CRISPR has been heralded as one of the most important breakthroughs in modern science, but there could be a hidden and potentially dangerous side effect to the wonders of its genetic editing technology, a new study reveals.

A systematic investigation of CRISPR/Cas9 genome editing in mouse and human cells has discovered that the technique appears to frequently cause extensive mutations and genetic damage that the researchers say wouldn’t be detected by existing DNA tests.

“This is the first systematic assessment of unexpected events resulting from CRISPR/Cas9 editing in therapeutically relevant cells,” explains geneticist Allan Bradley from the Wellcome Sanger Institute in the UK.

Canadian researchers have discovered a new and direct molecular mechanism to stop cancer cells from proliferating. In the prestigious journal Nature Cell Biology, scientists from Université de Montréal show that a disruption of a fine balance in the composition of ribosomes (huge molecules that translate the genetic code into proteins) results in a shutdown of cancer cell proliferation, triggering a process called senescence.

“Ribosomes are complex machines composed of both RNAs and proteins that make all the proteins necessary for cells to grow,” said UdeM biochemistry professor Gerardo Ferbeyre, the study’s senior author. Cancer cells grow and proliferate relentlessly and thus require a massive amount of ribosomes, he explained. Growing cells must coordinate the production of both ribosomal RNAs and ribosomal proteins in order to assemble them together in strict proportion to each other.

“We were surprised, however, to find that if the production of ribosomal RNA–protein proportions are driven out of balance in a cancer cell, proliferation can be shut down by in a very simple and direct manner,” said Ferbeyre.

“I believe gene therapy will become a mainstay in treating, and maybe curing, many of our most devastating and intractable illnesses,” said FDA commissioner Dr Scott Gottlieb after Luxturna’s approval.

As innovative gene and cell therapies continue to make the transition from the laboratory to the clinic, they are bringing with them the promise of truly personalised medicine. The last few years have seen the regulatory approval of the first gene therapies that take a patient’s own immune cells and genetically engineer them to target cancer cells more effectively.

These chimeric antigen receptor T-cell (CAR-T) therapies now represent a rapidly growing field, with Novartis’s Kymriah, the first CAR-T therapy approved by the US Food and Drug Administration (FDA) in August 2017 for the treatment of a rare blood cancer, seen as the tip of the iceberg for this treatment class’ potential. Approval of Kite Pharma’s Yescarta, a CAR-T treatment for certain forms of non-Hodgkin lymphoma, followed just a few months later.