Antisense oligonucleotides show promise as agents for controlling the expression of specific genes. However, the standard method of delivery of modified oligonucleotides has several difficulties: Toxicity of phosphorothioate and other derivaties is of concern, cell-specific delivery is difficult, and dose levels can only be controlled by frequency of injection. Delivery of RNA, directly or by in situ transcription from regulatable promoters (gene therapy approach), offers potential solutions to the above problems. However, mRNA sequences in coding regions cannot be blocked by simple RNA oligos due to disruption of complexes by ribosomes during translation. In the proposed research we test the efficacy of a new antisense agent, targeted against tumor necrosis factor (TNF) alpha, that is designed to lock onto its target mRNA so as to prevent dissociation during translation. Control of TNF alpha shows promise as a therapy for sepsis and arthritis. We will rely on a proven method of delivery to machrophages. If successful, this locking 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. Constructs will be tested for efficacy in down-regulating TNF alpha expression in mouse macrophages in vitro and in vivo. The approach is suitable for delivery of antisense constructs using lipid vehicles as well as by a gene therapy approach. The technique can also be adapted to antigene strategies.
Antisense and antigene technologies have the potencial for artificial modulation of the expression of many different genes with exquisite specificity and low toxicity. These technologies are being developed by a number of companies for therapeutic purposes. We offer a new general approach to antisense, applying it to down-regulating TNF alpha and using a proven delivery technique. Reducing TNF alpha is a promising approach for the treatment of sepsis and arthritis, conditions responsible for a great deal of mortality and morbidity. Other potential applications include genetic diseases or cancers in which a gene is improperly overexpressed, the treatment of viral diseases (including AIDS) by suppressing the expression of viral genes. Ribozyme Pharmaceuticals, Inc has expressed interest in helping to commercialize this work, and ISIS Pharmaceuticals will be collaborating with us to develop other applications of the same technology. Our business strategy is primarily to license the technology to larger companies such as RPI and ISIS until Somagenics is large enough to develop antisense therapies on its own.
| Dallas, Anne; Balatskaya, Svetlana V; Kuo, Tai-Chih et al. (2008) Hairpin ribozyme-antisense RNA constructs can act as molecular Lassos. Nucleic Acids Res 36:6752-66 |
