Clipping of news on Brazilian Culture, Law and Citizenship
19/01/2012
This article was translated by an automatic translation system, and was therefore not reviewed by people.
Changes of stem cells
International research with human embryonic stem cells reveals that chromosomal changes are observed after long cultivation in the laboratory, making it no longer has the ideal conditions for therapy in humans.
The study used samples of the BR-1, the first stem cell line developed in Latin America, prepared at the Institute of Biosciences (IB) of USP.
The results of the experiment were published in the journal Nature Biotechnology, published last December.
Cultivation of embryonic stem cells
The research was coordinated by the International Stem Cell Initiative (ISCI), an international organization that directs research involving embryonic stem cells.
The BR-1 is one of the 125 cell lines developed around the world analyzed in this study.
"The experiment sought to analyze the behavior of stem cells during prolonged cultivation," says researcher Ana Fraga, who participated in the survey. "It is known that cultured cells showed some instability, which may hinder its future use in therapy."
"The DNA extracted from cells of strain BR-1 was sent to epigenetic analysis in Singapore and a batch of frozen cells followed for the UK, for cytogenetic analysis."
Changes in chromosomes
The study found that with the passage of time and aging lines, cells in culture showed changes in a region of chromosome 20.
"This change causes the cells ceased to have the karyotype (chromosome number) considered ideal for further study," says Anne
By growing human embryonic stem cells, scientists "mimic" the methodology used for the analysis of cell lines from mice.
What the most recent studies are showing, according to Fraga, is that human cells do not behave exactly as the cells of the guinea pigs.
Stem cells have great ability to divide, and the process of cell differentiation, can turn into different types of body tissues.
Distant goal
Since not all genes involved in this chromosomal alteration are known, it is unclear what effect the stem cells would have if they were injected in the body.
"That is, their use for therapy would not be considered safe," says the researcher. "It is possible that the changes are selected by current cell culture conditions, which should be the subject of new studies."
According to Ana, the results of the experiment show that scientists are still far from obtaining optimal solutions for growing embryonic stem cells.
"The greatest merit of this initiative is to point out the peculiarities which have occurred in isolation and will contribute to the development of culture media and cultivation practices," he says.
Source: Journal of Health
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This article was translated by an automatic translation system, and was therefore not reviewed by people.