Archive for March 30th, 2011|Daily archive page


In ALL ARTICLES on March 30, 2011 at 1:00 pm

Recent research has shown once again that only adult stem cells are capable of treating humans.  Embryonic stem cells generate cysts and tumors and Induced Pluripotent stem cells develop genetic abnormalities when they are used.  (Induced Pluripotent stem cells are those stem cells created by scientist who take simple adult skin cells and then regress them to an embryonic like state – see article below) – dg


Genetic Abnormalities Discovered After Creation of (induced pluripotent) Stem Cells


Discovery sheds new light on the process of stem cell generation, and will help promote safer stem-cell based studies and future clinical trials
Thursday, 10 March 2011

Dr. Andras Nagy’s laboratory at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital and Dr. Timo Otonkoski’s laboratory at Biomedicum Stem Cell Center, University of Helsinki, as well as collaborators in Europe and Canada have identified genetic abnormalities associated with reprogramming adult cells to induced pluripotent stem (iPS) cells. The findings give researchers new insights into the reprogramming process, and will help make future applications of stem cell creation and subsequent use safer.

The study was published in Nature.

The team showed that the reprogramming process for generating iPS cells (i.e., cells that can then be ‘coaxed’ to become a variety of cell types for use in regenerative medicine) is associated with inherent DNA damage.

This damage is detected in the form of genetic rearrangements and ‘copy number variations,’ which are alterations of DNA in which a region of the genome is either deleted or amplified on certain chromosomes. The variability may either be inherited, or caused by de novo mutation.

“Our analysis shows that these genetic changes are a result of the reprogramming process itself, which raises the concern that the resultant cell lines are mutant or defective,” said Dr. Nagy, a Senior Investigator at the Lunenfeld.

“These mutations could alter the properties of the stem cells, affecting their applications in studying degenerative conditions and screening for drugs to treat diseases. In the longer term, this discovery has important implications in the use of these cells for replacement therapies in regenerative medicine.”

“Our study also highlights the need for rigorous characterization of generated iPS lines, especially since several groups are currently trying to enhance reprogramming efficiency,” said Dr. Samer Hussein, a McEwen post-doctoral scientist who initiated these studies with Dr. Otonkoski, before completing them with Dr. Nagy.

“For example, increasing the efficiency of reprogramming may actually reduce the quality of the cells in the long run, if genomic integrity is not accurately assessed.”

The researchers used a molecular technique called single nucleotide polymorphism (SNP) analysis to study stem cell lines, and specifically to compare the number of copy number variations in both early and intermediate-stage human iPS cells with their respective parental, originating cells.

Drs. Nagy and Otonkoski and their teams found that iPS cells had more genetic abnormalities than their originating cells and embryonic stem cells. Interestingly, however, the simple process of growing the freshly generated iPS cells for a few weeks selected against the highly mutant cell lines, and thus most of the genetic abnormalities were eventually ‘weeded out.’

“However, some of the mutations are beneficial for the cells and they may survive during continued growth,” said Dr. Otonkoski, Director and Senior Scientist at the Biomedicum Stem Cell Center.

Stem cells have been widely touted as a source of great hope for use in regenerative medicine, as well as in the development of new drugs to prevent and treat illnesses including Parkinson’s disease, spinal cord injury and macular degeneration. But techniques for generating these uniquely malleable cells have also opened a Pandora’s Box of concerns and ethical quandaries. Health Canada, the U.S. Food and Drug Administration and the European Union consider stem cells to be drugs under federal legislation, and as such, subject to the same regulations.

“Our results suggest that whole genome analysis should be included as part of quality control of iPS cell lines to ensure that these cells are genetically normal after the reprogramming process, and then use them for disease studies and/or clinical applications,” said Dr. Nagy.

“Rapid development of the technologies in genome-wide analyses will make this more feasible in the future,” said Dr. Otonkoski.

“In addition, there is a need to further explore if other methods might mitigate the amount of DNA damage generated during the generation of stem cells,” both investigators agreed.


In STEM CELLS IN THE NEWS on March 30, 2011 at 12:47 pm
Could Stem Cell Transplants Save Japan’s Nuclear Workers?

Scientists say Japan’s faceless heroes — the nuclear workers toiling inside the radioactive, quake-stricken Fukushima plant — could get a life-saving boost from a procedure normally used on cancer patients: stem cell transplants.


Before and After: Fukushima Plant

An infusion of blood stem cells can be used to boost bone marrow in cancer patients ravaged by radiation treatment. But experts say the procedure could also save the lives of Japan’s nuclear workers, who’ve been exposed to high levels of radioactive contamination while battling nuclear fallout at the country’s Fukushima Dai-ichi plant, 150 miles north of Tokyo.

About 400 workers have been staying at a building about half a mile from Fukushima’s blown-out Reactor No. 1, while residents within a surrounding 12-mile radius have evacuated altogether.

At least two workers were hospitalized last week after coming in contact with radioactive water as they tried to lay electricity cables. The exact level of radiation the workers are constantly exposed to hasn’t been made public.

Now, Japanese authorities are considering plans to collect and freeze cells from some of the workers, in case they’re in need of blood stem cell transplants later on, when the true amount of contamination is known, and if workers begin to fall ill.

Workers who’ve been exposed to high levels of contamination could develop acute radiation syndrome. “The survival rate of patients with this syndrome decreases with increasing [radiation] dose,” the U.S. Centers for Disease Control and Prevention says on its website. “The primary cause of death is the destruction of the bone marrow.”

That’s where the stem cell transplants might come in…

Could Stem Cell Transplants Save Japan’s Nuclear Workers?.

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