RNA Interference Using c-Myc–Conjugated Nanoparticles Suppresses Breast and Colorectal Cancer Models

Abstract

In this article, we report the development and preclinical validation of combinatorial therapy for treatment of cancers using RNA interference (RNAi). RNAi technology is an attractive approach to silence genes responsible for disease onset and progression. Currently, the critical challenge facing the clinical success of RNAi technology is in the difficulty of delivery of RNAi inducers, due to low transfection efficiency, difficulties of integration into host DNA and unstable expression. Using the macromolecule polyglycidal methacrylate (PGMA) as a platform to graft multiple polyethyleneimine (PEI) chains, we demonstrate effective delivery of small oligos (anti-miRs and mimics) and larger DNAs (encoding shRNAs) in a wide variety of cancer cell lines by successful silencing/activation of their respective target genes. Furthermore, the effectiveness of this therapy was validated for in vivo tumor suppression using two transgenic mouse models; first, tumor growth arrest and increased animal survival was seen in mice bearing Brca2/p53-mutant mammary tumors following daily intratumoral treatment with nanoparticles conjugated to c-Myc shRNA. Second, oral delivery of the conjugate to an Apc-deficient crypt progenitor colon cancer model increased animal survival and returned intestinal tissue to a non-wnt-deregulated state. This study demonstrates, through careful design of nonviral nanoparticles and appropriate selection of therapeutic gene targets, that RNAi technology can be made an affordable and amenable therapy for cancer. Mol Cancer Ther; 14(5); 1259-69. Ó2015 AACR.

shRNA-WT1 Potentiates Anticancer Effects of Gemcitabine and Cisplatin Against B16F10 Lung MetastasesIn VitroandIn Vivo

“…RNA concentration and integrity were determined by measuring the absorbance at 260 nm. The cDNA was performed using 5 μg of total RNA, 200 U of Superscript III, and 0.5 μg of oligo dT (12)(13)(14)(15)(16)(17)(18) under the following conditions: 42˚C for 90 min, followed by heating at 70˚C for 10 min. The cDNA obtained was amplified using Taq DNA polymerase (Life Technologies) and Wt1 primers: 5'-AACGCCCCTTCATGTGTGC-3' and 5'-GCTGGTCTGAACGAGAAAACCTTC-3' to amplify a fragment of 150 bp.…”

“…For this reason, WT1 is considered a good target for anticancer therapy (12). The silencing of genes involved in proliferation and apoptosis are an attractive strategy for the development of anticancer therapies (13)(14)(15), and for sensitizing tumor cells to chemotherapy (14). It has been observed that silencing genes such as B-cell lymphoma 2 (BCL2) and BCL-xL sensitizes cisplatin-resistant cells (16,17).…”

Therapeutic aspects of c-MYC signaling in inflammatory and cancerous colonic diseases

“…However, the used 21 base siRNA duplexes were quite unstable. ShRNAs with a transient period of expression are better suited for long-term effectiveness, due to their ability to produce siRNAs continuously within cancer cells, thus resulting in prolonged suppression of target genes[ 126 ]. Until today, shRNAs have been delivered effectively in vivo using viral vectors.…”

“…Furthermore, the effectiveness of this therapy was validated for in vivo tumor suppression using transgenic mouse models. It was found that oral delivery of the c-Myc- conjugated nanoparticles to an Apc -deficient crypt progenitor colon cancer model resulted in an increased host survival and re-entered intestinal tissue to a non- Wnt -deregulated state[ 126 ]. According to these results, it seems that careful design of nonviral nanoparticles may help to made RNA interference technology an affordable and amenable therapy for CRC.…”

Antisense Oligonucleotides against miR-21 Inhibit the Growth and Metastasis of Colorectal Carcinoma via the DUSP8 Pathway

“… 9 For example, Tangudu et al. 10 reported that upregulation of p53 using anti-miR-21 ASOs linked to rhodamine-labeled nanoparticles and could suppress a CRC model. Kasiri et al.…”