Recruitment of leukocytes to injured tissue and their migration out of the vasculature is mediated in part by expression of cell adhesion molecules, including vascular cell adhesion molecule-1 (vCAM-1), on the surface of endothelial cells. Prolonged elevation of these substances is associated with a number of pathologies involving inflammation and may contribute to tissue damage through increased trafficking of leukocytes to the diseased tissue.
This research aims to develop new therapeutic tools to control undesirable inflammation through down-regulation of VCAM-1. We plan to employ a novel variant of antisense therapy that directly blocks translation through an unusually strong sense-antisense interaction, allowing the targeting of coding regions of mRNAs, where existing antisense approaches are not generally effective, apparently due to disruption of the sense-antisense complex by translocating ribosomes. The new technique permits delivery of the antisense agent by a gene therapy approach as well as direct delivery of RNA using cationic lipid carriers. We will design antisense constructs targeted to regions of VCAM-1 mRNA that appear to be accessible in the cell based on published results, and deliver them using cationic lipids to HUVEC cells, assaying for their ability to down-regulate VCAM-1. If successful, this approach, which can be extended to any antisense target, is likely to increase both the effectiveness of antisense therapy in general and the number of sequences that can be targeted. The technique can also be adapted to antigene strategies. In this case, a triplex is formed in which the added third strand is tightly bound to the target duplex DNA.
Sustained, inappropriate inflammation is a hallmark of a number of chronic diseases, including atherosclerosis, asthma, and inflammatory bowel disease, and numerous efforts are underway to develop more effective and safe anti-inflammatory therapies to treat such conditions. The technology we are developing to treat these conditions, improvements to antisense and antigene pharmaceuticals, has the potential for therapeutic regulation of disease-mediating genes with exquisite specificity and low toxicity. Antisense technologies are being developed by a number of pharmaceutical companies. Our proposed improvements could greatly strengthen the effectiveness of antisense and antigene approaches to therapy. These approaches are quite general and, besides inflammatory diseases they could have applications to cancer as well as genetic and viral diseases (including MDS)-any condition where a gene is improperly overexpressed. Ribozyme Pharmaceuticals. Inc. and Isis Pharmaceuticals have both expressed interest in helping to commercialize this work.
