Posted on 07/18/2013 1:48:00 PM PDT by neverdem
Patient-specific cells could be made without genetic manipulation.
Scientists have demonstrated a new way to reprogram adult tissue to become cells as versatile as embryonic stem cells — without the addition of extra genes that could increase the risk of dangerous mutations or cancer.
Researchers have been striving to achieve this since 2006, when the creation of so-called induced pluripotent (iPS) cells was first reported. Previously, they had managed to reduce the number of genes needed using small-molecule chemical compounds, but those attempts always required at least one gene, Oct42, 3.
Now, writing in Science, researchers report success in creating iPS cells using chemical compounds only — what they call CiPS cells1.
Hongkui Deng, a stem-cell biologist at Peking University in Beijing, and his team screened 10,000 small molecules to find chemical substitutes for the gene. Whereas other groups looked for compounds that would directly stand in for Oct4, Deng's team took an indirect approach: searching for small-molecule compounds that could reprogram the cells in the presence of all the usual genes except Oct4.
Then came the most difficult part. When the group teamed the Oct4 replacements with replacements for the other three genes, the adult cells did not become pluripotent, or able to turn into any cell type, says Deng.
Fine-tuning
The researchers tinkered with the combinations of chemicals for more than a year, until they finally found one that produced some cells that were in an early stage of reprogramming. But the cells still lacked the hallmark genes indicating pluripotency. By adding DZNep, a compound known to catalyse late reprogramming stages, they finally got fully reprogrammed cells, but in only very small numbers. One further chemical increased efficiency by 40 times. Finally, using a cocktail of seven compounds, the group was able to get 0.2% of cells...
(Excerpt) Read more at nature.com ...
My, my, the materials and methods are an open PDF!
FReepmail me if you want on or off my stem cell/regenerative medicine ping list.
Put me on your regent Med ping list?
Isn’t that what thalidomide did?
How many people will read that and remain convinced that we need more funding for embryonic stem cell research?
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