A team led by Tokyo Medical University researchers have identified a microRNA that regulates extracellular vesicle (EV) secretion from prostate cancer cells, offering a potential new therapeutic target for the disease. Given the role of aberrant miRNA expression in cancer and the importance of EVs to cancer progression, the scientists screened thousands of miRNAs using ExoScreen, a liquid biopsy technique they previously developed for detecting disease-specific EVs. As reported in Science Advances, they find that miR-26a, which has been reported as a tumor suppressor, actively regulates EV secretion in prostate cancer cells. The researchers also identify three genes — SHC4, PFDN4, and CHORDC1 — involved in EV secretion in prostate cancer cells. Notably, both reduced miR-26a expression and upregulation of these three genes was observed in prostate cancer tissue versus normal tissue.
A study describing the impact of prokaryote-derived horizontal gene transfer (HGT) on a key group of eukaryotic plankton is presented in Science Advances this week. The report provides evidence against the differential loss hypothesis for the presence of prokaryote-derived genes in eukaryotes. In the study, a group led by researchers from the Chinese Academy of Fishery Sciences focused on the ecologically important plankton lineages encompassed by cryptophytes, rhizarians, alveolates, stramenopiles, and haptophytes — collectively known as CRASH. Using phylogenomics and other techniques, the scientists provide evidence of prokaryotic HGTs in CRASH taxa affecting functions such as polysaccharide biosynthesis. Numbers of HGTs range from 0.16 percent to about 1.5 percent of CRASH species gene inventories, comparable to the roughly 1 percent prokaryote-derived HGTs found in the genomes of extremophilic red algae, they write. "We predict that additional prokaryote-derived HGTs will be identified as a larger number of high-quality phytoplankton and other eukaryote genomes based on long-read sequencing become available in the coming years."