Fli-1 mRNA.


CONCLUSIONS
Thus, both nanocapsules and nanospheres may be considered as promising systems for AON delivery in vivo.
Maksimenko
Andrei
A
CNRS UMR 1582, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif cedex, France.
Malvy
Claude
C
Lambert
Gregory
G
Bertrand
Jean-Rémy
JR
Fattal
Elias
E
Maccario
Jean
J
Couvreur
Patrick
P
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D015152:Blotting, Northern; D001859:Bone Neoplasms / Q000188:drug therapy; D002214:Capsules; D016503:Drug Delivery Systems; D018014:Gene Transfer Techniques; D051379:Mice; D008819:Mice, Nude; D036103:Nanotechnology; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage / Q000627:therapeutic use*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D010316:Particle Size; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D012512:Sarcoma, Ewing / Q000188:drug therapy; D014157:Transcription Factors / Q000235:genetics*
D000970:Antineoplastic Agents; D002214:Capsules; C106031:EWS-FLI fusion protein; D016376:Oligonucleotides, Antisense; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors