Hair Follicle Stem Cell May Hold Key to Ethical Medical Breakthroughs

An article in the San Diego Union-Tribune reports on effects by Salk Institute for Biological Research scientists to improve the method for reprogramming human cells to act like embryonic stem cells. They scientists, the paper said, literally pulled their hair out trying to achieve the results they wanted.

The Salk scientists showed they learned how to improve the process used to coax cells from an adult human backward down the development pathway so they become just like embryonic stem cells. These so-called induced pluripotent stem cells, or IPS cells, are then capable of turning into the 200 different cell types in the body.

Their secret? They used cells taken from the root of a hair follicle, called keratinocytes.

A team of Japanese researchers created a global stir last year when they showed they had reprogrammed human tissue cells to become IPS cells.

IPS cells are desirable because they do not require the destruction of a human embryo. And if ultimately used in a stem cell therapy, the recipient would not have an immune rejection reaction to his or her own cells.

If these IPS cells are ultimately used for therapeutic use, it would be simpler to use a single strand of hair to create them, rather than the Japanese team’s use of human tissue, said Juan Carlos Izpisua Belmonte, the lead author on the Salk paper.

The Japanese team needed 10,000 tissue cells to create one IPS cell. The Salk team used about 100 cells to create one IPS cell. While the Japanese team took about a month to reprogram the cells, Belmonte said, the Salk team did it in a week.

The Salk team found that the cells had a memory of the type of cell they used to be. Hair cells develop from ectodermal cells, which also develop into nerve, skin and neuronal cells. Although the hair keratinocytes could become any cells, it was easier to make them become one of the ectodermal cell types, Belmonte said.

The world is seeing rapid advances in the creation of IPS cells, said Evan Snyder, who heads the stem cell program at the Burnham Institute for Medical Research in La Jolla.

“This paper is in line with incremental advances that are being made in this field, moving toward greater efficiency, greater speed and less invasiveness,” Snyder said.

However, scientists still must figure out how to manipulate these cells without using viruses, as has been done by all researchers, he said. The viruses have been linked to cancer.

“I’m confident we’ll get there . . . soon,” Snyder said.