Scientists at the Feinberg School of Medicine associated with Northwestern University have identified a small RNA molecule called miR-182 that can suppress cancer-causing genes in mice with glioblastoma multiforme (GBM), one of the deadliest variants of brain cancer. Currently, there is no cure for the disease.
Image Source: Don Bishop
Although chemotherapy is a treatment option for GBM, the process damages DNA in order to prevent the reproduction of cancer cells. The premise of chemotherapy is that it eradicates every cell in the process of cell reproduction — even noncancerous ones. The goal of the treatment is to shrink the cancer until it is insignificant (partial remission) or even completely eradicated (complete remission), or to the point where it is more easily surgically removed.
Successful chemotherapy does not mean the patient is entirely in the clear. The cancer usually continues to grow back after each treatment, as the mutated DNA that produces the cancer cells has not been fully removed. Moreover, chemotherapy has the unfortunate effect of also impacting normal, noncancerous rapidly dividing cells that make up hair follicles, skin, and the lining of the digestive tract. Indeed, this is the reason why cancer patients who undergo chemotherapy experience hair loss. However, it is crucial to understand that the good done from chemotherapy heavily outweighs the harm, which is why doctors continue to administer it.
Returning to the study, this newly discovered RNA molecule — miR-182 — takes chemotherapy one step further, stopping the cancer at the source by repressing genes that cause overproduction of certain proteins. The study used a nanostructure called spherical nucleic acids (SNAs), composed of multiple strands of densely packed DNA and RNA around a nanoparticle center, to safely deliver miR-182 across the blood-brain barrier to reach tumor cells. There, it targets multiple oncogenes (genes that have the potential to cause cancer), increasing cancer cell death and reducing cancer cell growth.
“We demonstrate a more specific, more personalized approach to therapy,” Stegh, an assistant professor in the Ken and Ruth Davee department of neurology at Feinberg, said. “SNAs are a very promising platform to silence the particular genes that drive or contribute to cancer progression in individual patients.”
There are roughly 16,000 new cases of glioblastoma multiforme annually. The prognoses for these cases are usually dire, with the median survival length merely 14 to 16 months, making this research even more significant.
But why does miR-182 only affect brain cancer? Can it be utilized on humans? Will it revolutionize the way we treat cancer in the future? Find out next week in “Cancer Genes Turned Off in Deadly Brain Cancer: Part II!”