This army of DNA nanorobots journeys through the body hunting down cancer and killing tumours
It may sound like the opening of a science-fiction novel but a study into the use of DNA nanorobots could pave the way to a new era of targeted cancer treatments.
A paper, published in Nature Biotechnology, explains how a team of scientists successfully cured cancer in mice using programmed DNA to cut off the blood supply to tumours in the animals.“Using tumour-bearing mouse models, we demonstrate that intravenously injected DNA nanorobots deliver thrombin specifically to tumor-associated blood vessels and induce intravascular thrombosis, resulting in tumor necrosis and inhibition of tumor growth,” the paper describes.
The issue with current cancer treatments, such as chemotherapy and radiation treatment, is that they damage all types of cells, not only malignant tumours. Researchers are attempting to come up with more precise treatments, able to specifically target cancer cells and this latest study suggests DNA nanorobots could be an effective solution.
What is a DNA nanorobot?
Making a DNA nanorobot involves extracting DNA from a virus, modifying it with specific enzymes and folding it like a piece of origami along with extra bits of DNA that bind to molecules found in cancer cells. In this case, the tiny robot is folded in a tube shape around the enzyme thrombin, which can clot blood.
This payload is guided to cancer cells thanks to the sections of DNA that bind with tumours, which then tell the DNA tube to open and release the thrombin. The idea is that an army of these nanorobots cause blood clots throughout the malignant cells, cutting off blood supply and killing the tumour.
(Above: DNA Nanorobots. Credit: Nature Biotechnology)
To test this, the scientists injected the DNA nanorobots into mice that had been infected with human breast cancer, ovarian cancer, melanoma and lung cancer. Within 48 hours, the tiny bots managed to choke off the blood supply to cancer cells, eventually leading to slowed or reversed tumour growth. In the melanoma subjects, the nanorobots were able to prevent the spread of the cancer to the liver. The lung cancer subjects, meanwhile, showed evidence of self-repair after the tumour growth had been curbed.
Most impressively, the study showed that the DNA nanorobots did not cause blood clots in non-cancerous cells. The pieces of DNA that guided the robot to cancer cells worked effectively, meaning the bots were successfully programmed to specifically target tumours. The researchers also demonstrated this in the healthy tissue of Bama miniature pigs, adding weight to the finding that the nanorobot is, as they describe it, “safe and immunologically inert”.
The eventual aim will be to test these DNA nanorobots in humans, although more work is needed before a human trial can be attempted. Regardless, the results are promising, and moves are already being made to translate the experimental technique into a viable therapy:
“Our research shows that DNA-based nanocarriers have been shown to be an effective and safe cancer therapy,” Guangjun Nie, one of the authors of the study, said in a statement. “We are currently working with a biotech firm to translate this revolutionary technology into a viable anti-tumor therapeutic.”