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Folate-linked lipid-based nanoparticles for synthetic siRNA delivery in KB tumor xenografts
Takashi Yoshizawa1, Yoshiyuki Hattori, Motoki Hakoshima
1Institute of Medicinal Chemistry, Hoshi University, Tokyo, Japan.
Abstract:
RNA interference (RNAi) is a sequence-specific gene-silencing mechanism triggered by synthetic small interfering RNA (siRNA), and is utilized in a wide range of fields including cancer gene therapy by down-regulating a specific target protein. In this study, for tumor-targeted siRNA delivery, we developed a folate-linked nanoparticle (NP-F), and evaluated the potential of NP-F-mediated tumor gene therapy in human nasopharyngeal KB cells, which overexpressed folate receptor (FR). NP-F was composed of cholesteryl-3beta-carboxyamidoethylene-N-hydroxyethylamine (OH-Chol), Tween 80 and folate-poly(ethylene glycol)-distearoylphosphatidylethanolamine conjugate (f-PEG(2000)-DSPE), and NP-P was substituted f-PEG(2000)-DSPE in NP-F PEG(2000)-DSPE for a non-targeting nanoparticle. The NP-F and siRNA complex (nanoplex) formed at a charge ratio (+/-) of 2/1 in the presence of 5mM NaCl was injectable size and increased transfection efficiency in the cells. NP-F showed a significantly higher intracellular amount of siRNA and stronger localization of siRNA in the cytoplasm than NP-P. When Her-2 siRNA was transfected into cells by NP-F and NP-P, NP-F significantly inhibited tumor growth, and selectively suppressed Her-2 protein expression more than NP-P. In in vivo gene therapy, a NP-F nanoplex of Her-2 siRNA by intratumoral injection significantly inhibited tumor growth of KB xenografts compared with control siRNA, but a NP-P nanoplex did not. These results of the experiments have provided optimal conditions to form folate-linked nanoparticle complexes with siRNA for folate-targeted gene therapy.
Insights
Folate-linked nanoparticles effectively deliver small interfering RNA (siRNA) for targeted cancer gene therapy. This targeted approach significantly inhibited tumor growth and suppressed Her-2 protein expression in nasopharyngeal cancer cells.
Area of Science:
- Biotechnology
- Nanomedicine
- Molecular Biology
Background:
- RNA interference (RNAi) offers sequence-specific gene silencing for applications like cancer gene therapy.
- Targeted delivery of small interfering RNA (siRNA) is crucial for effective gene therapy.
- Folate receptor (FR) is overexpressed in certain cancers, making it a potential target for drug delivery.
Purpose of the Study:
- To develop and evaluate folate-linked nanoparticles (NP-F) for targeted siRNA delivery in cancer gene therapy.
- To assess the efficacy of NP-F-mediated gene therapy in human nasopharyngeal KB cells overexpressing FR.
- To optimize conditions for forming folate-linked nanoparticle-siRNA complexes for enhanced gene therapy.
Main Methods:
- Developed folate-linked nanoparticles (NP-F) using OH-Chol, Tween 80, and f-PEG(2000)-DSPE.
- Created non-targeting nanoparticles (NP-P) by substituting f-PEG(2000)-DSPE.
- Formed NP-F/siRNA complexes (nanoplexes) and evaluated their size, transfection efficiency, intracellular siRNA uptake, and localization in KB cells.
- Assessed tumor growth inhibition and Her-2 protein suppression in vitro and in vivo using Her-2 siRNA delivered by NP-F and NP-P.
Main Results:
- NP-F/siRNA nanoplexes exhibited optimal characteristics for transfection and increased intracellular siRNA delivery compared to NP-P.
- NP-F demonstrated significantly higher intracellular siRNA amounts and cytoplasmic localization than NP-P.
- In vitro, NP-F significantly inhibited tumor cell growth and suppressed Her-2 protein expression.
- In vivo, intratumoral injection of NP-F/Her-2 siRNA nanoplexes significantly inhibited KB xenograft tumor growth, unlike NP-P nanoplexes.
Conclusions:
- Folate-linked nanoparticles are effective carriers for targeted siRNA delivery in cancer gene therapy.
- NP-F facilitates enhanced intracellular uptake and cytoplasmic localization of siRNA.
- NP-F-mediated gene therapy shows significant potential for inhibiting tumor growth and suppressing target gene expression in FR-overexpressing cancers.
