Monday, May 18, 2009

Induced Pluripotent Stem Cells

Research in stem cells and the origin and treatment of disease is definitely moving away from destructive embryonic stem cell research toward induced pluripotent stem cells (iPS).

A fantastic review that connects Japan's Dr. Yamanaka, San Francisco's Srivastava, the University of Texas Southwestern Medical Center in Dallas, and the Burnetts of Sulphur Springs, Texas, is published in the Japan Times. (Written by Rob Waters for Bloomberg news.)

Yamanaka, a professor at Kyoto University, developed a technology that may make the argument moot. Yamanaka, who has two daughters, started his effort 10 years ago, after peering at a tiny embryo through a microscope and reflecting that it might form a child if it wasn't used to make stem cells, he said in an interview.

"That's the moment I thought about this project," he said. "I saw that if we could make pluripotent stem cells without using human embryos, that would be ideal."

In 2006, he scored his first success. Using a virus to insert four genes into the skin cells of mice, he started a process that returned the cells to a primordial state able to form any other cell in the body. Yamanaka named them induced pluripotent stem, or iPS, cells. The next year, he repeated the feat with human cells.

Yamanaka and researchers elsewhere are now racing to find better ways to achieve the same effect. They would like to get rid of the virus, which can cause the genes to lodge permanently in the structure of the cell and may trigger the growth of tumors.

Yamanaka's technique exploits a basic fact of human biology — that every cell in a person contains the genetic instructions that set that person's traits, from hair color to inherited disease. By taking skin cells from a person with a disease and turning them into cells in the heart, brain or pancreas that are affected by a genetic disease, researchers can experiment with disorders at their earliest stages, Harvard's Melton said.

Labs are now creating iPS cells because making them is far simpler than getting cells from embryos, said Jeanne Loring, founding director of the Center for Regenerative Medicine, part of the Scripps Research Institute in La Jolla, Calif.

"Every stem-cell researcher I know has made about a dozen," Loring said.

She estimates that researchers have made 300 different so-called lines of iPS cells, a number that may double this year. Each line is a colony of cells descended from the first ones made. Scientists keep them alive in culture and the cells keep replicating.

Read it all here.

1 comment:

renuu said...

Induced pluripotent stem (iPS) cells is an alternative methods for studying diseases that are more robust and better simulate how the disease develops in humans. The concerns expressed regarding chimerism may be a bit strong. Technological improvements with traditional ES cell microinjections have resulted in embryos which are 100% derived from the donor, not receipient, cells. Thus the first mice born are true clones of the source ES cells.
My url:
I also invite people to use my links and read more.