Researchers Find a Cancer Kill Switch That Could Replace Chemotherapy
“We think this is how multicellular organisms eliminated cancer before the development of the adaptive immune system, which is about 500 million years old,” Peter said in a statement in 2017. “It could be a fail-safe that forces rogue cells to commit suicide. We believe it is active in every cell, protecting us from cancer.”
However, they still needed to determine what caused the cells to self-destruct. The team found that a sequence of six nucleotides (6mers) in small RNAs created a toxic environment for cancer. Nucleotides are present in both DNA as G, C, A, or T and U in RNA.
In the study, Peter and his team tested all 4,096 combinations of nucleotide sequences in the 6mers. They finally determined the most harmful combination included mostly G nucleotides. MicroRNAs use this 6mer to eliminate cancer cells in the body.
The research on how the microRNAs use the kill switch to extinguish cancer cells was published in Nature Communications. Peter and his team also did a subsequent study detailing how protein-coding large RNAs can convert to small RNAs.
They wanted to determine how the body develops microRNAs that activate the DISE sequence. In the second study, the team determined that our cells break down a more significant RNA strand into multiple microRNAs.
The cells chop a gene involved in tumor growth (Fas ligand) into small pieces that act as toxins to cancer. Peter’s team found that around 3% of all large protein-coding RNAs in the genome can trigger DISE.
That research was published in the journal eLife.
“Based on what we have learned in these two studies, we can now design artificial microRNAs that are much more powerful in killing cancer cells than even the ones developed by nature,” Peter said.
The Future of the Cancer Treatment
“We absolutely need to turn this into a novel form of therapy,” Peter added. He and his team have begun investigating ways to trigger a cancer kill switch. However, he notes that a possible treatment may take decades to develop.
The Northwestern team published groundbreaking research in Oncotarget in 2017 on a potential therapy. They utilized nanoparticles to transfer DISE microRNAs to human ovarian cancer cells grafted in mice.
Remarkably, the treatment reduced tumor growth dramatically without any dangerous side effects. The team hopes to increase the efficiency of the treatment in the future.
“My goal was not to come up with a new artificial toxic substance,” Peter said. “I wanted to follow nature’s lead. I want to utilize a mechanism that nature developed.”
