Salk Institute researchers have succeeded in producing induced stem cells from a single human hair. Do we have to keep the hairs of our heads from now on?
About six years ago, the British royal house received an unusual warning: a media outlet intended to steal a lock of the young Prince Harry's hair. Why? Before you continue to the next paragraph, you are invited to stop and think for a moment why anyone would want a piece of the prince's clothes.
If you also answered, "To clone him!" A sign that you read too much science fiction, and too little real science. But that's fine, that's how most people in Europe answered - and they were wrong. The efficiency of the cloning process six years ago was extremely low in mice, and was not tried at all in humans. If the purpose of the theft was to clone Prince Harry in all his glory, then all his hairs, along with his scalp, would have had to be ripped out, just for the chance of producing one reasonable clone.
The real goal was actually relatively innocent - to make sure once and for all that Harry is indeed the son of Prince Charles, and not the fruit of an illicit affair. To this end, the researchers intended to extract DNA from the individual hair follicle cells attached to the hair, and compare it to the DNA of the putative parents. But judging by an article recently published in Nature Biotechnology, we are now closer than ever to the day when we will have to guard our hair. Salk Institute researchers were able to effectively convert hair follicle cells into induced stem cells. Other laboratories have shown that induced stem cells can be transplanted into a young embryo, causing them to differentiate and divide as if they were part of the developing baby. The final product is a chimera: a creature composed of many cells, not all of which are originally his.
The method, described in the prestigious scientific journal, provides a simple solution to the problem of immune rejection from foreign tissues. With the help of the stem cells transduced from hair follicle cells, it will be possible in the future to create tissues with immune markers identical to those of the hair donor. The tissues, which will be grown in the laboratory, can be transplanted in their own right, thus solving the problem of the shortage of organs in the world.
The process in which skin cells - fibroblasts - turn into induced stem cells was simultaneously invented two years ago in several laboratories around the world. During the transformation, the cells are infected with unique genes using viruses. Those genes - Oct4, Sox2, Klf4 and C-Myc - change the expression pattern of the other genes in the cell, and cause the cells to become induced stem cells, capable of differentiating into all types of cells present in the body.
Despite the enthusiasm with which the process was received among the population of biologists, its actual effectiveness was lacking. And as evidence, only one fibroblast out of 10,000 was able to go through the complete transformation and become an induced stem cell. In the current study, the researchers from the Salk Institute were able to optimize the reprogramming of the cells more than a hundred times, and shorten the process time by two times. It seems that the keratinocytes - hair follicle cells - are able to undergo the transformation into stem cells more easily than other cells that the researchers tested. In fact, they are able to go through the process with such ease that the researchers plucked a single hair from the head of a research assistant, transformed the hair follicle cells and received induced stem cells with the same immune markers as the researcher who donated the hair.
The main challenge that remains now is to characterize the induced stem cells and make sure that they will not become cancerous cells, as some of the induced stem cells used to do in the past. When the way is found to transform the cells without fear of cancerous development, the induced stem cells will be able to start being used in the field of tissue engineering and medical engineering.
Abstract of the scientific research in Nature Biotechnology
More on the science website
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light,
The problem today is that the induced stem cells insert many copies of important genes into the cell's genetic code. These genes can affect the way the cell divides in two ways:
1. They encourage the cell to return to the embryonic stage, in which it divides many times without stopping. From this point it only takes one or two more small mutations for the cell to become cancerous. To overcome this problem, a better way must be found to control the copies of the genes that are inserted into the cells. You can, for example, try to insert only one copy of each gene so that it is easier for the cell to visit the new gene.
2. The genes that are inserted into the cell enter the genome, and sometimes 'fall' in the center of another important gene. In this case they may themselves create a dangerous mutation in the cell that will lead to cancer. To address this problem, they are currently trying to use ways to introduce genes that do not require their assimilation into the genetic code. The genes will exist in the cell as separate units, lead to the beginning of the transformation into stem cells and then break down by themselves.
Shabbat Shalom,
Roy.
At what stage will it be possible to make sure that cancer will not develop? How can you be sure about this?
Even for that, nature found a solution (at least for me).
baldness.
I wonder how long it will be possible to reproduce organs such as heart, lungs and kidneys
You're right. The researchers knowingly used keratinocytes - cells found in the hair follicle and attached to it when it is removed from the scalp.
As far as I know hairs are not made of cells, but of proteins and they do not contain DNA, genetic code. I'm wrong?