A Stanford University-led tea of researchers has developed a new mouse model to study the ramifications of retinoblastoma (RB) tumor suppressor inactivation. They used a controllable, shRNA approach to knock down RB. The knockdown mice, they note, exhibited phenotypes similar to those of RB knockout mice like the development of pituitary and thyroid tumors. And, as they report in PLOS Genetics, the re-expression of RB in the knockdown mice blocked cell cycle progression and tumor growth. This suggests that "continuous loss of RB in this context is required for long-term tumor growth," the researchers say. They note that other studies have found its re-expression only leads to transient cell-cycle arrest, which leads to "the question of when RB activation will be sufficient to stop the proliferation of cancer cells."
Researchers have homed in on a handful of genes where protein-altering variants may increase someone's susceptibility leprosy. As they report in PLOS Neglected Tropical Diseases, researchers from McGill University used deep resequencing of 34 genes previously tied to leprosy susceptibility through a genome-wide association study or linkage analysis. They posited that the burden of rare, protein-altering variants in leprosy susceptibility genes would differ between their cohorts of 555 Vietnamese individuals with leprosy and 500 healthy controls. Through this, the researchers uncovered a depletion of protein-altering variants in IL18R1 and BCL10, indicating these gens could have a protective role, and suggestive signals at the CDSN and PSORS1C2 genes. "Our results show that deep resequencing can identify leprosy candidate susceptibility genes that had been missed by classic linkage and association approaches," the McGill team writes.
Researchers from the Philippines and Japan have compared two testing approaches for rabies: a direct fluorescent antibody test that is performed on brain samples collect after opening the skull and a lateral flow device-based test that is performed on samples collected through an approach in which a straw is inserted into the skull that can be more easily performed in resource-poor areas. They collected specimens from 97 animals suspected of having rabies for analysis by both approaches and, as they also report in PLOS Neglected Tropical Diseases, of those samples, 53 were positive for rabies via direct fluorescent antibody testing and 50 were positive for rabies by lateral flow testing, indicating a similar performance between the approaches. "This methodology can be beneficial and is a strong tool to overcome limited animal surveillance in remote areas," the team adds. "However, because of the limited data in our study, more data and optimization are urgently needed for further implementation."