15 April 2009

Myths and Truth about Stem Cells

Irina Fedoskina, newspaper "Honest Word" (Novosibirsk), No. 16-2009

The media today is full of reports that many politicians, businessmen, screen and stage stars use "almighty stem cells" for rejuvenation. Sensing considerable profits (a rejuvenation session costs about half a million rubles), private clinics from small to large rushed to grow cells in incubators and ... But then reality sharply diverges from promises. Oleg Leonidovich Serov, Head of the Laboratory of Developmental Genetics at the Institute of Cytology and Genetics SB RAS, Professor, Doctor of Biological Sciences, acts as a scientific consultant on the pages of our newspaper.

– Oleg Leonidovich, why do semi-artisanal technologies for working with cells flourish in our country? It seems that they write a lot about stem cells, but the people are illiterate anyway.
– Firstly, there is a conscious confusion in terminology. If we talk about "omnipotent stem cells", we mean exclusively embryonic stem cells (ESCs). They are the precursors of cells of all human organs and tissues. Only from them are formed cells of all other types – hematopoietic, nervous, cardiovascular systems, bone, muscle tissue, etc. Knowing the level of development of medicine and biology in Russia, I can say that there are no embryonic stem cells used for treatment in Russia. And there are no drugs based on them. Research in this regard is just going on: there are two laboratories in Moscow and St. Petersburg, and here we have several lines of study of ESCs.

– That is, what does it turn out to be? That there are only charlatans around?
– There are a lot of charlatans in Russia, including those who do not specifically indicate what kind of stem cells they use. Or they are called incorrectly: they take cells from abortive material and call them embryonic. But, believe me, there is nothing in common between them and ESK. And such "doctors" are no better than spellcasters, and they fool people well, especially in cosmetology. In principle, there is a technology, piece-by-piece and expensive, to remove wrinkles. It is based on the fact that the cells of our subcutaneous fat - fibroblasts – microinject into the "bottom" of wrinkles. These cells multiply in a limited way and gradually fill the skin depression, wrinkle. After 6 to 8 months, this operation must be repeated, because the cells die. But there are also complications, dramatic cases when these cells grow excessively, and instead of a wrinkle, a bulge turns out – like Viktor Yushchenko's face. A similar case was with a leading local TV company in Yekaterinburg. She sued the clinic, but there is no strict legislation, nothing can be achieved.

– What about those stem cells that are taken from the patient's bone marrow or fat, grown in special incubators, and then injected as close as possible to the affected organ? Yes, these cells are not embryonic, but they say that they are miraculous – and the heart and even the nerves will be restored…
– There really are such cellular technologies. They are based on the fact that immature, non-specialized stem cells (the "repair team" of the body) are found in some tissues and organs of adults. The most famous of them are hematopoietic stem cells of the bone marrow, the transplantation of which is widely used for the rapid restoration of hematopoiesis. Stem cells were also found in other tissues: in particular, adipose. Immature (stromal) adipose tissue cells are in some cases successfully used to heal the affected skin (after burns, ulcers) and to restore damaged bone and cartilage tissue (with fractures, ruptures of cartilage and ligaments). But such use of immature bone marrow and adipose tissue cells does not mean that these adult cells are capable of giving rise to other types of specialized cells, such as neurons, pancreatic or liver cells. There is no reliable evidence of such a possibility. From time to time, publications appear about the possibility of converting stromal cells of adipose tissue or bone marrow into cardiomyocytes, but the data are contradictory and most researchers perceive them as preliminary, requiring further research. Of course, it's too early to talk about clinical use.

– But let's go back to embryonic stem cells (ESCs) – where do they actually come from?
– Billions of different cells of a growing organism originate from just one cell (zygote), which is formed as a result of the fusion of male (sperm) and female (egg) germ cells (gametes). The zygote begins to divide so that a "ball" is formed from exactly the same non-specialized cells. After about four and a half days, this "ball" forms a blastocyst, which consists of an outer layer of cells and a cavity filled with fluid and cells of the inner mass. It is from the latter that the future adult organism develops. There are only 20-40 such cells, but they will give rise to all the other cells of the body. More than twenty years ago, scientists learned how to cultivate such cells and called them embryonic stem cells (ESCs), thereby emphasizing their ability to give rise to any types of adult cells. In 1998, Thompson and his colleagues (USA) obtained the first human ESC cultures from human embryos obtained "in vitro". The technology of obtaining human embryos is widely used in reproduction centers. Artificially induced ovulation in women allows you to get 8-10 eggs, which are then fertilized with sperm. Embryos develop to the blastocyst stage, that is, to the stage when it is possible to obtain an ESC culture from the cells of the internal mass. Currently, the technique of obtaining a human ESC has already been sufficiently developed. However, large-scale potential use of ESCs is hindered by tissue incompatibility. Just as we cannot exchange pieces of skin with you, so we cannot exchange cells – they will be rejected by the body.

– You say that the main obstacle to application is tissue incompatibility. But imagine this situation: I myself go to the reproduction center and go through the whole procedure to get a bank of such cells.
– They will still be incompatible, because only half of the genes will be yours, and half of the male sperm donor. For the same reason, cells taken from abortive material, which are also qualitatively different from ESCs, will not help to "rejuvenate" in any way. Of course, ideally, each of us could have our own bank of ESCs, which, with skillful exposure, can be grown up and transplanted for treatment into any affected organ. At the temperature of liquid nitrogen, cells can be stored for at least a lifetime. That is, it is almost a universal "repair base" for our body. Biological science is already making great efforts to get liver, muscle, nerve and other cells from ESCs, that is, a real prospect of the emergence of a new medicine opens up. In the future, in 10-15 years, humanity will have cell replacement therapy. Today, the first experiments on the transformation of ESCs into nerve cells are being conducted abroad. They are conducted very carefully and at an extremely high level. The main thing is oncological safety. So far, experiments are being carried out on mice and quite successfully.

– Does this mean that the barrier of tissue incompatibility has been removed? If so, how?
– Indeed, a new discovery appeared in August 2006. Studying ESCs, scientists have found that their unique properties are determined by a set of genes that are inactive in ordinary cells, and there are only four main ones. With the help of genetically engineered structures, these four genes were introduced into the culture of fibroblasts, where they began to function. As a result, fibroblasts acquired properties very similar to ESCs. And artificially obtained ESCs were called IPSC cells. That is, it became possible to obtain personalized cells, similar to ESCs, from pieces of human skin. The obstacle of genomic incompatibility has been removed. Technologies for the safe production and implementation of IPSC cells are being worked out now. The second scientific direction, which I have already mentioned, is the production of all other cells from IPSC cells. I would like to emphasize once again that we are talking only about research, and not about transplantation. Experiments are performed on mice.

– These studies are probably well funded?
– In the West, they invest a lot of money there. Laboratories that work in the United States on such topics do not have less than $ 10 million per year. Arnold Schwarzenegger as governor gave $3 billion for embryonic stem cell research in his state. And we, as you know, do not have enough funding. But we are fighting.

– Oleg Leonidovich, thank you so much for the conversation! I think that now our readers will not fall for advertising rods about omnipotent stem cells.

 

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