Ants can learn to smell human cancer cells, as dogs already do but even more quickly, according to a scientific study that proposes to explore that clue. Several experiments have recently shown that the canine sense of smell can detect some cancerous tumors that emit volatile organic compounds (VOCs), which a human cannot perceive.
But this method requires long training – between 6 months and 1 year per dog – and is expensive, in the order of tens of thousands of dollars, Baptiste Piqueret, lead author of the study published this week in the journal iScience, explained to AFP.
This ethologist from the Sorbonne Paris Nord university tried the experiment with ants, an insect that uses its powerful sense of smell for its daily tasks and learns quickly. The scientist, supported by a team from French institutions such as the Curie Institute, chose the most common ant species in the northern hemisphere, Formica fusca.
The insects were subjected to learning protocols in the laboratory, in which they associated an odor with a reward (a drop of sugar water). In a first training session, the ant “walked around freely until it came across a drop of sugar water. While it drank it, it sniffed the environment (with its antennae) impregnated with a particular odor”, explains the researcher.
In the next stage, the insect had the option of going to a place with the smell it had learned and to another with a different smell, this time without a drop of sugar water. “If the ant had learned correctly, it would spend much more time hanging around the odor associated with sugar water, looking for the reward”, he said.
These tests were carried out with odors from healthy human cells and cancer cells (produced by ovarian cancer) to see if the ants learned to differentiate between them. And then, with 2 diseased cells -from breast cancer- to see if the insects differentiated between those 2 subtypes of cancer. “3 training sessions of less than 1 hour was enough for them to learn” the difference between these 2 subtypes, the researcher assured.
The protocol is very simple, and the training was done at home, during the confinement that France suffered during the spring of 2020, the researcher explained. Now it is necessary to analyze “the effectiveness of this method thanks to clinical tests with a complete human organism“, specified a statement from the French research organization that supported the experience (CNRS). Preliminary experiments are being carried out with the urine of mice suffering from cancer.