The Tel Aviv University research team, led by Professor Dan Peer and PhD student Yasmin Granot Matok, encoded a toxin produced by bacteria into messenger RNA (mRNA) molecules. These mRNA particles were directly delivered to cancer cells, triggering the cells to produce the toxin, which ultimately led to their demise.

The findings of their study were recently published in peer-reviewed Theranostics.

Unlike traditional chemotherapy treatment, the toxins did not harm nearby cells.

“Our idea was to deliver safe mRNA molecules encoded for a bacterial toxin directly to the cancer cells – inducing these cells to actually produce the toxic protein that would later kill them. It’s like placing a Trojan horse inside the cancer cell,” Peer said.

First, the research team encoded the genetic info of the toxic protein produced by bacteria of the pseudomonas family into mRNA molecules — resembling the procedure in which genetic info of COVID-19’s ‘spike’ protein was encoded into mRNA molecules to create the coronavirus vaccine.

The mRNA molecules were then packaged in lipid nanoparticles for delivery to the cancer cells. These LNPs were developed in Peer’s laboratory. To ensure that the instructions for producing the toxin would reach the targeted cancer calle, the lipid nanoparticles were coated with antibodies.

The molecules were tested by injecting them into the tumors of animal models with melanoma skin cancer. The researchers found that after a single injection, between 44-60% of the cancer cells vanished.

“When the cancer cell reads the ‘recipe’ at the other end it starts to produce the toxin as if it were the bacteria itself and this self-produced toxin eventually kills it. Thus, with a simple injection to the tumor bed, we can cause cancer cells to ‘commit suicide’ without damaging healthy cells,” Peer explained.

“Moreover, cancer cells cannot develop resistance to our technology as often happens with chemotherapy – because we can always use a different natural toxin.”