Extrachromosomal DNA , DNA circles carrying cancer-associated genes, play a critical role in cancer development, according to new research led by Stanford Medicine. These DNA circles can be found in precancerous cells, and their presence accelerates the transformation to a cancerous state. This discovery paves the way for potential early diagnosis and intervention methods in cancer treatment.harbor cancer-associated oncogenes and immunomodulatory genes promoting cancer development.
Previous research had suggested that the circles, which are widespread in human cancers but rarely found in healthy cells, primarily arise in advanced tumors as the abnormal cells increasingly botch the intricate steps required to copy their DNA before each cell division. But the new study shows that the roly-poly circles can be found even in precancerous cells — and their presence jump-starts a cancerous transformation.
. Howard Chang, MD, PhD, professor of genetics and the Virginia and D.K. Ludwig Professor in Cancer Research, is also a senior author.
But these assumptions hinge on the idea that all of a tumor’s DNA is neatly contained on chromosomes, which are evenly divided among daughter cells each time a cancer cell divides — ensuring that each new cell gets one, and only one, copy of each chromosome. The researchers assessed the prevalence of ecDNA, and identified the genes they carried, in biopsies from nearly 300 people with Barrett’s esophagus or esophageal cancer treated at the University of Cambridge or at Seattle’s Fred Hutchison Cancer Center, where individual patients were studied as the cancer developed.
“We want to learn more about the landscape of ecDNA in precancers and the risks it confers,” Mischel said. “We also want to know if we can stop its formation or activity; how to improve our ability to detect their presence; how they affect the immune system; and whether there are opportunities for new, novel therapies. There is much more to learn, and our team is excited to tackle all these issues. But what we do know for certain is that these tiny DNA circles are a very big deal in cancer.