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Populations of cancer cells are subject to the same core evolutionary processes as asexually reproducing, unicellular organisms. Transmissible cancers are particularly striking examples of these processes. These unusual cancers are clonal lineages that can spread through populations via physical transfer of living cancer cells from one host individual to another, and they have achieved long-term success in the colonization of at least eight different host species. Population genetic theory provides a use- ful framework for understanding the shift from a multicellular sexual animal into a unicellular asexual clone and its long-term effects on the genomes of these cancers. In this Review, we consider recent findings from transmissible cancer research with the goals of developing an evolutionarily informed perspective on transmissible cancers, examining possible implications for their long-term fate and identifying areas for future research on these exceptional lineages.
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This content will become publicly available on August 1, 2025
Evolution of transmissible cancers: an adaptive, plastic strategy of selfish genetic elements?
Agrowing number of studies have applied evolutionary and ecological principles to understanding cancer.However, few such studies have examined whether phenotypic plasticity––the ability of a single individual or genome to respond differently to different environmental circumstances––can impact the origin and spread of cancer. Here, we propose the adaptive horizontal transmission hypothesis to explain how flexible decision-making by selfish genetic elements can cause them to spread from the genome of their original host into the genomes of other hosts through the evolution of transmissible cancers. Specifically, we hypothesize that such cancers appear when the likelihood of successful vertical transmission is sufficiently low relative to the likelihood of successful horizontal transmission. We develop an evolutionary optimization model of this hypothesis, highlight empirical findings that support it, and offer suggestions for future research. Generally, phenotypically plastic selfish genetic elements might play an important role in the evolution of transmissible cancers.
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- Award ID(s):
- 2306276
- PAR ID:
- 10537809
- Publisher / Repository:
- Cell Press
- Date Published:
- Journal Name:
- iScience
- ISSN:
- 2589-0042
- Page Range / eLocation ID:
- 110740
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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