Scientists Force Mature Cells to Revert to Stem Cells

Scientists have turned back the hands of time in cells within a living creature.

Researchers in Spain used a technique created seven years ago to force mature cells in mice to revert to an original form of stem cell with the potential to change into any type of living tissue. Previously, scientists were only been able to achieve this change in a petri dish.

The newest experiment, outlined today in the journal Nature, may one day let doctors work entirely inside the body to regenerate tissue and, perhaps, more complex organs, said George Daley, director of stem cell transplantation at Boston Childrens Hospital. This could include reconnecting a severed spinal cord or generating healthy heart cells.

This is the next step along a continuum, said Daley, a professor at Harvard Medical School in Boston who wrote an accompanying editorial on the work, which he wasnt involved with. What this is hinting at is that maybe we can, by regressing tissues in the patient, regenerate this embryonic potential and, with direction, regenerate a particular tissue.

The reverted mouse cells were also found to be more primitive than stem cells taken from embryos or created in the lab. This means they can be turned into a placenta and other embryonic-support membranes, a factor beyond the capacity of the other cells, the researchers wrote.

The latest finding modifies a technique that won Shinya Yamanaka the Nobel Prize for medicine last year. Using mice whose genes could be manipulated at will, the scientists duplicated the factors Yamanaka had used to regress adult cells into stem cells. The cells that regressed in the dosed mice were in the stomach, the intestines, kidneys, and pancreas.

You dont need the milieu of the petri dish, Daley said in a telephone interview. You can just do this right in the tissues. Thats surprising.

In todays report, some of the mice had tumors that developed in embryonic support structures as well as a yolk sac, suggesting they were more primitive and powerful than other stem cells, the scientists wrote.

These embryo-like structures are a reflection of going back to a more-primitive state, Daley said. Thats honestly what blew me away about the paper.

Its not clear why the cells developed in live mice are more powerful than those developed in petri dishes, said Maria Abad, a study author and researcher at the Spanish National Cancer Research Center in Madrid. Those grown in live bodies are more malleable, and behave differently when transplanted into a petri dish, she said.

Read more:
Scientists Force Mature Cells to Revert to Stem Cells