CRISPR-Cas9 is a customizable tool that lets scientists cut and insert small pieces of DNA at precise areas along a DNA strand. Its widely heralded for its potential to completely disrupt the biotech industry, with huge impacts from everything from GMO crops to, perhaps, human health.

Two new studies, however, are causing a stir after they found the technology could cause cancer in human cells. But despite media coverage framing the findings as a cause for concern, the authors themselves are far more reserved, stating “reactions have been exaggerated.”

One of the studies was carried out by researchers at Novartis, a private pharmaceutical firm, one of the few that has a gene-editing therapy approved by the FDA. The other was published by researchers at the Karolinska Institute, Sweden.

Both research studies independently found evidence that the p53 gene either blocks CRISPR from working properly in human cells or breaks apart during the molecular procedure. This gene is responsible for repairing DNA or, failing that, it can tell a cell to die — both are effective ways of preventing cancer. A defective p53 gene can thus cause cancer. Previous studies have associated defective p53 genes to several cancers like those affecting the breast, lung, ovaries, stomach, colon, and pancreas.

The news caused a wave of panic, hitting some biotech companies hard. Quartz informs that Crispr Therapeutics AG, based in Switzerland, and Intellia Therapeutics Inc, based in the US state of Massachusetts, saw their stocks drop 12.6% and 9.8%, respectively, only one day after the studies were published.

1) Beware exaggeration and overstated headlines. The papers say after #CRISPR Cas9 DSB P53 signaling is activated. They don't say #CRISPR could cause #cancer
2) One of the paper was posted a year ago on BioRxiv #preprint server -> not a new finding https://t.co/6HeNFukU7b

— Gaetan Burgio (@GaetanBurgio) June 11, 2018

The authors of the studies themselves are not worried, however. Why? For one, just because something occurs at the cellular level, that doesn’t necessarily translate at the macro-level, in the living body. Secondly, there are other proteins besides Cas9 that can be used to cut DNA. Another protein, Cpf1, can be used instead of Cas9, which is even simpler and more precise. Perhaps, future studies will find those proteins that do not interfere with p53 gene expression at all, thereby dispelling any concerns.  

Ultimately, before a study shows that a CRISPR-edited animal model has higher-than-expected cancer rates, the gene editing tool is still fair game. Of course, the two studies should make scientists act with caution in the future. At the same time, the takeaway is that CRISPR is still an extremely promising technology with no major safety concerns identified so far.

Both studies appeared in the journal Nature (1 and 2). 

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