News of Note—Changing multiple genes with CRISPR; Accelerating recovery after chemo and radiation

Teams in Switzerland and the U.S. are reporting progress in modifying the gene-editing system CRISPR-Cas9 to make it more efficient and applicable to a wide range of medical research. (Ernesto del Aguila III, National Human Genome Research Institute, NIH)

Using CRISPR to change 25 genes at once

The evolving gene-editing technology CRISPR-Cas9 is useful for changing one gene, or maybe a few genes at a time. A team at ETH Zurich has tweaked the technology so they can change 25 different gene sites at once. Instead of using the Cas9 enzyme to do the DNA cutting, though, they used Cas12a. That allowed them to create a long “address list” of gene sites to target, they explained in the journal Nature Methods. They created a DNA molecule called a plasmid to store the list, inserted it in human cells and were able to modify several genes, they reported. (Release)

A drug to speed recovery from chemo and radiation

Chemotherapy and radiation suppress blood stem cells, often for several weeks or even months after cancer treatments are complete. This leaves patients vulnerable to infections and other health problems. Scientists at the University of California, Los Angeles have created a new drug that targets the protein tyrosine phosphatase-sigma (PTP-sigma), which is prevalent on blood stem cells. They showed that blocking the protein in rodent models with the drug, called DJ009, helped blood cells recover more quickly after they were damaged by radiation. They published their findings in the journal Nature Communications. (Release)

CRISPR plus stem cells for studying brain diseases

Induced pluripotent stem cells can be used to make human neurons to study brain diseases. But it’s difficult to manipulate genes in those stem cells using CRISPR, because the DNA-cutting part of the technology, the enzyme Cas9, can be toxic to stem cells. Scientists from the University of California, San Francisco and the National Institutes of Health figured out how to deactivate Cas9 and create a version of CRISPR that can target and manipulate genes in stem cells and neurons without killing them. They then used their version of CRISPR, which they call CRISPRi, to identify genes that extend the lives of neurons and that build neurites, projections that help transmit nerve signals, they reported in the journal Neuron. They believe that neurons created using this altered form of CRISPR will prove useful for studying a wide range of brain diseases. (Release)