http://www.digitaljournal.com/tech-and-science/science/is-reversible-gene-editing-possible/article/506862

Is reversible gene editing possible?

Posted Nov 5, 2017 by Tim Sandle
Researchers have proposed altering gene-editing technology with the view of combating diseases without having to trigger permanent changes to the DNA of people. Current gene editing is based on permanently altering DNA.
Scientists have used a new gene-editing technique to manipulate cells to fight cancer with a one-yea...
Scientists have used a new gene-editing technique to manipulate cells to fight cancer with a one-year-old girl in Britain the first in the world to be treated
Spencer Platt, Getty/AFP/File
The genome editing technique CRISPR has revolutionized scientific research, as Digital Journal has reported (see: "Is CRISPR technology set to change biological science?”). This is a biological cut-and-paste technique that allows researchers detect a gene defect within living cells and then use molecular “scissors” to make changes. Changes include deleting the gene; repairing it; or replacing it.
CRISPR is an abbreviation of Clustered Regularly Interspaced Short Palindromic Repeats. In practice, CRISPR has been used successfully to produce better crops yields; to develop malaria-resistant mosquitoes; to harvest transplantable organs in animals; and to research rare genetic diseases that affect humans, such as sickle cell disease and muscular dystrophy. The genome editing technology known as CRISPR/Cas9 allows permanent modification of genes within organisms.
The basis of the proposed new technology is to edit RNA instead of DNA. The function of RNA is to act as the messenger that is tasked with carrying a gene’s instructions. These instructions initiative a protein manufacturing process within cells. By altering RNA, the production of defective proteins can be haltered.
Explaining this further, lead researcher Dr. Feng Zhang of the Broad Institute of MIT told Bioscience Technology: “If you edit RNA, you can have a reversible therapy.” Dr. Zhang’s new approach uses a protein called Cas13, which can affix to RNA instead of cutting I t (as with the Cas9 protein used to gene edit DNA).
A key advantage, the researcher states, is with protecting people for if a change to DNA is made and where the wrong spot is cut, this could lead to unintended and dangerous side-effects. Moreover, repairing DNA can be difficult within certain cells, like brain and muscle cells. This makes the focus on RNA more advantageous when dealing with these types of cells.
To achieve these goals the researchers are developing an RNA-targeting version of CRISPR. Trials have been performed in the laboratory and these hold considerable promise. However, further research is required.
This potential shift in biological technology has been set out in a paper published in the journal Science. The research paper is titled “RNA editing with CRISPR-Cas13.”