Lead Into Gold: IPSCs Pass Another Hurdle
Labels: Lead Into Gold. IPSCs. Use of Viruses to Introduce Genes.
IPSCs were first created in humans only about 10 1/2 months ago. Yet, hurdles to their full use in regenerative medicine fall at a rate not seen with ESCR or, for sure, therapeutic cloning. And now another one. From the story: Scientists are reporting today that they have overcome a major obstacle to using a promising alternative to embryonic stem cells, bolstering the prospects for bypassing the political and ethical tempest that has embroiled hopes for a new generation of medical treatments.
The researchers said they found a safe way to coax adult cells to regress into an embryonic state, alleviating what had been the most worrisome uncertainty about developing the cells into potential cures. "We have removed a major roadblock for translating this into a clinical setting," said Konrad Hochedlinger, a Harvard University stem cell researcher whose research was published online today by the journal Science. "I think it's an important advance."Scientists last year shook up the scientific and political landscape by discovering how to manipulate the genes of adult cells to revert them into the equivalent of embryonic cells--entities dubbed "induced pluripotent stem" or "iPS" cells -- which could then be transformed into any type of cell in the body. Subsequent work has found that the cells can alleviate symptoms of Parkinson's disease and sickle cell anemia in mice.
This does not resolve the problem with all pluripotent cells, e.g., they cause teratomas--a different tumor issue than the cancer fear with IPSCs that seems to have been overcome. But boy, is this field moving fast.
But the first iPS cells were created by ferrying four genes into the DNA of adult cells using retroviruses, which can cause cancer in animals. There was also concern because the viruses integrated their genes into the cells' DNA in the course of transforming them. In the new work, Hochedlinger and his colleagues used a different type of virus, known as an adenovirus, which does not integrate its genes into a cell's DNA and therefore is believed to be harmless, to ferry the same four transformative genes into the DNA of mouse skin and liver cells.
"The adenovirus will infect the cells but then will clear themselves from the cells. After a few cell divisions there are no traces of the virus in the cell," he said. "You can't tell the virus was ever there."
posted by Wesley J. Smith @ 2:58 PM
5 Comments
5 Comments:
Moving fast indeed. It won't be long before they make induced totipotent cells (i.e. embryos) out of skin cells.
I also note that this adenoviral system was 100 times less efficient than retroviral systems, but with the easy supply of cells, this may not be a problem.
I doubt very much that they will be able to induce totipotency in anything like the same way. That's just a factual prediction.
The teratoma issue is sufficiently urgent that my own guess remains that the actual clinical breakthrough will come at the level of using cells that are only multipotent.
Query: Which type of cells were used to create that mini-liver? Were they pluripotent or multipotent?
I doubt whether introducting genes to change the expression of a differentiated cell, which is what IPSC is, will ever result in an embryo. If it could, doing that, not dedifferentiating, should be outlawed.
Lydia: The mini livers were, off the top of my head, either created with blood or bone marrow stem cells.
Lydia, it was cord blood cells. So says BBC Tuesday, 31 October 2006. I have the file, but not the link.
Joshua,
Let me summarize what they seem to believe in regards to the potential of IPSc - what they've said is not possible, in this thread and in the past, and even if it becomes possible , which they dont believe it will, but should be outlawed at that point as the research on embryonic type cells that used to be objectionable in the past has become preferable thanks to methods they disapprove of, used to discover new techniques which they now approve of, but when told of their potential they ignore - until shown that they are really what we said they were in the first place, which is a viable organism of undiffed stem cells, at which point they will want to make that illegal too if they don't meet the narrow range of conditions put forth by some artificial determination that they feel supersedes the importance of the research itself until that research progresses to unfold another wrinkle in their logic of what is and isn't morally objectionable.
They've been very clear. But it doesn't really matter any way. Either Presidential candidate and future Congress will become much friendlier to ALL stem cell research than the incompetent and narrow leadership of the current administration and its diminishing faithful.
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