Tumour suppression and subdual of cancer (tussc) in elephants: An in vitro study to shed light on Peto’s paradox

Abstract

Logic would suggest that cancer incidence is related to body mass and longevity. Gigantic animals such as elephants with a longer lifespan (more lifetime of cell divisions) and a larger body size (more cells) will have more time during their lifetime to accumulate a cancer-causing mutation in comparison to small-bodied, short-lived animals, such as mice. However, several studies and the mere existence of large-bodied, long-lived mammals such as elephants and whales, suggest that there is no correlation between body mass, lifespan and cancer incidence across different mammalian species. This is a phenomenon known as Peto’s paradox. As there is a selection for large body size in evolution, there is likely also a selection for cancer suppression mechanisms that allow an organism to grow large and reproduce successfully. One of the rationales in the African savanna elephant (Loxondonta africana) is the duplication of a crucial tumour suppressor gene (TP53) encoding the tumour protein 53 (p53).