title: Naturally occurring tumours in the basal metazoan Hydra.
abstract: The molecular nature of tumours is well studied in vertebrates, although their evolutionary origin remains unknown. In particular, there is no evidence for naturally occurring tumours in pre-bilaterian animals, such as sponges and cnidarians. This is somewhat surprising given that recent computational studies have predicted that most metazoans might be prone to develop tumours. Here we provide first evidence for naturally occurring tumours in two species of Hydra. Histological, cellular and molecular data reveal that these tumours are transplantable and might originate by differentiation arrest of female gametes. Growth of tumour cells is independent from the cellular environment. Tumour-bearing polyps have significantly reduced fitness. In addition, Hydra tumours show a greatly altered transcriptome that mimics expression shifts in vertebrate cancers. Therefore, this study shows that spontaneous tumours have deep evolutionary roots and that early branching animals may be informative in revealing the fundamental mechanisms of tumorigenesis.
authors: 1] Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany [2] Laboratory of Evolutionary Genetics, Division of Molecular Biology, Ruder Bošković Institute, Bijenička cesta 54, HR-10000 Zagreb, Croatia [3] Catholic University of Croatia, Ilica 242, HR-10000 Zagreb, Croatia [4].
authors: Tomislav
authors: T
authors: Domazet-Lošo
authors: 1] Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany [2].
authors: Alexander
authors: A
authors: Klimovich
authors: Zoological Institute of Russian Academy of Sciences, Universitetskaya emb. 1, 199034 St Petersburg, Russia.
authors: Boris
authors: B
authors: Anokhin
authors: Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany.
authors: Friederike
authors: F
authors: Anton-Erxleben
authors: Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany.
authors: Mailin J
authors: MJ
authors: Hamm
authors: Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany.
authors: Christina
authors: C
authors: Lange
authors: Zoological Institute, Christian-Albrechts-University Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany.
authors: Thomas C G
authors: TC
authors: Bosch
mesh_terms: D000818:Animals; D005075:Biological Evolution; D056890:Eukaryota / Q000145:classification / Q000235:genetics; D005260:Female; D006829:Hydra / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008297:Male; D009369:Neoplasms / Q000235:genetics / Q000503:physiopathology / Q000662:veterinary*; D014714:Vertebrates / Q000145:classification / Q000235:genetics*