Philadelphia, September 13, 1999 - Stem cells plucked from the bone marrow of adult mice can display characteristics of nerve cells when inserted into the brains of newborn mice, a finding that may hold promise for future treatment of Alzheimer's and other neurological disease, researchers said.

Adult cells appeared to have the properties of embryonic stem cells - undeveloped cells that can become any type of cell in the body, said investigators from the MCP Hahnemann School of Medicine in Philadelphia.

Because adult stem cells are more specialized than blank -slate embryonic cells, until recently scientist's thought they could not change their basic mission.

"Taking cells from one part of the body and re-injecting them into another region such as the brain, where they not only survive and multiply but adopt many of the same genetic characteristics as the host cells, is something that only existed in the best science fiction," said Dr. Darwin Prockop, the lead researcher and director of the Center for Gene Therapy at Hahnemann.

The technique won't be ready for human study for another year or two, he said in an interview, and will be tested first on Parkinson's disease at the gene center. More work is needed to determine if the bone marrow stem cells become fully functioning nerve cells, he said.

The study appears in tomorrow's Proceedings of the National Academy of Sciences.

In January, a different team of investigators produced mirror-image findings: They found that nerve stem cells taken from the brains of mice could be reprogrammed into blood cells in bone marrow. In that study, published in Science, the nerve cells dropped their brain cell identities and started to produce blood cells instead.

Scores of researchers and several companies, including Geron Corp., are working with stem cells in hopes of creating new treatments for everything from degenerative diseases to human tissue transplants that don't carry the risk of rejection -any ailment in which damaged cells could be replaced by healthy ones.

In Alzheimer's disease, for example, nerve cells in the brain gradually die and aren't replaced, causing dementia and other symptoms. One day, stem cells might be used to replace the destroyed brain cells, Prockop said.

In previous research, stem cells extracted from adult bone marrow was coaxed into becoming muscle, fat, or cartilage -although the cells are less malleable than embryonic stem cells. However, stem cells from human embryos and fetal cells can be difficult to obtain because of ethical and legal considerations.

Doctors using adult stem cells would be able to give their patients back their own cells, eliminating the need for fetal cells and the risk of rejection or virus transmission, Prockop said..