Delivery of MDR1 Small Interfering RNA by Self-Complementary Recombinant Adeno-Associated Virus Vector

Abstract

Small interfering RNAs (siRNAs) are potentially powerful tools for therapeutic gene regulation. DNA cassettes encoding RNA polymerase III promoter-driven hairpin siRNAs allow long-term expression of siRNA in targeted cells. A variety of viral vectors have been used to deliver such cassettes to cells. Here we report on the development and use of a self-complementary recombinant adeno-associated virus (scAAV) vector for siRNA delivery into mammalian cells. We demonstrate that this modified vector efficiently delivers siRNA into multidrug-resistant human breast and oral cancer cells and suppresses MDR1 gene expression. This results in rapid, profound, and durable reduction in the expression of the P-glycoprotein multidrug transporter and a substantial reversion of the drug-resistant phenotype. This research suggests that scAAV-based vectors can be very effective agents for efficient delivery of therapeutic siRNA.

Administration of PLK-1 small interfering RNA with atelocollagen prevents the growth of liver metastases of lung cancer

“…Numerous methods to transfect siRNA into cells have been developed, and viral vectors are the most efficient among them (31,32). However, the feasibility of viral vectors is limited because they can disrupt important genes and induce mutagenesis and the development of cancers (33,34).…”

Crippling of HIV at Multiple Stages with Recombinant Adeno-Associated Viral Mediated RNA Interference

“…Furthermore, rAAV vectors show only a modest frequency of integration into the host genome, thus avoiding insertional mutagenesis, which has been a stumbling block for the clinical use of retroviral or lentiviral vectors. Development of self-complimentary (also known as double stranded) vectors to avoid delay in trans-gene expression (96,114) and packaging with capsid mutants (115) to increase transduction efficiency has further contributed to rAAV vectorology. Recent advances in our understanding of RNAi make rAAV an especially attractive candidate for anti-HIV-1 gene therapy, and rAAV-based RNAi approaches can be combined with other therapeutic modalities to make a combinatorial therapy akin to HAART.…”

Adeno-associated virus vectors: potential applications for cancer gene therapy

“…We have used scAAV2 vectors to successfully deliver hairpin siRNA into multidrug-resistant human breast cancer and Cancer gene therapy with AAV C Li et al oral cancer cells, and dramatically reduce P-glycoprotein expression levels resulting in substantial reversal of the MDR phenotype in the cells. 159 …”