Antisense and triple helix-forming oligonucleotides (TFOs) have great potential as therapeutic agents to specifically block the expression of deleterious genes. We are proposing to develop novel delivery vehicles, to improve the cellular internalization and membrane permeability of oligonucleotides. These compounds are polyaminolipids that contain both cationic and lipophilic moieties, and they are designed to be biodegradable and relatively nontoxic to cells and animals. The utility of the potential uptake enhancers will be validated in a quantitative, anti-oncogene assay system. Specifically, we have established sensitive in vitro assays to measure the inhibition of Epidermal Growth Factor Receptor (EGFR) expression in glioblastoma cells. The candidate uptake enhancers will be coadministered with anti-EGFR TFOs to cells, and any gain in the biological efficacy of the TFOs will be quantified. A variety of TFO and polyaminolipid formulations will be tested. The toxicity and pharmacokinetic properties of the most effective formulation will be monitored in animal studies. The most promising uptake enhancers will be tested for in vivo pharmacological activity in Phase Il of these studies. In principle, the approach should be of utility in optimizing the cellular delivery of not only oligonucleotides, but also longer pieces of DNA for gene therapy.
This research may lead to simple and efficient drug delivery systems for nucleic acid pharmaceuticals, including triple helix-forming oligonucleotides and antisense compounds. The method may also be suitable for improving the cellular and nuclear delivery of genes utilized in gene therapy application.
