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Dual bioluminescence and near-infrared fluorescence monitoring to evaluate spherical nucleic acid nanoconjugate activity in vivo
- Source :
- Proceedings of the National Academy of Sciences of the United States of America. 114(16)
- Publication Year :
- 2017
-
Abstract
- RNA interference (RNAi)-based gene regulation platforms have shown promise as a novel class of therapeutics for the precision treatment of cancer. Techniques in preclinical evaluation of RNAi-based nanoconjugates have yet to allow for optimization of their gene regulatory activity. We have developed spherical nucleic acids (SNAs) as a blood-brain barrier-/blood-tumor barrier-penetrating nanoconjugate to deliver small interfering (si) and micro (mi)RNAs to intracranial glioblastoma (GBM) tumor sites. To identify high-activity SNA conjugates and to determine optimal SNA treatment regimens, we developed a reporter xenograft model to evaluate SNA efficacy in vivo. Engrafted tumors stably coexpress optical reporters for luciferase and a near-infrared (NIR) fluorescent protein (iRFP670), with the latter fused to the DNA repair protein O6-methylguanine-DNA-methyltransferase (MGMT). Using noninvasive imaging of animal subjects bearing reporter-modified intracranial xenografts, we quantitatively assessed MGMT knockdown by SNAs composed of MGMT-targeting siRNA duplexes (siMGMT-SNAs). We show that systemic administration of siMGMT-SNAs via single tail vein injection is capable of robust intratumoral MGMT protein knockdown in vivo, with persistent and SNA dose-dependent MGMT silencing confirmed by Western blotting of tumor tissue ex vivo. Analyses of SNA biodistribution and pharmacokinetics revealed rapid intratumoral uptake and significant intratumoral retention that increased the antitumor activity of coadministered temozolomide (TMZ). Our study demonstrates that dual noninvasive bioluminescence and NIR fluorescence imaging of cancer xenograft models represents a powerful in vivo strategy to identify RNAi-based nanotherapeutics with potent gene silencing activity and will inform additional preclinical and clinical investigations of these constructs.
- Subjects :
- 0301 basic medicine
Biodistribution
Mice, SCID
Nanoconjugates
Biology
Fluorescence
03 medical and health sciences
Mice
0302 clinical medicine
In vivo
RNA interference
medicine
Temozolomide
Tumor Cells, Cultured
Gene silencing
Animals
Humans
RNA, Small Interfering
neoplasms
Antineoplastic Agents, Alkylating
DNA Modification Methylases
Gene knockdown
Multidisciplinary
Brain Neoplasms
Tumor Suppressor Proteins
Biological Sciences
Molecular biology
Xenograft Model Antitumor Assays
Dacarbazine
030104 developmental biology
DNA Repair Enzymes
030220 oncology & carcinogenesis
Spherical nucleic acid
Female
RNA Interference
Glioblastoma
Ex vivo
medicine.drug
Subjects
Details
- ISSN :
- 10916490
- Volume :
- 114
- Issue :
- 16
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Accession number :
- edsair.doi.dedup.....a9b12fa6d29da5354b83d2715397f2d0