Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia.
LIttoral, ENvironnement et Sociétés (LIENSs), UMR7266, CNRS Université de La Rochelle, 2 rue Olympe de Gouges, 17042 La Rochelle Cedex, France.
Environ Int. 2021 Apr;149:106391. doi: 10.1016/j.envint.2021.106391. Epub 2021 Jan 27.
Due to the interconnectedness of aquatic ecosystems through the highly effective marine and atmospheric transport routes, all aquatic ecosystems are potentially vulnerable to pollution. Whilst links between pollution and increased mortality of wild animals have now been firmly established, the next steps should be to focus on specific physiological pathways and pathologies that link pollution to wildlife health deterioration. One of the pollution-induced pathologies that should be at the centre of attention in ecological and evolutionary research is cancer, as anthropogenic contamination has resulted in a rapid increase of oncogenic substances in natural habitats. Whilst wildlife cancer research is an emerging research topic, systematic reviews of the many case studies published over the recent decades are scarce. This research direction would (1) provide a better understanding of the physiological mechanisms connecting anthropogenic pollution to oncogenic processes in non-model organisms (reducing the current bias towards human and lab-animal studies in cancer research), and (2) allow us to better predict the vulnerability of different wild populations to oncogenic contamination. This article combines the information available within the scientific literature about cancer occurrences in aquatic and semi-aquatic species. For the first aim, we use available knowledge from aquatic species to suggest physiological mechanisms that link pollution and cancer, including main metabolic detoxification pathways, oxidative damage effects, infections, and changes to the microbiome. For the second aim, we determine which types of aquatic animals are more vulnerable to pollution-induced cancer, which types of pollution are mainly associated with cancer in aquatic ecosystems, and which types of cancer pollution causes. We also discuss the role of migration in exposing aquatic and semi-aquatic animals to different oncogenic pollutants. Finally, we suggest novel research avenues, including experimental approaches, analysis of the effects of pollutant cocktails and long-term chronic exposure to lower levels of pollutants, and the use of already published databases of gene expression levels in animals from differently polluted habitats.
由于水生生态系统通过高效的海洋和大气传输途径相互关联，所有水生生态系统都可能容易受到污染。虽然现在已经确定了污染与野生动物死亡率增加之间的联系，但下一步应该集中关注将污染与野生动物健康恶化联系起来的特定生理途径和病理学。在生态和进化研究中，应该关注的一种由污染引起的病理学是癌症，因为人为污染导致自然栖息地中致癌物质的迅速增加。虽然野生动物癌症研究是一个新兴的研究课题，但对近几十年来发表的许多案例研究进行系统回顾的研究很少。这一研究方向将：（1）更好地了解将人为污染与非模式生物致癌过程联系起来的生理机制（减少癌症研究中对人类和实验动物研究的当前偏见），（2）使我们能够更好地预测不同野生动物种群对致癌污染的脆弱性。本文结合了科学文献中关于水生和半水生物种癌症发生的信息。对于第一个目标，我们利用水生物种的现有知识，提出将污染与癌症联系起来的生理机制，包括主要的代谢解毒途径、氧化损伤效应、感染和微生物组的变化。对于第二个目标，我们确定哪些类型的水生动物更容易受到污染引起的癌症的影响，哪些类型的污染主要与水生生态系统中的癌症有关，以及哪些类型的癌症污染会引起。我们还讨论了迁徙在使水生和半水生动物暴露于不同致癌污染物中的作用。最后，我们提出了新的研究途径，包括实验方法、分析污染物混合物的影响和长期慢性暴露于较低水平的污染物，以及利用已经发表的来自不同污染栖息地的动物基因表达水平数据库。
