Circulating cell-free DNA originating from malignant tumors appears to have shorter fragment lengths than other cell-free DNA in the blood, according to a study in PLOS Genetics by a team from the University of Utah and elsewhere. Starting with a comparison of circulating tumor DNA from human cancers in rats, the researchers went on to show that ctDNA fragments also tend to be shorter in humans with melanoma or lung cancer compared with cell-free DNA fragments in unaffected control individuals. "These findings provide compelling evidence that experimental or bioinformatic isolation of a specific subset of fragment lengths from cell-free DNA may improve detection of ctDNA," they write. GenomeWeb has more on the study, here.
In PLOS Neglected Tropical Diseases, researchers from the University of Porto in Portugal introduce a free, online genomic resource for those searching for strategies to detect and prevent infections with the Ebola virus. The database, known as EbolaID, "provides an interface for browsing, filtering, and downloading data from published oligonucleotide sequences … annotate according to the reference genome," the study's authors explain. EbolaID currently contains information gleaned from peer-reviewed papers published over more than a decade, from the late 1990s to 2014, they note, as well as information on dozens of Ebola virus-related oligonucleotides.
For a paper in PLOS One, a Wake Forest School of Medicine-led team takes a look at potential type 2 diabetes-related loci identified from insulin secretion patterns in African Americans. Using data from five prior T2D genome-wide association studies — together with SNP profiles in nearly 500 African Americans enrolled in the Insulin Resistance Atherosclerosis Family Study with documented insulin secretion and glucose dynamics — the researchers searched for genetic ties between T2D-associated variants and those implicated in acute insulin response to glucose in the African American cohort. In the process, they uncovered two loci that with apparent T2D interactions when considered as part of a genetic risk score, along with a handful of other loci showing potential interactions with the disease.