First genetically engineered rat derived from rat ES cells developed with StemCells' technology

StemCells, Inc. (Nasdaq:STEM) announced today that its technology was recently used by independent researchers to achieve the first genetically engineered rat derived from rat embryonic stem (ES) cells. This breakthrough, published this month in the international peer-reviewed journal Nature, opens the door to the types of genetic manipulations previously only possible in mice, and paves the way for modeling a broader range of human diseases with the rat. Both mice and rats are used as animal models of human disease; however certain aspects of the rat's physiology, behavior, and metabolism are closer to the human, making rats the preferred species for drug development and studying human disease.  The creation of this first rat model using rat ES cells validates intellectual property owned by StemCells, which includes the rights to patents covering both rat ES and rat induced pluripotent stem (iPS) cells as well as genetically engineered rats derived from these cells. 

StemCells' broad rat pluripotent stem cell intellectual property portfolio is based upon groundbreaking research led by prominent academic researchers at the University of Edinburgh, including Dr. Qi-Long Ying who was the first to succeed in deriving and culturing the true germline competent rat ES cells required for precise genetic engineering. In this newly published study, Dr. Qi-Long Ying and his colleagues at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at the University of Southern California demonstrated for the first time the creation of genetically modified rats using rat ES cells that have been gene targeted via homologous recombination, a method which involves adding DNA sequences to the cells to delete ('knock-out'), add ('knock-in') or otherwise modify genes of interest. This latest work resulted in the successful generation of knock-out rats missing the tumor suppressor gene p53 for use in studying cancer, and serves as a proof-of-principle for creating genetically engineered rats using rat ES cells.  

 "The fact that we can now use rat ES cells to carry out genetic manipulation in this well characterized and widely studied species is truly revolutionary, and will lead to the creation of new, more sophisticated rat models that could advance the development of treatments for various human diseases," said Dr. Ann Tsukamoto, Executive Vice President of Research and Development at StemCells, Inc. "We intend to develop additional rat models with Dr. Ying for a broad range of diseases, and look forward to exploring licensing and development opportunities with third parties wishing to commercialize rat models derived from rat ES cells."

The rat ES cells used to generate the genetically engineered rats were cultured using a special '2i' inhibitor-based media formulation developed by Dr. Ying and his colleagues while at the University of Edinburgh. This proprietary 2i media is exclusively licensed to StemCells, Inc. and marketed as GS1-R™.  GS1-R is part of the Company's SC Proven^® line of specialty cell culture products, and is the first and only commercially available medium shown to enable the derivation and long-term maintenance of the true rat ES cells required for precise genetic manipulation. For more information about GS1-R and the Company's other SC Proven^® specialty cell culture products, interested parties are invited to visit www.scproven.com.