cytochrome-c-t and Nasopharyngeal-Carcinoma

Bacterial pore-forming toxins, BinA and BinB together known as the binary toxin are potent insecticidal proteins, that share structural homology with antitumor bacterial parasporin-2 protein. The underlying molecular mechanism of Bin toxin-induced cancer cell cytotoxicity requires more knowledge to understand whether the toxin induced human cytotoxic effects occur in the same way as that of parasporin-2 or not.. In this study, anticancer properties of Lysinibacillus sphaericus derived Bin toxin on HK1 were evaluated through MTT assay, morphological analysis and lactate dehydrogenase efflux assay. Induction of apoptosis was determined from RT-qPCR, caspase activity and cytochrome c release assay. Internalization pattern of Bin toxin in HK1 cells was studied by confocal laser-scanning microscopic analysis.. Activated Bin toxin had strong cytocidal activity to HK1 cancer cell line at 24 h postinoculation. Both BinA and BinB treated HK1 cells showed significant inhibition of cell viability at 12 μM. Induction of apoptotic mediators from RT-qPCR and caspase activity analyses indicated the activation of programmed cell death in HK1 cells in response to Bin toxin treatment. Internalization pattern of Bin toxin studied by using confocal microscopy indicated the localization of BinA on cell surface and internalization of BinB in the cytoplasm of cancer cells as well as colocalization of BinA with BinB. Evaluation of cytochrome c release also showed the association of BinB and BinA+BinB with mitochondria.. Bin toxin is a cytotoxic protein that induces cytotoxic and apoptotic events in HK1 cells, and may have high therapeutic potential as an anti-cancer agent.

Topics: Apoptosis; Bacterial Toxins; Caspases; Cytochromes c; Humans; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms

BACKGROUND Nasopharyngeal carcinoma results in high patient morbidity and mortality, due to early metastasis, and toxicity due to chemotherapy. Mukonal is plant-derived carbazole alkaloid that has been used in traditional Chinese medicine to treat several types of cancer. This study aimed to investigate the effects of mukonal on cell proliferation, apoptosis, autophagy, and the mitochondrial membrane potential of nasopharyngeal carcinoma cells in vitro. MATERIAL AND METHODS CNE1 human nasopharyngeal carcinoma cells and NP69 normal nasopharyngeal epithelial cells were cultured with and without treatment with increasing doses of mukonal. Cell viability was determined by the MTT assay. Fluorescence microscopy was used to detect reactive oxygen species (ROS), mitochondrial membrane potential, and the release of cytochrome C. Flow cytometry was used to examine changes in the cell cycle, electron microscopy examined cell autophagy, and Western blot was performed to measure levels of proteins associated with autophagy and apoptosis. RESULTS Mukonal had an antiproliferative effect on CNE1 cells, with an IC₅₀ of 9 µM and there were effects of toxicity on normal NP69 cells. Mukonal triggered ROS-mediated changes in mitochondrial membrane potential which was also accompanied by the discharge of cytochrome C in the CNE1 cells. Mukonal activated autophagy and apoptosis in CNE1 cells, which was also associated with upregulation of the autophagy-related proteins, LC3 II and beclin-1, as well as apoptosis-associated proteins, Bax, cleaved caspase-3 and -9. Mukonal treatment also resulted in CNE1 cells cycle arrest at G₂/M. CONCLUSIONS Mukonal inhibited the growth of human CNE1 nasopharyngeal carcinoma cells in vitro.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Beclin-1; Carbazoles; Carcinoma; Cell Cycle; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; China; Cytochromes c; Humans; Membrane Potential, Mitochondrial; Nasopharyngeal Carcinoma; Plant Extracts; Reactive Oxygen Species

The therapeutic strategy for advanced nasopharyngeal carcinoma (NPC) is still challenging. It is an urgent need to uncover novel treatment targets for NPC. Therefore, understanding the mechanisms underlying NPC tumorigenesis and progression is essential for the development of new therapeutic strategies. Here, we showed that TP53-regulated inhibitor of apoptosis (TRIAP1) was aberrantly overexpressed and associated with poor survival in NPC patients. TRIAP1 overexpression promoted NPC cell proliferation and suppressed cell death in vitro and in vivo, whereas TRIAP1 knockdown inhibited cell tumorigenesis and enhanced apoptosis through the induction of mitochondrial fragmentation, membrane potential alteration and release of cytochrome c from mitochondria into the cytosol. Intersecting with our previous miRNA data and available bioinformatic algorithms, miR-320b was identified and validated as a negative regulator of TRIAP1. Further studies showed that overexpression of miR-320b suppressed NPC cell proliferation and enhanced mitochondrial fragmentation and apoptosis both in vitro and in vivo, while silencing of miR-320b promoted tumor growth and suppressed apoptosis. Additionally, TRIAP1 restoration abrogated the proliferation inhibition and apoptosis induced by miR-320b. Moreover, the loss of miR-320b expression was inversely correlated with TRIAP1 overexpression in NPC patients. This newly identified miR-320b/TRIAP1 pathway provides insights into the mechanisms leading to NPC tumorigenesis and unfavorable clinical outcomes, which may represent prognostic markers and potential therapeutic targets for NPC treatment.

Topics: Adult; Aged; Animals; Apoptosis; Carcinoma; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Cytochromes c; Cytosol; Disease Progression; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Liver Neoplasms; Male; Membrane Potentials; Mice; Mice, Inbred BALB C; MicroRNAs; Middle Aged; Mitochondria; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neoplasm Metastasis; Proportional Hazards Models; Signal Transduction

Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC) cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid). The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-κB binding to the COX-2 promoter, and promoted the NF-κB translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-κB signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC.

Topics: Antineoplastic Agents; Apoptosis; Apoptotic Protease-Activating Factor 1; Carcinoma; Caspases; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclooxygenase 2; Cytochromes c; Diterpenes, Kaurane; Humans; Mitogen-Activated Protein Kinases; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; NF-kappa B; Protein Binding; Proto-Oncogene Proteins c-akt; Signal Transduction; Tracheophyta

One water-soluble polysaccharide fraction (WACP) was purified from the Artemisia capillaris by DEAE-cellulose anion-exchange and Sephacryl S-400 gel-permeation chromatography. Based on gas chromatography (GC) analysis, WACP was an arabinogalactan (AG), consisting of arabinose and galactose in the ratio of 4:2. Its molecular weight was about 5.8×10(4) Da. The present study demonstrated the anticancer potential of WACP on human nasopharyngeal carcinoma CNE-2 cells and elucidated its possible mechanisms. MTT and flow cytometric analysis identified that WACP had a potent anti-proliferation activity on CNE-2 cells by inducing apoptosis, which was parallel with the morphological changes of CNE-2 cells under inverted microscope. In addition, WACP triggered the apoptosis via the mitochondrial apoptotic pathway, which included the loss of mitochondrial membrane potential, release of cytochrome c and activation of caspase-3/9. Taken together, these results suggest that WACP has anticancer potential in the treatment of human nasopharyngeal carcinoma.

Topics: Antineoplastic Agents; Apoptosis; Artemisia; Carcinoma; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cytochromes c; Enzyme Activation; Humans; Mitochondria; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Polysaccharides; Solubility; Water

EBV (Epstein-Barr virus) is considered to be a major factor that causes NPC (nasopharyngeal carcinoma), which is one of the sneakiest cancers frequently occurring in Southeast Asia and Southern China. Apoptosis and pro-apoptotic signals have been studied for decades; however, few have extended the prevailing view of EBV to its impact on NPC in perspective of apoptosis. One of the important proteins named VDAC1 (voltage-dependent anion protein 1) on the mitochondrial outer membrane controls the pro-apoptotic signals in mammalian cells. The impact of EBV infection on VDAC1 and related apoptotic signals remains unclear. In order to study the VDAC1's role in EBV-infected NPC cells, we employ siRNA (small interfering RNA) inhibition to analyse the release of Ca2+ and Cyto c (cytochrome c) signals in the cytoplasm, as they are important pro-apoptotic signals. The results show a decrease of Ca2+ release and up-regulation of Cyto c with EBV infection. After siRNA transfection, the dysregulation of Cyto c is neutralized, which is evidence that the level of Cyto c release in virus-infected NPC cells is the as same as that of non-infected NPC cells. This result indicates that EBV infection changes the cytoplasmic level of Cyto c through regulating VDAC1. In summary, this study reports that EBV changes the release of Ca2+ and Cyto c in the cytoplasm of NPC cells, and that Cyto c changes are mediated by VDAC1 regulation.

Topics: Calcium; Carcinoma; Cell Line, Tumor; Cytochromes c; Cytoplasm; Epstein-Barr Virus Infections; Herpesvirus 4, Human; Humans; Ions; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; RNA Interference; RNA, Small Interfering; Signal Transduction; Up-Regulation; Voltage-Dependent Anion Channel 1

Betulinic acid (BetA) is an effective and potential anticancer chemical derived from plants. BetA can kill a broad range of tumor cell lines, but has no effect on untransformed cells. The chemical also kills melanoma, leukemia, lung, colon, breast, prostate and ovarian cancer cells via induction of apoptosis, which depends on caspase activation. However, no reports are yet available about the effects of BetA on nasopharyngeal carcinoma (NPC), a widely spread malignancy in the world, especially in East Asia. In this study, we first showed that BetA can effectively kill CNE2 cells, a cell line derived from NPC. BetA-induced CNE2 apoptosis was characterized by typical apoptosis hallmarks: caspase activation, DNA fragmentation, and cytochrome c release. Overexpression of Bcl-2 and Bcl-xL could partially prevent apoptosis caused by BetA. Moreover, Bax was not activated during the induction of apoptosis. Bax/Bak knockdown and wild-type CNE2 cells showed the same kinetics of cytochrome c release. We then showed that BetA may impair mitochondrial permeability transition pores (mPTPs), which may partially contribute to cytochrome c release. These observations suggest that BetA may serve as a potent and effective anticancer agent in NPC treatment. Further exploration of the mechanism of action of BetA could yield novel breakthroughs in anti-cancer drug discovery.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Betulinic Acid; Carcinoma; Caspases; Cell Death; Cell Line, Tumor; Cytochromes c; DNA Fragmentation; Humans; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Pentacyclic Triterpenes; Triterpenes

A traditional Chinese medicine Selaginella doederleinii Hieron has been combined with radiotherapy for the treatment of human nasopharyngeal carcinoma in clinic in China. However, the detailed mechanism of anti-tumor effect of Selaginella doederleinii remains elusive.. This study was designed to investigate the anti-tumor effect of ethanol extract of Selaginella doederleinii (SDE) on human nasopharyngeal carcinoma and its possible mechanisms.. Viability, apoptosis and protein expression of tumor cells were analyzed by MTT, Annexin V staining and Western blot, respectively. Formation of intracellular reactive oxygen species was determined using dichlorofluorescin fluorescence. The in vivo anti-tumor effect was evaluated by measuring tumor volume changes and TUNEL staining in nude mice.. SDE significantly inhibited the growth and induced apoptosis in human nasopharyngeal carcinoma CNE cells. In addition, SDE triggered the mitochondrial/caspase apoptotic pathway indicated by enhanced Bax-to-Bcl-2 ratio, loss of mitochondrial membrane potential, cytochrome c release, and caspase cascade. Moreover, SDE provoked the generation of reactive oxygen species in CNE cells, while the antioxidant N-acetyl cysteine almost completely blocked SDE-induced disruption of mitochondrial membrane potential, caspases activation and apoptosis. Furthermore, a transplantable nude mice model was utilized to estimate the effectiveness of SDE in vivo. The treated mice displayed decreased tumor size, which was associated with enhanced apoptotic cell death.. These results, offering solid evidence of the induction of mitochondria-related apoptosis in tumor cells, provide the molecular theoretical basis of clinical application of Selaginella doederleinii for the treatment of human nasopharyngeal carcinoma.

Topics: Acetylcysteine; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Carcinoma; Caspases; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Disease Models, Animal; Female; Humans; Membrane Potential, Mitochondrial; Mice; Mice, Inbred BALB C; Mice, Nude; Mitochondria; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Phytotherapy; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Selaginellaceae