benzyloxycarbonylvalyl-alanyl-aspartyl-fluoromethyl-ketone and Bile-Duct-Neoplasms

The study aimed to evaluate the effects of β-escin on human cholangiocarcinoma cell lines (QBC939, Sk-ChA-1 and MZ-ChA-1) and to explore its mechanisms. Cell growth, cell cycle and apoptosis were investigated, respectively, by MTT assay, single PI and FITC/PI double-staining flow cytometry, and fluorescence microscopy. The protein expression was determined by western blotting. The study revealed that β-escin inhibited cholangiocarcinoma cell growth in a dose- and time-dependent manner, and the cell cycle of QBC939 and Sk-ChA-1 cells was arrested in the G2/M phase, and MZ-ChA-1 cells in G1 phase. Apoptosis of the three cholangiocarcinoma cell lines induced by β-escin was associated with the collapse of the mitochondrial membrane potential and the activation of caspase-3. The apoptotic effect of β-escin was suppressed by pancaspase inhibitor z-VAD-fmk. Molecular dissection revealed that the antiapoptotic protein bcl-2 was down-regulated after cholangiocarcinoma cell lines were treated with β-escin, while the protein levels of bax and p53 were unchanged. Apoptosis was accompanied by an increase in reactive oxygen species (ROS). These results suggest that β-escin induces apoptosis of cholangiocarcinoma cells through an intrinsic mitochondrial caspase-dependent pathway, and the increase in the bax/bcl-2 ratio and ROS may play important roles in β-escin-induced apoptosis of cholangiocarcinoma cells.

Topics: Aesculus; Amino Acid Chloromethyl Ketones; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cholangiocarcinoma; DNA-Binding Proteins; Dose-Response Relationship, Drug; Down-Regulation; Escin; Humans; Membrane Potential, Mitochondrial; Mitochondria; Nuclear Proteins; Phytotherapy; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Signal Transduction; Tumor Protein p73; Tumor Suppressor Proteins