A Crispr Conundrum

I am trying to keep up on the evolution of CRISPR and its possible performance in curing or treating Kennedy's Disease and other progressive neuromuscular disorders. Here is the latest from The New York Times. To read the entire article, click on the link above or the heading below.

A Crispr Conundrum: 

How Cells Fend Off Gene Editing

Human cells resist gene editing by turning on defenses against cancer, ceasing reproduction and sometimes dying, two teams of scientists have found.

The findings, reported in the journal Nature Medicine, at first appeared to cast doubt on the viability of the most widely used form of gene editing, known as Crispr-Cas9 or simply Crispr, sending the stocks of some biotech companies into decline on Monday.

Crispr Therapeutics fell by 13 percent shortly after the scientists’ announcement. Intellia Therapeutics dipped, too, as did Editas Medicine. All three are developing medical treatments based on Crispr.

But the scientists who published the research say that Crispr remains a promising technology, if a bit more difficult than had been known.

“The reactions have been exaggerated,” said Jussi Taipale, a biochemist at the University of Cambridge and an author of one of two papers published Monday. The findings underscore the need for more research into the safety of Crispr, he said, but they don’t spell its doom.

“This is not something that should stop research on Crispr therapies,” he said. “I think it’s almost the other way — we should put more effort into such things.” ...

... A team of scientists at the Novartis Institutes for Biomedical Research in Cambridge, Mass., got similar results with a different kind of cells, detailed in a paper also published Monday.

They set out to develop new versions of Crispr to edit the DNA in stem cells. They planned to turn the stem cells into neurons, enabling them to study brain diseases in Petri dishes.

Someday, they hope, it may become possible to use Crispr to create cell lines that can be implanted in the body to treat diseases.

When the Novartis team turned Crispr on stem cells, however, most of them died. The scientists found signs that Crispr had caused p53 to switch on, so they shut down the p53 gene in the stem cells. ...

...“We should definitely be cautious,” said George Church, a geneticist at Harvard and a founding scientific adviser at Editas.

He suspected that p53’s behavior would not translate into any real risk of cancer, but “it’s a valid concern.”

And those concerns may be moot in a few years. The problem with Crispr is that it breaks DNA strands. But Dr. Church and other researchers are now investigating ways of editing DNA without breaking it.

“We’re going to have a whole new generation of molecules that have nothing to do with Crispr,” he said. ...