cytochrome-c-t and casticin

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspases; Cell Line, Tumor; Cell Survival; Cytochromes c; Drug Synergism; Flavonoids; Fluorouracil; Humans; Leukemia; Membrane Potential, Mitochondrial; Mice; Mitochondria; Reactive Oxygen Species; Signal Transduction

To assess if casticin induces caspase-mediated apoptosis via activation of mitochondrial pathway and upregulation of DR5 in human lung cancer cells.. Human non-small-cell lung carcinoma cell lines H460, A549 and H157 were cultured in vitro. The cytotoxic activities were determined using MTT assay. The apoptotic cells death was examined by flow cytometry using PI staining and DNA agarose gel electrophoresis. The activities of caspase-3, -8 and -9 were measured via ELISA. Cellular fractionation was determined by flow cytometry to assess release of cytochrome c and the mitochondrial transmembrane potential. Bcl-2/Bcl-XL/XIAP/Bid/DR5 and DR4 proteins were analyzed using western blot.. The concentrations required for a 50% decrease in cell growth (IC(50)) ranged from 1.8 to 3.2 μM. Casticin induced rapid apoptosis and triggered a series of effects associated with apoptosis by way of mitochondrial pathway, including the depolarization of the mitochondrial membrane, release of cytochrome c from mitochondria, activation of procaspase-9 and -3, and increase of DNA fragments. Moreover, the pan caspase inhibitor zVAD-FMK and the caspase-3 inhibitor zDEVD-FMK suppressed casticin-induced apoptosis. In addition, casticin induced XIAP and Bcl-XL down-regulation, Bax upregulation and Bid clearage. In H157 cell line, casticin increased expression of DR5 at protein levels but not affect the expression of DR4. The pretreatment with DR5/Fc chimera protein effectively attenuated casticin-induced apoptosis in H157 cells. No correlation was found between cell sensitivity to casticin and that to p53 status, suggesting that casticin induce a p53-independent apoptosis.. Our results demonstrate that casticin induces caspase-mediated apoptosis via activation of mitochondrial pathway and upregulation of DR5 in human lung cancer cells.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Caspases; Cell Line, Tumor; Cell Survival; Cytochromes c; Flavonoids; Humans; Lung Neoplasms; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; Up-Regulation

Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an IC50~28.8 μM. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.

Topics: Apoptosis; bcl-2-Associated X Protein; Carcinoma; Cell Cycle Checkpoints; Cell Death; Cell Division; Cell Line, Tumor; Cytochromes c; Down-Regulation; Flavonoids; G2 Phase; Humans; Male; Medicine, Chinese Traditional; Membrane Potential, Mitochondrial; Mitochondria; Plant Extracts; Prostatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Up-Regulation