What causes one of the most deadly cancers in the world today? Researchers found novel genetic disruption in DNA that leads to brain cancer.
The New York Times reports on brain cancer.
Scientists have been tirelessly searching the DNA of brain tumors to figure out what causes them to multiply so fast but could not find any growth causing genes that usually exist in such cancers.
The research group reported that the three-dimensional structure and organization of the DNA had been disrupted. “As a result, two genetic neighborhoods that are usually separated, as if they are two gated communities, were merged. The effect was to allow a powerful snippet of DNA from one neighborhood into the one next door, where it woke up a near-dormant growth gene,” according to The Times.
Researchers said that this is a completely new way for cells to become cancerous, and is probably not unique to the brain cancers, low- and intermediate-grade gliomas, which were the main focus of the study. How does this new information help patients? Will it lead to a more effective treatment plan?
Dr. Bradley Bernstein, pathology professor at Massachusetts General Hospital, led the study. He said the new discovery will help him figure out how to use an existing chemotherapy drug to treat the disease.
Dr. Jeremy Rich, a cancer specialist at Cleveland Clinic, commented on the study. He said, “What this tells me is that I know a lot less than I did before.”
The study focuses on gliomas, which are the most common type of brain tumor in adults today. Glioblastomas, are the most aggressive type of gliomas, they have a survival rate of 18 months even with the best current treatment available.
Researchers say the lower-grade gliomas usually hit younger adults, and survival times can be much longer. The Times explains, “Yet despite extensive study of gliomas, doctors have made little progress in treating them. Doctors usually remove the lower-grade tumors and treat patients with radiation and chemotherapy.” This plan does not work out so well though. The tumors often return and when they do they turn into aggressive glioblastomas that resist cancer therapy.
Scientists did realize one surprising feature in up to 80 percent of low, and moderate-grade gliomas; a common gene that seemed to have no particular relevance to cancer was often mutated. “The gene, isocitrate dehydrogenase, or IDH, had long been considered humdrum, a so-called housekeeping gene that directs cells to make an enzyme used in energy production,” according to The Times.
Dr. Bernstein said he immediately took notice of this and focused on it to figure out how a metabolism gene was causing cancer. The frequency of the metabolism gene was shockingly high. The team realized that every time this gene was mutated it was stuck with methyl tags, which might be what is causing the change to the three dimensional DNA.
Human DNA forms 10,000 loops like a shoe lace. Dr. Bernstein’s team finds that the DNA gets altered when the loops get submerged with an adjacent loop and a certain gene accidentally gets turned on. Dr. Bernstein is doing further testing to figure out whether his hypothesis are accurate and if so he may have a new, more effective, treatment plan to put in place.