Researchers at City of Hope have shown for the first time that mutations in certain molecules that help control genes may play a role in a major mental disorder. The findings, published July 1 in the online journal PLoS ONE, give researchers new insight into how the disease schizophrenia might arise and offer a potential new way to screen those at risk for it.
Schizophrenia is a severe, disabling brain disorder affecting about 2.5 million adults in the U.S. Usually arising in a person’s late teens or early adult years, it can cause hallucinations, delusions and disordered thinking, among other symptoms.
|A research team including Jinong Feng found a possible link between microRNA and schizophrenia. (Photo by Thomas Brown)|
Researchers believe genetics lie behind the disease, but its exact cause remains elusive.
Now, research led by John J. Rossi, Ph.D., Lidow Family Research Chair and chair of the Department of Molecular Biology, and former City of Hope researcher Steve Sommer, M.D., Ph.D., has linked mutations in microRNA to the disease.
MicroRNA, commonly called miRNA, has come to light in recent years as a major controller of gene expression, the process by which the genetic code is translated from DNA into proteins.
Consisting of short pieces of ribonucleic acid, or RNA, miRNA directs machinery in the cell to block gene expression. The process occurs as a natural part of cell control, but researchers can exploit it to influence gene expression for a variety of uses, including treatment of disease.
“Other research has suggested miRNA is linked to mental disorders,” said Rossi, “so we thought we’d look for mutations in miRNA that might be unique to people with schizophrenia.”
The recent study compares miRNA in 191 healthy people and 193 who had schizophrenia symptoms. Specifically, the researchers wanted to see if mutations in miRNA were more common in people with the disease.
They found eight extremely rare mutations in some of the patients with schizophrenia but not in any of the healthy people.
“We were very excited to see the results,” said Jinong Feng, Ph.D., associate researcher scientist in the Department of Immunology and lead author on the paper. MicroRNA likely is involved in many diseases, “but this is the first strong evidence showing miRNA mutations may contribute to schizophrenia.” He cautioned that more studies are needed to confirm the link, however.
Other City of Hope researchers on the study included former graduate student Guihua Sun, Ph.D., the Department of Surgery’s Wenyan Li and Jin Yan, Ph.D., and Jeff Longmate, Ph.D., director of biostatistics.