title: Cancer in the parasitic protozoans Trypanosoma brucei and Toxoplasma gondii.
abstract: Cancer is a general name for more than 100 malignant diseases. It is postulated that all cancers start from a single abnormal cell that grows out of control. Untreated cancers can cause serious consequences and deaths. Great progress has been made in cancer research that has significantly improved our knowledge and understanding of the nature and mechanisms of the disease, but the origins of cancer are far from being well understood due to the limitations of suitable model systems and to the complexities of the disease. In view of the fact that cancers are found in various species of vertebrates and other metazoa, here, we suggest that cancer also occurs in parasitic protozoans such as Trypanosoma brucei, a blood parasite, and Toxoplasma gondii, an obligate intracellular pathogen. Without treatment, these protozoan cancers may cause severe disease and death in mammals, including humans. The simpler genomes of these single-cell organisms, in combination with their complex life cycles and fascinating life cycle differentiation processes, may help us to better understand the origins of cancers and, in particular, leukemias.
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China; Key Laboratory of Tropical Diseases and Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China; Ecosystems and Environment and Biomedical Research Centres, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, United Kingdom; lsslzr@mail.sysu.edu.cn g.hide@salford.ac.uk fjayala@uci.edu.
authors.forename: Zhao-Rong
authors.initials: ZR
authors.lastname: Lun
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: De-Hua
authors.identifier: http://orcid.org/0000-0002-4709-1507
authors.initials: DH
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: Yan-Zi
authors.initials: YZ
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Zheng
authors.affiliation: Key Laboratories of Pathogen Biology and Zoonoses, Anhui Province and Department of Parasitology, Anhui Medical University, Hefei 230032, People's Republic of China;
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: Ting-Bo
authors.initials: TB
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China;
authors.forename: Liang-Hu
authors.initials: LH
authors.lastname: Qu
authors.affiliation: Ecosystems and Environment and Biomedical Research Centres, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, United Kingdom; lsslzr@mail.sysu.edu.cn g.hide@salford.ac.uk fjayala@uci.edu.
authors.forename: Geoff
authors.initials: G
authors.lastname: Hide
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697 lsslzr@mail.sysu.edu.cn g.hide@salford.ac.uk fjayala@uci.edu.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Ayala
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D006801:Humans; D008018:Life Cycle Stages; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000235:genetics / Q000473:pathology*; D010271:Parasites / Q000502:physiology*; D014122:Toxoplasma / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
keywords: evolution; malignancy; mammals; single-cell organisms; transmissible