RT Journal Article SR Electronic T1 Radiation resistance in Placozoa: Trichoplax adhaerens upregulates DNA repair genes and extrudes cells after exposure JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.12.24.424349 DO 10.1101/2020.12.24.424349 A1 Angelo Fortunato A1 Alexis Fleming A1 Athena Akpitis A1 Carlo C. Maley YR 2020 UL http://biorxiv.org/content/early/2020/12/24/2020.12.24.424349.abstract AB Trichoplax adhaerens is the simplest multicellular animal with tissue differentiation and somatic cell turnover. Like all other multicellular organisms, it should be vulnerable to cancer, yet there have been no reports of cancer in T. adhaerens, or any other placozoan. We investigated the cancer resistance of T. adhaerens, discovering that they are able to tolerate high levels of radiation damage (240 Gy). To investigate how T. adhaerens survive levels of radiation that are lethal to other animals, we examined gene expression after the X-ray exposure, finding overexpression of genes involved in DNA repair and apoptosis including the MDM2 gene. We also discovered that T. adhaerens extrudes clusters of inviable cells after X-ray exposure. T. adhaerens is a valuable model organism for studying the molecular, genetic and tissue-level mechanisms underlying cancer suppression.Competing Interest StatementThe authors have declared no competing interest.