SBIR-STTR Award

Somatic gene therapy is expected to provide new and improved therapies for many diseases. We are developing a new class of DNA-based therapeutics, "gene medicines" which are expected to provide unique clinical benefits for the treatment of a broad range of diseases. Gene medicines utilize tissue-specific DNA expression vectors and novel vector delivery systems for the in vivo delivery of therapeutic proteins. Cfinically effective and safe gene medicines will require the development of reliable methods to regulate gene expression such that synthesis of the therapeutic protein is not only restricted to the proper cell-type and tissue but is also at a level that remains within the therapeutic range appropriate for the disease being treated. Our previous work at our laboratories and in the founder's laboratories has led to the development of a muscle-specific vector system (MVS) capable of directing the synthesis of proteins in muscle in vivo. The control of gene expression in eukaryotic cells is complex, involving the interaction of a variety of tissue-specific positive and negative trans-acting protein factors with specific regulatory sequences associated with tissue-regulated genes. MVS vectors incorporate upstream and downstream regulatory sequences derived from the well-characterized chicken skeletal all ha-actin gene to control the expression, mRNA stability and translation of clinically relevant proteins. The purpose of this research is to develop synthetic muscle-specific vectors which will provide higher levels of expression in mammalian muscle cells than natural promoter elements. We will construct a series of synthetic promoter/enhancer fragments based on the sequences of transcriptional control elements involved in the activation and regulation of genes in mammalian muscle cells.Awardee's statement of the potential commercial applications of the research:This research will lead to the development of synthetic muscle-specific vectors which will provide higher levels of expression in mammalian muscle cells than natural promoter elements. There is a significant market for the short-term delivery of therapeutic proteins to muscle cells and into the general circulation of humans using human genetic therapy, provided it can be established to be safe, effective and economical. Genetic therapy obviates many of the practical problems associated with protein therapy.National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

The new technology developed during Phase I offers a novel approach to treating ischemia effectively and safely. We developed muscle-specific promoters that provide higher levels of expression than natural promoters and altered regulatory properties. The aim of the Phase II research is to apply these advances to develop non-viral gene medicines that will stimulate angiogenesis and provide a safe and effective therapy for ischemia. GENEMEDICINE has developed a novel approach using polymeric formulations to enhance gene delivery. We have shown in rats that IM injection of muscle-specific GH gene medicine formulated in PVP resulted in levels 10-15-fold higher than the plasmid in saline. This proposal describes the development of a muscle-specific plasmid that expresses hVEGF. The hVEGF expression plasmid will be optimized for high level, tissue-restricted expression by including a synthetic muscle-specific promoter and a hVEGF coding sequence that contains optimized human codons. The muscle-specific gene medicine will consist of the muscle- specific, codon optimized hVEGF expression plasmid complexed with the polymeric gene delivery system. As such, it has significant advantages over the CMV-based plasmids delivered in saline developed by others. The gene medicine will be tested in the rabbit ischemia model and the preclinical studies completed for clinical trials. PROPOSED COMMERCIAL APPLICATIONS: Currently, the prognosis for patients with chronic critical leg ischemia is grim. Approximately 150,000 people per, year have been reported to have ischemia severe enough to require lower limb amputation because they are unresponsive to conventional medical or surgical treatment. Following amputation, the mortality rate is high. There is a compelling need for effective treatment strategies.

Thesaurus Terms:
gene targeting, gene therapy, genetic manipulation, ischemia, nonhuman therapy evaluation, striated muscle, transfection vector angiogenesis, gene expression, genetic promoter element, method development, plasmid, polyvinylpyrrolidone, vascular endothelial growth factor HeLa cell, enzyme linked immunosorbent assay, flow cytometry, human tissue, laboratory mouse, laboratory rabbit, molecular cloning, polymerase chain reaction