Researchers at Massachusetts General Hospital Cancer Center might have identified a new biomarker for cancer. Writing in the journal Science, the team discovered a previously unknown feature of common tumor cells--massive overexpression of certain DNA sequences that do not code for proteins. These DNA sequences--called satellite repeats--had never previously been a suspect in cancers.
"Satellite repeats make up a large part of our genome but had been thought to be inactive," David Ting, co-lead author of the Science paper, said in a statement. "We found that these regions are, in fact, very active in cancer but not in normal tissue. The findings may give us a novel cancer biomarker, as well as new insights into how cancers behave."
The team first studied samples from a mouse model of pancreatic cancer and were surprised to find that satellite DNA was expressed at levels more than 100 times what would be expected in normal tissues. They found the same thing in mouse colon and lung tumors. So, they moved on to human tumor samples with similar results--powerful overexpression of two satellites called HSATII and ALR in the majority of cancers studied, including tumors of the pancreas, lung and prostate.
"If confirmed in large prospective clinical trials, Ting says, "satellite RNA expression may provide a new and highly specific biomarker relevant to multiple types of epithelial cancers."
- read the MassGen release
- check out the abstract in Science