Medical News Today (Internet) 05/24/06 Using one of the newest and most powerful tools of biomedical science, University of Texas Medical Branch at Galveston (UTMB) researchers have scored a dramatic success in the battle against colorectal cancer. The scientists were the first to use what are known as "small interfering RNAs" to block the spread of human colorectal cancer cells implanted in laboratory mice. Small interfering RNAs (siRNAs), first described in 2001, are tiny bits of genetic material that can prevent the translation of genes into proteins -- including specific proteins involved in biochemical reactions that promote cancer and other diseases.