Ants could one day help save lives by acting as inexpensive biodetectors. Their keen sense of smell allows them to detect subtle molecular differences in biological samples that we would otherwise need expensive equipment to detect.
A new proof-of-concept study just showed that this ability can be used to detect cancer in urine samples, at least from laboratory mice.
“Ants show the potential to become a fast, efficient, inexpensive, and non-invasive tool for detecting human tumors,” said Baptiste Piqueret, an ethologist at Sorbonne University, and colleagues write on your paper.
Cancer remains the leading cause of death worldwide, with more than 19 million cases in 2020. The earlier cancer is detected, the better a patient’s chance of recovery, but current detection methods are invasive or expensive, which can discourage patients from undergoing screening as early as possible.
So researchers turned to the animals for help, from mice To dogsto see if this process could be more accessible. Piqueret and the team have now also put ants to the test.
They conditioned 35 silk ants (Formica fusca) to link healthy mouse urine to a sugar water treat, and another 35 to link mouse urine odor to human cancerous tumors.
The ants only needed three training sessions to distinguish smells. These ants are known for their rapid learning and memory performance; They can be tested nine times without a reward before their answers wear off.
In their previous studythe researchers found that ants can distinguish between cancerous and healthy cell samples and different types of cancer cells.
After training, the ants spent about 20 percent more time near the target scent than others, searching for that sugary reward while providing a clear and accurate signal of the presence or absence of breast cancer in the mouse’s urine.
This is despite the fact that the cancer biomarkers from the transplanted human tumor may have been altered while passing through the mouse’s body and mixed with other odors in the mouse’s urine.
Chemical analysis confirmed that the smelly volatile molecules in the urine of the mice with cancer are indeed different from those without cancer. In addition, the larger the cancer tumor, the more different the smells.
However, the ants showed no difference in their ability to detect the presence of small tumors compared to large tumors in the mice; They could sniff out large and small tumors from cancer-free controls as well.
While these results are promising, there is still work to be done before potential use in clinical settings is possible.
“A limitation of our study is that the odors we used may not represent the wide variety of cancer odors found in nature,” the team said writes.
“In a real-world situation, confounding factors such as age, diet, condition, or stress can contribute to inter-individual variability in individual body odors. Our method needs to be further validated using different tumor/cancer types and especially samples of direct human origin before it can be used as a routine test for cancer screening.”
This research was published in the Proceedings of the Royal Society B: Biological Sciences.
