The safest induced pluripotent stem cells
Japanese scientists have created safe induced stem cells
Ksenia Naka, RIA Novosti
Induced stem cells derived from stomach cells, unlike others, are minimally likely to provoke tumors, which opens the way to the widespread use of such cells. Such data are given in the report of Japanese scientists, which they made at the symposium "Stem cells and their versatility" in the city of Toyonaka.
The method of creating stem cells from ordinary human cells, the so–called induced pluripotent stem cells (iPS), developed in 2006, can rid science of ethical problems associated with the use of embryonic stem cells. However, the use of this method was hindered by the high risk of cancer when using iPS cells.
A group of Japanese scientists said that this obstacle may have been overcome.
The authors of the report – researchers from Kyoto University under the leadership of Professor Shinya Yamanaka, who holds the primacy in the creation of induced cells, and Keio University under the leadership of Professor Hideyuki Okano created 36 variants of iPS cells and transplanted them to experimental rats.
As a starting material, they used four types of ordinary cells – skin cells of a baby, skin cells of the tail, stomach and liver of adult rats. From the obtained iPS stem cells, the scientists grew cells that form nerve tissue, which were then transplanted into experimental rats.
No cases of oncological neoplasms were detected in rats that were transplanted with stem cells obtained from stomach cells. A low level of tumor occurrence was also found in rats that were transplanted with cells obtained from the skin cells of cubs.
At the same time, 80% of rats who received stem cell transplants created from adult rat skin cells and from the liver began to develop oncological neoplasms.
The scientists concluded that the risk of cancer after transplantation of induced pluripotent stem cells (iPS) is directly related to the type of source cells.
"Not all cells derived from skin and liver cells were able to turn into nerve cells. It is from these cells that oncological tumors are formed. A similar mechanism should also work in the case of growing heart muscle cells and others," Professor Okano said.
For the first time, stem cells of non–embryonic origin, the so-called induced pluripotent stem cells (iPS) of humans, were obtained by Shinya Yamanaka in 2006. Scientists have managed to create a stem cell from an ordinary human cell.
Since then, scientists have pinned great hopes on iPS cells, which can become a material for creating human tissues and organs and be used in the treatment of various diseases.
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