title: Flower-deficient mice have reduced susceptibility to skin papilloma formation.
abstract: Skin papillomas arise as a result of clonal expansion of mutant cells. It has been proposed that the expansion of pretumoral cell clones is propelled not only by the increased proliferation capacity of mutant cells, but also by active cell selection. Previous studies in Drosophila describe a clonal selection process mediated by the Flower (Fwe) protein, whereby cells that express certain Fwe isoforms are recognized and forced to undergo apoptosis. It was further shown that knock down of fwe expression in Drosophila can prevent the clonal expansion of dMyc-overexpressing pretumoral cells. Here, we study the function of the single predicted mouse homolog of Drosophila Fwe, referred to as mFwe, by clonal overexpression of mFwe isoforms in Drosophila and by analyzing mFwe knock-out mice. We show that clonal overexpression of certain mFwe isoforms in Drosophila also triggers non-autonomous cell death, suggesting that Fwe function is evolutionarily conserved. Although mFwe-deficient mice display a normal phenotype, they develop a significantly lower number of skin papillomas upon exposure to DMBA/TPA two-stage skin carcinogenesis than do treated wild-type and mFwe heterozygous mice. Furthermore, mFwe expression is higher in papillomas and the papilloma-surrounding skin of treated wild-type mice compared with the skin of untreated wild-type mice. Thus, we propose that skin papilloma cells take advantage of mFwe activity to facilitate their clonal expansion.
authors.affiliation: Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro, 3, Madrid, 28034, Spain.
authors.forename: Evgeniya
authors.initials: E
authors.lastname: Petrova
authors.forename: Jesús M
authors.initials: JM
authors.lastname: López-Gay
authors.forename: Christa
authors.initials: C
authors.lastname: Rhiner
authors.forename: Eduardo
authors.initials: E
authors.lastname: Moreno
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology*; D004198:Disease Susceptibility / Q000473:pathology*; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D056426:Genetic Loci; D060227:Imaginal Discs / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D010212:Papilloma / Q000235:genetics / Q000473:pathology*; D010641:Phenotype; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology*; D014921:Wings, Animal / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D029721:Drosophila Proteins; C577694:Flower protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; C543900:fwe protein, Drosophila