title: Tumor suppression by cell competition through regulation of the Hippo pathway.
abstract: Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib(-) cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does not explain how scrib(-) cells are prevented from overproliferating. We report that cell competition between scrib(-) and wild-type cells prevents hyperproliferation by suppressing Yki activity in scrib(-) cells. Suppressing Yki activation is critical for scrib(-) clone elimination by cell competition, and experimental elevation of Yki activity in scrib(-) cells is sufficient to fuel their neoplastic growth. Thus, cell competition acts as a tumor-suppressing mechanism by regulating the Hippo pathway in scrib(-) cells.
authors.affiliation: Department of Biochemistry and Molecular Biology and Program in Genes and Development, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Chiao-Lin
authors.initials: CL
authors.lastname: Chen
authors.forename: Molly C
authors.initials: MC
authors.lastname: Schroeder
authors.forename: Madhuri
authors.initials: M
authors.lastname: Kango-Singh
authors.forename: Chunyao
authors.initials: C
authors.lastname: Tao
authors.forename: Georg
authors.initials: G
authors.lastname: Halder
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D005838:Genotype; D060227:Imaginal Discs / Q000166:cytology / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D000091102:YAP-Signaling Proteins; D000099317:Hippo Kinases
chemical_list: D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D000091102:YAP-Signaling Proteins; C404683:Scrib protein, Drosophila; C503814:Yki protein, Drosophila; C499474:hpo protein, Drosophila; D000099317:Hippo Kinases