Abstract
Studies of model animals like mice and rats have led to great advances in our understanding of the process of tumorigenesis, but this line of study has less to offer for understanding the mechanisms of cancer resistance. Increasing the diversity of nonmodel species from the perspective of molecular mechanisms of natural cancer resistance can lead to new insights into the evolution of protective mechanisms against neoplastic processes and to a wider understanding of natural cancer defense mechanisms. Such knowledge could then eventually be harnessed for the development of human cancer therapies. We suggest here that seabirds are promising, albeit currently completely ignored candidates for studying cancer defense mechanisms, as they have a longer maximum life span than expected from their body size and rates of energy metabolism and may have thus evolved mechanisms to limit neoplasia progression, especially at older ages. We here apply a novel, intraspecific approach of comparing old and young seabirds for improving our understanding of aging and neoplastic processes in natural settings. We used the long‐lived common gulls (Larus canus) for studying the age‐related pattern of expression of cancer‐related genes, based on transcriptome analysis and databases of orthologues of human cancer genes. The analysis of differently expressed cancer‐related genes between young and old gulls indicated that similarly to humans, age is potentially affecting cancer risk in this species. Out of eleven differentially expressed cancer‐related genes between the groups, three were likely artifactually linked to cancer. The remaining eight were downregulated in old gulls compared to young ones. The downregulation of five of them could be interpreted as a mechanism suppressing neoplasia risk and three as increasing the risk. Based on these results, we suggest that old gulls differ from young ones both from the aspect of cancer susceptibility and tumor suppression at the genetic level.
Highlights
Malignant, “selfish” cells affect all multicellular organisms (Giraudeau, Sepp, Ujvari, Ewald, & Thomas, 2018; Leroi, Koufopanou, & Burt, 2003; Madsen et al, 2017; Roche, Møller, Degregori, & Thomas, 2017)
These eight transcripts were linked to the following cancer-related genes: TRIM33, USP6, PRDM16, SETD1B, MLLT3, Kelch-like ECH-associated protein 1 (KEAP1), CHD2, and DCAF12L2 (Figure 1 and Table 2)
While there has been a push toward applying transcriptome methods in ornithological studies over the recent years (Jax, Wink, & Kraus, 2018), little is known about the age-specific gene expression in birds
Summary
“selfish” cells affect all multicellular organisms (Giraudeau, Sepp, Ujvari, Ewald, & Thomas, 2018; Leroi, Koufopanou, & Burt, 2003; Madsen et al, 2017; Roche, Møller, Degregori, & Thomas, 2017). A recent longitudinal study in greater mouse-eared bats indicated that, several miRNAs acting as tumor suppressors were upregulated, while miRNAs promoting cell cycle or carcinogenesis were downregulated with age (Huang et al, 2019) From this perspective, seabirds are a promising, albeit currently completely ignored candidate for studying cancer defense mechanisms, as they have a longer maximum life span than expected from their body size and rates of energy metabolism (Holmes & Ottinger, 2003). We analyzed whether the cancer-related genes differently expressed in our analyses overlap with aging-associated genes in other species, to understand whether the age-related patterns of cancer resistance in gulls are more likely phylogenetically conserved or unique to long-lived seabirds
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
