Custom-built human organs come closer to reality

November 21st, 2007 - 1:24 pm ICT by admin  

Washington, Nov 21 (ANI): University of Wisconsin-Madison researchers have reprogrammed human cells to act like embryonic stem cells, a development that could ease political, ethical, and medical concerns over the ongoing controversy about embryonic stem cell research, and pave the way for custom-building organs for individuals.

Similar to embryonic stem cells, the new cells, known as induced pluripotent cells, have the potential of developing into most types of cells in the body. However, the new lines can be created without the use of an embryo.

Such cells could possibly also be custom-made for any adult, sidestepping debates of cell rejection.

“The advantage of using [such] reprogrammed skin cells is that any cells developed for therapeutic purposes can be customized to the patient. They are probably more clinically relevant than embryonic stem cells,” National Geographic quoted James Thompson, a biologist at the University of Wisconsin, Madison, who led one of the studies, as saying.

Research of embryonic stem cell has long been delayed in controversy. Such cells may lead to medical treatments such as tissue and organ replacement, but harvesting the cells typically requires the destruction of an embryo.

Since the year 2001, the US government has restricted public funding to a limited number of embryonic stem cell lines, a move many American scientists say has stifled their research.

The urge to develop induced pluripotent cells in humans began last year, when researchers at Kyoto University in Japan announced they had inserted genes into cells from the tails of mice and reprogrammed them into cells with properties of embryonic stem cells.

Thompson and his colleagues announced that they had finally translated the research to humans by using viruses to ferry four genesOCT4, SOX2, NANOG, and LIN28into skin cells. The findings are published in this week’s issue of the journal Science.

In the other paper, published in the journal Cell, a group led by Shinya Yamanaka of Kyoto University reported that they have also given human cells taken from skin and connective tissues stem cell properties.

Employing the same technique as that of Thompson but with a slightly different combination of genes, the Japanese researchers report they were able to reprogram 10 cells out of every 50,000. The Wisconsin team got one pluripotent cell for every 10,000 cells.

“We should now be able to generate patient- and disease-specific [induced pluripotent stem] cells and then make various cells, such as cardiac cells, liver cells, and neural cells,” team leader Shinya Yamanaka of Kyoto University said.

He said that in addition to alleviating concerns over embryonic stem cells, the new techniques might reduce the need to carry out somatic cell nuclear transfer; a controversial technique that uses harvested eggs to clone cells.

Such a procedure is used to create animal clones, such as Dolly the sheep, and is being explored as a way to create human stem cell lines.

“This approach, if generally applicable, may be a good alternative to somatic cell nuclear transfer. If it turns out to be a good alternative, obtaining donated human oocytes [eggs] may be less important for research progress,” he said.

Timothy Caulfield, research director of the Health Law Institute at the University of Alberta added that the advancement, if it proves generally applicable, would allow the creation of cell lines that are genetically identical to an individual needing stem cell therapy.

This would eliminate the possibility of tissue rejection, one of several barriers still impeding the development of stem-cell-based medical treatments. The findings hold “tremendous amount of potential, but (applications) could be years and years away, Caulfield said.

“There are many other issues to consider. If these cells are truly pluripotent, could they form eggs and sperm? If so, what then?” he added. (ANI)

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