title: Butein induces apoptosis in human uveal melanoma cells through mitochondrial apoptosis pathway.
abstract: OBJECTIVE
  To study the cytotoxic effects and related signaling pathways of butein on human uveal melanoma cells in vitro.
  
  
  METHODS
  Three human uveal melanoma cell lines (M17, SP6.5, and C918), retinal pigment epithelial (RPE) cells and scleral fibroblasts were treated with butein at different dosages. The effects of butein on cell viability were assessed by using the MTT assay. Cell apoptosis was determined using annexin V-FITC/ethidium homodimer III flow cytometry. Mitochondrial transmembrane potential changes were assessed by using the JC-1 fluorescent reader, cytosol cytochrome c levels, and the activities of caspase-3, -8, and -9 were measured by using an enzyme-linked immunosorbent assay or colorimetric assay.
  
  
  RESULTS
  Butein reduced the cell viability of cultured human uveal melanoma cells in a dose-dependent manner (10, 30, and 100 μM), with IC50 at 13.3 μM and 15.8 μM in SP6.5 and M17 cell lines, respectively. Similar effects were also found in a highly aggressive and metastatic C918 cell line (IC50 16.7 μM). Butein at lower concentrations (10-30 μM) selectively reduced the cell viability of uveal melanoma cells, without affecting cell viability of RPE cells and fibroblasts. Butein-induced apoptosis of melanoma cells, increased mitochondrial permeability and the level of cytosol cytochrome c, caspase-9 and -3 activities (but not caspase-8) in a dose-dependent manner.
  
  
  CONCLUSIONS
  Butein has selectively potent pro-apoptotic effects on cultured human uveal melanoma cells via the intrinsic mitochondrial pathway.
authors.affiliation: Department of Ophthalmology, The First Hospital, Jilin University, Changchun, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Cui
authors.forename: E
authors.initials: E
authors.lastname: Song
authors.forename: Dan-Ning
authors.initials: DN
authors.lastname: Hu
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Richard
authors.initials: R
authors.lastname: Rosen
authors.forename: Steven A
authors.initials: SA
authors.lastname: McCormick
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D047188:Chalcones / Q000494:pharmacology*; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000473:pathology; D014407:Tumor Cells, Cultured; D014604:Uveal Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D017304:Annexin A5; D047188:Chalcones; D024101:Mitochondrial Proteins; C040918:butein; D045304:Cytochromes c; D020169:Caspases