Experimental drug may halt tumor growth

JACKSONVILLE, Fla., Jan. 20 (UPI) -- U.S. scientists have found an experimental anaplastic thyroid cancer drug can activate a powerful tumor suppressor that has the ability to halt cell growth.

Researchers at the Mayo Clinic campus in Jacksonville, Fla., say few other cancer drugs have that ability and the drug, called RS5444, might be useful in treating other cancers.

The researchers found human anaplastic thyroid tumor cells treated with RS5444 expressed a protein known as p21, which inhibited cell replication and tumor growth.

"This is very unusual," said the study's lead investigator, John Copland. "Drugs typically target genes and proteins that are over-expressed and turn them off. We found that RS5444 turns on a valuable tumor suppressor gene. We rarely find a drug that can take a suppressed gene and cause it to be re-expressed."

The research is to be reported in the Feb. 15 issue of Cancer Research and is now available online at the journal's Web site.