moneoa
November 20th, 2007, 07:53 PM
Bio-wizards have come up with "simple" recipes to reprogram skin cells and give them the power to become any cell in the human body.
The new techniques, unveiled Tuesday by teams in Japan and the U.S, are seen as a major leap forward for the controversial field of regenerative medicine which aims to use stem cells to repair severed spines, damaged hearts and failing minds.
The teams have used genes to produce the potent cells from regular skin cells, avoiding the destruction of days-old human embryos, until now the source of the "pluripotent" cells which can morph into any of the 200 different cell types in the body. A scientific team from the University of Wisconsin-Madison created genetic modifications in skin cells, pictured here, to induce the cells into what scientists call a pluripotent state - a condition that is essentially the same as that of embryonic stem cells. A scientific team from the University of Wisconsin-Madison created genetic modifications in skin cells to induce the cells into what scientists call a pluripotent state - a condition that is essentially the same as that of embryonic stem cells.
The new gene technique is expected to enable scientists to bypass many of the thorny ethical problems that have surrounded the field for close to a decade and hampered stem cell work in Canada, the U.S. and other countries.
"It's a stunning advance," says Dr. Michael Rudnicki, scientific director the Canadian Stem Cell Network. "It has shocked a lot of people that it actually works."
He says the new techniques frees more scientists to get involved, since it is now possible to grow the potent cells with "no need" for an embryo.
"You're not going go to jail," says Rudnicki, in reference to the cloning techniques, illegal in Canada, that some foreign teams have been using to try to generate human embryonic cells. He jokes that ethicists will now have to find other things to worry about.
While the treatments based on the new techniques are still years away, competition in the field is so fierce the U.S. and Japanese teams rushed their findings into print Tuesday.
The Japanese team reports, in an advance online publication of the journal Cell, how it reprogrammed skin cells taken from the face of a 36-year-old woman and the connective tissue of a 69-year-old man. Shinya Yamanaka and his colleagues at Kyoto University, who pioneered the technique in mice, inserted four genes into the human cells and were able to generate several "pluripotent" cell lines.
The U.S. team reports a similar feat in the journal Science, which lifted its normally strict embargo and posted a paper online to coincide with the Cell publication.
The University of Wisconsin-Madison group, led by Junying Yu, also ferried four genes into human skin cells, which they took from the fetal skin and the foreskin of a newborn boy. The genes, two of them different than the ones used by the Japanese, induced the skin cells to revert to a pluripotent state, a condition the team describes as "essentially the same" as that of embryonic stem cells.
They "do all the things embryonic stem cells do," says biologist James Thomson, who heads the Wisconsin-Madison lab and created international headlines and controversy when he first harvested stem cells from human embryos in 1998.
The fabled cells have the potential to grow into any kind of cell, from insulin-secreting islet cells for diabetics to new brain or heart tissue. Scientists have for years talked of customizing cells for patients through research cloning, which would take nuclear material from the patient's own cells and transfer it into eggs and then harvesting the stem cells from the resulting cloned embryo.
The new gene technique is so promising that Ian Wilmut of the University of Edinburgh in the United Kingdom, who cloned Dolly the sheep, has abandoned plans to try to create pluripotent human cells through such "research cloning." The new technique, Wilmut told Science, "is so much more practical."
Research cloning, also known as nuclear transfer, is illegal in Canada and scientists have long argued the rules are too strict.
"Now we don't need to fight that battle," says Rudnicki, who is also director of the regenerative medicine program at the Ottawa Health Research Institute. "We can work on these alternative technologies. It's probably easier and faster to do it directly from skin cells."
Bioethicists and pro-life activists welcomed the new technique, which alleviates concerns about exploiting women for their eggs and destruction of human embryos.
"This is a method for creating a stem cell line without ever having to work through, at any stage, an entity that is a viable embryo," bioethicist Alta Charo, at the University of Wisconsin, said in a statement.
Richard Doerflinger, of the secretariat for pro-life activities at the U.S. Conference of Catholic Bishop, described it has a "win" for both science and ethics.
Although the technique is expected to speed development of new cell-based therapies, researchers caution much work remains to be done. They need to figure out how to remove the viruses used to ferry the genes into the skin cells. And the genes, one of which has been associated with cancer, need to be turned off or removed once they've completely their job.
The scientists also say research needs to continue on stem cells from human embryos to better characterize and understand the cells. These cell lines, including some produced in Canada, are created by harvesting cells from leftover embryos donated by people who have undergone fertility treatment. The embryos are days old when the cells are removed, a process that destroys the embryo. This research is legal in Canada and overseen by a federal stem cell oversight committee.
http://www.canada.com/topics/technology/science/story.html?id=b7ed3907-38cc-421c-83c5-3b21b6c9fbe0
The new techniques, unveiled Tuesday by teams in Japan and the U.S, are seen as a major leap forward for the controversial field of regenerative medicine which aims to use stem cells to repair severed spines, damaged hearts and failing minds.
The teams have used genes to produce the potent cells from regular skin cells, avoiding the destruction of days-old human embryos, until now the source of the "pluripotent" cells which can morph into any of the 200 different cell types in the body. A scientific team from the University of Wisconsin-Madison created genetic modifications in skin cells, pictured here, to induce the cells into what scientists call a pluripotent state - a condition that is essentially the same as that of embryonic stem cells. A scientific team from the University of Wisconsin-Madison created genetic modifications in skin cells to induce the cells into what scientists call a pluripotent state - a condition that is essentially the same as that of embryonic stem cells.
The new gene technique is expected to enable scientists to bypass many of the thorny ethical problems that have surrounded the field for close to a decade and hampered stem cell work in Canada, the U.S. and other countries.
"It's a stunning advance," says Dr. Michael Rudnicki, scientific director the Canadian Stem Cell Network. "It has shocked a lot of people that it actually works."
He says the new techniques frees more scientists to get involved, since it is now possible to grow the potent cells with "no need" for an embryo.
"You're not going go to jail," says Rudnicki, in reference to the cloning techniques, illegal in Canada, that some foreign teams have been using to try to generate human embryonic cells. He jokes that ethicists will now have to find other things to worry about.
While the treatments based on the new techniques are still years away, competition in the field is so fierce the U.S. and Japanese teams rushed their findings into print Tuesday.
The Japanese team reports, in an advance online publication of the journal Cell, how it reprogrammed skin cells taken from the face of a 36-year-old woman and the connective tissue of a 69-year-old man. Shinya Yamanaka and his colleagues at Kyoto University, who pioneered the technique in mice, inserted four genes into the human cells and were able to generate several "pluripotent" cell lines.
The U.S. team reports a similar feat in the journal Science, which lifted its normally strict embargo and posted a paper online to coincide with the Cell publication.
The University of Wisconsin-Madison group, led by Junying Yu, also ferried four genes into human skin cells, which they took from the fetal skin and the foreskin of a newborn boy. The genes, two of them different than the ones used by the Japanese, induced the skin cells to revert to a pluripotent state, a condition the team describes as "essentially the same" as that of embryonic stem cells.
They "do all the things embryonic stem cells do," says biologist James Thomson, who heads the Wisconsin-Madison lab and created international headlines and controversy when he first harvested stem cells from human embryos in 1998.
The fabled cells have the potential to grow into any kind of cell, from insulin-secreting islet cells for diabetics to new brain or heart tissue. Scientists have for years talked of customizing cells for patients through research cloning, which would take nuclear material from the patient's own cells and transfer it into eggs and then harvesting the stem cells from the resulting cloned embryo.
The new gene technique is so promising that Ian Wilmut of the University of Edinburgh in the United Kingdom, who cloned Dolly the sheep, has abandoned plans to try to create pluripotent human cells through such "research cloning." The new technique, Wilmut told Science, "is so much more practical."
Research cloning, also known as nuclear transfer, is illegal in Canada and scientists have long argued the rules are too strict.
"Now we don't need to fight that battle," says Rudnicki, who is also director of the regenerative medicine program at the Ottawa Health Research Institute. "We can work on these alternative technologies. It's probably easier and faster to do it directly from skin cells."
Bioethicists and pro-life activists welcomed the new technique, which alleviates concerns about exploiting women for their eggs and destruction of human embryos.
"This is a method for creating a stem cell line without ever having to work through, at any stage, an entity that is a viable embryo," bioethicist Alta Charo, at the University of Wisconsin, said in a statement.
Richard Doerflinger, of the secretariat for pro-life activities at the U.S. Conference of Catholic Bishop, described it has a "win" for both science and ethics.
Although the technique is expected to speed development of new cell-based therapies, researchers caution much work remains to be done. They need to figure out how to remove the viruses used to ferry the genes into the skin cells. And the genes, one of which has been associated with cancer, need to be turned off or removed once they've completely their job.
The scientists also say research needs to continue on stem cells from human embryos to better characterize and understand the cells. These cell lines, including some produced in Canada, are created by harvesting cells from leftover embryos donated by people who have undergone fertility treatment. The embryos are days old when the cells are removed, a process that destroys the embryo. This research is legal in Canada and overseen by a federal stem cell oversight committee.
http://www.canada.com/topics/technology/science/story.html?id=b7ed3907-38cc-421c-83c5-3b21b6c9fbe0