Tumor Site–Specific Silencing ofNF-κB p65by Targeted Hollow Gold Nanosphere–Mediated Photothermal Transfection

NF-kappaB transcription factor is a critical regulator of the expression of genes involved in tumor formation and progression. Successful RNA interference (RNAi) therapeutics targeting NF-kappaB is challenged by small interfering RNA (siRNA) delivery systems, which can render targeted in vivo delivery, efficient endolysosomal escape, and dynamic control over activation of RNAi. Here, we report near-IR (NIR) light-inducible NF-kappaB downregulation through folate receptor-targeted hollow gold nanospheres carrying siRNA recognizing NF-kappaB p65 subunit. Using micro-positron emission tomography/computed tomography imaging, the targeted nanoconstructs exhibited significantly higher tumor uptake in nude mice bearing HeLa cervical cancer xenografts than nontargeted nanoparticles following i.v. administration. Mediated by hollow gold nanospheres, controllable cytoplasmic delivery of siRNA was obtained on NIR light irradiation through photothermal effect. Efficient downregulation of NF-kappaB p65 was achieved only in tumors irradiated with NIR light but not in nonirradiated tumors grown in the same mice. Liver, spleen, kidney, and lung were not affected by the treatments, in spite of significant uptake of the siRNA nanoparticles in these organs. We term this mode of action "photothermal transfection." Combined treatments with p65 siRNA photothermal transfection and irinotecan caused substantially enhanced tumor apoptosis and significant tumor growth delay compared with other treatment regimens. Therefore, photothermal transfection of NF-kappaB p65 siRNA could effectively sensitize the tumor to chemotherapeutic agents. Because NIR light can penetrate the skin and be delivered with high spatiotemporal control, therapeutic RNAi may benefit from this novel transfection strategy while avoiding unwanted side effect.

[1]  L. Medina-Kauwe,et al.  Intracellular trafficking of nonviral vectors , 2005, Gene Therapy.

[2]  Chun Li,et al.  Bifunctional Gold Nanoshells with a Superparamagnetic Iron Oxide-Silica Core Suitable for Both MR Imaging and Photothermal Therapy. , 2007, The journal of physical chemistry. C, Nanomaterials and interfaces.

[3]  Samit Shah,et al.  Light-activated RNA interference. , 2005, Angewandte Chemie.

[4]  Matthew Tirrell,et al.  Laser-Activated Gene Silencing via Gold Nanoshell-siRNA Conjugates. , 2009, ACS nano.

[5]  C. Cerri,et al.  Monocyte/Macrophage-Derived Microparticles Up-Regulate Inflammatory Mediator Synthesis by Human Airway Epithelial Cells1 , 2006, The Journal of Immunology.

[6]  Michael Karin,et al.  NF-κB in cancer: from innocent bystander to major culprit , 2002, Nature Reviews Cancer.

[7]  K. Hamad-Schifferli,et al.  Selective release of multiple DNA oligonucleotides from gold nanorods. , 2009, ACS nano.

[8]  Tammy Y. Olson,et al.  Synthesis, characterization, and tunable optical properties of hollow gold nanospheres. , 2006, The journal of physical chemistry. B.

[9]  Jennifer A. Dougan,et al.  Enhanced oligonucleotide–nanoparticle conjugate stability using thioctic acid modified oligonucleotides , 2007, Nucleic acids research.

[10]  B. Williams,et al.  Light controllable siRNAs regulate gene suppression and phenotypes in cells. , 2006, Biochimica et biophysica acta.

[11]  P. Jain,et al.  Gold nanoparticles: interesting optical properties and recent applications in cancer diagnostics and therapy. , 2007, Nanomedicine.

[12]  William G Telford,et al.  Detection of localized caspase activity in early apoptotic cells by laser scanning cytometry. , 2002, Cytometry.

[13]  R. Schiffelers,et al.  Photochemical internalization enhances silencing of epidermal growth factor receptor through improved endosomal escape of siRNA. , 2007, Biochimica et biophysica acta.

[14]  E. Hovig,et al.  Evaluation of various polyethylenimine formulations for light-controlled gene silencing using small interfering RNA molecules. , 2008, Oligonucleotides.

[15]  Wolfgang A. Weber,et al.  Impact of tumor-specific targeting on the biodistribution and efficacy of siRNA nanoparticles measured by multimodality in vivo imaging , 2007, Proceedings of the National Academy of Sciences.

[16]  Arezou A Ghazani,et al.  Determining the size and shape dependence of gold nanoparticle uptake into mammalian cells. , 2006, Nano letters.

[17]  C. Murphy,et al.  Gold nanoparticles are taken up by human cells but do not cause acute cytotoxicity. , 2005, Small.

[18]  R. Weissleder.  A clearer vision for in vivo imaging , 2001, Nature Biotechnology.

[19]  Younan Xia,et al.  Gold Nanocages: Engineering Their Structure for Biomedical Applications , 2005 .

[20]  R. Gaynor,et al.  Enhanced Chemosensitivity to Irinotecan by RNA Interference-Mediated Down-Regulation of the Nuclear Factor-κB p65 Subunit , 2004, Clinical Cancer Research.

[21]  D. Crommelin,et al.  Preparation and characterization of folate-targeted pEG-coated pDMAEMA-based polyplexes. , 2003, Journal of controlled release : official journal of the Controlled Release Society.

[22]  H. Dai,et al.  Targeted single-wall carbon nanotube-mediated Pt(IV) prodrug delivery using folate as a homing device. , 2008, Journal of the American Chemical Society.

[23]  Wei Lu,et al.  Targeted Photothermal Ablation of Murine Melanomas with Melanocyte-Stimulating Hormone Analog–Conjugated Hollow Gold Nanospheres , 2009, Clinical Cancer Research.

[24]  Wei Lu,et al.  In vitro and in vivo targeting of hollow gold nanoshells directed at epidermal growth factor receptor for photothermal ablation therapy , 2008, Molecular Cancer Therapeutics.

[25]  Valery Tuchin,et al.  Gold nanoshell photomodification under a single-nanosecond laser pulse accompanied by color-shifting and bubble formation phenomena , 2008, Nanotechnology.

[26]  P. Low,et al.  Endocytosis of folate-protein conjugates: ultrastructural localization in KB cells. , 1993, Journal of cell science.

[27]  R. Stafford,et al.  Nanoshell-mediated near-infrared thermal therapy of tumors under magnetic resonance guidance , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[28]  Alexander M. Klibanov,et al.  Conjugation to gold nanoparticles enhances polyethylenimine's transfer of plasmid DNA into mammalian cells , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[29]  M J May,et al.  NF-kappa B and Rel proteins: evolutionarily conserved mediators of immune responses. , 1998, Annual review of immunology.

[30]  M. Álvarez,et al.  Rapid generation of protein aerosols and nanoparticles via SAW atomisation , 2008 .

[31]  T. Tuschl,et al.  Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells , 2001, Nature.

[32]  Hironobu Takahashi,et al.  Controlled release of plasmid DNA from gold nanorods induced by pulsed near-infrared light. , 2005, Chemical communications.

[33]  M. El-Sayed,et al.  Laser-Induced Shape Changes of Colloidal Gold Nanorods Using Femtosecond and Nanosecond Laser Pulses , 2000 .

[34]  Dong Liang,et al.  Influence of anchoring ligands and particle size on the colloidal stability and in vivo biodistribution of polyethylene glycol-coated gold nanoparticles in tumor-xenografted mice. , 2009, Biomaterials.

[35]  Yi-Cheng Chen,et al.  DNA-gold nanorod conjugates for remote control of localized gene expression by near infrared irradiation. , 2006, Journal of the American Chemical Society.