A clinical trial of a gene-silencing treatment for reducing excessive scarring is now underway, bringing the number of active clinical trials for the as-yet-unproven gene-silencing process known as RNA interference to nearly 20.

RNAi was discovered in 1998 and has since exploded as a research tool for turning off genes of choice in lab settings. Soon thereafter, biotech and pharmaceutical companies turned their attention to siRNAs—short pieces of RNA, DNA's cousin, that can prevent the activity of the specific gene they complement—as a potential therapeutic tool, but so far no one has successfully commercialized the technology. The technology holds the potential to reduce the effects of almost any gene in a human cell, if only the interfering RNAs can get inside.

 

"Because RNA does not normally pass through the membrane of the cell, that delivery step is a major challenge," says Phil Sharp, a molecular biologist at MIT and a cofounder of an RNAi company called Alynylam (Sharp previously discussed the therapeutic potential of RNAi with Technology Review).