CRISPR Modifications for Faster DNA Editing

The top bioscience news headlines of last week are centered on the achievement of a Chinese research team, which fixed a genetic disorder in cloned human embryos using “base editing,” a modification of the CRISPR–Cas9 DNA editing technique. As explained in a research paper published in Protein & Cell, base editing permits swapping DNA base pairs, converting guanine (‘G’) to adenine (‘A’), and cytosine (‘C’) to thymine (‘T’).

“Our study opens new avenues for therapy of β-thalassaemia and other inherited diseases,” said research leader Junjiu Huang. “Base editing can repair the mutant site and block it from being passed on to the next generation.”

"We are the first to demonstrate the feasibility of curing genetic disease in human embryos by base editor system," Huang told BBC News. Another CRISPR modification pioneered at Uppsala University (see below) could make CRISPR gene editing faster.

In promising advances on natural ways to combat cancer, scientists have suggested that dietary supplements that contain zinc and chemical compounds found in the plant ambrosia arborescens could help fight the growth and spread of cancer.

Like perhaps many of you readers, I am always hungry and like to eat with a lot of salt. Unfortunately, being overweight and consuming too much salt are known to carry serious health risks. Now, neuroscientists have found brain circuits that play key roles in cravings for food and salt. It’s to be hoped that these discoveries will soon open the way to better ways to control weight and reduce salt intake, without making life too hard to bear.

A faster CRISPR. Researchers at Uppsala University have found out how CRISPR-Cas9 “molecular scissors,” which are widely expected to revolutionize medicine, can search the genome for a specific DNA sequence. The new research findings, published in Science, show how Cas9 can be improved to make the molecular scissors faster and more reliable. The scientists have designed faster molecular scissors, based on “PAM sequences” that determine where and how often Cas9 opens up the DNA double helix, which are still sufficiently versatile to edit various genes but simultaneously fast enough to be medically usable.

Smart engineered molecules against cancer. UCSD scientists have engineered smart protein molecules that can reprogram white blood cells to ignore a self-defense signaling mechanism that cancer cells use to survive and spread in the body. A study, published in Nature Communications, is the first to demonstrate how both sensing and activating capabilities can be combined into a single molecule. The smart proteins, called “iSNAPS” (integrated sensing and activating proteins), are designed to detect precise molecular signals in live cells and, in response, act upon those signals to enable the cells to fight disease or perform other beneficial functions.

Advances in brain-like computing. Scientists from Oxford, Münster and Exeter Universities have developed photonic computer chips that, using light rather than electricity, imitate the way the brain’s synapses operate. A research paper, published in Science Advances, describes how the engineers combined phase-change materials, commonly found in household items such as re-writable optical discs, with specially designed integrated photonic circuits to deliver a biological-like synaptic response. In related news, Intel has developed an energy-efficient, self-learning neuromorphic chip, codenamed Loihi, which mimics how the brain functions by learning to operate based on various modes of feedback from the environment.

Nano-chemical recording of molecular structures. Researchers at Harvard’s Wyss Institute of Biologically Inspired Engineering have developed a DNA nanotechnology-based method that allows for repeated, non-destructive recording of molecular structures, rendering a detailed view of their components and geometries. A study, published in Nature Communications, shows how the new method, dubbed “Auto-cycling Proximity Recording” (APR), acts as a continuous biochemical recorder of the molecular structures. In the future, the approach could help researchers understand how changes in molecular complexes control biological processes in living cells.