US Patent Application 20080260706 : Transient Transfection with RNA. Received October 23, 2008. Full text from Patent Office

Inventors: Peter M. Rabinovich, Sherman M. Weissman, Marina E. Komarovskaya, Erkut Bahceci

Background

Biologists frequently transfect foreign DNA into cells; if the DNA encodes a functional gene, the normal machinery within the cell will transcribe the DNA into RNA, which will be translated to protein.  Expressing either foreign proteins or altered versions of native proteins within cells is extremely useful for determining protein function, or for altering cell behavior.  “Gene therapy” involves introducing foreign genes within cells in the human body to ameliorate disease.

Though it is possible to introduce the proteins themselves into a cell, the techniques for doing so are very cumbersome relative to nucleic acid introduction.  Additionally, the location of expression is very important–different cells may introduce modifications into proteins as they are expressed, so the same protein may have different properties depending on the cell that produces it.  A foreign protein may not have the same properties as one that is produced locally.

The patent

The patent application prepared by Rabinovich, et al., aims to protect an improvement on the expression of foreign proteins: the transfection of the gene-coding RNA itself.  The authors claim that transfecting RNA is more efficient than transfecting DNA and also has a number of other advantages, including allowing more precise regulation of the quantities of protein produced, something that would be particularly important in a gene-therapy context.  The introduction of RNA is also inherently transient, avoiding the long-term exposure to exogenous genes that results from other forms of gene therapy, such as those employing viral vectors.  Short-term gene therapy would be particularly useful for a protein-based treatment regimen, rather than the permanent genetic change intended by viral gene-therapy.

Specifically, the patent application specifies the transfection of RNA “that encodes a therapeutic, prophylactic or diagnostic polypeptide or nucleic acid molecule”.    This process includes the in vitro transcription into RNA of DNA including a gene and other sequence elements necessary for efficient transcription and translation.

Implications

If granted, the patent would appear to protect the use of one of the two information-containing biological polymers, RNA, for medical puposes involving transient transfection.  Moreover, it claims invention of the process for production of RNA molecules for those medical purposes.

Viral gene therapy systems have been patented, including this patent held by Mount Sinai School of Medicine.