The New York Times and other foreign news reported that there is no need to provide eggs or make embryos, thus opening a new chapter in stem cell research that is not bound by the bioethics of embryonic stem cells.
▽ "Embryonic stem cells can be obtained without eggs"
Three research groups, including Kyoto University, Whitehead Institute and Harvard University, jointly announced that the experiment of injecting four genetic factors into skin cells to make them return to the primitive cell stage with the same function as embryonic stem cells was successful without cloning by egg, embryo and somatic cell nuclear transfer.
Professor shinya yamanaka of Kyoto University and Dr Rudolf J of whitehead Institute published the above research results in the latest issue of the British scientific journal Nature, and Dr Conrad Howard Ringer of Harvard University published the first issue of Cell-Stem Cells.
These research groups injected four genetic factors (Oct4, Sox2, c-Myc, Klf4) that will be activated in embryonic stem cell stage into the fiber hair cells extracted from mouse skin cells by virus. It is found that the grown-up cells go against the growth stage and return to the undifferentiated primitive cell state before developing into specific cells.
The primitive cells thus reduced have the characteristics of being able to differentiate into various cells like embryonic stem cells, so they differentiate into cells such as heart, liver and kidney. Because this cell is similar to embryonic stem cells, but its species are different, the research team named it "Induced Pluripotent Stem Cells (iPS)".
This technology was first published by Dr. shinya yamanaka last year, but it didn't attract attention because of the "Huang Yuxi incident" at that time. This time, with the success of three research groups in the same experiment, its possibility has been confirmed.
▽ "Milestone Achievement of Stem Cell Research"
Experts say that this research is an epoch-making achievement, which can go beyond the limitations of embryonic stem cell research and adult stem cell research so far.
Embryonic stem cells are extracted from embryos, which are produced by removing egg nuclei and transplanted cell nuclei to their positions and conducting electric shocks. Although it has the advantage of differentiating into any organ, it will inevitably destroy the embryo in the process of research, so it will be controversial in bioethics. It is also difficult to ensure a large number of eggs needed for research.
However, although there is no ethical problem in extracting and culturing adult stem cells from bone marrow or umbilical cord blood, they can only be extracted from some organs, so there is a limitation that the amount is small and they cannot differentiate into various organs.
Unlike this, iPS only uses ordinary somatic cells, so it can avoid ethical arguments and easily obtain a large number of stem cells. In addition, because the patient's own cells are used, immune rejection will not occur, and cells that match the patient can be made. Moreover, genetic factor transplantation is technically easier than nuclear transplantation, which is also its advantage.
Park Shibi, head of the stem cell research center of Jeju University, commented: "It is a great research achievement that cells with the same function as stem cells can be produced only by somatic cells." He added: "Its advantage is that a large number of cells needed for the experiment can be easily obtained on the skin, and because the patient's own cells are used, there is no immune rejection at all, which is technically easier than somatic cell nuclear transplantation."
The Wall Street Journal also said: "Therefore, this study will ease the bioethical controversy surrounding stem cells." It is predicted that there will be a lot of related research in the United States in the future. However, there are still many difficulties to overcome in applying iPS to human body. The New York Times pointed out: "There are still many problems to be solved, such as the possibility of cancer induced by injected genetic factors or the possibility of virus mutation."