Conditionally reprogrammed stem cells: dreams come true?

New type of stem cells will help restore limbs – scientists

RIA Novosti (ask them what the limbs have to do with it – VM).

American biologists have discovered a new type of stem cells that are not similar in their properties and method of production to embryonic and "reprogrammed" cells that can be used to restore limbs and organs without the risk of getting a cancerous tumor, according to an article published in the journal Proceedings of the National Academy of Sciences (Suprynowicz et al., Conditionally reprogrammed cells represent a stem-like state of adult epithelial cells – VM).

"It is possible that we can use them to grow tissues for damaged organs or treat diabetes. In particular, we can extract the remnants of insulin "islands" from the pancreas, enlarge them and transplant them back into the human body. A similar technique can be used to treat congenital liver diseases. In such cases, we can extract liver cells, insert normal genes into them, multiply and return them to their rightful owner," said Richard Schlegel, the head of the group from the Medical Center at Georgetown University (USA).

Schlegel and his colleagues conducted experiments with various lines of healthy and cancer cells, studying their reaction to the appearance of various hormones and proteins in the nutrient medium. In December 2011, the authors of the article developed a technique that disables the defense mechanisms in healthy cells and allows them to divide indefinitely, which is very similar to the behavior of stem cell cultures.

In the new work, a group led by Schlegel studied the properties of cells in such cultures and compared them with embryonic and "reprogrammed" stem cells.

To do this, scientists collected samples of "adult" cells from the walls of the cervix and placed them in a nutrient medium. Then they added two key components to it – "nurse" cells from human connective tissue, as well as a special enzyme that prevents the mechanism of cellular self-destruction.

Biologists allowed cells to divide for several generations, after which they compared the contents of their cytoplasm with a set of proteins, RNA and other organic molecules in stem cells.

It turned out that the cells from the cultures were very similar not to the basic stem cells capable of turning into any kind of body tissue, but to their descendants – "blank" cells that form the basis of the future cervix in the human embryo. According to scientists, such cells are safe from the point of view of cancer development – growth and development genes, which are considered the main cause of tumor development, are disabled in them.

The cells of Schlegel and his colleagues have another interesting property – they "remembered" their previous role three days after the scientists stopped adding a mixture of "nurse" cells and an enzyme to the nutrient medium. As a result of this process, tissue from several layers of cells similar to those found in the cervix grew on the walls of the Petri dish.

The scientists repeated their experiments on cells extracted from the skin of the hands and lung tissues, and obtained similar results. According to them, such universality of the technique allows us to hope that this type of cells, to which scientists have given the name "conditionally reprogrammed cells" (CRC), will find wide application in regenerative medicine.

"It seems that this is the kind of cells that is needed in order to turn regenerative medicine from a dream into a reality," concludes Schlegel.

Portal "Eternal youth" http://vechnayamolodost.ru20.11.2012