Nose to malignancy: Like dogs, ants can also identify cancer cells by smell, scientists have shown in experiments. After a short training phase, insects can even distinguish between different forms of cancer. The researchers say that due to their simplicity and rapid success in training, they can provide an alternative to the more costly use of dogs in cancer diagnosis. However, this potential should now be further explored.
Early detection is very important: In cancer medicine, diagnosis is of great importance. However, tissue sample evaluation procedures are relatively complex and expensive, and therefore alternative methods are always welcome. Scientists have been trying to use the abilities of animals for this purpose – namely smell. Dogs have already impressively shown that their thin noses can distinguish cancer cells from healthy tissue. This is because the degenerate cells release special volatile substances that can be detected by the animal’s very sensitive sensory system. Dogs can even recognize some forms of cancer by sniffing body fluids.
Six-legged spies instead of four-legged?
However, the use of dogs has a catch: animals must be intensively trained in order to act as diagnosticians. This is costly and time consuming, greatly reducing the concept’s potential. This is why scientists, led by Baptiste Piqueret of the Sorbonne University in Paris Nord, have now turned to animals as a possible alternative that initially seems strange: ants. However, as the scientists explain, it was already known that these insects also have, at least in principle, the key abilities that dogs also possess: ants have a very sensitive sense of smell and are able to learn quickly.
The team has now investigated the extent to which creepers can also smell cancer in the ants of the Formica fusca species, which is widespread in Central Europe and which can be easily bred and reproduced in artificial systems. Scientists prepared various olfactory samples for the experiments. For this purpose, laboratory cultures of different types of cancer cells and healthy reference cells were converted into sample material. The test animals were calibrated to the cancer samples by adding a sugar solution thereto.
As it turned out, during the very short training phase, the ants especially liked the olfactory qualities of cancer samples: when they were then given a choice between cancer cell solutions and equally sweet control cell solutions, they ran straight to the sample they encountered earlier, with a special odor pattern. As further experiments have shown, insects can even distinguish between different forms of cancer. Scientists have trained ants to recognize two types of breast cancer, leading to different courses in patients. Again, experiments have shown that insects can detect subtle differences in the smell of different types of cells. The researchers explain that ants, like dogs, are based on the ability to perceive cancer-specific patterns of certain volatile substances. As part of the research, they were also able to detect these substances using gas chromatography / mass spectrometry.
‘Our results suggest that ants are useful live tools for detecting human cancer biomarkers,’ the researchers write. In particular, they emphasize that insects are easy to breed and do not require many months of training and time-consuming care like dogs. “Our approach can also be extended to a range of other complex odor detection tasks, such as detecting drugs, explosives, spoiled food or other diseases such as malaria or diabetes,” writes the team.
However, it will likely be some time before ants find their way to diagnostic laboratories as the concept is in an early stage of development: the effectiveness of this method needs to be investigated more closely first. ‘Our research will now aim to broaden the spectrum of cancer-related odors that can be detected by the ants,’ write the researchers. They also want to know to what extent insects can also detect traces of odors emitted directly by the body.
Source: iScience, doi: 10.1016 / j.isci.2022.103959