methyl-jasmonate and Carcinoma--Hepatocellular

Methyl jasmonate has recently been found to have anti-cancer activity. Methyl jasmonate detached hexokinase 2 from a voltage dependent anion channel causing a reduction in mitochondrial transmembrane potential that led to the release of cytochrome C and apoptosis inducing factor resulting in intrinsic apoptosis. Blocked adenosine triphosphate synthesis caused by mitochondrial injury hampered oxidative phosphorylation and led to cell necrosis. The results were applied to the in vivo treatment of nude mice with a satisfactory effect. Collectively, our results suggest that methyl jasmonate may be an adjuvant therapy for liver tumors due to its mechanism in cancer cells compared to that in normal cells: The major function is to inhibit glycolysis instead of changing aerobic metabolism.

Topics: Acetates; Animals; Apoptosis; Carcinoma, Hepatocellular; Caspases; Cell Line, Tumor; Cell Proliferation; Cyclopentanes; Disease Models, Animal; Drug Resistance, Neoplasm; Energy Metabolism; Glycolysis; Hexokinase; Humans; Liver Neoplasms; Membrane Potential, Mitochondrial; Mice; Mitochondria; Necrosis; Oxylipins; Plant Growth Regulators; Xenograft Model Antitumor Assays

To study the effects of methyl jasmonate on multidrug resistance in a mouse model of hepatocellular carcinoma.. Multidrug resistant H22 (H22/FAP) hepatocellular carcinoma cells were produced in vitro by continuous exposure to increasing doses of doxorubicin, cisplatin and 5-fluorouracil (FAP regimen). Cell toxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolum bromide (MTT) assay. Survival time was calculated for BALB/c mice that received intraperitoneal injections of H22/FAP cells followed by treatment with methyl jasmonate or verapamil in combination with FAP for 7 days. Adenosine triphosphate (ATP) hydrolysis was used to measure the activity of permeability-glycoprotein (P-gp) ATPase activity in plasma membranes.. The MTT assay showed that methyl jasmonate significantly enhanced the cytotoxicity of the FAP regimen in multidrug resistant H22/FAP cells. Methyl jasmonate (10 mg/kg and 5 mg/kg) combined with FAP significantly increased survival time in BALB/c mice by 44.25% and 48.01%, respectively, compared with FAP. Methyl jasmonate increased P-gp ATPase activity.. The combined use of methyl jasmonate and the FAP regimen might be a novel strategy for overcoming the multidrug resistance often observed in hepatocellular carcinoma.

Topics: Acetates; Adenosine Triphosphate; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; ATP Binding Cassette Transporter, Subfamily B, Member 1; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Survival; Cisplatin; Cyclopentanes; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Drug Synergism; Injections, Intraperitoneal; Liver Neoplasms; Mice; Mice, Inbred BALB C; Neoplasms, Experimental; Oxylipins; Survival Analysis; Tegafur; Uracil; Verapamil

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/APO2L), a member of the TNF gene superfamily, induces apoptosis upon engagement of cognate death receptors. While TRAIL is relatively non-toxic to normal cells, it selectively induces apoptosis in many transformed cells. Nevertheless, some human hepatoma cells are particularly resistant to the effects of TRAIL. In this study, we show that J7, a novel methyl jasmonate analogue, sensitizes TRAIL-resistant HepG2 human hepatocarcinoma cells to TRAIL-mediated apoptosis. Our results indicate that J7 substantially enhances TRAIL-induced apoptosis, compared with treatment with either agent alone. Combined treatment with J7 and TRAIL effectively induced Bid cleavage, down-regulation of XIAP, cIAP-1 and Bcl-xL, activation of caspases, and cleavage of poly(ADP-ribose) polymerase and phopholipase γ-1. In addition, generation of reactive oxygen species (ROS) showed a significant increase in cells following exposure to J7 in a time-dependent manner. However, the cytotoxic effects induced by co-treatment with J7 and TRAIL were markedly attenuated by caspase inhibitors, indicating an important role for caspases. Administration of N-acetyl cysteine, a scavenger of ROS, also resulted in significant inhibition of apoptosis induced by combinatory treatment with J7 and TRAIL. These results support a mechanism whereby J7 plus TRAIL induces apoptosis of HepG2 human hepatoma cells through a signaling cascade involving a ROS-mediated caspase pathway.

Topics: Acetates; Apoptosis; bcl-X Protein; Carcinoma, Hepatocellular; Caspases; Cell Line, Tumor; Cyclopentanes; Humans; Inhibitor of Apoptosis Proteins; Liver Neoplasms; Oxylipins; Reactive Oxygen Species; TNF-Related Apoptosis-Inducing Ligand; Up-Regulation; X-Linked Inhibitor of Apoptosis Protein

We reported previously that jasmonates can kill human cancer cells. Many chemotherapeutic drugs induce mitochondrial membrane permeability transition, membrane depolarization, osmotic swelling, and release of cytochrome c, involving the opening of the permeability transition pore complex (PTPC). Because jasmonates exert their cytotoxic effects independent of transcription, translation, and p53 expression, we hypothesized that these compounds may act directly on mitochondria. Mitochondrial membrane depolarization was determined by flow cytometry, and cytochrome c release by Western blotting. Mitochondria were isolated by mechanical lysis and differential centrifugation. Cytotoxicity was measured by a tetrazolium-based assay, and mitochondrial swelling by spectrophotometry. Jasmonates induced membrane depolarization and cytochrome c release in intact human cancer cell lines. Jasmonates induced swelling in mitochondria isolated from Hep 3B hepatoma cells, but not in mitochondria isolated from 3T3 nontransformed cells or from normal lymphocytes, in a PTPC-mediated manner. Methyl jasmonate induced the release of cytochrome c from mitochondria isolated from cancer cell lines in a PTPC-mediated manner, but not from mitochondria isolated from normal lymphocytes. A correlation was found between cytotoxicity of methyl jasmonate and the percentage of leukemic cells in the blood of patients with chronic lymphocytic leukemia (CLL). Jasmonates induced membrane depolarization in CLL cells, and swelling and release of cytochrome c in mitochondria isolated from these cells. In conclusion, jasmonates act directly on mitochondria derived from cancer cells in a PTPC-mediated manner, and could therefore bypass premitochondrial apoptotic blocks. Jasmonates are promising candidates for the treatment of CLL and other types of cancer.

Topics: Acetates; Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Calcium; Carcinoma, Hepatocellular; Cell Membrane Permeability; Cells, Cultured; Cyclopentanes; Cytochromes c; Fibroblasts; Flow Cytometry; Humans; Ion Channels; Leukemia, Lymphocytic, Chronic, B-Cell; Liver Neoplasms; Lymphocytes; Membrane Potentials; Mice; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Mitochondrial Swelling; Oxylipins; Plant Growth Regulators