In an unprecedented feat of biological alchemy, researchers have turned human skin cells into stem cells that hold the same medical promise as the controversial embryonic stem cells.
Both teams of researchers -- one led by Kyoto University's Shinya Yamanaka, the other by the University of Wisconsin's Junying Yu -- used a virus to add four new genes to skin cells. Thus transformed, the reprogrammed cells became capable of transforming into nearly any cell type in the human body. Embryonic stem cells are also have this ability, and researchers say such cells may someday be used to cure degenerative diseases, grow new organs and even replace limbs.
"It's a new era for stem cells," said Robert Lanza, chief science officer of Advanced Cell Technologies, a cloning company in California. "It's the holy grail. It's like turning lead into gold."
The technique could sidestep many ethical issues involving the destruction of embryos and collection of human eggs. Embryonic stem cell research is a lightning rod issue that crosses political and religious lines.
If the new method proves successful, "we can disconnect the whole stem cell debate from the culture war, from battles over embryo politics and abortion rights," said Marcy Darnovsky, associate director of the Center for Genetics and Society.
In a field accustomed to breathless proclamations of breakthroughs, the research -- published Tuesday in two papers appearing in the journals Cell and Science -- has provoked wonder among many scientists. They say the advance is more significant to medical research than last week's announcement that scientists had cloned the first monkey embryo.
Even Ian Wilmut of Dolly-the-sheep cloning fame said he's abandoning cloning with the prospect of this new research.
The technique essentially reverts mature cells to an embryo-like state. Normally, skin and other mature adult cells are locked into their biological fate. Scientists say the cells have "differentiated." But in the new research, scientists added genes to mature cells that turned back their cellular clocks, or dedifferentiated them, restoring them to an immature, unprogrammed state.
"Nobody knows exactly what happens, but when we introduce the genes, it basically changes gene expression inside the cell, and that changes the fate of the skin cells," Yu said. "Some eventually turn into stem cells."
Yamanaka and Yu say they must now learn to guide their cells' development. So far, the reprogrammed cells have been successfully turned into heart, muscle and brain tissue.
------------------
technosorcery at its finest...
No comments:
Post a Comment