Transferrin receptor-targeted lipid nanoparticles for delivery of an antisense oligodeoxyribonucleotide against Bcl-2.
Antisense oligonucleotide G3139-mediated down-regulation of Bcl-2 is a potential strategy for overcoming chemoresistance in leukemia. However, the limited efficacy shown in recent clinical trials calls attention to the need for further development of novel and more efficient delivery systems. In order to address this issue, transferrin receptor (TfR)-targeted, protamine-containing lipid nanoparticles (Tf-LNs) were synthesized as delivery vehicles for G3139. The LNs were produced by an ethanol dilution method, and lipid-conjugated Tf ligand was then incorporated by a postinsertion method. The resulting Tf-LNs had a mean particle diameter of approximately 90 nm and G3139 loading efficiency of 90.4%. Antisense delivery efficiency of Tf-LNs was evaluated in K562, MV4-11, and Raji leukemia cell lines. The results showed that Tf-LNs were more effective than nontargeted LNs and free G3139 (p < 0.05) in decreasing Bcl-2 expression (by up to 62% at the mRNA level in K562 cells) and in inducing caspase-dependent apoptosis. In addition, Bcl-2 down-regulation and apoptosis induced by Tf-LN G3139 were shown to be blocked by excess free Tf and thus were TfR-dependent. Cell lines with higher TfR expression also showed greater Bcl-2 down-regulation. Furthermore, up-regulation of TfR expression in leukemia cells by iron chelator deferoxamine resulted in a further increase in antisense effect (up to 79% Bcl-2 reduction in K562 at the mRNA level) and in caspase-dependent apoptosis (by approximately 3-fold) by Tf-LN. Tf-LN-mediated delivery combined with TfR up-regulation by deferoxamine appears to be a potentially promising strategy for enhancing the delivery efficiency and therapeutic efficacy of antisense oligonucleotides.
Yang
Xiaojuan
X
Division of Pharmaceutics, The Ohio State University, Columbus, Ohio 43210, USA.
Koh
Chee Guan
CG
Liu
Shujun
S
Pan
Xiaogang
X
Santhanam
Ramasamy
R
Yu
Bo
B
Peng
Yong
Y
Pang
Jiuxia
J
Golan
Sharon
S
Talmon
Yeshayahu
Y
Jin
Yan
Y
Muthusamy
Natarajan
N
Byrd
John C
JC
Chan
Kenneth K
KK
Lee
L James
LJ
Marcucci
Guido
G
Lee
Robert J
RJ
D017209:Apoptosis; D045744:Cell Line, Tumor; D003102:Colloids; D020285:Cryoelectron Microscopy; D015536:Down-Regulation; D016503:Drug Delivery Systems; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020319:Oligodeoxyribonucleotides, Antisense / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010316:Particle Size; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism*; D011990:Receptors, Transferrin / Q000737:chemistry* / Q000378:metabolism*
D003102:Colloids; D008055:Lipids; D020319:Oligodeoxyribonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D011990:Receptors, Transferrin