title: Polyamines modulate epithelial-to-mesenchymal transition.
abstract: Epithelial-to-mesenchymal transition and mesenchymal-to-epithelial transition are biologic processes responsible for conversion of epithelial cells into a mesenchymal phenotype or viceversa, respectively. They occur during embryo- and foetal-development and, in adult organisms, are involved in wound healing, in the genesis and progression of organ fibrosis as well as in the invasiveness of epithelial cancer cells. The key event of epithelial-to-mesenchymal transition is the loss of E-cadherin expression due to repressor activity of the transcriptional factor Snai1. Intracellular Snai1 levels are controlled through translational and post-translational events such as phosphorylation and de-phosphorylation, potentially modulated by polyamine content. Epithelial MDCK cells exposed to TGF-β(1) acquired a fibroblastoid phenotype and expressed mesenchymal markers. These changes were emphasized in cells that were also exposed to DFMO in order to decrease the intracellular levels of polyamines. Addition of exogenous polyamines almost completely abolished the combined action of DFMO and TGF-β(1) and rapidly reverted to epithelial phenotype MDCK cells previously undergone to mesenchymal phenotype. Nuclear extracts of cells treated with DFMO + TGF-β(1) revealed the presence of Snai1 immunopositive bands in a range of molecular weight between 55 and 72 kDa, with additional positive bands detected at MW greater than 170 kDa. Same bands resulted positive to anti-Sumo 2/3 antibody, suggesting that an intracellular low level of polyamines favours Snai1 nuclear accumulation under the form of polysumoylated proteins.
authors: Department of Experimental Medicine and Oncology, University of Torino, via Michelangelo 27B, 10126, Turin, Italy.
authors: Alessandra
authors: A
authors: Compagnone
authors: Compagnone
authors: C
authors: Alessandra
authors: Andrea
authors: A
authors: Bandino
authors: Bandino
authors: B
authors: Andrea
authors: Floriana
authors: F
authors: Meli
authors: Meli
authors: M
authors: Floriana
authors: Vittoria
authors: V
authors: Bravoco
authors: Bravoco
authors: B
authors: Vittoria
authors: Carlo
authors: C
authors: Cravanzola
authors: Cravanzola
authors: C
authors: Carlo
authors: Maurizio
authors: M
authors: Parola
authors: Parola
authors: P
authors: Maurizio
authors: Sebastiano
authors: S
authors: Colombatto
authors: C
authors: C
authors: Sebastiano
mesh_terms: D000818:Animals; D015317:Biogenic Polyamines / Q000502:physiology*; D015153:Blotting, Western; D002460:Cell Line; D004285:Dogs; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology*; D006801:Humans; D010766:Phosphorylation
chemical_list: D015317:Biogenic Polyamines