cytochrome-c-t and norcantharidin

To study the therapeutic effect of norcantharidin (NCTD) combined with ABT-737 on hepatocellular carcinoma cells and the molecular mechanism.. Two hepatocellular carcinoma (HCC) cell lines, HepG2 and SMMC-7721, were selected. ABT-737 and NCTD were allocated into groups to be used alone or in combination. HepG2 and SMMC-7721 cells were cultured in vitro. Liver cancer cells in the logarithmic phase of growth were vaccinated and cultured to the cell wall stage; these cells were treated for 48 h with different concentrations of NCTD, or ABT-737, or NCTD combined with ABT-737. The cell proliferation inhibition rate was detected by methyl thiazolyl tetrazolium. The expression of Mcl in HCC cells was detected by Western Blotting, and the cells in each group after treatment had apoptosis detected by flow cytometry. The proliferation inhibition rate, the expression of Mcl-1 in cells and the apoptosis inducing effect of treatment were observed in each group, and the effect of NCTD on ABT-737 in the treatment of HCC and its mechanism of action were analyzed.. As the concentration of NCTD increased, the cell proliferation inhibition rate gradually decreased; and the treatment effect of ABT-737 1-3 μm combined with NCTD on cell proliferation inhibition was stronger than that of ABT-737 alone. The difference was statistically significant (P < 0.05). In observing the expression of Mcl-1 in cells after the treatment of different concentrations of NCTD, this was partially inhibited after treatment with NCTD 15 μm, and the expression of Mcl-1 was almost undetectable after treatment with NCTD 30 μm and 60 μm. The effect on inducing apoptosis with the treatment of ABT-737 or NCTD alone for 48 h was lower than that of the control group. The difference was not statistically significant (P > 0.05). The effect on inducing apoptosis in HepG2 and SMMC-7721 cells with the treatment of ABT-737 combined with NCTD for 48 h was greater than that of ABT-737 or NCTD alone. The difference was statistically significant (P < 0.05).. NCTD combined with ABT-737 has a positive role in the treatment of HCC, and it has great value in clinical research.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Biphenyl Compounds; Bridged Bicyclo Compounds, Heterocyclic; Carcinoma, Hepatocellular; Cell Proliferation; Cytochromes c; Dose-Response Relationship, Drug; Hep G2 Cells; Humans; Liver Neoplasms; Myeloid Cell Leukemia Sequence 1 Protein; Nitrophenols; Piperazines; Sulfonamides; Time Factors

Norcantharidin, a modified pure compound from blister beetles, was previously demonstrated to induce apoptosis of cancer cells. This study investigated its anti-cancer activity in prostate cancer cells and the mechanisms involved.. Two human prostate cancer cell lines, 22Rv1 and Du145, were treated with norcantharidin at concentrations ranging from 3 to 30μg/ml. Cytotoxic effect of norcantharidin was determined by use of the 3-(4,5-dimethylthiazol-yl)-diphenyl tetrazoliumbromide (MTT) assay. The effects of apoptosis were evaluated by cell death assay, Caspase-3, -8, -9 activity and cytochrome c release. The apoptotic related protein expressions (Bcl-2 family and inhibitor of apoptosis proteins) were determined using western blotting.. An MTT assay revealed that norcantharidin induced cytotoxicity against both prostate cancer cells in dose- and time-dependent manners. Treatment with norcantharidin at 3μg/ml or higher significantly increased oligonucleosomal formation with concomitant appearance of PARP cleavage, implicating the induction of apoptosis. Norcantharidin intrinsically elevated cytosolic cytochrome c levels and activated caspase-3, -8, and -9. Extrinsically, it upregulated the expression of not only the death receptors Fas and DR5 in 22Rv1 cells, but also of RIP and TRADD adaptor proteins in Du145 cells. Mechanistically, norcantharidin increased ratios of pro-/anti-apoptotic proteins and decreased expression of IAP family member proteins, including cIAP1 and survivin, regardless of the distinct status of androgen receptor expression in both cells.. Norcantharidin exhibited cytotoxicity against 22Rv1 and Du145 prostate cancer cells by inducing both intrinsic and extrinsic apoptotic pathways and could thus potentially be a remedy for prostate cancer.

Topics: Apoptosis; bcl-2-Associated X Protein; Bridged Bicyclo Compounds, Heterocyclic; Caspases; Cell Line, Tumor; Cytochromes c; fas Receptor; Humans; Male; Prostatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; TNF Receptor-Associated Death Domain Protein; Up-Regulation

Norcantharidin (NCTD), a demethylated analog of cantharidin derived from blister beetles, has attracted considerable attentions in recent years due to their definitely toxic properties and the noteworthy advantages in stimulating bone marrow and increasing the peripheral leukocytes. Hence, it is worth studying the anti-tumor effect of NCTD on human prostate cancer cells DU145. It was found that after the treatment of NCTD with different concentrations (25-100 μM), the cell proliferation was significantly inhibited, which led to the appearance of micronucleus (MN). Moreover, the cells could be killed in a dose-/time-dependent manner along with the reduction of PCNA (proliferating cell nuclear antigen) expression, destruction of mitochondrial membrane potential (MMP), down-regulation of MnSOD, induction of ROS, depletion of ATP, and activation of AMPK (Adenosine 5'-monophosphate -activated protein kinase) . In addition, a remarkable release of cytochrome c was found in the cells exposed to 100 μM NCTD and exogenous SOD-PEG could eliminate the generation of NCTD-induced MN. In conclusion, our studies indicated that NCTD could induce the collapse of MMP and mitochondria dysfunction. Accumulation of intercellular ROS could eventually switch on the apoptotic pathway by causing DNA damage and depleting ATP.

Topics: Adenosine Triphosphate; AMP-Activated Protein Kinases; Antineoplastic Agents; Apoptosis; Bisbenzimidazole; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Dose-Response Relationship, Drug; Flow Cytometry; Humans; In Situ Nick-End Labeling; Male; Membrane Potential, Mitochondrial; Micronucleus Tests; Mitochondria; Proliferating Cell Nuclear Antigen; Prostatic Neoplasms; Reactive Oxygen Species; Superoxide Dismutase

Many lines of evidence have shown that Chinese medicine contains many chemical compounds with anticancer effects. Therefore, we tested whether the active ingredients of blister beetles have a therapeutic effect on hepatoma. The aim of this study was to investigate the inhibitive effects of norcantharidin which is extracted from blister beetles on human hepatoma cells HepG2 in vitro and its anticancer mechanism.MTT assay, agarose gel electrophoresis and flow cytometry were used to evaluate HepG2 cells proliferation and apoptosis. The role of caspase activities were assayed using caspase apoptosis detection kit. Western blot analysis was used to evaluate the level of Bcl-2/Bax expression. Our results indicate that norcantharidin inhibited HepG2 cell growth in a time- and dose-dependent manner by MTT assay. HepG2 cells treated with norcantharidin showed typical characteristics of apoptosis including the DNA fragmentation. The activities of caspase-3, -9 were up-regulated after norcantharidin treatment. By western blot analysis, we found the level of Bcl-2 were down-regulated, whereas, the level of Bcl-2 Up-regulated.so we suggest that up-regulation of mitochondrial Bax expression and down-regulation of Bcl-2 expression participated in the apoptosis induced by NCTD. These results suggest that norcantharidin triggers apoptosis in hepato cancer cell lines via the activation of the caspses, mitochondrial pathways, and that this agent may be useful for developing new therapeutic regimens for the treatment of colorectal carcinoma.

Topics: Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Caspase 3; Caspase 9; Cell Culture Techniques; Cell Cycle; Cell Proliferation; Cytochromes c; DNA; Electrophoresis, Agar Gel; Enzyme Activation; Fluorescence; Hep G2 Cells; Humans; Propidium; Proto-Oncogene Proteins c-bcl-2; Time Factors

Involvement of activities of mitogen-activated protein kinases (MAPKs) and signal transducers and activators of transcription (STATs) remains unsolved in norcantharidin-associated breast cancer cell apoptosis. This study investigated the anti-cancer effect of norcantharidin and its underlying mechanism in two human breast cancer cell lines, estrogen receptor (ER)- HS-578T and ER+ MCF-7 cells. Norcantharidin induced potent cytotoxicity and arrested cell growth through increasing phosphorylation of Chk1, Chk2 and total p21(Waf1/Cip1) and reducing cyclin B and cdc25c expression. It also induced apoptosis through extrinsic death receptor and intrinsic mitochondrial pathways by cytochrome c release, caspase activation, oligonucleosome appearance, PARP cleavage, and aberration of Bcl-2 family protein expression and phosphorylation. Although norcantharidin did not affect STAT1, STAT3, and STAT5 protein expression, it suppressed STAT3 and STAT5 phosphorylation in HS-578T cells, whereas it up-regulated STAT1 phosphorylation and down-regulated STAT5 phosphorylation in MCF-7 cells. Moreover, norcantharidin activated MAPK family member proteins, extracellular signal-regulated kinase (ERK), p38(MAPK) and c-Jun N-terminal kinase (JNK), were all phosphorylated by treatment. Pretreatment with selective kinase inhibitors significantly attenuated the norcantharidin-induced cytotoxicity in breast cancer cells. These findings suggest the potential involvement of MAPK and STAT pathways in norcantharidin-induced apoptogenesis. Norcantharidin may be an effective anti-cancer drug against breast cancer.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Survival; Cytochromes c; Drug Screening Assays, Antitumor; Female; Humans; Mitogen-Activated Protein Kinases; STAT Transcription Factors

Norcantharidin exhibits cytotoxicity in many cancer cell lines, including colorectal cancer (CRC) cells. Its cytotoxic potency on primary CRC cells and other normal constituent cells of the human body remains elusive. This study investigates whether norcantharidin differentially exhibits cytotoxicity on primarily isolated CRC cells and dermal fibroblasts. The in vitro chemosensitivity of norcantharidin was measured using a MTT tetrazolium assay and compared with 73 primary tumor cells from surgically excised colorectal tumors, six human CRC cell lines and dermal fibroblasts. Observations of cytotoxicity to primary tumor cells reveal significant differences among genders and histological types; however, drug-induced chemosensitivity was not correlated with age or clinical stages of CRC patients. Norcantharidin had a similar cytotoxic effect on primary tumor cells and CRC cell lines in a dose-dependent manner. In contrast, normal fibroblasts were more resistant to norcantharidin-induced cytotoxicity than CRC cells. DAPI staining results demonstrated that norcantharidin caused CRC cell apoptosis by nuclear fragmentation and chromatin condensation. The release of cytochrome c and the triggering of caspase-3, -8 and -9 activation mediated apoptotic induction. Conversely, pretreatment with caspases or mitogen-activated protein kinase (MAPK) inhibitors significantly suppressed norcantharidin-induced CRC cytotoxicity. These in vitro results suggest that norcantharidin may be a safe and effective anti-cancer drug for CRC.

Topics: Aged; Antineoplastic Agents; Apoptosis; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Caspases; Cell Line, Tumor; Colorectal Neoplasms; Cytochromes c; DNA Fragmentation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Enzyme-Linked Immunosorbent Assay; Female; Fibroblasts; Fluorescent Dyes; Histones; Humans; Indoles; Male; Middle Aged; Mitogen-Activated Protein Kinases

To investigate the mechanism of norcantharidin (NCTD)-induced SMMC-7721 hepatoma cell apoptosis.. SMMC-7721 cell growth inhibition was measured by the MTT method. Apoptosis was detected by Annexin V/propidium iodide staining. The mitochondrial membrane potential was measured by flow cytometry. Western blot analysis was used to evaluate the level of cytochrome c, caspase-3, AIF, Bcl-2 and Bax expression.. NCTD inhibited SMMC-7721 cell growth in a time- and dose-dependent manner. The cells treated with NCTD showed the loss of mitochondrial membrane potential. The activities of caspase-3, cytochrome c, AIF, and Bax were up-regulated after NCTD treatment at different doses. The expression of Bcl-2 was decreased after treatment with NCTD.. NCTD could induce SMMC-7721 cell apoptosis. The activation of the mitochondrial pathway was involved in the process of NCTD-induced SMMC-7721 cell apoptosis.

Topics: Apoptosis; Apoptosis Inducing Factor; bcl-2-Associated X Protein; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Caspase 3; Cell Line, Tumor; Cytochromes c; Flow Cytometry; Humans; Liver Neoplasms; Membrane Potentials; Mitochondria

Norcantharidin, the demethylated analog of cantharidin derived from a traditional Chinese medicine, Mylabris, has been used in the treatment of anti-cancer effects. However, the detailed mechanisms underlying this process are generally unclear. The aim of this study was to investigate the mechanism of NCTD-induced apoptosis in HepG2 cells.. The cytotoxicity was measured by MTT assay for cellular viability and by flow cytometry. The mitochondrial membrane potential and reactive oxygen species production was evaluated by flow cytometry analysis. The role of caspase activities were assayed using caspase apoptosis detection kit . Western blot analysis was used to evaluate the level of Cyto-C, Bcl-2, Bax, Bid, caspase 3, -9, -8 and PARP expression. After treatment with NCTD, a decrease in the viability of HepG2 cells and increase in apoptosis were observed. NCTD-induced apoptosis was accompanied by an increase in ROS production, loss of mitochondrial membrane potential and release of cytochrome c(cyto-c) from the mitochondria to the cytosol and down-regulation of anti-apoptotic protein Bcl-2 levels with concurrent up-regulation in pro-apoptotic protein Bax levels. However, another pro-apoptotic molecule, Bid, showed no change in such same treatment. NCTD-increased activity of caspase 9,caspase 3 and the subsequent cleavage caspase substrate PARP were also observed. The expression levels of pro-caspase-8 were not changed after NCTD treatment.. These results indicate that NCTD induced cytotoxicity in HepG2 cells by apoptosis, which is mediated through ROS generation and mitochondrial pathway.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; BH3 Interacting Domain Death Agonist Protein; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Caspases; Cell Proliferation; Cell Survival; Cytochromes c; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Flow Cytometry; Hep G2 Cells; Humans; Liver Neoplasms; Membrane Potential, Mitochondrial; Mitochondria, Liver; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Time Factors

Norcantharidin (NCTD), the demethylated analogue of cantharidin, has been used to treat human cancers in China since 1984. It was recently found to be capable of inducing apoptosis in human colon carcinoma, hepatoma and glioblastoma cells by way of an elusive mechanism. In this study, we demonstrated that NCTD also induces apoptosis in human oral cancer cell lines SAS (p53 wild-type phenotype) and Ca9-22 (p53 mutant) as evidenced by nuclear condensation, TUNEL labeling, DNA fragmentation and cleavage of PARP. Apoptosis induced by NCTD was both dose- and time-dependent. We found NCTD did not induce Fas and FasL, implying that it activated other apoptosis pathways. Our data showed that NCTD caused accumulation of cytosolic cytochrome c and activation of caspase-9, suggesting that apoptosis occurred via the mitochondria mediated pathway. NCTD enhanced the expression of Bax in SAS cells consistent with their p53 status. Moreover, we showed that NCTD downregulated the expression of Bcl-2 in Ca9-22 and Bcl-XL in SAS. Our results suggest that NCTD-induced apoptosis in oral cancer cells may be mediated by an increase in the ratios of proapoptotic to antiapoptotic proteins. Since oral cancer cells with mutant p53 or elevated Bcl-XL levels showed resistance to multiple chemotherapeutic agents, NCTD may overcome the chemoresistance of these cells and provide potential new avenues for treatment.

Topics: Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Caspases; Cell Line, Tumor; Cytochromes c; Dose-Response Relationship, Drug; Enzyme Activation; Flow Cytometry; Humans; In Situ Nick-End Labeling; Mouth Neoplasms; Proto-Oncogene Proteins c-bcl-2