title: Functional inhibition of aquaporin-3 with a gold-based compound induces blockage of cell proliferation.
abstract: AQP3 has been correlated with higher transport of glycerol, increment of ATP content, and larger proliferation capacity. Recently, we described the gold(III) complex Auphen as a very selective and potent inhibitor of AQP3's glycerol permeability (Pgly ). Here we evaluated Auphen effect on the proliferation of various mammalian cell lines differing in AQP3 expression level: no expression (PC12), moderate (NIH/3T3) or high (A431) endogenous expression, cells stably expressing AQP3 (PC12-AQP3), and human HEK293T cells transiently transfected (HEK-AQP3) for AQP3 expression. Proliferation was evaluated in the absence or presence of Auphen (5 μM) by counting number of viable cells and analyzing 5-bromo-2'-deoxyuridine (BrdU) incorporation. Auphen reduced ≈50% the proliferation in A431 and PC12-AQP3, ≈15% in HEK-AQP3 and had no effect in PC12-wt and NIH/3T3. Strong arrest in the S-G2/M phases of the cell cycle, supported by analysis of cyclins (A, B1, D1, E) levels, was observed in AQP3-expressing cells treated with Auphen. Flow-cytometry of propidium iodide incorporation and measurements of mitochondrial dehydrogenases activity confirmed absence of cytotoxic effect of the drug. Functional studies evidenced ≈50% inhibition of A431 Pgly by Auphen, showing that the compound's antiproliferative effect correlates with its ability to inhibit AQP3 Pgly . Role of Cys-40 on AQP3 permeability blockage by Auphen was confirmed by analyzing the mutated protein (AQP3-Ser-40). Accordingly, cells transfected with mutated AQP3 gained resistance to the antiproliferative effect of Auphen. These results highlight an Auphen inhibitory effect on proliferation of cells expressing AQP3 and suggest a targeted therapeutic effect on carcinomas with large AQP3 expression.
authors.affiliation: Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla (Departamento de Fisiología Médica y Biofísica), Seville, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Serna
authors.forename: Ana
authors.initials: A
authors.lastname: Galán-Cobo
authors.forename: Claudia
authors.initials: C
authors.lastname: Rodrigues
authors.forename: Ismael
authors.initials: I
authors.lastname: Sánchez-Gomar
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Toledo-Aral
authors.forename: Teresa F
authors.initials: TF
authors.lastname: Moura
authors.forename: Angela
authors.initials: A
authors.lastname: Casini
authors.forename: Graça
authors.initials: G
authors.lastname: Soveral
authors.forename: Miriam
authors.initials: M
authors.lastname: Echevarría
mesh_terms: D000818:Animals; D051400:Aquaporin 3 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D005990:Glycerol / Q000378:metabolism; D006046:Gold / Q000494:pharmacology* / Q000633:toxicity; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D016297:Mutagenesis, Site-Directed; D041681:NIH 3T3 Cells; D016716:PC12 Cells; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D014867:Water / Q000378:metabolism
chemical_list: D056831:Coordination Complexes; D012333:RNA, Messenger; D014867:Water; D051400:Aquaporin 3; D006046:Gold; D001973:Bromodeoxyuridine; D005990:Glycerol