cytochrome-c-t and artenimol

To investigate the effect of dihydroartemisinin on apoptosis of human pancreatic cancer cell line JF-305 and the role of reactive oxygen species(ROS) in the apoptosis of JF-305 cells induced by dihydroartemisinin. MTT assays were used to detect effect of different concentrations of dihydroartemisinin on cells proliferation of JF-305 lines. Cell cycle was detected by flow cytometry, and the apoptotic morphology was observed by Hoechst 333258 fluorescence staining. Annexin V fluorescence staining was used to detect the apoptosis changes of JF-305 cells, while DCFH-DA was used to detect the changes of ROS during apoptosis process. Western blot was used to detect the protein expression changes of Bax, Bcl-2, Cleaved caspase-3, Cleaved caspase-9 and Cyto C. As compared with the control group, the JF-305 cells proliferation was inhibited significantly(P<0.05) after treatment with different concentrations of dihydroartemisimin for 48 h; cell cycle was blocked in the G2/M phase; apoptotic morphology of nuclear condensation, aggregation, and fragmentation was found, and the apoptosis ratio was increased(P<0.05). DCFH-DA detection showed that the cell ROS was increased significantly after dihydroartemisinin treatment(P<0.05). Western blot results showed that the expression of Bcl-2 protein was down-regulated; the expression of Bax protein was up-regulated; the ration of Bax/Bcl-2 was increased and the protein expression levels of Cleaved caspase-3, Cleaved caspase-9 and Cyto C were increased after dihydroartemisinin treatment. Therefore, dihydroartemisinin could induce apoptosis of JF-305 cells, and the possible mechanism may be related to the formation and increasing of ROS.

Topics: Apoptosis; Artemisinins; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cell Proliferation; Cytochromes c; Humans; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species

Dihydroartemisinin (DHA), a semi-synthetic derivative and active metabolite of artemisinin, has been shown to have profound anticancer potential in addition to its strong anti-malarial activity. The purpose of the present study was to thoroughly investigate the anti-neoplastic effects induced by DHA and to provide a molecular basis for the use of DHA in the treatment of breast cancer. Our results demonstrated that DHA could significantly inhibit the cell proliferation of breast cancer in a dose- and time-dependent manner that was associated with induced apoptosis and G0/G1 cell cycle arrest, and the half maximal inhibitory concentrations (IC50) of DHA treatment were 60.03, 33.86 and 17.18 µM for 24, 48 and 72 h, respectively. Moreover, the DHA treatment dramatically increased the protein expression of caspase-8, cleaved caspase-9, activated Bid and induced the release of cytochrome c from mitochondria into the cytosol. In addition, the apoptotic action of DHA was associated with the increased expression of the pro-apoptotic gene Bim and a decreased expression of the anti-apoptotic gene Bcl-2. Therefore, the mitochondrial pathway is involved in the apoptosis of breast cancer cells induced by DHA and the imbalance of the Bim/Bcl-2 interaction may promote the beneficial effect against breast cancer cells. Overall, our study provides the scientific rationale for the clinical usage of DHA for breast cancer.

Topics: Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Artemisinins; bcl-2-Associated X Protein; Bcl-2-Like Protein 11; Breast Neoplasms; Caspase 8; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Dose-Response Relationship, Drug; Female; Humans; Membrane Proteins; Microbial Sensitivity Tests; Mitochondria; Proto-Oncogene Proteins

Due to the mutations of the Bcr/Abl oncogene that obstacle the binding of the protein with imatinib, the resistance to imatinib has developed in a significant portion of chronic myeloid leukemia (CML) patients. It stimulated the search for novel molecules for treatment of imatinib-resistance CML. Inhibiting the amplification of Bcr/Abl oncogene is believed to be a new effective strategy to override the imatinib resistance on CML cells. In present research, we demonstrated that dihydroartemisinin (DHA), a safe and effective antimalarial analog of artemisinin, could significantly inhibit the Bcr/Abl fusion gene at the mRNA level in CML cells sensitive or resistant to imatinib (including the primary CML cells with T315I mutation) and induce cell death. Moreover, dihydroartemisinin could also lead to the inhibition of the Bcr/Abl protein expression and tyrosine kinase activity, and strongly suppress on the downstream signals of Bcr/Abl, which included inhibition of tyrosine kinase activity of AKT and ERK, promotion of cytochrome c release from the mitochondria and the consequential activation of caspase-9/3 in imatinib-resistant CML cells. These results suggest for the first time that Dihydroartemisinin might be a potential novel drug candidate for treatment of imatinib-resistant CML and worthy of further study.

Topics: Antimalarials; Apoptosis; Artemisinins; Benzamides; Caspase 3; Caspase 9; Cell Line, Tumor; Cytochromes c; Drug Resistance, Neoplasm; Fusion Proteins, bcr-abl; Genes, abl; Humans; Imatinib Mesylate; K562 Cells; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; MAP Kinase Signaling System; Mitochondria; Piperazines; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-akt; Pyrimidines; RNA, Messenger

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has been shown to exhibit inhibitory effects on human cancer cells. However, its antitumor ability toward hepatocellular carcinoma (HCC) has not been studied. In this study, we demonstrated that DHA significantly inhibited HCC cell growth in vitro and in vivo via inducing G2/M cell cycle arrest and apoptosis. The induction of p21 and the inhibition of cyclin B and CDC25C contributed to DHA-induced G2/M arrest. DHA-induced apoptosis was associated with mitochondrial membrane depolarization, release of cytochrome c, activation of caspases, and DNA fragmentation. Activation of caspase 9 and caspase 3, but not caspase 8, was detected in DHA-treated cells. Attenuation of apoptosis in cells pretreated with Z-VAD-FMK suggested the involvement of caspase cascade. Furthermore, p53 facilitated apoptosis caused by DHA. Bcl-2 family proteins were also responsible for DHA-induced apoptosis. DHA exposure decreased Mcl-1 expression but increased the levels of Noxa and active Bak. Bak was released from the Mcl-1/Bak complex due to the decline of Mcl-1. Further study revealed that Mcl-1 was rapidly degraded in DHA-treated cells and that DHA-induced apoptosis was largely inhibited by overexpression of Mcl-1 or RNAi-mediated decrease of Bak and Noxa. In a HCC-xenograft mouse model, the intraperitoneal injection of DHA resulted in significant inhibition of HCC xenograft tumors. Taken together, our data, for the first time, demonstrate the potential antitumor activity of DHA in HCC.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Artemisinins; bcl-2 Homologous Antagonist-Killer Protein; Carcinoma, Hepatocellular; Caspases; Cell Cycle Checkpoints; Cell Line, Tumor; Cytochromes c; Drug Screening Assays, Antitumor; Genes, p53; Humans; Liver Neoplasms; Mice; Mitochondrial Membranes; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2; Xenograft Model Antitumor Assays

Liver cancer ranks in prevalence and mortality among top five cancers worldwide. Accumulating interests have been focused in developing new strategies for liver cancer treatment. We have previously showed that dihydroartemisinin (DHA) exhibited antitumor activity towards liver cancer. In this study, we demonstrated that histone deacetylase inhibitors (HDACi) significantly augmented the antineoplastic effect of DHA via increasing apoptosis in vitro and in vivo. Inhibition of ERK phosphorylation contributed to DHA-induced apoptosis, due to the fact that inhibitor of ERK phosphorylation (PD98059) increased DHA-induced apoptosis. Compared with DHA alone, the combined treatment with DHA and HDACi reduced mitochondria membrane potential, released cytochrome c into cytoplasm, increased p53 and Bak, decreased Mcl-1 and p-ERK, activated caspase 3 and PARP, and induced apoptotic cells. Furthermore, we showed that HDACi pretreatment facilitated DHA-induced apoptosis. In Hep G2-xenograft carrying nude mice, the intraperitoneal injection of DHA and SAHA resulted in significant inhibition of xenograft tumors. Results of TUNEL and H&E staining showed more apoptosis induced by combined treatment. Immunohistochemistry data revealed the activation of PARP, and the decrease of Ki-67, p-ERK and Mcl-1. Taken together, our data suggest that the combination of HDACi and DHA offers an antitumor effect on liver cancer, and this combination treatment should be considered as a promising strategy for chemotherapy.

Topics: Animals; Apoptosis; Artemisinins; Cell Line, Tumor; Cytochromes c; Drug Synergism; Enzyme Activation; Flow Cytometry; Histone Deacetylase Inhibitors; In Situ Nick-End Labeling; Liver Neoplasms; Mice; Mice, Nude; Mitogen-Activated Protein Kinases; Phosphorylation

In our previous publication, we have shown that dihydroartemisinin could significantly inhibit the growth of CML K562 cells by its anti-proliferative and inducing apoptotic effects. Given the pivotal effect of Bcr/Abl tyrosine kinase and its downstream signal factors on CML cell proliferation and survival, we extend our study to investigate the effect of DHA on Bcr/Abl and related signal factors to further illuminate the possible mechanisms of the effect of DHA on CML cells.. The expression of Bcr/Abl was analyzed with PCR and Western blotting methods at both mRNA and protein levels. Measurement of protein expression and tyrosine phosphorylation activity of Bcr/Abl, AKT, ERK1/2, NF-κB and cytochrome c were performed with Western blotting and immunoprecipitation methods. Using the activity kits analyzed the activity of caspase 9 and caspase 3.. The treatment with DHA results in a significant suppression on Bcr/Abl expression and leads to a concentration-dependent reduction on the Bcr/Abl tyrosine activity. Moreover, it also results in a strong influence on the downstream signal factors of Bcr/Abl, which includes inhibition of tyrosine kinase activity of AKT and ERK1/2, suppression of NF-κB protein expression, promotion of the cytochrome c release and the consequential activation of caspase 3/9 in CML K562 cells.. Together with our previous report, our data show that the growth inhibitory effect of DHA on CML cells might be due to the influence on Bcr/Abl expression and its downstream signal factors. DHA might be a potential novel anti-CML drug candidate and worthy of further study.

Topics: Artemisinins; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Down-Regulation; Fusion Proteins, bcr-abl; Growth Inhibitors; Humans; K562 Cells; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; MAP Kinase Signaling System; NF-kappa B; Phosphorylation; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-akt; RNA, Messenger

Artemisinin, the active principle of the Chinese medicinal herb Artemisia annua, and its derivatives (i.e. dihydroartemisinin, DHA) were reported to exhibit anti-tumor activity both in vitro and in vivo. The purpose of the present study was to investigate the functional role of Mitogen-Activated Protein Kinase (MEK)/Extracellular signal-regulated protein Kinase (ERK) signaling cascade in dihydroartemisinin (DHA)-induced apoptosis in human leukemia cells in vitro and anti-leukemic activity in vivo. Human leukemia cells were treated with DHA in dose- and time-dependent manners, after which apoptosis, caspase activation, Mcl-1 expression, and cell signaling pathways were evaluated. Parallel studies were performed in AML and ALL primary human leukemia cells. In vivo anti-leukemic activity mediated by DHA was also investigated using U937 xenograft mouse model. Exposure of DHA resulted in a pronounced increase in apoptosis in both transformed and primary human leukemia cells but not in normal peripheral blood mononuclear cells. DHA-induced apoptosis was accompanied by caspase activation, cytochrome c release, Mcl-1 down-regulation, as well as MEK/ERK inactivation. Pretreatment with MEK inhibitor PD98059, which potentiated DHA-mediated MEK and ERK inactivation, intensified DHA-mediated apoptosis. Conversely, enforced expression of a constitutively active MEK1 attenuated DHA-induced apoptosis. Furthermore, DHA-mediated inhibition of tumor growth of mouse U937 xenograft was associated with induction of apoptosis and inactivation of ERK. The findings in the present study showed that DHA-induced apoptosis in human leukemia cells in vitro and exhibited an anti-leukemic activity in vivo through a process that involves MEK/ERK inactivation, Mcl-1 down-regulation, culminating in cytochrome c release and caspase activation.

Topics: Animals; Antineoplastic Agents; Apoptosis; Artemisinins; Caspases; Cytochromes c; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Humans; Leukemia; MAP Kinase Kinase Kinases; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; U937 Cells; Xenograft Model Antitumor Assays

The present study was designed to determine the effects of artemisinin (ARS) and its derivatives on human ovarian cancer cells, to evaluate their potential as novel chemotherapeutic agents used alone or in combination with a conventional cancer chemotherapeutic agent, and to investigate their underlying mechanisms of action. Human ovarian cancer cells (A2780 and OVCAR-3), and immortalized non-tumourigenic human ovarian surface epithelial cells (IOSE144), were exposed to four ARS compounds for cytotoxicity testing. The in vitro and in vivo antitumour effects and possible underlying mechanisms of action of dihydroartemisinin (DHA), the most effective compound, were further determined in ovarian cancer cells. ARS compounds exerted potent cytotoxicity to human ovarian carcinoma cells, with minimal effects on non-tumourigenic ovarian surface epithelial (OSE) cells. DHA inhibited ovarian cancer cell growth when administered alone or in combination with carboplatin, presumably through the death receptor- and, mitochondrion-mediated caspase-dependent apoptotic pathway. These effects were also observed in in vivo ovarian A2780 and OVCAR-3 xenograft tumour models. In conclusion, ARS derivatives, particularly DHA, exhibit significant anticancer activity against ovarian cancer cells in vitro and in vivo, with minimal toxicity to non-tumourigenic human OSE cells, indicating that they may be promising therapeutic agents for ovarian cancer, either used alone or in combination with conventional chemotherapy.

Topics: Apoptosis; Artemisinins; Carboplatin; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cytochromes c; Drug Screening Assays, Antitumor; Female; Humans; Membrane Potential, Mitochondrial; Mitochondrial Membranes; Models, Biological; Ovarian Neoplasms