Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced the publication of a study demonstrating the use of zinc finger nucleases (ZFNs) to produce genetically modified pigs. The study, which was published in the Proceedings of the National Academy of Sciences (PNAS), represents a significant advancement in the development of improved, less immunogenic animal tissue as a source for transplant into humans.
Transplantation is considered to be the best treatment option for thousands of patients every year whose own organs are damaged or diseased. However, the supply of human organ and tissues available for transplantation is insufficient to satisfy the demand.
"This work is a major advance because it provides an efficient method of knocking out any desired gene in the pig. ZFN-mediated genome editing can be used to make porcine cells and tissues less immunogenic and more suitable for transplantation into humans," said Richard Insel, M.D., Chief Scientific Officer for the Juvenile Diabetes Research Foundation (JDRF) who was not associated with the study. "In the example of type 1 diabetes, pancreatic islets can be replaced by transplanting functioning ones into a patient. However, we face a severe shortage of human cadaver organs in the U.S. and cannot satisfy the transplantation needs of people with the disease. Using ZFN-modified pigs as a source of tissues for human transplantation may prove to be a promising solution to the shortage of donated human organs for diabetes and other diseases."
As part of their mission to ultimately find a cure for type 1 diabetes, JDRF has helped pioneer islet cell transplantation research since the 1970s.
The paper, entitled "Efficient Generation of a Biallelic Knockout in Pigs Using Zinc-Finger Nucleases," describes a general method for the generation of animals in which a chosen gene is specifically removed or "knocked out" from the pig's genome. In the published example, Sangamo scientists and their collaborators in the laboratory of Prof. Dr. Heiner Niemann of the Institute of Farm Animal Genetics in Germany, knocked out both copies of the 1,3-galactosyl transferase (GGTA-1) gene from pig cells and used these to produce cloned animals that lack the target gene. Knockout of the GGTA-1 gene has been shown to lead to significantly improved organ survival in a pig-to-baboon organ transplantation model.
"Sangamo's mission is to develop novel ZFP Therapeutics to address unmet medical needs and make paradigm-shifting therapeutic solutions a reality," stated Edward Lanphier, Sangamo's president and chief executive officer. "This proof of concept study lays the foundation for the use of our validated ZFP platform technology to modify animal organs for human transplantation."
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