Japan to Start 1st Research to Grow Human Organs in Animals

Tokyo, July 24 (Jiji Press)--A science ministry expert committee Wednesday approved Japan's first research to inject human induced pluripotent stem, or iPS, cells into fertilized animal eggs to grow human organs. The project by a team led by Hiromitsu Nakauchi, project professor at University of Tokyo, is expected to receive the final go-ahead by the ministry in August. The research will begin after that. The government in March lifted a ban on research to place human cells into fertilized animal eggs, put them back inside the bodies of the animals and have them give birth. In June, the team submitted its research plan to the ministry after gaining approval from an ethics committee at the university. The team aims to use human organs obtained through the method for transplantation in the future. But it is still difficult to grow human organs inside animals. In similar research in the United States, only small amounts of human cells were included in the resulting animal fetuses. The Japanese team will start its experiment with mice and rats. Human iPS cells will be placed into fertilized eggs of such animals genetically modified not to create specific organs such as the pancreas. The fertilized eggs will be then put back into the animal wombs. The team will examine to what extent human cells are mixed into the resulting fetuses. The animals that are born will be kept for up to two years for research into the conditions of their organs. In the future, the team will try to grow human organs inside the bodies of pigs, whose organs are similar in size to their counterparts in humans. The team succeeded in improving diabetic symptoms in mice by transplanting in them mouse pancreases grown inside the bodies of rats. But it is considered difficult to grow human organs inside the bodies of mice or pigs because of the wide genetic differences. "Our research was approved at last after sufficient discussions," Nakauchi said. END