In Science this week, a team of British researchers reports data pointing to a link between genetics, epigenetics, and in utero diet. In the study, the researchers examined two groups of pregnant mice — one fed a protein-restricted diet and one fed a control diet. They analyzed the methylation of the offspring's sperm and found that animals with mothers on protein-restricted diets experienced a greater level of ribosomal DNA methylation and weighed less at weaning as compared with their control counterparts. The investigators demonstrated that the effects of the methylation depended on gene variants, and analyzed data from other studies of methylation during early-stage development to show that disparate results are likely due to genetic variants.
In Science Translational Medicine, a Stanford University team reports data on a new blood test that uses gene expression to distinguish bacterial and viral infections. The researchers previously identified 11 genes linked to sepsis that predicted whether inflammation is due to a bacterial infection. In their latest study, they mined publicly available gene expression data to pinpoint seven genes that consistently distinguished bacterial from viral infections across a broad range of diseases. By combining the two gene sets, the researchers were able to accurately diagnose bacterial, viral, and non-infectious illnesses in large cohorts of more than 1,000 patients, as well as in 96 children with sepsis. GenomeWeb has more on this here.
Also in Science Translational Medicine, an international group of researchers presents a study suggesting that the presence of tumor DNA in the circulation of colon cancer patients may predict disease recurrence. The researchers developed a blood test that can detect circulating tumor DNA (ctDNA) and used it to analyze blood samples from 230 stage II colon cancer patients who had undergone surgery. They found that those who tested positive for ctDNA typically relapsed when not treated with chemotherapy, while those with no detectable ctDNA remained recurrence-free. Additionally, a small group of patients with ctDNA after both surgery and chemotherapy showed poorer responses to treatment.