ES cell lines are obtained by culturing cell clusters from blastocysts, an early stage of development from fertilized eggs, under special conditions. They are used to elucidate the causes of diseases, develop new medicines such as cell therapy and regenerative medicine.
ES cell research began in 1981 with the discovery of mouse ES cells (human ES cell lines were first established in 1998 in USA). In Japan, the first human ES cell line was established in 2003 by a team of Dr. Norio Nakatsuji (Professor Emeritus, Kyoto University), a member of our board of directors.
In accordance with the Guidelines for the Establishment of Human ES Cell Lines (Note 1), Professor Nakatsuji’s team at Kyoto University (ES cell line establishment organization) received a small number of donated embryos from the large number of surplus embryos that had been determined to be discarded. Establishment of human ES cell lines was carried out by strictly following the Japanese government guideline. Established ES cell lines have been distributed for research and therapeutic purposes.
For therapeutic application in Japan, the National Center for Child Health and Development has conducted a clinical trial using hepatocytes derived from human ES cell lines for congenital urea cycle disorders (Note 2, 3), and it was reported in the media that an application for approval as a regenerative medicine product will be filed during fiscal 2023. If approved, this will be the first ES cell-based therapy in Japan. Clinical trials using ES cells have been conducted overseas for more than 10 years, and ES cells are still used in about half of all clinical trials using pluripotent stem cells (Note 4).
(Note 1)(Japanese)
“Guidelines for the Establishment of Human ES Cells” (Ministry of Education, Culture, Sports, Science and Technology, Ministry of Health, Labor and Welfare)
Urea cycle disorders; a group of diseases in which there is a congenital abnormality in the pathway that breaks down ammonia and synthesizes urea in hepatocytes, resulting in hyperammonemia. Liver transplantation is an absolute indication for urea cycle disorders in the neonatal period, but hyperammonemia may occur while the patient is waiting for the age of possible liver transplantation, resulting in irreversible neuropathy. Hepatocyte transplantation is performed as a bridge before the liver transplants. (Source: National Center for Child Health and Development)
(Note 3)
Press release from the National Center for Child Health and Development (May 21, 2020)
