Ethanol extract of Kalopanax septemlobus leaf induces caspase-dependent apoptosis associated with activation of AMPK in human hepatocellular carcinoma cells
| Autor: | Sung Ok Kim, Yong-Joo Kim, Geun-Bae Go, Su-Hyun Hong, Cheol Park, Young Hyun Yoo, Yung Hyun Choi, Gi-Young Kim, Ji-Suk Jeong, Yeon-Kwon Jung, Jin-Woo Jeong |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Cancer Research Carcinoma Hepatocellular Cell Survival Apoptosis AMP-Activated Protein Kinases Inhibitor of apoptosis Caspase-Dependent Apoptosis 03 medical and health sciences 0302 clinical medicine Bcl-2-associated X protein Humans Viability assay Caspase Cell Proliferation bcl-2-Associated X Protein Membrane Potential Mitochondrial biology Cell growth Plant Extracts Kalopanax Liver Neoplasms AMPK Hep G2 Cells Caspase Inhibitors Cell biology Gene Expression Regulation Neoplastic Plant Leaves 030104 developmental biology Oncology 030220 oncology & carcinogenesis Caspases biology.protein |
| Zdroj: | International journal of oncology. 48(1) |
| ISSN: | 1791-2423 |
| Popis: | The Kalopanax septemlobus leaf (Thunb.) Koidz. has been used as a traditional medicine herb for the treatment of various human diseases for hundreds of years. In this study, we investigated the mechanism underlying the inhibitory effects of an ethanol extract of K. septemlobus leaf (EEKS) on proliferation of HepG2 hepatocellular carcinoma cells. For this study, cell viability and apoptosis were evaluated using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, DAPI (4,6-diamidino-2-phenylindole) staining, agarose gel electrophoresis, and flow cytometry. Measurements of the mitochondrial membrane potential (MMP), caspase activity assays and western blots were conducted to determine whether HepG2 cell death occurred by apoptosis. Treatment of HepG2 cells with EEKS concentration-dependently reduced cell survival while significantly increasing the ratio of apoptotic cells. EEKS treatment increased the levels of the death receptors (DRs), DR4 and DR5, and activated caspases, as well as promoting proteolytic degradation of poly(ADP-ribose)-polymerase associated with the downregulation of protein expression of members of the inhibitor of apoptosis protein family. Treatment with EEKS also caused truncation of Bid, translocation of pro-apoptotic Bax to the mitochondria, and loss of mitochondrial membrane permeabilization, thereby inducing the release of cytochrome c into the cytosol. However, treatment of HepG2 cells with a pan-caspase inhibitor reversed EEKS-induced apoptosis and growth suppression, indicating that EEKS appears to induce apoptosis though a caspase-dependent mechanism involving both intrinsic and extrinsic apoptotic pathways. In addition, the phosphorylation level of AMP-activated protein kinase (AMPK) was elevated when cells were exposed to EEKS. A specific inhibitor for AMPK attenuated the EEKS-induced activation of caspases, and consequently prevented the EEKS-induced apoptosis and reduction in cell viability. Overall, our findings suggest that EEKS inhibits the growth of HepG2 cells by inducing AMPK-mediated caspase-dependent apoptosis, suggesting the potential therapeutic application of EEKS in the treatment or prevention of cancers. |
| Databáze: | OpenAIRE |
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