For the first time, the study team created a DNA strand with the shape of a hairpin that can trigger an immune response to target and eliminate particular cancerous cells.
By using synthetic DNA, researchers have discovered a novel method of killing cancer cells that may one day lead to the development of a treatment for the condition. The current cancer treatments have their limitations, but researchers think that medications based on RNA and DNA might be able to fight the deadly disease. According to research results that were last week published in the Journal of the American Chemical Society, scientists at the University of Tokyo were able to specifically target and eradicate cells that were derived from human cervical cancer and breast cancer by chemically synthesising hairpin-shaped cancer-killing DNA. Additionally, the DNA pairs were applied to mouse malignant melanoma cells.
The University of Tokyo research team, lead by Assistant Professor Kunihiko Morihiro and Professor Akimitsu Okamoto from the Graduate School of Engineering, stated that they were motivated to use synthetic DNA as an alternative to traditional anti-cancer chemical treatments.
Notably, nucleic acids (namely DNA and RNA) medications have proven challenging in the past. It was due to their inability to distinguish between cancer cells and other healthy cells. They are not commonly employed for cancer therapies. As a result, there is a chance that the patient’s immune system could suffer if the healthy cells are unintentionally assaulted.
“We thought that if we can create new drugs that work by a different mechanism of action from that of conventional drugs, they may be effective against cancers that have been untreatable up to now,†said Okamoto.
This prompted the study team to create the first hairpin-shaped DNA strand. It can trigger a natural immune response to target and eliminate particular malignant cells.
The mechanism:
Cancer cells have the ability to overexpress. It involves making an excessive number of copies of a protein, RNA, DNA, or other molecule, preventing them from functioning normally and possibly accelerating the growth of the disease. Therefore, the Tokyo team developed something called artificial oncolytic, which are the aforementioned DNA pairs known as oHPs, to both slow and halt its growth.
After injecting the hairpin-shaped DNA into the cancer cell, oHPs were stimulated to create longer DNA strands. When oHPs came into contact with the miR-21 microRNA, which is overproduced in some malignancies. These molecules then started to unravel and bind together. It produced an immunological response. Furthermore, these lengthy DNA chains were able to stop the growth of the diseased tissue by killing the cancer cells themselves. Because of their curved hairpin design, oHPs typically don’t create longer strands. But in this instance, the synthetic oHPs were able to get over this restriction and opened up to join with the target microRNA and produce a longer strand. The immune system then perceives the presence of the differentially expressed miR-21 as potentially harmful.
The research discovered that the test was efficient against overexpressed miR-21 identified in human triple-negative breast cancer cells, human cervical cancer cells, and mouse malignant melanoma cells.
Future:
In a statement, Okamoto asserted that the first instances of the usage of miR-21 as a “selective immune amplification response which can target cancer regression” were the production of DNA strands as a result of interaction between short DNA oHPs and overexpressed miR-21.
The study’s findings on this interaction lead to “a new class of nucleic acid medication candidates with a mechanism that is fundamentally distinct from recognised nucleic acid therapeutics,” the researcher added.
The employment of a similar approach to treat viral infections and hereditary problems is another way that the research is anticipated to change medicine in the future. The team is sure about the advantages of nucleic acids. It will help in discovering novel drugs. But there is still a long way to go before the technique can really be employed as a medicine and made accessible to the general population.
Parvathy Sukumaran 
