Apoptosis Mechanism of Human Cholangiocarcinoma Cells Induced by Bile Extract from Crocodile

• Published in: Applied biochemistry and biotechnology 2012-02, Vol.166 (4), p.942-951
• Main Authors: Kang, Jin-He, Zhang, Wen-Qing, Song, Wei, Shen, Dong-Yan, Li, Shan-Shan, Tian, Ling, Shi, Yan, Liang, Ge, Xiong, You-Xiong, Chen, Qing-Xi
• Format: Article
• Language: English
• Subjects: Alligators and Crocodiles; Animals; Apoptosis; Apoptosis - drug effects; Aquatic reptiles; Bile; Bile - chemistry; Bile Duct Neoplasms - metabolism; Bile Duct Neoplasms - pathology; Biochemistry; Biological and medical sciences; Biotechnology; Blotting, Western; Caspase 3 - genetics; Caspase 3 - metabolism; Cell cycle; Cell Line, Tumor - drug effects; Cell Survival - drug effects; Chemistry; Chemistry and Materials Science; Cholangiocarcinoma - metabolism; Cholangiocarcinoma - pathology; Complex Mixtures - pharmacology; Crocodiles; Cytochromes c - analysis; Dose-Response Relationship, Drug; Fluorescence microscopy; Fundamental and applied biological sciences. Psychology; G1 Phase - drug effects; Gene Expression - drug effects; Humans; Membrane Potential, Mitochondrial - drug effects; Mitochondria - drug effects; Mitochondria - metabolism; Proto-Oncogene Proteins c-bcl-2 - genetics; Proto-Oncogene Proteins c-bcl-2 - metabolism; Reactive Oxygen Species - metabolism; Signal Transduction - drug effects
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-011-9482-x

Animal bile is popularly used as a traditional medicine in China, and bile acids are their major bioactive constituents. In the present study, effects of bile extract from crocodile gallbladder on QBC939 cell growth, cell cycle, and apoptosis were investigated by MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, scanning electron microscopy, PI single- and FITC/PI double-staining flow cytometry, and western blotting. Our data have revealed that bile extract inhibited cells growth significantly, and the cell cycle was arrested in G1 phase. Bile extract induced QBC939 cell apoptosis, which was associated with collapse of the mitochondrial membrane potential and increase of ROS. In bile extract-treated cells, it was observed that the expression of bcl -2 decreased and cytochrome c released to cytosol, but the expression of bax remained unchanged. The data indicated that mitochondrial pathway might play an important role in bile extract-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of bile extract on cholangiocarcinoma cells.