Abstract | BACKGROUND: The development of effective drug delivery systems capable of transporting small interfering RNA ( siRNA) has been elusive. We have previously reported that colorectal cancer tumor xenograft growth was arrested following treatment with liposomal preparation of siDCAMKL-1. In this report, we have utilized Nanoparticle (NP) technology to deliver DCAMKL-1 specific siRNA to knockdown potential key cancer regulators. In this study, mRNA/ miRNA were analyzed using real-time RT-PCR and protein by western blot/immunohistochemistry. siDCAMKL-1 was encapsulated in Poly(lactide-co-glycolide)-based NPs (NP-siDCAMKL-1); Tumor xenografts were generated in nude mice, treated with NP-siDCAMKL-1 and DAPT (γ- secretase inhibitor) alone and in combination. To measure let-7a and miR-144 expression in vitro, HCT116 cells were transfected with plasmids encoding the firefly luciferase gene with let-7a and miR-144 miRNA binding sites in the 3'UTR. RESULTS: Administration of NP-siDCAMKL-1 into HCT116 xenografts resulted in tumor growth arrest, downregulation of proto-oncogene c-Myc and Notch-1 via let-7a and miR-144 miRNA-dependent mechanisms, respectively. A corresponding reduction in let-7a and miR-144 specific luciferase activity was observed in vitro. Moreover, an upregulation of EMT inhibitor miR-200a and downregulation of the EMT-associated transcription factors ZEB1, ZEB2, Snail and Slug were observed in vivo. Lastly, DAPT-mediated inhibition of Notch-1 resulted in HCT116 tumor growth arrest and down regulation of Notch-1 via a miR-144 dependent mechanism. CONCLUSIONS: These findings demonstrate that nanoparticle-based delivery of siRNAs directed at critical targets such as DCAMKL-1 may provide a novel approach to treat cancer through the regulation of endogenous miRNAs.
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Authors | Sripathi M Sureban, Randal May, Fadee G Mondalek, Dongfeng Qu, Sivapriya Ponnurangam, Panayotis Pantazis, Shrikant Anant, Rama P Ramanujam, Courtney W Houchen |
Journal | Journal of nanobiotechnology
(J Nanobiotechnology)
Vol. 9
Pg. 40
(Sep 19 2011)
ISSN: 1477-3155 [Electronic] England |
PMID | 21929751
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Dipeptides
- Intracellular Signaling Peptides and Proteins
- MAS1 protein, human
- MIRN144 microRNA, human
- MIRN200 microRNA, human
- MYC protein, human
- MicroRNAs
- N-(N-(3,5-difluorophenacetyl)alanyl)phenylglycine tert-butyl ester
- NOTCH1 protein, human
- Proto-Oncogene Mas
- Proto-Oncogene Proteins c-myc
- Receptor, Notch1
- Transcription Factors
- mirnlet7 microRNA, human
- DCLK1 protein, human
- Doublecortin-Like Kinases
- Protein Serine-Threonine Kinases
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Topics |
- Animals
- Carcinoma
(drug therapy)
- Colorectal Neoplasms
(drug therapy)
- Dipeptides
(pharmacology)
- Doublecortin-Like Kinases
- Down-Regulation
- Gene Expression Regulation, Neoplastic
(drug effects)
- HCT116 Cells
- Humans
- Intracellular Signaling Peptides and Proteins
(pharmacology)
- Mice
- Mice, Nude
- MicroRNAs
(metabolism)
- Nanoparticles
(administration & dosage)
- Protein Serine-Threonine Kinases
(pharmacology)
- Proto-Oncogene Mas
- Proto-Oncogene Proteins c-myc
(metabolism)
- Receptor, Notch1
(metabolism)
- Transcription Factors
(metabolism)
- Up-Regulation
- Xenograft Model Antitumor Assays
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