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Post Date: 23 Nov 2010 Research work completed at the Hebrew University of Jerusalem arouses a cautionary notice in the developing area of the growth of stem cells as a way for future treatment of individuals through replacement of infected or damaged cells using the patient's own stem cells. The study suggests a possible risk of malignant tissue growth in the usage of such cells. Embryonic stem cells, which are undifferentiated cells, have the potential to develop in to all cell kinds of the adult human anatomy, and a large number of scientists all around the globe are trying to develop the methods which can make possible their ultimate application. Study in the area has been completed originally using embryonic stem cells obtained from human embryos. Nevertheless, a development occurred when, numerous years back, Japanese researchers succeeded in making embryonic-like stem cells from adult human cells via an activated "reprogramming" process. That managed to get possible to acquire stem cells from the individual which may be utilized in their own therapy, thus preventing the chance of cell rejection. These cells are called activated pluripotent base (iPS) cells. So as for stem cells to be properly used in the center, nevertheless, they have to be increased in countries for a long time. During this time period, it's been noticed that embryonic stalks cells experienced genetic changes, including changes that define malignant tumefaction development. Research that's been completed in the laboratory headed by Nissm Benvenisty, the Herbert Cohn Professor of Cancer Research at the Silberman Institute of Life Sciences at the Hebrew University of Jerusalem, has now demonstrated that the iPS cells also bear irregular genetic changes in culture. Prof. A new analytical method was developed by Benvenisty, together with his post-doctoral fellow Yoav Mayshar and his doctoral student Uri Ben-David, for determining the genetic composition of the chromosomes in the iPS cells through determining the patterns of gene expression. Each cell broadly speaking contains two copies of each chromosome in the genome. The Hebrew University scientists found that, in time, three copies of chromosomes (trisomy) started initially to look in the culture, and that the cells with the additional chromosome could quickly overcome the other, standard cells in the culture. Such trisomies can be found in abnormal muscle growth, including malignant growths. The researchers analyzed more than 100 cell lines which were printed by 18 different laboratories around the globe, along with the iPS countries increased within their own laboratory, and in this way were able to steadily confirm a large number of genetic changes in cell lines that so far were considered typical. Within an report printed in Cell Stem Cell diary, their discovery has been reported by the Hebrew University researchers. They observed that the genetic changes weren't accidental, but instead seemed methodically on chromosome 12 and required up-regulation of particular genes which stay on that chromosome. This finding is likely to impede progress on the growth of the use of individual iPS cells in future treatment due to the tumorigenic risk involved. "Our results show that individual iPS cells aren't steady in culture, as was once believed, and need reassessment of the genetic composition of those cells," said Prof. Benvenisty. "Also, our work shows for the very first time the gene expression changes that accompany these genetic aberrations present in the tradition, paving just how for our just starting to understand the system through which these changes occur. "The genetic changes in these iPS cells need great care to be exercised by everyone in continuing to work well with them, because these changes obviously may affect the potential and the tumorigenic risk of these cells." Based on Prof. Benvenisty, "The technique we've designed for determining genetic changes through gene expression will probably function also in other work involving evaluation of different types of cells, including cancer cells. It's easy to utilize and allows the changes to be observed by one with out to specifically evaluate the DNA of the cells." The finding is branded by Yissum, the Technology Transfer Company of the Hebrew University of Jerusalem, that will be currently looking for industrial companions for development and further research. Sources: Hebrew University of Jerusalem, AlphaGalileo Basis.