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NOVA scienceNOW: Stem Cells Breakthrough

Program Overview

Scientists discuss how they transformed fully mature skin cells into the equivalent of an embryonic stem cell.

This NOVA scienceNOW segment:

• describes sickle-cell anemia, a blood disease caused by a single faulty gene. Though it was the first genetic disease identified, still no cure exists.

• reports on a new potential treatment for sickle-cell anemia involving pluripotent embryonic stem cells—cells that can be turned into any cell type in the body.

• details the method scientists used to identify the four genes responsible for transforming fully developed skin cells into pluripotent embryonic stem cells. These new cells are called induced Pluripotent Stem (iPS) cells.

• describes the technique scientists first used to make iPS cells from the skin cells of adult mice: Scientists initiated the process by attaching the four key genes to a virus, which inserted them into the skin cells. The four genes "erased" all skin functions and turned the skin cells into iPS cells.

• points out that iPS and embryonic stem cells look the same and seem to function identically.

• mentions that researchers have used iPS cells to cure sickle-cell disease in trials run on mice.

• reports that in less than one year after the discovery, other scientists transformed human skin cells into iPS stem cells.

• points out challenges that must be overcome before iPS cells can help patients like those with sickle cell anemia. For example, one of the four genes can mutate a patient's DNA and cause cancer.

• explains that scientists are uncertain whether iPS cells can dependably grow into all cell types. Until this is confirmed, embryonic stem cells remain the gold standard of stem cells.

Taping Rights: Can be used up to one year after the program is taped off the air.