A Natural Lock on Tumor Growth
At the University of California, researchers have been studying RNA interface(RNAi), a naturally occurring system that turns genes on and off, and the proteins drosha and dicer. The research has focused on spacial and temporal regulations of RNAi. Researchers hope that a better understanding of these regulations will help to lead to improved medical applications of controlling the RNAi system. This emerging research is going to be essential in future medical endeavors especially in biomedical applications such as gene therapy.
Research on drosha and dicer proteins is already being applied to the medical field. According to a study in the New England Journal of Medicine, women who had ovarian tumors with high levels of the proteins Dicer and Drosha survived for an average of 11 years or more, while women who had lower levels survived only a median of around 3 years. Researchers hope that a better understanding of Dicer and Drosha might someday help guide treatment or lead to new types of therapy. These two proteins are essential in RNA interference. In the study, Anil K. Sood, M.D., University of Texas M.D. Anderson Cancer Center, in Houston, and his colleagues looked for Dicer and Drosha in the tissue from 111 women with advanced epithelial ovarian cancer. They found that 60 percent of the cancer tissues had low levels of Dicer, 51 percent had low levels of Drosha, and 39 percent had low levels of both. This study is the largest yet to link RNA interface with any cancer survival rates.
“In the past, people used to think that miRNA might actually promote tumor growth, but there is some emerging thought that some of the miRNAs might keep tumors from growing and actually function as a tumor suppressor,” says Sood, who is an associate professor of cancer biology.
Unfortunately this research does not have immediate application for women with ovarian cancer. However the finding may eventually help doctors to better determine if a patient needs more aggressive treatments.
This new research is causing many biotechnology companies to look at this lock-and-key mechanism as a potential way to fight other diseases. They are working to create new synthetic molecules called small interfering RNAs. These siRNAs are being tested as a way to treat eye disease and age-related macular degeneration.
J. Am. Chem. Soc., 2009. DOI: 10.1021/ja905596t