cytochrome-c-t and butein

Butein is a polyphenol, one of the compounds of chalcones, which are flavonoids that are widely biosynthesized in plants, and exhibits different pharmacological activities. Plants containing butein have been used in Chinese traditional medicine. Recently, it has been reported that butein suppresses proliferation and triggers apoptosis in various human cancer cells in vitro and in vivo. The aim of this study was to investigate its pro-apoptotic effect and mechanisms in two cultured human ovarian cancer cells (ES-2 and TOV-21G). The effects of butein on cell viability were assessed by a MTT assay at 3, 10, 30, and 100 μ/M. The apoptotic pathway related factors, including the mitochondrial transmembrane potential (MTP), cytochrome c, caspase cascade, and Bcl-2 family proteins, were examined. MTT assay revealed that butein was cytotoxic to both ovarian cancer cells in a dose- and time-dependent manner. JC-1 flow cytometry, cytochrome c, and caspase activity assays revealed that butein damaged the MTP, increased the level of cytosol cytochrome c and the activities of caspase-3, -8, and -9 in the two ovarian cancer cells. Western blot analysis revealed that butein down-regulated the anti-apoptotic proteins Bcl-2 and Bcl-xL and increased the pro-apoptotic proteins Bax and Bad. These findings suggest that butein-induced apoptosis in ovarian cancer cells via the activation of both extrinsic and intrinsic pathways. In addition, butein also down-regulated the expressions of the inhibitor of apoptosis (IAP) proteins, XIAP, survivin, CIAP-1, and CIAP-2. This indicates that the inhibition of IAP proteins was also involved in butein-induced apoptosis. The results of our study suggest that butein may be a promising anticancer agent in treating ovarian cancer.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Baculoviral IAP Repeat-Containing 3 Protein; bcl-X Protein; Caspases; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chalcones; Cytochromes c; Dose-Response Relationship, Drug; Female; Gene Expression; Humans; Inhibitor of Apoptosis Proteins; Membrane Potential, Mitochondrial; Molecular Targeted Therapy; Ovarian Neoplasms; Phytotherapy; Proto-Oncogene Proteins c-bcl-2; Survivin; Ubiquitin-Protein Ligases; X-Linked Inhibitor of Apoptosis Protein

To study the cytotoxic effects and related signaling pathways of butein on human uveal melanoma cells in vitro.. 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.. 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.. Butein has selectively potent pro-apoptotic effects on cultured human uveal melanoma cells via the intrinsic mitochondrial pathway.

Topics: Annexin A5; Apoptosis; Caspases; Cell Survival; Chalcones; Cytochromes c; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Fluorescent Antibody Technique, Indirect; Humans; Melanoma; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Proteins; Retinal Pigment Epithelium; Tumor Cells, Cultured; Uveal Neoplasms