Chinese researchers have created a cocktail of drugs that can turn a pluripotent stem cell into a totipotent one – the one from which life originates. This has the potential to help grow organisms, bypassing the need for sperm and eggs. The research was published in Nature journal.
Not all stem cells are equal, they have a certain hierarchy depending on their potential. Multipotent stem cells are found in many adult tissues. Here, they transform into several types of cells needed in this tissue or organ and help repair it.
One step higher are the pluripotent stem cells, which are found in the embryo and are capable of transforming into almost any cell in the body. The highest in the hierarchy are totipotent stem cells, which can become any body cell or tissue such as the placenta.
This is the first cell, single cell that is formed from a fertilized egg. Totipotent stem cells persist for several stages of development and then they turn into pluripotent, which then become different cells of the body.
In recent years, scientists have been able to transform adult cells into pluripotent stem cells, creating the basis for regenerative medicine. However, now researchers at Tsinghua University have moved a step further, returning pluripotent stem cells to a totipotent state for the first time ever.
Researchers went through thousands of combinations of small molecules until they found three that could potentially cause totipotency in mouse stem cells. The mixture was called a TAW cocktail because it included TTNPB, 1-Azakenpaullone, and WS6 molecules.
Molecular tests have shown that the cocktail causes totipotency at all levels. Hundreds of genes inherent in totipotent stem cells were turned on, and inherent in pluripotent were turned off. When the cells were cultured in laboratory cups and live mouse embryos, the scientists noticed that they behaved as totipotent. In the case of mice, they were divided into embryonic and extraembryonic (such as placenta) cell lines.
In the long run, this will help create an organism from a mature cell without the need for sperm and eggs. The invention can be used to treat infertility or save species on the verge of extinction. However, it will certainly cause a lot of controversy about its ethics.