title: The antiproliferative effects of ouabain and everolimus on adrenocortical tumor cells.
abstract: Ouabain is a cardiotonic steroid obtained from Strophanthus. Recently its role as antiproliferative agent has been investigated in tumor cells. Everolimus is a derivative of rapamycin and acts as a signal transduction inhibitor. Adrenocortical carcinoma is a rare cancer, with poor prognosis. This research focuses on antineoplastic properties of ouabain and its association with everolimus. We analyzed the effects of drugs on cells by MTT assay, by [(3)H] thymidine assay, by Wright's staining, by homogeneous caspases assay, by flow cytometry analysis and by Western blot analysis on H295R and SW13 cells and on primary adrenocortical tumor cells. Ouabain induced cell viability reduction in SW13, H295R and 5 primary adrenocortical tumor cells. Combination of ouabain with everolimus produced a stronger cytotoxic effect on cell proliferation and viability. Marked morphological changes were observed in both SW13 and H295R cell lines after ouabain treatment, with an increase in necrosis. Cell cycle distribution was altered by ouabain in SW13. Analysis of apoptosis demonstrated an increase in caspase activity, clearly evident for SW13 at 72h. FACS analysis by Annexin V-FITC kit and propidium iodide confirmed an increased level of necrosis at higher concentrations. Western blot analysis showed that PI3k/Akt signaling pathway was modified after ouabain treatments in SW13. Ouabain exerts antiproliferative effects on SW13 and H295R cell lines and on primary adrenocortical tumor cells. These data suggest that ouabain or ouabain derivatives may be potential anticancer agents.
authors.affiliation: Endocrinology Unit, Department of Medicine, University of Padova, Padova 35128, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pezzani
authors.forename: Beatrice
authors.initials: B
authors.lastname: Rubin
authors.forename: Marco
authors.initials: M
authors.lastname: Redaelli
authors.forename: Claudia
authors.initials: C
authors.lastname: Radu
authors.forename: Susi
authors.initials: S
authors.lastname: Barollo
authors.forename: Maria Verena
authors.initials: MV
authors.lastname: Cicala
authors.forename: Monica
authors.initials: M
authors.lastname: Salvà
authors.forename: Caterina
authors.initials: C
authors.lastname: Mian
authors.forename: Carla
authors.initials: C
authors.lastname: Mucignat-Caretta
authors.forename: Paolo
authors.initials: P
authors.lastname: Simioni
authors.forename: Maurizio
authors.initials: M
authors.lastname: Iacobone
authors.forename: Franco
authors.initials: F
authors.lastname: Mantero
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D000328:Adult; D000970:Antineoplastic Agents; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D000068338:Everolimus; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000008:administration & dosage*; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D000970:Antineoplastic Agents; D010042:Ouabain; D000068338:Everolimus; D020169:Caspases; D020123:Sirolimus