Blood diseases are CRISPR's likely in-vivo foot-in-the-door
CRISPR is a gene-editing technique which is inexpensive to use and has the potential to be used as a medical therapy, particularly in the case of diseases like sickle cell anaemia and other genetic blood conditions. With research showing that CRISPR knowledge is constantly growing, especially in recent experiments to edit bone marrow cells from humans with sickle cell anaemia, it seems more and more likely that CRISPR could help remove cell mutations from sufferers of inherited blood conditions in the future.
You know you’ve struck marketing gold when a brand becomes a so-called “proprietary eponym.” Need to blow your nose? Grab a Kleenex. Track some sand from the beach onto your floor? Hoover it up.

In biology, Crispr is the proprietary eponym of the moment. The gene-editing technique is so inexpensive and easy to use that, in just four years, it’s become a ubiquitous tool in labs across the world. And soon, it could jump from bench-top workhorse to human therapeutic. In late October, a Chinese team deleted a gene out of a lung cancer patient’s lymphocytes and then injected the edited cells back into his bloodstream, and more cancer-related trials are planned next year in both the US and China.

But the jury’s still out on whether Crispr will be as transformative as a medical therapy as it has been as lab tool. Plenty of gene-editing techniques have been attempted as therapies, but few have made significant impacts---especially when it comes to diseases as complex as cancer. A better place to start testing gene therapies is with inherited blood disorders, like sickle cell anemia and beta thalassemia.

These diseases are a good comparison point because they’re relatively easy to treat. Both arise from mutations to a single gene, which in this case result in malfunctioning red blood cells that starve the body’s organs of oxygen. And while it’s tricky to edit cells in a body while they’re in a body, it’s much easier with blood diseases: You just take blood cells out, treat them, and put them back—better known as a bone-marrow transplant.

Researchers have thrown a number of gene-editing techniques at these diseases, hoping one might become the standard of care for the more than 100,000 people in the US who suffer from them. But if you ask experts in the field, the smart money’s on Crispr. “The Crispr field is moving at such a lightning-speed rate,” says Stuart Orkin, a hematologist-oncologist at Boston Children's Hospital. “Many of the issues that people raise as potential problems are being solved—and they’re being solved at a faster rate than other techniques.”

A potential competitor?

Early this month, researchers reported harnessing Crispr to edit bone marrow stem cells from humans with sickle cell. Then they grafted them into mice to see how long the edited cells survived. Stem cells in the bone marrow give rise to all cells in the blood, including red blood cells; so presumably editing them would mean the correct gene would be incorporated into the red blood cells they create.

After four months, edited cells remained in the mouse’s bone marrow, making up about 6 percent of the total population. That was a three-fold improvement on a similar study from Berkeley scientists, who less than a month earlier reported finding only 2 percent edited cells in the marrow of mice after the same amount of time elapsed.

Meanwhile, in late October, over on the East coast, a team from Yale and Carnegie Mellon revealed results of a new, alternative gene-editing technique—one that doesn’t require a transplant. They managed to find 7 percent of bone marrow cells to be edited after five months in mice with the human mutation for beta thalassemia, simply by injecting them with synthetic DNA-like polymers (usefully called PNAs) via IV.