Targeted gene silencing using RGD-labeled chitosan nanoparticles.
OBJECTIVE
This study aimed to develop an Arg-Gly-Asp (RGD) peptide-labeled chitosan nanoparticle (RGD-CH-NP) as a novel tumor targeted delivery system for short interfering RNA (siRNA).


METHODS
RGD peptide conjugated with chitosan by thiolation reaction was confirmed by proton-NMR (H-NMR). Binding of RGD-CH-NP with alphanubeta3 integrin was examined by flow cytometry and fluorescence microscopy. Antitumor efficacy was examined in orthotopic mouse models of ovarian carcinoma.


RESULTS
We show that RGD-CH-NP loaded with siRNA significantly increased selective intratumoral delivery in orthotopic animal models of ovarian cancer. In addition, we show targeted silencing of multiple growth-promoting genes (POSTN, FAK, and PLXDC1) along with therapeutic efficacy in the SKOV3ip1, HeyA8, and A2780 models using siRNA incorporated into RGD-CH-NP (siRNA/RGD-CH-NP). Furthermore, we show in vivo tumor vascular targeting using RGD-CH-NP by delivering PLXDC1-targeted siRNA into the alphanubeta3 integrin-positive tumor endothelial cells in the A2780 tumor-bearing mice. This approach resulted in significant inhibition of tumor growth compared with controls.


CONCLUSIONS
This study shows that RGD-CH-NP is a novel and highly selective delivery system for siRNA with the potential for broad applications in human disease.
Department of Gynecologic Oncology, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
Hee Dong
HD
Han
Lingegowda S
LS
Mangala
Jeong Won
JW
Lee
Mian M K
MM
Shahzad
Hye Sun
HS
Kim
Deyu
D
Shen
Eun Ji
EJ
Nam
Edna M
EM
Mora
Rebecca L
RL
Stone
Chunhua
C
Lu
Sun Joo
SJ
Lee
Ju Won
JW
Roh
Alpa M
AM
Nick
Gabriel
G
Lopez-Berestein
Anil K
AK
Sood
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D015153:Blotting, Western; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D009363:Neoplasm Proteins / Q000235:genetics; D009842:Oligopeptides / Q000008:administration & dosage* / Q000737:chemistry; D010051:Ovarian Neoplasms / Q000235:genetics / Q000628:therapy*; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023041:Xenograft Model Antitumor Assays
D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D009842:Oligopeptides; C510620:PLXDC1 protein, human; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; C047981:arginyl-glycyl-aspartic acid; D048271:Chitosan