By applying machine learning to the analysis of circulating tumor DNA (ctDNA), a team led by scientists from Sun Yat-sen University Cancer Center has developed a new method to noninvasively identify colorectal cancer (CRC) patients and predict their survival. The scientists first compared CRC tissue to normal blood leukocytes to identify CRC-specific methylation signatures. They then built a diagnostic model based on nine of the methylation markers using ctDNA from 801 CRC patients and 1,021 controls. The model, they write in Science Translational Medicine, could accurately discriminate patients with CRC from normal individuals with a sensitivity of 87.5 percent and a specificity 89.9 percent, outperforming the clinically available blood biomarker CEA. A modified prognostic model, meanwhile, effectively predicted the prognosis and survival of patients with CRC. Notably, one methylation marker proved particularly effective in detecting CRC and precancerous lesions in a high-risk population of 1,493 participants. GenomeWeb has more on this, here.
Mutations that inhibit the malaria parasite Plasmodium falciparum's ability to consume host red blood cells may also be involved in resistance to the widely used antimalarial drug artemisinin and its derivatives (ARTs), according to a study appearing in this week's Science. Previous research has linked artemisinin resistance with mutations in the Kelch13 protein, but details about the protein were unclear. In the study, scientists from the Bernhard Nocht Institute for Tropical Medicine demonstrate Kelch13's involvement in an endocytosis pathway required for the uptake of host cell hemoglobin and show that certain Kelch13 mutations lead to reduced hemoglobin endocytosis. Because ARTs are activated by degradation products of hemoglobin, lowered activity of Kelch13 and its interactors diminishes hemoglobin endocytosis and thereby ART activation, resulting in parasite resistance, the researchers write. The findings may inform the development of new treatment strategies for malaria.