Name: What Happens When CRISPR Backfires?
Uploaded: 2021-04-17T12:00:18.000Z
Duration: 3 min 32 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Modal verbs - B1

With all the hubbub about CRISPR in the news, it may feel like using it to pick your kids

Adverbs of degree

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But this seemingly miraculous gene-editing technology may not actually be as simple--or

Just so we're all on the same page, CRISPR (or more accurately CRISPR-cas9) works by

cutting the DNA of a cell at a designated spot, say a section of DNA that represents

Then, when the cell tries to repair the damaged DNA, it often ends up just disabling the gene

Maybe we want to turn off a gene that produces too much of a certain protein?

Say we want to see what a certain gene even does?

Ever since it was first used to edit living cells in 2013, CRISPR has been touted as a

promising technology for treating inherited disorders, cancer, and other diseases with

Teams of researchers around the globe had even hoped to begin human trials in 2018.

But none of those trials have taken place yet, with the exception of China, where researchers

have been working with CRISPR in humans since 2016--no results from these trials have been

And in the US, the FDA just placed a 'clinical hold' on the first proposed CRISPR gene

Several new studies released in the last few months suggest we need to be more cautious

Two of these studies found that when CRISPR performs its hallmark trick and cuts DNA,

that damage can kill the cell, or make it stop growing.

CRISPR modifications are also less likely to kill cells that have a defective version

P53 plays a role in preventing the onset of cancer by regulating a cell's life cycle,

so by leaving more of the defective cells alive than healthy ones*, CRISPR may be inadvertently

raising the risk of cancer in that patient.

Which is, like, the opposite of the goal.

And we haven't even gotten to the most recent study that raises concerns.

Up until now, CRISPR-cas9's cutting function has been accurate in the specific area of

interest--the spot in the DNA that's supposed to be cut.

But that's because researchers were only looking for mutations caused by CRISPR in

New research reveals that in about 20% of cells, CRISPR results in MUCH larger deletions

than we thought**-- up to more than 100 base pairs.

Researchers didn't notice this before because they were looking for harmful mutations and

didn't see any...but that's because the entire region was gone.

In CRISPR treatments that would target billions of cells inside the human body, this could

So the human trials have been delayed...where do we go from here?

CRISPR permanently alters your genome, so we want to make sure we get it right before

New and improved versions of this kind of technology are already racing forward, like

a genetic editing tool called REPAIR, which uses a different cutting enzyme--Cas13.

REPAIR works with RNA, instead of DNA, to make temporary or reversible changes.

There's also a newly engineered protein that can alter individual base pairs rather

than a whole chunk of DNA, acting more like surgical forceps than a pair of kitchen scissors.

So continued progress and exciting breakthroughs in this field are still happening--we're

It's just that we need to take a step back from the hype and carefully analyze what's

really going to be safe as we move forward.

To stay current with all the CRISPR news that's sure to be plentiful in the coming years,

subscribe to Seeker, and for more on how your body, specifically your immune system, interacts

with the technology, check out this video from Julian.

And, fun fact, CRISPR doesn't just present possibilities in human biology--it could be