Ants act as olfactory bio-detectors of tumour in patient-derived xenograft mice

Abstract

Early detection of cancer is critical in medical sciences, as the sooner a cancer is diagnosed, the higher the chances of recovery. Tumour cells are characterized by specific volatile organic compounds (VOCs) that can be used as cancer biomarkers. Through olfactory associative learning, animals can be trained to detect these VOCs. Insects, such as ants, have a refined sense of smell and can be easily and rapidly trained with olfactory conditioning. Using urine from patient-derived xenograft mice as stimulus, we demonstrate that individual ants can learn to discriminate the odour of healthy mice from that of tumour bearing mice, and do so after only three conditioning trials. Chemical analyses confirmed that the presence of the tumour changed the urine odour, supporting the behavioural results. Our study demonstrates that ants reliably detect tumour cues in mice urine and have the potential to act as efficient and inexpensive cancer bio detectors.

The neglected potential of invertebrates in detecting disease via olfaction

“…The VOCs profile produced by a single cell line is composed of dozens of single compounds (Piqueret et al, 2022a), but it is less complex than the odour of a whole organism composed of a myriad of different cell types. Even when using complex body odours, Formica ants demonstrated their abilities to discriminate cancer-free individuals from sick ones (Piqueret et al, 2022b). Human tumours were grafted on mice (Patient derived xenograft -PDX; Dobrolecki et al, 2016), and their urine served as odour stimuli.…”