Israeli researchers use gene editing to eliminate 50% of head, neck tumors in mice
Tel Aviv University scientists say they can inject CRISPR genetic ‘molecular scissors’ to shrink tumors by 90%; researcher ‘optimistic’ about clinical trials in 2 to 3 years
Reporter at The Times of Israel
Tel Aviv University (TAU) researchers say they have successfully eliminated 50 percent of head and neck tumors in mouse models using CRISPR gene editing technology.
The breakthrough study, led by Dr. Razan Masarwy from the lab of Prof. Dan Peer, director of TAU’s Laboratory of Precision Nanomedicine, continues Peer’s groundbreaking work using direct injections that target cancer at the genetic level.
The findings were recently published in the peer-reviewed journal Advanced Science.
“Oncologists need a big arsenal of weapons to treat cancer,” said Peer, speaking to The Times of Israel on a video call from Massachusetts, where he was presenting his findings at Harvard Medical School. “My dream is that we will replace chemotherapy with a better approach.”
‘Cancer cells are very smart’
Head and neck cancers are localized cancers, often starting in the tongue, throat, or neck, that can later metastasize, Peer explained. Existing therapies for these cancers “often lead to high treatment failure, and disease recurrence, resulting in poor survival rates.”
But if detected early, localized treatment can “effectively target the tumor,” he said.
Explaining that “cancer cells are very smart,” Peer said that the team’s goal was to find a way to target an essential gene “that the cancer cell cannot live without.”
That gene was SOX2, which is active in embryos because it helps young cells develop and grow. In healthy adult cells, the gene is suppressed, Peer said, because the body no longer needs it.
“However, in cancer cells, and predominantly in head and neck tumors, SOX2 proliferates again, for some reason that we don’t really understand,” he said. “So the idea was to take it out.”
Molecular scissors
In a study done in 2020, Peer showed an innovative way to use CRISPR to eliminate glioblastoma, an aggressive type of brain cancer, and metastatic ovarian cancer in mice.
CRISPR — clustered regularly interspersed short palindromic repeats — was developed by Frenchwoman Emmanuelle Charpentier and American Jennifer A. Doudna, who received the Nobel Prize in Chemistry for their work in 2020.
The idea of CRISPR is based on a simple defense mechanism found in nature. Some bacteria, for example, are able to protect themselves against an invader — a virus, say — by capturing snips of the intruder’s DNA and storing it as segments.
If the same virus attacks again, the bacteria use these saved DNA pieces to create short guides that help an enzyme called Cas to find and cut the virus’s DNA, using what Peer called “molecular scissors,” to stop the infection.
CRISPR can be used to change the DNA of animals, plants, and microorganisms.
However, said Peer, CRISPR needs to be delivered directly into the “tumor bed,” where caner cells are found.
To deliver CRISPR deep inside the cancer cells, the team encapsulated it in tiny fat-like bubbles called lipid nanoparticles. The researchers then injected these nanoparticles directly into the tumor in a mouse model — three injections spaced one week apart.
Then, Peer said, “We just waited.”
“Surprisingly, the injections led to a 90% shrinkage of tumors, and 50% of them disappeared completely after 84 days,” he said.
“The tumors became very small,” Peer continued. “They were made less aggressive. The treatment made the cancer more manageable.”
The next step is testing this therapy on other types of tumors in mice before moving on to human trials.
“I’m optimistic,” Peer said. “If we’re lucky, we could see clinical trials in two to three years.”
Science without borders
Peer said that he has been touring various cities, giving presentations on his research. He has spoken in Paris, Oxford, London, and Toronto and was also headed for Amsterdam.
Asked if he was confronted by anti-Israel protests, he said that nobody interfered in his talks.
“I think that science and medicine are really without borders,” Peer said. “I think people understand that, and they leave politics and the situation outside the lecture room.”
