In PLOS Genetics, the National Cancer Institute's Javed Khan and colleagues from the US, Australia, Spain, and Italy used whole-genome sequencing, targeted gene sequencing, and transcriptome sequencing to characterize 65 Ewing sarcoma tumors and three dozen cell lines. While the overall mutation rate was relatively low in Ewing sarcoma, the team found mutations in the cohesion complex subunit gene STAG2 in more than one-fifth of the tumors and almost half of the Ewing sarcoma cell lines — alterations that appear to correspond with poor patient outcomes. The samples were also prone to CDKN2A, TP53, and BRCA2 mutations. Though most samples contained known fusions involving the EWSR1 oncogene, the study's authors saw a subset of samples with distinct gene expression signatures that did not, suggesting other molecular subtypes may be present in the disease.
Washington University in St. Louis researchers turned to single-cell sequencing to track clonal architecture in secondary acute myeloid leukemia samples already assessed by bulk whole-genome sequencing for another PLOS Genetics study. By comparing variant patterns in 56 individual or two-cell sets nabbed from secondary AML tumors and comparing them to matched normal samples and samples from an earlier, non-cancerous condition called myelodysplastic syndrome, the group got a glimpse of the complexity and clonal architecture within the samples.
MicroRNAs that have been found to vary in their blood expression in those with certain diseases do not appear apt to dramatic expression changes that depend on fitness or exercise, according to a German team reporting in PLOS One. Researchers from Saarland University did array-based miRNA expression profiling of a dozen elite triathletes or cyclists and as many moderately active control individuals, using blood samples collected before and after a bout of exhaustive exercise. The results did not reveal significant miRNA expression differences between the endurance athletes and their moderately active counterparts, the study's authors report, though their analysis picked up modest miRNA changes that seemed to correspond with short-term exercise or long-term fitness.