title: The Concerted Action of Type 2 and Type 3 Deiodinases Regulates the Cell Cycle and Survival of Basal Cell Carcinoma Cells.
abstract: Thyroid hormones (THs) mediate pleiotropic cellular processes involved in metabolism, cellular proliferation, and differentiation. The intracellular hormonal environment can be tailored by the type 1 and 2 deiodinase enzymes D2 and D3, which catalyze TH activation and inactivation respectively. In many cellular systems, THs exert well-documented stimulatory or inhibitory effects on cell proliferation; however, the molecular mechanisms by which they control rates of cell cycle progression have not yet been entirely clarified. We previously showed that D3 depletion or TH treatment influences the proliferation and survival of basal cell carcinoma (BCC) cells. Surprisingly, we also found that BCC cells express not only sustained levels of D3 but also robust levels of D2. The aim of the present study was to dissect the contribution of D2 to TH metabolism in the BCC context, and to identify the molecular changes associated with cell proliferation and survival induced by TH and mediated by D2 and D3.
  
  
  
  We used the CRISPR/Cas9 technology to genetically deplete D2 and D3 in BCC cells and studied the consequences of depletion on cell cycle progression and on cell death. Cell cycle progression was analyzed by fluorescence activated cell sorting analysis of synchronized cells, and the apoptosis rate by annexin V incorporation.
  
  
  
  Mechanistic investigations revealed that D2 inactivation accelerates cell cycle progression thereby enhancing the proportion of S-phase cells and cyclin D1 expression. Conversely, D3 mutagenesis drastically suppressed cell proliferation and enhanced apoptosis of BCC cells. Furthermore, the basal apoptotic rate was oppositely regulated in D2- and D3-depleted cells.
  
  
  
  Our results indicate that BCC cells constitute an example in which the TH signal is finely tuned by the concerted expression of opposite-acting deiodinases. The dual regulation of D2 and D3 expression plays a critical role in cell cycle progression and cell death by influencing cyclin D1-mediated entry into the G1-S phase. These findings reinforce the concept that TH is a potential therapeutic target in human BCC.
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Caterina
authors.initials: C
authors.lastname: Miro
authors.affiliation: 2 Istituto di Ricovero e Cura a Carattere Scientifico-SDN , Naples, Italy .
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ambrosio
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: De Stefano
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Daniela
authors.initials: D
authors.lastname: Di Girolamo
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Emery
authors.initials: E
authors.lastname: Di Cicco
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Annunziata Gaetana
authors.initials: AG
authors.lastname: Cicatiello
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Mancino
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .
authors.forename: Tommaso
authors.initials: T
authors.lastname: Porcelli
authors.affiliation: 3 Centro di Ingegneria Genetica-Biotecnologie Avanzate s.c. a r.l., Naples, Italy .
authors.forename: Maddalena
authors.initials: M
authors.lastname: Raia
authors.affiliation: 3 Centro di Ingegneria Genetica-Biotecnologie Avanzate s.c. a r.l., Naples, Italy .
authors.forename: Luigi
authors.initials: L
authors.lastname: Del Vecchio
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .|3 Centro di Ingegneria Genetica-Biotecnologie Avanzate s.c. a r.l., Naples, Italy .
authors.forename: Domenico
authors.initials: D
authors.lastname: Salvatore
authors.affiliation: 1 Department of Clinical Medicine and Surgery, University of Naples "Federico II" , Napoli, Italy .|3 Centro di Ingegneria Genetica-Biotecnologie Avanzate s.c. a r.l., Naples, Italy .
authors.forename: Monica
authors.initials: M
authors.lastname: Dentice
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D064113:CRISPR-Cas Systems; D002280:Basal Cell Carcinoma / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D016923:Cell Death / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D019938:Cyclin D1; D005434:Flow Cytometry; D059585:G1 Phase Cell Cycle Checkpoints / Q000235:genetics*; D007453:Iodide Peroxidase / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D016297:Mutagenesis, Site-Directed; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism; D013963:Thyroid Hormones / Q000378:metabolism; D000097564:Iodothyronine Deiodinase Type II
chemical_list: D019938:Cyclin D1; D007453:Iodide Peroxidase; D013963:Thyroid Hormones; D000097564:Iodothyronine Deiodinase Type II; C530105:Ccnd1 protein, mouse; C117274:iodothyronine deiodinase type III
keywords: basal cell carcinoma; deiodinases; thyroid hormone metabolism