KYOTO--Japanese researchers have found a method using induced pluripotent stem (iPS) cells that could lead to a drug to treat the incurable disease amyotrophic lateral sclerosis (ALS).

A team comprising Haruhisa Inoue, a neurology professor at Kyoto University, and other scientists found a chemical compound that could deal with ALS, a disorder characterized by the weakening of muscles and other conditions, after using it on iPS cells derived from the skin of ALS patients.

The team also confirmed that the substance, used as a therapeutic agent for leukemia, was effective in inhibiting the progression of ALS in mice.

The findings were published in the U.S. medical journal Science Translational Medicine on May 25.

Inoue and his colleagues developed iPS cells from the skin of ALS patients and created motor nerve cells from the iPS cells.

They then analyzed those motor nerve cells and discovered that abnormal proteins had accumulated in them, resulting in more frequent cell death.

With the hope of identifying agents to inhibit cell death, they tested 1,416 kinds of existing drugs and other chemical compounds, using the nerve cells. The results showed 27 of them are effective in inhibiting cell death.

One of the more than 1,000 compounds, an anticancer drug to deal with chronic myelogenous leukemia proved clearly effective. It prevents abnormal proteins from accumulating by promoting decomposition of unnecessary proteins in cells.

Administration of the drug to 26 mice genetically modified to develop ALS showed the onset of the disease was delayed 11 days compared with ALS mice not given the drug. The treated mice lived eight days longer as well.

The agent cannot be used soon to treat the disorder, as whether administering the drug to human ALS patients is safe, along with other problems, have to be closely examined in the future.

“We will study the effective concentration and side effects of the drug,” a team member said.