The National Institutes of Health last month said that roughly $2.5 million has been earmarked to fund projects using oligonucleotide-based methods of gene modification, chiefly RNAi, to research the prevention and treatment of oral and craniofacial disorders.
“The primary objective of [the two-year funding opportunity] is to enhance translational research … by harnessing oligonucleotide-based approaches such as RNA interference to modify the expression of genes associated with oral, dental, and craniofacial diseases and disorders,” the NIH says.
“The ability to selectively silence or modify gene expression is fundamental to understanding complex disease processes and to developing possible therapeutics and prevention strategies,” the agency adds.
In recent years, oligo-based methods for modifying gene expression have become widely available “based on the ease of designing and testing oligonucleotides for any host gene or pathogen whose nucleic acid sequence is known,” the NIH says.
While there are a number of technologies to modify gene expression in vivo, including splice- and translation-blocking morpholinos, aptamers, and chromosome-targeted small duplex RNAs that can both trigger and repress gene expression, RNAi is thus far the most developed in terms of therapeutic applications, the institute notes.
Opko Health’s wet age-related macular degeneration drug bevasiranib recently entered phase III testing, and a number of phase I and phase II trials for other RNAi-based drugs are ongoing.
But these therapies are all directly delivered, evidence that the delivery hurdle facing the RNAi drug field is still present despite recent technological advances such as the use of cholesterol conjugation.
Still, effective siRNA uptake in the respiratory tract has been shown to be possible, though not simple, after intranasal topical application, while research into the topical delivery of siRNA to the cervix and vagina has been preliminary but promising.
Promega has a larger stake in Australian company Benitec after purchasing 1.8 million ordinary shares for $158,000, a 20 percent discount on the average trading price of Benitec shares over the past 60 days. Benitec, a ddRNAi technology developer, is also working on technology for an HIV therapeutic.
Apollo Bioscience is expanding its scope to include siRNA. The five-year-old company has been developing a silica-based delivery system and had focused on traditional chemotherapeutics. With its new siRNA efforts, Apollo will still be looking at cancer and is expanding in vitro and in vivo tests of its Pharmefex technology to see if it can deliver siRNA targeting pathways associated with mesothelioma.
Sigma-Aldrich signed a deal with the University of Montreal’s Institute of Research in Immunology and Cancer. The Montreal institute will be using Sigma’s Mission RNAi IP portfolio and its shRNA library collection for human and mouse genomes. Sigma will then use feedback from the Montreal studies to further refine its high-throughput drug research tools.
The Salk Institute for Biological Sciences and the University of Marburg joined Thermo Fisher’s RNAi Global Initiative, which promotes whole-genome RNAi screening, the development of research standards, and the sharing of information to advance RNAi gene-silencing techniques. The initiative now has 23 research institutions in 11 different nations.
US application 20070232555. C-Met Sirna Adenovirus Vectors Inhibit Cancer Cell Growth, Invasion and Tumorigenicity. Inventors: Nariyoshi Shinomiya, George Vande Woude. Filed: March 28, 2005.
In this patent application, the inventors say that using RNAi and adenoviruses carrying siRNA target sequences for the Met protein tyrosine kinase can noticeably reduce Met expression in mouse, dog, and human tumor cells. The inventors targeted this kinase to suppress the hepatocyte growth factor/scatter factor (HGF/SF)-Met signaling pathway and thus suppress tumor growth.
US application 20070191294. Short interfering rna (sirna) analogues. Inventors: Joacim Elmen, Claes Wahlestedt, Zicai Liang, Anders Sorensen, Henrik Orum, Troels Koch. Filed: March 22, 2004.
The invention deals with novel double-stranded short interfering analogues of locked nucleic acid monomers that induce sequence-specific, post-transcriptional gene silencing. According to the patent application, “the compounds [have] improved properties compared to non-modified siRNAs and may, accordingly, be useful as therapeutic agents, e.g., in the treatment of various cancer forms.”
Isis Pharmaceuticals received an NIH grant for $1.5 million to design single-stranded antisense drugs capable of triggering RNA interference.