cytochrome-c-t and Carcinoma--Ovarian-Epithelial

Brefeldin A induces apoptosis in various cancer cells; however, the apoptotic process in cancer cells exposed to brefeldin A remains unclear. In addition, it is unclear whether brefeldin A-induced apoptosis is mediated by the formation of reactive oxygen species. Furthermore, the effect of brefeldin A on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effect of brefeldin A on apoptosis, cell adhesion and migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that brefeldin A may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of brefeldin A seems to be mediated by formation of reactive oxygen species and depletion of GSH, which results in the activation of apoptotic caspases. Brefeldin A inhibited foetal bovine serum-induced adhesion and migration of OVCAR-3 cells. Brefeldin A may prevent the foetal bovine serum-induced cell adhesion and migration by limiting the focal adhesion kinase-dependent activation of cytoskeletal-associated components.

Topics: Apoptosis; BH3 Interacting Domain Death Agonist Protein; Brefeldin A; Carcinoma, Ovarian Epithelial; Caspase 8; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Survival; Cytochromes c; DNA Damage; DNA Fragmentation; Focal Adhesion Protein-Tyrosine Kinases; Humans; Membrane Potential, Mitochondrial; Mitochondria; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Reactive Oxygen Species

Hsp90 inhibitor geldanamycin and parthenolide have been shown to induce apoptosis in cancer cells. However, the combined effect of geldanamycin and parthenolide on epithelial ovarian cancer cells has not been studied. In respect of cell death process, we investigated the promoting effect of parthenolide on geldanamycin-induced apoptosis in the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. Geldanamycin induced a decrease in Bid, Bcl-2, Bcl-xL and survivin protein levels; an increase in Bax and tumour suppressor p53 levels; loss of the mitochondrial transmembrane potential; cytochrome c release; activation of caspases (-8, -9 and -3); cleavage of PARP-1; and increase in the reactive oxygen species formation. Parthenolide enhanced geldanamycin-induced changes in the apoptosis-related protein levels, reactive oxygen species formation, nuclear damage and cell death. The combined effect was inhibited by the addition of oxidant scavengers. The results suggest that parthenolide may potentiate the apoptotic effect of geldanamycin on ovarian carcinoma cell lines by the activation of the caspase-8- and Bid-dependent pathway and the mitochondria-mediated apoptotic pathway. The apoptosis-promoting effect seems to be mediated by the stimulatory effect on the formation of reactive oxygen species.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-2-Associated X Protein; Benzoquinones; Blotting, Western; Carcinoma, Ovarian Epithelial; Caspase 3; Caspase 8; Caspase 9; Cell Line, Tumor; Cell Survival; Cytochromes c; Female; HSP90 Heat-Shock Proteins; Humans; Lactams, Macrocyclic; Mitochondria; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Reactive Oxygen Species; Sesquiterpenes; Tumor Suppressor Protein p53

Histone deacetylase inhibitor-induced apoptosis in cancer cells may be mediated by the Ras/Raf/MEK/ERK and protein kinase B/Akt signaling pathways. However, inhibition of ERK and Akt activity has different effects on proliferation and apoptosis in cancer cells. We assessed and compared the inhibitory effects of Akt and ERK pathways on the apoptotic effect of trichostatin A using the human epithelial carcinoma cell lines OVCAR-3 and SK-OV-3. Trichostatin A induced nuclear damage, decrease in Bid and Bcl-2 protein levels, increase in Bax levels, cytochrome c release, activation of caspases (8, 9, and 3) and increase in tumor suppressor p53 levels. Akt inhibitor potentiated trichostatin A-induced apoptosis-related protein activation and cell death, whereas ERK inhibitor exhibited an additive toxic effect. These results suggest that the Akt and ERK inhibitors may have a differential effect on trichostatin A-induced apoptosis in human epithelial ovarian carcinoma cell lines. Akt inhibitor may potentiate the apoptotic effect of trichostatin A on ovarian carcinoma cell lines by increasing the activation of the caspase-8-dependent pathway and the mitochondria-mediated cell death pathway, leading to caspase activation. In contrast, ERK inhibitor may exhibit an additive toxic effect on trichostatin A toxicity by increasing apoptosis-related protein activation.

Topics: Apoptosis; bcl-2-Associated X Protein; BH3 Interacting Domain Death Agonist Protein; Blotting, Western; Carcinoma, Ovarian Epithelial; Caspase 8; Cell Line, Tumor; Cell Survival; Cytochromes c; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Activation; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Inositol Phosphates; Microscopy, Fluorescence; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Tumor Suppressor Protein p53