Lead Into Gold: IPS Cells Advances Continue
President Obama still hasn't rescinded the Bush stem cell policy. He will, but it may matter a lot less than people once thought. The IPSC advances continue, opening the door possibly for a way forward in biotechnology that all Americans can support. And, it is reported in the Washington Post! From the story:
Scientists have developed what appears to be a safer way to create a promising alternative to embryonic stem cells, boosting hopes that such cells could sidestep the moral and political quagmire that has hindered the development of a new generation of cures.The IPSCs are already being used in drug testing and etc. But can't be used in patients:
The researchers produced the cells by using strands of genetic material, instead of potentially dangerous genetically engineered viruses, to coax skin cells into a state that appears biologically identical to embryonic stem cells. "It's a leap forward in the safe application of these cells," said Andras Nagy of Mount Sinai Hospital in Toronto, who helped lead the international team of researchers that described the work in two papers being published online today by the journal Nature. "We expect this to have a massive impact on this field."
The alternative cells, known as induced pluripotent stem cells, or iPS cells, appear to have many of the same characteristics as embryonic stem cells but are produced by activating genes in adult cells to "reprogram" them into a more primitive state, bypassing the moral, political and ethical issues surrounding embryonic cells. Until now, however, their use has been limited because the genetic manipulation required the use of viruses, raising concerns the cells could cause cancer if placed in a patient. That has triggered a race to develop alternative approaches. "These viral insertions are quite dangerous," Nagy said.Well, so are embryonic stem cells. Pluripotency itself is a problem due to potential tumor formation, and if the stem cells come from "leftover" embryos, immune rejection issues--which is why with the exception of the Geron approved trial, they haven't been used in humans. And the story doesn't get into the amazing adult stem cell successes in early human trials, which are patient specific and don't appear to pose the tumor threat.
Be that as it may, let us all hope the IPSC advances continue. If they work, it could bring about a rapprochement between both sides of the great ESCR debate, while not opening the door to human cloning.
Labels: Lead Into Gold. Induced Pluripotent Stem Cells. Advances in Research.
posted by Wesley J. Smith @ 10:57 AM
10 Comments
10 Comments:
Here's where I am confused: upon further reading on this new "breakthrough" it seems to me that this research actually used embryos and embryonic stem cells, not adult.
From this story (my emphasis):
"In this study the researchers were able to show successful and efficient reprogramming of mouse and human fibroblasts taken from embryonic stem cell lines, but there is no reason in principle why this could not happen to fibroblasts taken from adult tissue."
And from this article (my emphasis):
"The researchers created a transposon carrying the four transcriptional factors, and introduced it into embryonic and adult mouse skin cells, and human embryonic skin cells. The researchers also introduced DNA carrying the code for an enzyme (called transposase), which can cut out the newly introduced piece of DNA (transposon) from the host when it has finished expressing the transcription factors. The researchers looked at whether the skin cells began to switch on genes that are typically expressed in pluripotent embryonic stem cells and began to look like embryonic stem cells.
In the experiments with embryonic mouse skin cells, the researchers also took the successfully reprogrammed cells and injected them into mouse embryos to see if they would successfully form different types of cell within the mouse embryo, that is, whether they were truly pluripotent."
If they were actually using ESCs and implanting them in embryos for this research, I wouldn't exactly call this a great breakthrough for "ethical" alternatives. Or is there something here that I am not understanding?
Another key paragraph from this article:
"Importantly, the cells that were converted to stem-cell-like cells were not originally human adult skin cells, but came from human embryonic fibroblasts (a type of connective tissue cell from embryos). Although adult mouse cells were used in one study, it still needs to be shown that the technique works in human adult skin cells."
And, yes, before someone points it out, I do see that they used some adult stem cells from mice.
Chelsea: They have made human IPSC lines with skin cells, hair follicles, and even wisdom teeth that had nothing to do with embryonic cells.
One of the early human experiments used fetal tissue, but that isn't necessary to their creation.
They are now using animal models to improve techniques. Then, it will be tried using human cells.
I realize that, and I understand the animal models, but unless I'm reading it wrong, they were also using HUMAN embryonic stem cells in these experiments. I'm all for this research advancing in order to find an ethical alternative to using embryos, but not if they're going to be using human ESCs in the process anyway. As they appear to have done here.
They were not embryonic stem cells, they were skin cells. This might mean fetal. I am trying to find out source of those cells.
Well, maybe you can find out better than I have been able to. I have not been able to figure out where a "human embryonic fibroblast" actually comes from. That's what got me confused...
Chelsea: This from a scientist I trust: "It was actually fetal skin cells (poor use of terms by the reporters & scientists) the short story is, since the 1960's the prevailing view has been that fetal tissue grows better & is more pliable than adult (of course, recent years have proven that dogma wrong.) Nonetheless, the scientists in these 2 studies still started with fetal skin cells (both mouse & human) to do their iPSC reprogramming with the piggyBac transposon.
It will work just as well with adult; they just need to do the expt & publish"
Thanks, Wesley, I really appreciate it! Although, I'm not sure I find this news much more palatable. I suppose it would depend on where those fetal cells came from... It would be nice if they would just make this stuff clear in the first place!
I don't think they want it to be clear, not only because they can't make it clear because they are incapable of it, but also because making it clear would hamper their agenda and detract from the "mystique" on which they depend to keep the money rolling in.
Post a Comment
Subscribe to Post Comments [Atom]
<< Home