MicroRNAs Debut as Key Actors in Health and Disease

Release Date:
Kirstie Saltsman

One of the dogmas of biology has been that proteins, the cellular workhorses of our bodies, perform the critical job of controlling gene activity. But a series of recent discoveries is painting a strikingly different picture.

A newly identified kind of RNA, called microRNA for its tiny size, appears to control a third of our genes. Scientists are finding that microRNAs play starring roles in a remarkably wide range of biological processes.

Two studies in 2005 implicate microRNAs in cancer. Using microscopic roundworms, Frank Slack, Ph.D., of Yale University in New Haven, Connecticut, discovered that one particular microRNA can quiet Ras, a protein known to be central to tumor formation when it is mutated. In a separate study, Gregory Hannon, Ph.D., of Cold Spring Harbor Laboratory in New York identified other microRNAs linked to the severity of B-cell lymphoma in mice. These findings open promising new avenues for preventing, diagnosing, and treating cancer.

In a third study, Richard Carthew, Ph.D., of Northwestern University in Evanston, Illinois, and Hannele Ruohola-Baker, Ph.D., of the University of Washington in Seattle uncovered telltale signs of microRNA involvement in stem cell growth. Unlike most cells, stem cells have the ability to continuously renew themselves, yet scientists do not understand how this happens. The new research, done in fruit flies, revealed that stem cells need certain microRNAs to maintain their ability to divide endlessly.

Research on microRNA is still in the early stages, but the recent discoveries linking microRNAs with cancer and stem cell biology are fueling excitement about the potential therapeutic uses of these multitalented molecules.