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Originally posted by BlackBlade:
There was a thread about this fairly recently, where diabetics were given an injection of blood modified by stem cells and it caused their pancreases to function properly for up to several years.

I earnestly hope that non embryonic stem cell research comes through for us all.

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Posts: 813 | Registered: Nov 1999  |  IP: Logged | 

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This article is a good example of how dangerous a little information can be. This is really nothing new and it doesn't particularly change anything. People have known about adult stems cells and have been working with them for a long time.

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Research reported this week by three different groups shows that normal skin cells can be reprogrammed to an embryonic state in mice1, 2, 3.

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Last year, Yamanaka introduced a system that uses mouse fibroblasts, a common cell type that can easily be harvested from skin, instead of eggs4. Four genes, which code for four specific proteins known as transcription factors, are transferred into the cells using retroviruses. The proteins trigger the expression of other genes that lead the cells to become pluripotent, meaning that they could potentially become any of the body's cells. Yamanaka calls them induced pluripotent stem cells (iPS cells). "It's easy. There's no trick, no magic," says Yamanaka.

The results were met with amazement, along with a good dose of scepticism. Four factors seemed too simple. And although the cells had some characteristics of embryonic cells — they formed colonies, could propagate continuously and could form cancerous growths called teratomas — they lacked others. Introduction of iPS cells into a developing embryo, for example, did not produce a 'chimaera' — a mouse carrying a mix of DNA from both the original embryo and the iPS cells throughout its body. "I was not comfortable with the term 'pluripotent' last year," says Hans Schöler, a stem-cell specialist at the Max Planck Institute for Molecular Biomedicine in Münster who is not involved with any of the three articles.

This week, Yamanaka presents a second generation of iPS cells1, which pass all these tests. In addition, a group led by Rudolf Jaenisch2 at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, and a collaborative effort3 between Konrad Hochedlinger of the Harvard Stem Cell Institute and Kathrin Plath of the University of California, Los Angeles, used the same four factors and got strikingly similar results.

"It's a relief as some people questioned our results, especially after the Hwang scandal," says Yamanaka, referring to the irreproducible cloning work of Woo Suk Hwang, which turned out to be fraudulent. Schöler agrees: "Now we can be confident that this is something worth building on."

The improvement over last year's results was simple. The four transcription factors used by Yamanaka reprogramme cells inconsistently and inefficiently, so that less than 0.1% of the million cells in a simple skin biopsy will be fully reprogrammed. The difficulty is isolating those in which reprogramming has been successful. Researchers do this by inserting a gene for antibiotic resistance that is activated only when proteins characteristic of stem cells are expressed. The cells can then be doused with antibiotics, killing off the failures.

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sigh... A similar claim was published to the accolades of many by a SouthKorean research team not too many years ago. Except no one else could dublicate it. And recently, the team leader got flamed, fired, and prosecuted for falsifying results.

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Posts: 26071 | Registered: Oct 2003  |  IP: Logged |